Also flagged:Cell cycleprophase Icalciump53Atmataxia telangiectasia mutated
Journal Article2009-07-31✓ 1 SnippetSpiller C, Wilhelm D, Koopman P.
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…encoding CDK5 subunitsCdk5rap1and Cdk5rap3 ,…
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<h4>Background information</h4>Primordial germ cells in developing male and female gonads are responsive to somatic cell cues that direct their sex-specific differentiation into functional gametes. The first divergence of the male and female pathways is a change in cell cycle state observed from 12.5 dpc (days post coitum) in mice. At this time XY and XX germ cells cease mitotic division and enter G1/G0 arrest and meiosis prophase I respectively. Aberrant cell cycle regulation at this time can lead to disrupted ovarian development, germ cell apoptosis, reduced fertility and/or the formation of germ cell tumours.<h4>Results</h4>In order to unravel the mechanisms utilized by germ cells to achieve and maintain the correct cell cycle states, we analysed the expression of a large number of cell cycle genes in purified germ cells across the crucial time of sex differentiation. Our results revealed common signalling for both XX and XY germ cell survival involving calcium signalling. A robust mechanism for apoptosis and checkpoint control was observed in XY germ cells, characterized by p53 and Atm (ataxia telangiectasia mutated) expression. Additionally, a member of the retinoblastoma family and p21 were identified, linking these factors to XY germ cell G1/G0 arrest. Lastly, in XX germ cells we observed a down-regulation of genes involved in both G1- and G2-phases of the cell cycle consistent with their entry into meiosis.<h4>Conclusion</h4>The present study has provided a detailed analysis of cell cycle gene expression during fetal germ cell development and identified candidate factors warranting further investigation in order to understand cases of aberrant cell cycle control in these specialized cells.
Also flagged:glycineTransferriniron transport proteinironacid secretiongastrin
Journal Article2009-07-31✓ 1 SnippetKovac S, Ferrand A, Estève JP, Mason AB, Baldwin GS.
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…hemochromatosis…
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Transferrin is the main iron transport protein found in the circulation, and the level of transferrin saturation in the blood is an important indicator of iron status. The peptides amidated gastrin(17) (Gamide) and glycine-extended gastrin(17) (Ggly) are well known for their roles in controlling acid secretion and as growth factors in the gastrointestinal tract. Several lines of evidence, including the facts that transferrin binds gastrin, that gastrins bind ferric ions, and that the level of expression of gastrins positively correlates with transferrin saturation, suggest the possible involvement of the transferrin-gastrin interaction in iron homeostasis. In the present work, the interaction between gastrins and transferrin has been characterized by surface plasmon resonance and covalent crosslinking. First, an interaction between iron-free apo-transferrin and Gamide or Ggly was observed. The fact that no interaction was observed in the presence of the chelator EDTA suggested that the gastrin-ferric ion complex was the interacting species. Moreover, removal of ferric ions with EDTA reduced the stability of the complex between apo-transferrin and gastrins, and no interaction was observed between Gamide or Ggly and diferric transferrin. Second, some or all of glutamates at positions 8-10 of the Ggly molecule, together with the C-terminal domain, were necessary for the interaction with apo-transferrin. Third, monoferric transferrin mutants incapable of binding iron in either the N-terminal or C-terminal lobe still bound Ggly. These findings are consistent with the hypothesis that gastrin peptides bind to nonligand residues within the open cleft in each lobe of transferrin and are involved in iron loading of transferrin in vivo.
Also flagged:systemic inflammatory disordersrheumatoid arthritisRAlymphoproliferative disordersmalignant tumorstumor-associated antigens
Journal Article2009-07-31No SnippetsAl-Anazi KA, Eltayeb KI, Bakr M, Al-Mohareb FI.
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For many years, methotrexate has been used in the treatment of certain chronic medical disorders e.g. rheumatoid arthritis and psoriasis as well as a number of malignant disorders e.g. acute lymphoblastic leukemia, certain types of lymphoma and breast carcinoma. Its use has been associated with various systemic toxicities and complications. The association between methotrexate therapy and the development of lymphoma and pseudolymphoma is well established. In patients treated with methotrexate, the development of leukemia has been attributed to either the primary disorder e.g. rheumatoid arthritis or to other drugs used concomitantly e.g. cyclophosphamide. Reported here are two patients with rheumatoid arthritis and one patient with psoriasis treated with low dose methotrexate for variable periods of time. Two of these patients developed acute myeloid leukemia on myelodysplastic syndrome background, while the third patient developed pre-B acute lymphoblastic leukemia that expressed few myeloid markers and had a positive philadelphia chromosome. To our knowledge, these are the first reported cases of methotrexate-induced acute leukemia.
<h4>Purpose</h4>To evaluate various types of neovascular age-related macular degeneration (AMD) by near-infrared fundus reflectance (NIR) as compared to fundus fluorescein angiography (FFA) and to test NIR for assessment of leakage due to choroidal neovascularization (CNV).<h4>Patients and methods</h4>Thirty-three patients with neovascular AMD (cases) and 20 age-matched patients with non-exudative AMD and healthy subjects (controls) were examined with a confocal scanning laser ophthalmoscope (Heidelberg Retina Angiograph 2). NIR images of neovascular AMD were qualitatively compared to the corresponding FFA and to age-matched controls. CNV membranes and exudation areas were manually segmented on FFA and NIR and analyzed quantitatively.<h4>Results</h4>Of all cases included, five eyes had classic CNV, six had minimal classic lesions, 15 occult CNV's and seven eyes had retinal angiomatous proliferation (RAP). A dark halo on NIR was found in all cases and showed high correspondence to leakage on FFA (r (2) = 0.93; p < 0,0005). In classic CNV and minimal classic CNV, the classic part of the lesion on FFA revealed strong correlation to a dark core surrounded by a bright reflecting ring on NIR (r (2) = 0.88; p < 0.0005). Occult parts on FFA of minimal classic CNV and occult CNV lesions appeared as poorly demarcated, jagged areas of increased NIR. RAP was characterized by speckled NIR located at the intraretinal neovascular complex.<h4>Conclusions</h4>NIR imaging in neovascular AMD revealed characteristic alterations depending on the type of CNV. These changes may reflect histological differences of the lesions. Leakage caused local darkening of NIR, presumably originating from increased light-scattering and absorbance by fluid accumulation and sub-cellular structure alterations.
Also flagged:TrkATATA binding proteinTBPtranscription factorRNA polymerasespolyglutamine
Journal Article2009-07-30✓ 1 SnippetShah AG, Friedman MJ, Huang S, Roberts M, Li XJ, Li S.
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…htt…
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TATA binding protein (TBP), a universal transcription factor, is broadly required by nuclear RNA polymerases for the initiation of transcription. TBP contains a polymorphic polyglutamine tract in its N-terminal region, and expansion of this tract leads to spinocerebellar ataxia type 17 (SCA17), one of nine dominantly inherited neurodegenerative diseases caused by polyglutamine expansion in the affected proteins. The expanded polyglutamine proteins are ubiquitously expressed, but cause selective and characteristic neurodegeneration in distinct brain regions in each disease. Unlike many other polyglutamine proteins, whose functions are not yet fully understood, TBP is a well-characterized transcription factor that is restricted to the nucleus. Thus, investigating how mutant TBP mediates neuropathology should help elucidate the mechanisms by which transcriptional dysregulation contributes to neuronal dysfunction and/or neurodegeneration in polyglutamine diseases. To this end, we characterized cellular and mouse models expressing polyQ-expanded TBP. The cell model exhibits characteristic features of neuronal dysfunction, including decreased cell viability and defective neurite outgrowth. We found that the high-affinity nerve growth factor receptor, TrkA, is down-regulated by mutant TBP in cells. Down-regulation of TrkA also occurs in the cerebellum of SCA17 transgenic mice prior to Purkinje cell degeneration. Mutant TBP binds more Sp1, reduces its occupancy of the TrkA promoter and inhibits the activity of the TrkA promoter. These findings suggest that the transcriptional down-regulation of TrkA by mutant TBP contributes to SCA17 pathogenesis.
<h4>Purpose</h4>Treatment of de-epithelialized human corneas with riboflavin (RF) + long-wavelength ultraviolet light (UVA; RFUVA) increases corneal stroma tensile strength significantly. RFUVA treatment retards the progression of keratoconus, perhaps by cross-linking of collagen molecules, but exact molecular mechanisms remain unknown. Research described here tested possible chemical mechanisms of cross-linking.<h4>Methods</h4>Corneas of rabbits and spiny dogfish sharks were de-epithelialized mechanically, subjected to various chemical pretreatments, exposed to RFUVA, and then subjected to destructive tensile stress measurements. Tensile strength was quantified with a digital force gauge to measure degree of tissue cross-linking.<h4>Results</h4>For both rabbit and shark corneas, RFUVA treatment causes significant cross-linking by mechanism(s) that can be blocked by the presence of sodium azide. Conversely, such cross-linking is greatly enhanced in the presence of deuterium oxide (D(2)O), even when RF is present at only one tenth the currently used clinical concentrations. Blocking carbonyl groups preexisting in the stroma with 2,4-dinitrophenylhydrazide or hydroxylamine blocks essentially all corneal cross-linking. In contrast, blocking free amine groups preexisting in the stroma with acetic anhydride or ethyl acetimidate does not affect RFUVA corneal cross-linking. When both carbonyl groups are blocked and singlet oxygen is quenched, no RFUVA cross-linking occurs, indicating the absence of other cross-linking mechanisms.<h4>Conclusions</h4>RFUVA catalyzes cross-linking reactions that require production of singlet oxygen ((1)O(2)), whose half-life is extended by D(2)O. Carbonyl-based cross-linking reactions dominate in the corneal stroma, but other possible reaction schemes are proposed. The use of D(2)O as solution media for RF would enable concentration decreases or significant strength enhancement in treated corneas.
The development of inflammatory diseases implies inactivation of regulatory T (Treg) cells through mechanisms that still are largely unknown. Here we showed that mast cells (MCs), an early source of inflammatory mediators, are able to counteract Treg inhibition over effector T cells. To gain insight into the molecules involved in their interplay, we set up an in vitro system in which all 3 cellular components were put in contact. Reversal of Treg suppression required T cell-derived interleukin-6 (IL-6) and the OX40/OX40L axis. In the presence of activated MCs, concomitant abundance of IL-6 and paucity of Th1/Th2 cytokines skewed Tregs and effector T cells into IL-17-producing T cells (Th17). In vivo analysis of lymph nodes hosting T-cell priming in experimental autoimmune encephalomyelitis revealed activated MCs, Tregs, and Th17 cells displaying tight spatial interactions, further supporting the occurrence of an MC-mediated inhibition of Treg suppression in the establishment of Th17-mediated inflammatory responses.
Also flagged:Spinal muscular atrophyspinal muscular atrophiesSpinal muscular atrophy with pontocerebellar hypoplasiaashypoplasia type1
Journal Article2009-07-30No SnippetsRenbaum P, Kellerman E, Jaron R, Geiger D, Segel R, Lee M, King MC, Levy-Lahad E.
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The spinal muscular atrophies (SMAs) are a genetically and clinically heterogeneous group of disorders characterized by degeneration and loss of anterior horn cells in the spinal cord, leading to muscle weakness and atrophy. Spinal muscular atrophy with pontocerebellar hypoplasia (SMA-PCH, also known as pontocerebellar hypoplasia type 1 [PCH1]) is one of the rare infantile SMA variants that include additional clinical manifestations, and its genetic basis is unknown. We used a homozygosity mapping and positional cloning approach in a consanguineous family of Ashkenazi Jewish origin and identified a nonsense mutation in the vaccinia-related kinase 1 gene (VRK1) as a cause of SMA-PCH. VRK1, one of three members of the mammalian VRK family, is a serine/threonine kinase that phosphorylates p53 and CREB and is essential for nuclear envelope formation. Its identification as a gene involved in SMA-PCH implies new roles for the VRK proteins in neuronal development and maintenance and suggests the VRK genes as candidates for related phenotypes.
Also flagged:Sox5Sox13sex-determining regionSryfactorsbinding
Journal Article2009-07-30✓ 5 SnippetsLefebvre V.
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…Sox5,Sox6, and Sox13 constitute…
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…Sox5 andSox6redundantly enhance chondrogen…
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…Sox6promotes erythropoiesis, and…
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…factors – Sox5,Sox6, and Sox13 –…
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…Sox6…
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Sox5, Sox6, and Sox13 constitute the group D of sex-determining region (Sry)-related transcription factors. They are highly conserved in the family-specific high-mobility-group (HMG) box DNA-binding domain and in a group-specific coiled-coil domain. The latter mediates SoxD protein dimerization and thereby preferential binding to pairs of DNA recognition sites. The SoxD genes have overlapping expression and cell-autonomously control discrete lineages. Sox5 and Sox6 redundantly enhance chondrogenesis, but retard gliogenesis. Sox5 hinders melanogenesis, promotes neural crest generation, and controls the pace of neurogenesis. Sox6 promotes erythropoiesis, and Sox13 modulates T cell specification and is an autoimmune antigen. SoxD proteins enhance transactivation by Sox9 in chondrocytes, but antagonize Sox9 and other SoxE proteins in oligodendrocytes and melanocytes, and also repress transcription through various mechanisms in several other lineages. While their biological and molecular functions remain incompletely understood, the SoxD proteins have thus already proven that they critically modulate cell fate in major lineages.
Also flagged:ubiquitinproteasomepolyglutamine (polyQ) disordersHuntington's diseaseHDN
Journal Article2009-07-30✓ 1 SnippetMaynard CJ, Böttcher C, Ortega Z, Smith R, Florea BI, Díaz-Hernández M, Brundin P, Overkleeft HS, Li JY, Lucas JJ, Dantuma NP.
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…Htt…
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Aggregation-prone proteins have been suggested to overwhelm and impair the ubiquitin/proteasome system (UPS) in polyglutamine (polyQ) disorders, such as Huntington's disease (HD). Overexpression of an N-terminal fragment of mutant huntingtin (N-mutHtt), an aggregation-prone polyQ protein responsible for HD, obstructs the UPS in cellular models. Furthermore, based on the accumulation of polyubiquitin conjugates in brains of R6/2 mice, which express human N-mutHtt and are one of the most severe polyQ disorder models, it has been proposed that UPS dysfunction is a consistent feature of this pathology, occurring in both in vitro and in vivo models. Here, we have exploited transgenic mice that ubiquitously express a ubiquitin fusion degradation proteasome substrate to directly assess the functionality of the UPS in R6/2 mice or the slower onset R6/1 mice. Although expression of N-mutHtt caused a general inhibition of the UPS in PC12 cells, we did not observe an increase in the levels of proteasome reporter substrate in the brains of R6/2 and R6/1 mice. We show that the increase in ubiquitin conjugates in R6/2 mice can be primarily attributed to an accumulation of large ubiquitin conjugates that are different from the conjugates observed upon UPS inhibition. Together our data show that polyubiquitylated proteins accumulate in R6/2 brain despite a largely operative UPS, and suggest that neurons are able to avoid or compensate for the inhibitory effects of N-mutHtt.
Also flagged:neonatal hemochromatosisimmunoglobulinironfailureimmunoglobulins
Journal Article2009-07-30✓ 2 SnippetsLecointre R, Lima S, Varlet MN, Combe C.
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…of transmitting neonatalhemochromatosis.…
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…risk of neonatalhemochromatosisin the context…
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Neonatal hemochromatosis is a rare disease characterized by iron deposits in several organs. The natural course leads to lethal liver failure. A preventive treatment was recently introduced: high-dose intravenous immunoglobulins during pregnancy to prevent fetomaternal allo-immunization. Nevertheless, the prescription of massive quantities of immunoglobulins can lead to a drug shortage which the hospital pharmacist must deal with. We report the case of a pregnant woman with high risk of transmitting neonatal hemochromatosis. We discuss the pharmaceutical difficulties encountered when managing patients with a high risk of neonatal hemochromatosis in the context of immunoglobulin shortage with the delivery quotas established by the French National Health Authority. In this context, a national stock would be useful to deal with rare diseases and thus to support hospitals.
Also flagged:chromatinchromosomalinfertilityDown syndromechromosomemale infertility
Journal Article2009-07-29✓ 1 SnippetReinholdt LG, Czechanski A, Kamdar S, King BL, Sun F, Handel MA.
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Aneuploidy, which leads to unpaired chromosomal axes during meiosis, is frequently accompanied by infertility. We previously showed, using three mouse models of Down syndrome, that it is an extra chromosome, but not extra gene dose, that is associated with male infertility and virtual absence of post-meiotic gem cells. Here, we test the hypothesis that aneuploid segments are differentially modified and expressed during meiosis, depending on whether they are present as an extra chromosome or not. In all three models examined, the trisomic region lacks a pairing partner, but in one case, spermatocytes have an extra (and unpaired) chromosome, while the two other models involve translocation of the trisomic region rather than an extra chromosome. An extra unpaired chromosome was always modified by phosphorylation of histone H2AX and lacked RNA PolII. But in the case of trisomic regions attached to a paired chromosome, assembly of these protein modifications was affected by the position of a trisomic region relative to a centromere and the physical extent of the unpaired chromatin. Analysis of gene expression in testes revealed that extra copy number alone was not sufficient for meiotic upregulation of genes in the trisomic interval. Additionally and unexpectedly, presence of meiotic gene silencing chromatin modifications was not sufficient for downregulation of genes in unpaired trisomic chromatin. Thus, the meiotic chromatin modifications that are cytologically visible are unlikely to be directly involved in sterility versus fertility of DS models. Finally, the presence of an extra unpaired chromosome, but not the presence of extra (trisomic) genes, caused global deregulation of transcription in spermatocytes. These results reveal mechanisms by which an extra chromosome, but not trisomic gene dose, impact on meiotic progress and infertility.
<h4>Background</h4>Natural history models of human papillomavirus (HPV) infection and disease have been used in a number of policy evaluations of technologies to prevent and screen for HPV disease (e.g., cervical cancer, anogenital warts), sometimes with wide variation in values for epidemiologic and clinical inputs. The objectives of this study are to: (1) Provide an updated critical and systematic review of the evidence base to support epidemiologic and clinical modeling of key HPV disease-related parameters in the context of an HPV multi-type disease transmission model which we have applied within a U.S. population context; (2) Identify areas where additional studies are particularly needed.<h4>Methods</h4>Consistent with our and other prior HPV natural history models, the literature review was confined to cervical disease and genital warts. Between October 2005 and January 2006, data were gathered from the published English language medical literature through a search of the PubMed database and references were examined from prior HPV natural history models and review papers. Study design and data quality from individual studies were compared and analyses meeting pre-defined criteria were selected.<h4>Results</h4>Published data meeting review eligibility criteria were most plentiful for natural history parameters relating to the progression and regression of cervical intraepithelial neoplasia (CIN) without HPV typing, and data concerning the natural history of HPV disease due to specific HPV types were often lacking. Epidemiologic evidence to support age-dependency in the risk of progression and regression of HPV disease was found to be weak, and an alternative hypothesis concerning the time-dependence of transition rates is explored. No data were found on the duration of immunity following HPV infection. In the area of clinical management, data were observed to be lacking on the proportion of clinically manifest anogenital warts that are treated and the proportion of cervical cancer cases that become symptomatic by stage.<h4>Conclusion</h4>Knowledge of the natural history of HPV disease has been considerably enhanced over the past two decades, through the publication of an increasing number of relevant studies. However, considerable opportunity remains for advancing our understanding of HPV natural history and the quality of associated models, particularly with respect to examining HPV age- and type-specific outcomes, and acquired immunity following infection.
Also flagged:Neurog2Ptf1aRbpjtranscription factorPTF1J
Journal Article2009-07-29✓ 1 SnippetHenke RM, Savage TK, Meredith DM, Glasgow SM, Hori K, Dumas J, MacDonald RJ, Johnson JE.
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…Pou3f2…
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PTF1-J is a trimeric transcription factor complex essential for generating the correct balance of GABAergic and glutamatergic interneurons in multiple regions of the nervous system, including the dorsal horn of the spinal cord and the cerebellum. Although the components of PTF1-J have been identified as the basic helix-loop-helix (bHLH) factor Ptf1a, its heterodimeric E-protein partner, and Rbpj, no neural targets are known for this transcription factor complex. Here we identify the neuronal differentiation gene Neurog2 (Ngn2, Math4A, neurogenin 2) as a direct target of PTF1-J. A Neurog2 dorsal neural tube enhancer localized 3' of the Neurog2 coding sequence was identified that requires a PTF1-J binding site for dorsal activity in mouse and chick neural tube. Gain and loss of Ptf1a function in vivo demonstrate its role in Neurog2 enhancer activity. Furthermore, chromatin immunoprecipitation from neural tube tissue demonstrates that Ptf1a is bound to the Neurog2 enhancer. Thus, Neurog2 expression is directly regulated by the PTF1-J complex, identifying Neurog2 as the first neural target of Ptf1a and revealing a bHLH transcription factor cascade functioning in the specification of GABAergic neurons in the dorsal spinal cord and cerebellum.
…Our aim was to identify sensitive and reliable biomarkers in premanifest carriers of mutated HTT and in individuals with early HD that could provide essential methodology for the assessment of therapeutic interventions.…
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<h4>Background</h4>Huntington's disease (HD) is an autosomal dominant, fully penetrant, neurodegenerative disease that most commonly affects adults in mid-life. Our aim was to identify sensitive and reliable biomarkers in premanifest carriers of mutated HTT and in individuals with early HD that could provide essential methodology for the assessment of therapeutic interventions.<h4>Methods</h4>This multicentre study uses an extensive battery of novel assessments, including multi-site 3T MRI, clinical, cognitive, quantitative motor, oculomotor, and neuropsychiatric measures. Blinded analyses were done on the baseline cross-sectional data from 366 individuals: 123 controls, 120 premanifest (pre-HD) individuals, and 123 patients with early HD.<h4>Findings</h4>The first participant was enrolled in January, 2008, and all assessments were completed by August, 2008. Cross-sectional analyses identified significant changes in whole-brain volume, regional grey and white matter differences, impairment in a range of voluntary neurophysiological motor, and oculomotor tasks, and cognitive and neuropsychiatric dysfunction in premanifest HD gene carriers with normal motor scores through to early clinical stage 2 disease.<h4>Interpretation</h4>We show the feasibility of rapid data acquisition and the use of multi-site 3T MRI and neurophysiological motor measures in a large multicentre study. Our results provide evidence for quantifiable biological and clinical alterations in HTT expansion carriers compared with age-matched controls. Many parameters differ from age-matched controls in a graded fashion and show changes of increasing magnitude across our cohort, who range from about 16 years from predicted disease diagnosis to early HD. These findings might help to define novel quantifiable endpoints and methods for rapid and reliable data acquisition, which could aid the design of therapeutic trials.
…HFE-associated hemochromatosis occurs predominantly in people of northern European extraction, other less-common mutations can lead to the same clinical syndrome…
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…HFE-associated hemochromatosis…
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…identification of theHFEgene and the…
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…substitution in theHFEprotein.…
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…WhileHFE-associated hemochromatosis oc…
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There have been major developments in the field of iron metabolism in the past decade following the identification of the HFE gene and the mutation responsible for the C282Y substitution in the HFE protein. While HFE-associated hemochromatosis occurs predominantly in people of northern European extraction, other less-common mutations can lead to the same clinical syndrome and these may occur in other populations in the Asian-Pacific region. The most common of these is the mutation that leads to changes in the ferroportin molecule, the protein responsible for the transport of iron across the basolateral membrane of the enterocyte and from macrophages. Recent research has unraveled the molecular processes of iron transport and regulation of how these are disturbed in hemochromatosis and other iron-loading disorders. At the same time, at least one new oral iron chelating agent has been developed that shows promise in the therapy of hemochromatosis as well as thalassemia and other secondary causes of iron overload. It is pertinent therefore to examine the developments in the global field of iron overload that have provided insights into the pathogenesis, disease penetrance, comorbid factors, and management.
Transforming growth-interacting factor (TGIF) is a homeobox transcriptional repressor that has been implicated in holoprosencephaly and various types of cancer. TGIF is expressed in hematopoietic stem cells and modulates TGF-beta and retinoic acid (RA) signaling, both of which play an important role in hematopoiesis. We recently reported that TGIF's levels correlate inversely with survival in patients with acute myelogenous leukemia. Here we present the first direct evidence of a role for TGIF in myelopoiesis. We used short hairpin RNA interference to define the effects of TGIF knockdown on proliferation and differentiation of myeloid leukemia-derived cell lines. Decreased TGIF expression resulted in reduced proliferation and differentiation and lower expression of CEBPbeta, CEBPepsilon, PU.1 and RUNX1, key myeloid transcription factors. Furthermore, TGF-beta signaling was increased and RA signaling was decreased. Further insights into the molecular basis of TGIF's effects were provided by a genome-wide chromatin immunoprecipitation-based elucidation of TGIF target genes. Together, these data suggest that TGIF has an important role myelopoiesis and may regulate the balance between proliferation and differentiation. Reduced TGIF expression could tip the balance toward quiescence thus providing progenitor as well as hematopoietic stem cells protection from anti-cycle agents.
Quantitative or complex traits are determined by the combined effects of many loci, and are affected by genetic networks or molecular pathways. In the present study, we genotyped a total of 138 mutations, mainly single nucleotide polymorphisms derived from 71 functional genes on a Wagyu x Limousin reference population. Two hundred forty six F(2) animals were measured for 5 carcass, 6 eating quality and 8 fatty acid composition traits. A total of 2,280 single marker-trait association runs with 120 tagged mutations selected based on the HAPLOVIEW analysis revealed 144 significant associations (P < 0.05), but 50 of them were removed from the analysis due to the small number of animals (< or = 9) in one genotype group or absence of one genotype among three genotypes. The remaining 94 single-trait associations were then placed into three groups of quantitative trait modes (QTMs) with additive, dominant and overdominant effects. All significant markers and their QTMs associated with each of these 19 traits were involved in a linear regression model analysis, which confirmed single-gene associations for 4 traits, but revealed two-gene networks for 8 traits and three-gene networks for 5 traits. Such genetic networks involving both genotypes and QTMs resulted in high correlations between predicted and actual values of performance, thus providing evidence that the classical Mendelian principles of inheritance can be applied in understanding genetic complexity of complex phenotypes. Our present study also indicated that carcass, eating quality and fatty acid composition traits rarely share genetic networks. Therefore, marker-assisted selection for improvement of one category of these traits would not interfere with improvement of another.
Also flagged:JNK1PUMAFree fatty acidsc-Jun N-terminal kinaseJNKpalmitate
Journal Article2009-07-28✓ 1 SnippetCazanave SC, Mott JL, Elmi NA, Bronk SF, Werneburg NW, Akazawa Y, Kahraman A, Garrison SP, Zambetti GP, Charlton MR, Gores GJ.
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…hemochromatosis…
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Free fatty acids (FFA) induce hepatocyte lipoapoptosis by a c-Jun N-terminal kinase (JNK)-dependent mechanism. However, the cellular processes by which JNK engages the core apoptotic machinery during lipotoxicity, especially activation of BH3-only proteins, remain incompletely understood. Thus, our aim was to determine whether JNK mediates induction of BH3-only proteins during hepatocyte lipoapoptosis. The saturated FFA palmitate, but not the monounsaturated FFA oleate, induces an increase in PUMA mRNA and protein levels. Palmitate induction of PUMA was JNK1-dependent in primary murine hepatocytes. Palmitate-mediated PUMA expression was inhibited by a dominant negative c-Jun, and direct binding of a phosphorylated c-Jun containing the activator protein 1 complex to the PUMA promoter was identified by electrophoretic mobility shift assay and a chromatin immunoprecipitation assay. Short hairpin RNA-targeted knockdown of PUMA attenuated Bax activation, caspase 3/7 activity, and cell death. Similarly, the genetic deficiency of Puma rendered murine hepatocytes resistant to lipoapoptosis. PUMA expression was also increased in liver biopsy specimens from patients with non-alcoholic steatohepatitis as compared with patients with simple steatosis or controls. Collectively, the data implicate JNK1-dependent PUMA expression as a mechanism contributing to hepatocyte lipoapoptosis.
Also flagged:tumorautoantigenscolorectal cancerautoantibodiescancerautoantibody
Journal Article2009-07-28No SnippetsBabel I, Barderas R, Díaz-Uriarte R, Martínez-Torrecuadrada JL, Sánchez-Carbayo M, Casal JI.
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There is a mounting evidence of the existence of autoantibodies associated to cancer progression. Antibodies are the target of choice for serum screening because of their stability and suitability for sensitive immunoassays. By using commercial protein microarrays containing 8000 human proteins, we examined 20 sera from colorectal cancer (CRC) patients and healthy subjects to identify autoantibody patterns and associated antigens. Forty-three proteins were differentially recognized by tumoral and reference sera (p value <0.04) in the protein microarrays. Five immunoreactive antigens, PIM1, MAPKAPK3, STK4, SRC, and FGFR4, showed the highest prevalence in cancer samples, whereas ACVR2B was more abundant in normal sera. Three of them, PIM1, MAPKAPK3, and ACVR2B, were used for further validation. A significant increase in the expression level of these antigens on CRC cell lines and colonic mucosa was confirmed by immunoblotting and immunohistochemistry on tissue microarrays. A diagnostic ELISA based on the combination of MAPKAPK3 and ACVR2B proteins yielded specificity and sensitivity values of 73.9 and 83.3% (area under the curve, 0.85), respectively, for CRC discrimination after using an independent sample set containing 94 sera representative of different stages of progression and control subjects. In summary, these studies confirmed the presence of specific autoantibodies for CRC and revealed new individual markers of disease (PIM1, MAPKAPK3, and ACVR2B) with the potential to diagnose CRC with higher specificity and sensitivity than previously reported serum biomarkers.
Also flagged:Wilson's diseaseHypocaeruloplasminaemiaironmetabolismcopper
Journal Article2009-07-28✓ 5 SnippetsSorbello O, Sini M, Civolani A, Demelia L.
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…HFE gene mutations and Wilson's disease in Sardinia.…
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…The HFE gene mutations may be an addictional factor in iron overload in Wilson's disease.…
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…prevalence of the HFE gene mutation , its role…
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…The HFE gene encodes a protein that is intimately involved in intestinal iron absorption.<h4>Aims</h4>The aim of this study was to determine the prevalence of the HFE gene mutation, its role in iron metabolism of Wilson's disease patients and the interplay of therapy in copper and iron homeostasis.<h4>Methods</h4>The records of 32 patients with Wilson's disease were reviewed for iron and copper indices, HFE gene mutations and liver biopsy.<h4>Results</h4>Twenty-six patients were negative for HFE gene mutations and did not present significant alterations of iron metabolism.…
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…HFEgene mutations and…
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<h4>Background</h4>Hypocaeruloplasminaemia can lead to tissue iron storage in Wilson's disease and the possibility of iron overload in long-term overtreated patients should be considered. The HFE gene encodes a protein that is intimately involved in intestinal iron absorption.<h4>Aims</h4>The aim of this study was to determine the prevalence of the HFE gene mutation, its role in iron metabolism of Wilson's disease patients and the interplay of therapy in copper and iron homeostasis.<h4>Methods</h4>The records of 32 patients with Wilson's disease were reviewed for iron and copper indices, HFE gene mutations and liver biopsy.<h4>Results</h4>Twenty-six patients were negative for HFE gene mutations and did not present significant alterations of iron metabolism. The HFE mutation was significantly associated with increased hepatic iron content (P<0.02) and transferrin saturation index (P<0.03). After treatment period, iron indices were significantly decreased only in HFE gene wild-type.<h4>Conclusions</h4>The HFE gene mutations may be an addictional factor in iron overload in Wilson's disease. Our results showed that an adjustment of dosage of drugs could prevent further iron overload induced by overtreatment only in patients HFE wild-type.
Also flagged:apoptosis signal-regulating kinase 1endoplasmic reticulumHuntington diseaseHuntington's diseaseHDchorea
Journal Article2009-07-28✓ 5 SnippetsCho KJ, Lee BI, Cheon SY, Kim HW, Kim HJ, Kim GW.
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Abstract)
…We analyzed the expression of Ask1 and huntingtin (htt) within the striatum and cortex and also examined the interaction of Ask1 with htt fragments in HD (R6/2) mice.…
Huntington's disease (HD) is characterized clinically by chorea, psychiatric disturbances, and dementia, while it is characterized pathologically by neuronal inclusions as well as striatal and cortical neurodegeneration. The neurodegeneration arises from the loss of long projection neurons in the cortex and striatum. In this study, we investigated the role of apoptosis signal-regulating kinase 1 (Ask1) in the pathogenesis of HD. We analyzed the expression of Ask1 and huntingtin (htt) within the striatum and cortex and also examined the interaction of Ask1 with htt fragments in HD (R6/2) mice. Additionally, we inhibited Ask1 and analyzed the resulting changes in brain-derived neurotrophic factor (BDNF) expression, motor function, and striatal atrophy. Ask1 activity was blocked using an Ask1 antibody raised against the C-terminus of the Ask1 protein. The anti-Ask1 antibody was infused into the striatum of the HD mice for four weeks using a micro-osmotic pump. The levels of Ask1 protein and endoplasmic reticulum (ER) stress were increased in HD mice. Binding of inactivated Ask1 to htt fragments was more prevalent in the cytosol than the nucleus of cortical neurons. Binding of inactivated Ask1 to htt fragments prevented translocation of the htt fragments into the nucleus, resulting in an improvement in motor dysfunction and atrophy. In the normal state, active Ask1 may help htt fragments enter the nucleus, while inactivated Ask1 hinders this translocation by binding to but not releasing fragmented htt into the nucleus. We propose that Ask1 may interact with htt fragments and subsequently induce ER stress. BDNF depletion may be prevented by targeting Ask1; this would decrease ER stress and possibly ameliorate behavioral or anatomical abnormalities that accompany HD. Therefore, regulating the amounts and activity of the Ask1 protein is a novel strategy for treatment of HD.
Also flagged:CD39transcription factorbinding-thalassaemiaHb
Journal Article2009-07-28✓ 1 SnippetGamarra S, Garcia-Effron G, Monteserin C, Lopez-Villar I, Gilsanz F, Martinez-Lopez J, Martinez-Lopez J.
In-Text Gene Mentions
Methods)
…been diagnosed ofhemochromatosisdue to iron…
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A Spanish male patient with beta-thalassaemia major was studied. Compound heterozygosity was found for one of the most common beta-globin gene mutations in the Spanish population (codon 39 C --> T) and for a mutation in the TATA box element of the beta-globin gene promoter (-28 A --> C mutation). To our knowledge this is the first report of a CD39 C --> T and -28 A --> C change association and the first report of the -28 A --> C substitution in a Spanish patient.
Also flagged:epithelial to mesenchymal transitionmetastatic prostate cancerproteasomeRKIPtumornuclear factor
Journal Article2009-07-27No SnippetsBaritaki S, Chapman A, Yeung K, Spandidos DA, Palladino M, Bonavida B.
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Metastasis is associated with the loss of epithelial features and the acquisition of mesenchymal characteristics and invasive properties by tumor cells, a process known as epithelial to mesenchymal transition (EMT). Snail expression, through nuclear factor (NF)-kappaB activation, is an EMT determinant. The proteasome inhibitor, NPI-0052, induces the metastasis tumor suppressor/immune surveillance cancer gene, Raf kinase inhibitor protein (RKIP), via NF-kappaB inhibition. We hypothesized that NPI-0052 may inhibit Snail expression and, consequently, the metastatic phenotype in DU-145 prostate cancer cells. Cell treatment with NPI-0052 induced E-cadherin and inhibited Snail expression and both tumor cell invasion and migration. Inhibition of Snail inversely correlated with the induction of RKIP. The underlying mechanism of NPI-0052-induced inhibition of the metastatic phenotype was corroborated by: (1) treatment with Snail siRNA in DU-145 inhibited EMT and, in contrast, overexpression of Snail in the nonmetastatic LNCaP cells induced EMT, (2) NPI-0052-induced repression of Snail via inhibition of NF-kappaB was corroborated by the specific NF-kappaB inhibitor DHMEQ and (3) RKIP overexpression mimicked NPI-0052 in the inhibition of Snail and EMT. These findings demonstrate, for the first time, the role of NPI-0052 in the regulation of EMT via inhibition of NF-kappaB and Snail and induction of RKIP.
Recent studies have shown that bone morphogenetic proteins (BMPs) are important regulators in the pituitary-gonadal endocrine axis. We here investigated the effects of BMPs on GNRH production controlled by estrogen using murine GT1-7 hypothalamic neuron cells. GT1-7 cells expressed estrogen receptor alpha (ERalpha; ESR1 as listed in MGI Database), ERbeta (ESR2 as listed in MGI Database), BMP receptors, SMADs, and a binding protein follistatin. Treatment with BMP2 and BMP4 had no effect on Gnrh mRNA expression; however, BMP6 and BMP7 significantly increased Gnrh mRNA expression as well as GnRH production by GT1-7 cells. Notably, the reduction of Gnrh expression caused by estradiol (E(2)) was restored by cotreatment with BMP2 and BMP4, whereas it was not affected by BMP6 or BMP7. E(2) activated extracellular signal-regulated kinase (ERK) 1/2 and stress-activated protein kinase/c-Jun NH(2)-terminal kinase (SAPK/JNK) signaling but did not activate p38-mitogen-activated protein kinase (MAPK) signaling in GT1-7 cells. Inhibition of ERK1/ERK2 reversed the inhibitory effect of estrogen on Gnrh expression, whereas SAPK/JNK inhibition did not affect the E(2) actions. Expression levels of Eralpha and Erbeta were reduced by BMP2 and BMP4, but were increased by BMP6 and BMP7. Treatment with an ER antagonist inhibited the E(2) effects on Gnrh suppression including reduction of E(2)-induced ERK phosphorylation, suggesting the involvement of genomic ER actions in Gnrh suppression. BMP2 and BMP4 also suppressed estrogen-induced phosphorylation of ERK1/ERK2 and SAPK/JNK signaling, suggesting that BMP2 and BMP4 downregulate estrogen effects by attenuating ER-MAPK signaling. Considering that BMP6 and BMP7 increased the expression of alpha1E-subunit of R-type calcium channel (Cacna1e), which is critical for GNRH secretion, it is possible that BMP6 and BMP7 directly stimulate GNRH release by GT1-7 cells. Collectively, a newly uncovered interaction of BMPs and ER may be involved in controlling hypothalamic GNRH production and secretion via an autocrine/paracrine mechanism.
Also flagged:acute myeloid leukemiaAMLpathogenesistumoroncogenesleukaemia
Journal Article2009-07-27No SnippetsWalter MJ, Payton JE, Ries RE, Shannon WD, Deshmukh H, Zhao Y, Baty J, Heath S, Westervelt P, Watson MA, Tomasson MH, Nagarajan R, O'Gara BP, Bloomfield CD, Mrózek K, Selzer RR, Richmond TA, Kitzman J, Geoghegan J, Eis PS, Maupin R, Fulton RS, McLellan M, Wilson RK, Mardis ER, Link DC, Graubert TA, DiPersio JF, Ley TJ.
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Cytogenetic analysis of acute myeloid leukemia (AML) cells has accelerated the identification of genes important for AML pathogenesis. To complement cytogenetic studies and to identify genes altered in AML genomes, we performed genome-wide copy number analysis with paired normal and tumor DNA obtained from 86 adult patients with de novo AML using 1.85 million feature SNP arrays. Acquired copy number alterations (CNAs) were confirmed using an ultra-dense array comparative genomic hybridization platform. A total of 201 somatic CNAs were found in the 86 AML genomes (mean, 2.34 CNAs per genome), with French-American-British system M6 and M7 genomes containing the most changes (10-29 CNAs per genome). Twenty-four percent of AML patients with normal cytogenetics had CNA, whereas 40% of patients with an abnormal karyotype had additional CNA detected by SNP array, and several CNA regions were recurrent. The mRNA expression levels of 57 genes were significantly altered in 27 of 50 recurrent CNA regions <5 megabases in size. A total of 8 uniparental disomy (UPD) segments were identified in the 86 genomes; 6 of 8 UPD calls occurred in samples with a normal karyotype. Collectively, 34 of 86 AML genomes (40%) contained alterations not found with cytogenetics, and 98% of these regions contained genes. Of 86 genomes, 43 (50%) had no CNA or UPD at this level of resolution. In this study of 86 adult AML genomes, the use of an unbiased high-resolution genomic screen identified many genes not previously implicated in AML that may be relevant for pathogenesis, along with many known oncogenes and tumor suppressor genes.
…the serotonin transporter (5-HTT) gene and verbal…
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The purpose of this study was to examine the potential association between the S (short) and L (long) alleles of the 5-HTTLPR polymorphism of the serotonin transporter (5-HTT) gene and verbal and figural creative ability. Sixty-two unrelated Caucasian university students (29 men and 33 women) participated in the experiment. The results showed a significant association between verbal and figural creativity scores and the 5-HTTLPR polymorphism. The subjects with S/S and L/S genotypes demonstrated higher verbal creativity scores in comparison with the L/L genotype carriers. The carriers of S/S genotype demonstrated also higher figural creativity scores in comparison with the carries of L/S and L/L genotypes. Thus, it is the first report on a significant association between the 5-HTTLPR polymorphism and creative achievements. As the 5-HTTLPR polymorphism is associated with genetically defined alteration in the brain serotonergic neurotransmission our result provides an evidence of the involvement of the central serotonin system in creativity regulation.
Also flagged:cardiopulmonary diseasespathogenesischronic obstructive lung diseaseasthmacoronary artery diseasecongestive heart failure
Journal Article2009-07-25✓ 2 SnippetsHuang YC, Ghio AJ.
In-Text Gene Mentions
Introduction)
…Subjects with twohemochromatosis(HFE) gene polymorphisms…
Introduction)
…with two hemochromatosis (HFE) gene polymorphisms (C282Y…
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Epidemiologic studies have established an association between exposures to air pollution particles and human mortality and morbidity at concentrations of particles currently found in major metropolitan areas. The adverse effects of pollution particles are most prominent in susceptible subjects, including the elderly and patients with cardiopulmonary diseases. Controlled human exposure studies have been used to confirm the causal relationship between pollution particle exposure and adverse health effects. Earlier studies enrolled mostly young healthy subjects and have largely confirmed the capability of particles to cause adverse health effects shown in epidemiological studies. In the last few years, more studies involving susceptible populations have been published. These recent studies in susceptible populations, however, have shown that the adverse responses to particles appear diminished in these susceptible subjects compared to those in healthy subjects. The present paper reviewed and compared control human exposure studies to particles and sought to explain the "unexpected" response to particle exposure in these susceptible populations and make recommendations for future studies. We found that the causes for the discrepant results are likely multifactorial. Factors such as medications, the disease itself, genetic susceptibility, subject selection bias that is intrinsic to many controlled exposure studies and nonspecificity of study endpoints may explain part of the results. Future controlled exposure studies should select endpoints that are more closely related to the pathogenesis of the disease and reflect the severity of particle-induced health effects in the specific populations under investigation. Future studies should also attempt to control for medications and genetic susceptibility. Using a different study design, such as exposing subjects to filtered air and ambient levels of particles, and assessing the improvement in biological endpoints during filtered air exposure, may allow the inclusion of higher risk patients who are likely the main contributors to the increased particle-induced health effects in epidemiological studies.
Also flagged:gene expressionhistone methyltransferaseshistone deacetylaseshistone demethylaseshistone acetyltransferasescell differentiation
Journal Article2009-07-24✓ 1 SnippetVincent A, Van Seuningen I.
In-Text Gene Mentions
Abstract)
…few years thatchromatin modifiermodifier enzymes (i.e.…
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Establishment and maintenance of epigenetic profiles are essential steps of development during which stem cells, despite identical genetic information, will acquire different and selective gene expression patterns, specific for their fate. This highly complex programming process involves mechanisms that are not yet completely understood although it has been established over the past few years that chromatin modifier enzymes (i.e. DNA and histone methyltransferases, histone deacetylases, histone demethylases, histone acetyltransferases) play essential roles in the establishment of transcriptional programs accompanying cell differentiation. Investigators in this field have been studying a wide variety of cell types including neural, muscular, mesenchymal and blood cells. This review will focus on epithelial cells of the digestive tract, intestinal stem cell niches being a model of choice to understand how epigenetic changes can drive nuclear programming and specific cell differentiation. Moreover, deregulation of epigenetic programming is frequently observed in human tumours and therefore, decoding these molecular mechanisms is essential to better understand both developmental and cancerous processes.
Also flagged:antibodyangiogenesisfibronectininterleukin 2antibodiesimmunocytokines
Journal Article2009-07-24✓ 1 SnippetVentura E, Sassi F, Fossati S, Parodi A, Blalock W, Balza E, Castellani P, Borsi L, Carnemolla B, Zardi L.
In-Text Gene Mentions
Text
…129/SvHsd mice…
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We report a novel strategy to engineer and express stable and soluble human recombinant polyvalent/polyspecific fusion proteins. The procedure is based on the use of a central skeleton of uteroglobin, a small and very soluble covalently linked homodimeric protein that is very resistant to proteolytic enzymes and to pH variations. Using a human recombinant antibody (scFv) specific for the angiogenesis marker domain B of fibronectin, interleukin 2, and an scFv able to neutralize tumor necrosis factor-alpha, we expressed various biologically active uteroglobin fusion proteins. The results demonstrate the possibility to generate monospecific divalent and tetravalent antibodies, immunocytokines, and dual specificity tetravalent antibodies. Furthermore, compared with similar fusion proteins in which uteroglobin was not used, the use of uteroglobin improved properties of solubility and stability. Indeed, in the reported cases it was possible to vacuum dry and reconstitute the proteins without any aggregation or loss in protein and biological activity.
Also flagged:NFATcalcium/calmodulin-dependent phosphatase calcineurinnuclear factor of activated T cellnucleusmyosin heavy chainMyHC-slow
Journal Article2009-07-24No SnippetsCalabria E, Ciciliot S, Moretti I, Garcia M, Picard A, Dyar KA, Pallafacchina G, Tothova J, Schiaffino S, Murgia M.
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The intracellular signals that convert fast and slow motor neuron activity into muscle fiber type specific transcriptional programs have only been partially defined. The calcium/calmodulin-dependent phosphatase calcineurin (Cn) has been shown to mediate the transcriptional effects of motor neuron activity, but precisely how 4 distinct muscle fiber types are composed and maintained in response to activity is largely unknown. Here, we show that 4 nuclear factor of activated T cell (NFAT) family members act coordinately downstream of Cn in the specification of muscle fiber types. We analyzed the role of NFAT family members in vivo by transient transfection in skeletal muscle using a loss-of-function approach by RNAi. Our results show that, depending on the applied activity pattern, different combinations of NFAT family members translocate to the nucleus contributing to the transcription of fiber type specific genes. We provide evidence that the transcription of slow and fast myosin heavy chain (MyHC) genes uses different combinations of NFAT family members, ranging from MyHC-slow, which uses all 4 NFAT isoforms, to MyHC-2B, which only uses NFATc4. Our data contribute to the elucidation of the mechanisms whereby activity can modulate the phenotype and performance of skeletal muscle.
Also flagged:pulmonary arterial hypertensionHPAHbone morphogenetic receptor type 2idiopathic pulmonary arterial hypertensionIPAHBMPR2
Journal Article2009-07-24No SnippetsAustin ED, Loyd JE, Phillips JA.
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Tremendous progress has been made in understanding the genetics of hereditable pulmonary arterial hypertension (HPAH) since its description in the 1950s. Germline mutations in the gene coding bone morphogenetic receptor type 2 ( BMPR2) are detectable in the majority of cases of HPAH, and in a small proportion of cases of idiopathic pulmonary arterial hypertension (IPAH). HPAH is an autosomal dominant disease characterized by reduced penetrance, variable expressivity, female predominance, and genetic anticipation. These characteristics suggest that endogenous and exogenous factors modify disease expression and areas of emphasis for future investigation. The variable clinical expression makes genetic counseling complex because the majority of carriers of a BMPR2 mutation will not be diagnosed with the disease. This issue will become increasingly important, as clinical testing for BMPR2 mutations is now available for the evaluation of patients and family members with HPAH and IPAH.
Cytolethal distending toxins (CDTs) are proteins produced and secreted by facultative pathogenic strains of Gram-negative bacteria with potentially genotoxic effects. Mammalian cells exposed to CDTs undergo cell type-dependent cell-cycle arrest or apoptosis; however, the cell fate responses to such intoxication are mechanistically incompletely understood. Here we show that both normal and cancer cells (BJ, IMR-90 and WI-38 fibroblasts, HeLa and U2-OS cell lines) that survive the acute phase of intoxication by Haemophilus ducreyi CDT possess the hallmarks of cellular senescence. This characteristic phenotype included persistently activated DNA damage signalling (detected as 53BP1/gammaH2AX(+) foci), enhanced senescence-associated beta-galactosidase activity, expansion of promyelocytic leukaemia nuclear compartments and induced expression of several cytokines (especially interleukins IL-6, IL-8 and IL-24), overall features shared by cells undergoing replicative or premature cellular senescence. We conclude that analogous to oncogenic, oxidative and replicative stresses, bacterial intoxication represents another pathophysiological stimulus that induces premature senescence, an intrinsic cellular response that may mechanistically underlie the 'distended' morphology evoked by CDTs. Finally, the activation of the two anticancer barriers, apoptosis and cellular senescence, together with evidence of chromosomal aberrations (micronucleation) reported here, support the emerging genotoxic and potentially oncogenic effects of this group of bacterial toxins, and warrant further investigation of their role(s) in human disease.
<h4>Background</h4>Because secondary hemochromatosis is due to hereditary or acquired anemia, phlebotomy is not a suitable means of removing excess iron in this situation. Rather, the treatment is based on the targeted elimination of iron by means of iron chelators.<h4>Methods</h4>Selective review of the literature.<h4>Results</h4>Disorders causing secondary hemochromatosis (e.g., thalassemia) are characterized by ineffective erythropoiesis leading to increased duodenal uptake of iron. Most patients are also chronically transfusion-dependent and receive 200-250 mg of iron with each transfused unit of packed red blood cells. As the excess iron cannot be actively excreted, iron overload ensues, which can cause organ damage. Most patients with this condition in Germany are elderly persons with myelodysplastic syndromes (MDS). The standard treatment to date, parenterally administered deferoxamine, is often hampered by poor compliance. In September 2006, a new oral iron chelator, deferasirox, was approved for use in Germany. According to current findings, this medication is safe, except for a low risk of renal or hepatic failure.<h4>Conclusions</h4>Iron chelation is a treatment option not only for thalassemia patients, but also for those with lower-risk MDS who can be expected to need several years of transfusion therapy.
Also flagged:tubulininsulinsecretionHuntington's diseaseneurodegenerative disorderIT15
Journal Article2009-07-23No SnippetsSmith R, Bacos K, Fedele V, Soulet D, Walz HA, Obermüller S, Lindqvist A, Björkqvist M, Klein P, Onnerfjord P, Brundin P, Mulder H, Li JY.
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Huntington's disease is a severe progressive neurodegenerative disorder caused by a CAG expansion in the IT15 gene, which encodes huntingtin. The disease primarily affects the neostriatum and cerebral cortex and also associates with increased incidence of diabetes. Here, we show that mutant huntingtin disrupts intracellular transport and insulin secretion by direct interference with microtubular beta-tubulin. We demonstrate that mutant huntingtin impairs glucose-stimulated insulin secretion in insulin-producing beta-cells, without altering stored levels of insulin. Using VSVG-YFP, we show that mutant huntingtin retards post-Golgi transport. Moreover, we demonstrate that the speed of insulin vesicle trafficking is reduced. Using immunoprecipitation of mutant and wild-type huntingtin in combination with mass spectrometry, we reveal an enhanced and aberrant interaction between mutant huntingtin and beta-tubulin, implying the underlying mechanism of impaired intracellular transport. Thus, our findings have revealed a novel pathogenetic process by which mutant huntingtin may disrupt hormone exocytosis from beta-cells and possibly impair vesicular transport in any cell that expresses the pathogenic protein.
Thyroid hormone receptors (TRs) are hormone-regulated transcription factors that control multiple aspects of physiology and development. TRs are expressed in vertebrates as a series of distinct isoforms that exert distinct biological roles. We wished to determine whether the two most widely expressed isoforms, TR alpha 1 and TR beta 1, exert their different biological effects by regulating different sets of target genes. Using stably transformed HepG2 cells and a microarray analysis, we were able to demonstrate that TR alpha 1 and TR beta 1 regulate a largely overlapping repertoire of target genes in response to T(3) hormone. However, these two isoforms display very different transcriptional properties on each individual target gene, ranging from a much greater T(3)-mediated regulation by TR alpha 1 than by TR beta 1, to near equal regulation by both isoforms. We also identified TR alpha 1 and TR beta 1 target genes that were regulated by these receptors in a hormone-independent fashion. We suggest that it is this gene-specific, isoform-specific amplitude of transcriptional regulation that is the likely basis for the appearance and maintenance of TR alpha 1 and TR beta 1 over evolutionary time. In essence, TR alpha 1 and TR beta 1 adjust the magnitude of the transcriptional response at different target genes to different levels; by altering the ratio of these isoforms in different tissues or at different developmental times, the intensity of T(3) response can be individually tailored to different physiological and developmental requirements.
Protection of chromosome ends from DNA repair and degradation activities is mediated by specialized protein complexes bound to telomere repeats. Recently, it has become apparent that epigenetic regulation of the telomeric chromatin template critically impacts on telomere function and telomere-length homeostasis from yeast to man. Across all species, telomeric repeats as well as the adjacent subtelomeric regions carry features of repressive chromatin. Disruption of this silent chromatin environment results in loss of telomere-length control and increased telomere recombination. In turn, progressive telomere loss reduces chromatin compaction at telomeric and subtelomeric domains. The recent discoveries of telomere chromatin regulation during early mammalian development, as well as during nuclear reprogramming, further highlights a central role of telomere chromatin changes in ontogenesis. In addition, telomeres were recently shown to generate long, non-coding RNAs that remain associated to telomeric chromatin and will provide new insights into the regulation of telomere length and telomere chromatin. In this review, we will discuss the epigenetic regulation of telomeres across species, with special emphasis on mammalian telomeres. We will also discuss the links between epigenetic alterations at mammalian telomeres and telomere-associated diseases.
Also flagged:heat shock protein 70chaperoneHSP70BAGendoplasmic reticulumJ-protein
Journal Article2009-07-23✓ 1 SnippetFujikawa T, Munakata T, Kondo S, Satoh N, Wada S.
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I A O 0000326)
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The genome of Ciona intestinalis contains eight genes for HSP70 superfamily proteins, 36 genes for J-proteins, a gene for a J-like protein, and three genes for BAG family proteins. To understand the stress responses of genes in the HSP70 chaperone system comprehensively, the transcriptional profiles of these 48 genes under heat stress and endoplasmic reticulum (ER) stress were studied using real-time reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. Heat stress treatment increased the messenger RNA (mRNA) levels of six HSP70 superfamily genes, eight J-protein family genes, and two BAG family genes. In the cytoplasmic group of the DnaK subfamily of the HSP70 family, Ci-HSPA1/6/7-like was the only heat-inducible gene and Ci-HSPA2/8 was the only constitutively active gene which showed striking simplicity in comparison with other animals that have been examined genome-wide so far. Analyses of the time course and temperature dependency of the heat stress responses showed that the induction of Ci-HSPA1/6/7-like expression rises to a peak after heat stress treatment at 28 degrees C (10 degrees C upshift from control temperature) for 1 h. ER stress treatment with Brefeldin A, a drug that is known to act as ER stress inducer, increased the mRNA levels of four HSP70 superfamily genes and four J-protein family genes. Most stress-inducible genes are conserved between Ciona and vertebrates, as expected from a close evolutionary relationship between them. The present study characterized the stress responses of HSP70 chaperone system genes in Ciona for the first time and provides essential data for comprehensive understanding of the functions of the HSP70 chaperone system.
Also flagged:neuropsychiatric disordersschizophreniabipolar disorderGABA A receptorsγ-amino butyric acid type A (GABA A ) receptorsGABA A receptor
Journal Article2009-07-23No SnippetsCharych EI, Liu F, Moss SJ, Brandon NJ.
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Gamma-aminobutyric acid type A (GABA(A)) receptors play an important role in mediating fast synaptic inhibition in the brain. They are ubiquitously expressed in the CNS and also represent a major site of action for clinically relevant drugs. Recent technological advances have greatly clarified the molecular and cellular roles played by distinct GABA(A) receptor subunit classes and isoforms in normal brain function. At the same time, postmortem and genetic studies have linked neuropsychiatric disorders including schizophrenia and bipolar disorder with GABAergic neurotransmission and various specific GABA(A) receptor subunits, while evidence implicating GABA(A)R-associated proteins is beginning to emerge. In this review we discuss the mounting genetic, molecular, and cellular evidence pointing toward a role for GABA(A) receptor heterogeneity in both schizophrenia etiology and therapeutic development. Finally, we speculate on the relationship between schizophrenia-related disorders and selected GABA(A) receptor associated proteins, key regulators of GABA(A) receptor trafficking, targeting, clustering, and anchoring that often carry out these functions in a subtype-specific manner.
Also flagged:Acute Myocardial Infarctionheart failurechemokinesstromal derived factor oneSDF-1inflammatory response
Journal Article2009-07-23No SnippetsTraverse JH, Henry TD, Vaughan DE, Ellis SG, Pepine CJ, Willerson JT, Zhao DX, Piller LB, Penn MS, Byrne BJ, Perin EC, Gee AP, Hatzopoulos AK, McKenna DH, Forder JR, Taylor DA, Cogle CR, Olson RE, Jorgenson BC, Sayre SL, Vojvodic RW, Gordon DJ, Skarlatos SI, Moye' LA, Simari RD, Cardiovascular Cell Therapy Research Network (CCTRN).
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Several previous studies have demonstrated that administration of autologous bone marrow-derived mononuclear cells (BMMNCs) improves cardiac function in patients after acute myocardial infarction (AMI). However, optimum timing of administration has not been investigated in a clinical trial. The Cardiovascular Cell Therapy Research Network was developed and funded by the National Heart, Lung, and Blood Institute to address important questions such as timing of cell delivery and to accelerate research in the use of cell-based therapies. The TIME trial is a randomized, phase II, double-blind, placebo-controlled clinical trial. The 5 member clinical sites of the Cardiovascular Cell Therapy Research Network will enroll 120 eligible patients with moderate-to-large anterior AMIs who have undergone successful percutaneous coronary intervention of the left anterior descending coronary artery and have a left ventricular (LV) ejection fraction </=45% by echocardiography. Participants will have bone marrow aspirations and intracoronary infusions of 150 x 10(6) BMMNCs or placebo on day 3 or day 7 post-AMI. Objectives of this study are (1) to evaluate effects of BMMNCs on regional and global LV function compared to placebo therapy in patients with acute AMI as assessed by cardiac magnetic resonance imaging at 6 months and (2) to assess whether effects of BMMNC infusion on global and regional LV function and safety are influenced by the time of administration. This study will provide further insight into the clinical feasibility and appropriate timing of autologous BMMNC therapy in high-risk patients after AMI and percutaneous coronary intervention.
Also flagged:L-selectinsulfotransferaseGlcNAc6ST-2PCOSendometriosisinfertility
Journal Article2009-07-22No SnippetsMargarit L, Gonzalez D, Lewis PD, Hopkins L, Davies C, Conlan RS, Joels L, White JO.
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<h4>Background</h4>L-selectin ligands, localized to the luminal epithelium at the time of implantation, may support the early stages of blastocyst attachment. We have assessed the expression of two L-selectin ligands, defined by MECA-79 and HECA-452 monoclonal antibodies, and the sulfotransferase GlcNAc6ST-2, involved in generation of L-selectin ligand epitopes, in the secretory phase of the endometrium from fertile and infertile patients.<h4>Methods</h4>Endometrial samples were obtained from 33 fertile, 26 PCOS, 25 endometriosis and 33 patients diagnosed with unexplained infertility. L-selectin ligands and GlcNAc6ST-2 expression was assessed by immunohistochemistry and immunoblotting.<h4>Results</h4>Immunohistochemical staining of uterine epithelium, from fertile and infertile women, demonstrated differential expression of MECA-79 and HECA-452 epitopes. In fertile women in the secretory phase MECA-79 was more strongly expressed, particularly on the lumen, than in infertile women. HECA-452 staining was significantly stronger in the glands in PCOS and endometriosis patients than in fertile women. GlcNAc6ST-2 expression was reduced in infertile patients, correlating with MECA-79 expression.<h4>Conclusions</h4>This study demonstrated significant differences in expression of L-selectin ligands between fertile and infertile women in natural cycles, and could contribute to patient assessment prior to initiating fertility treatment.
Also flagged:bindingadeninepairingthiaminepyrophosphateguanine
Journal Article2009-07-22No SnippetsSharma M, Bulusu G, Mitra A.
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Riboswitches are structural cis-acting genetic regulatory elements in 5' UTRs of mRNAs, consisting of an aptamer domain that regulates the behavior of an expression platform in response to its recognition of, and binding to, specific ligands. While our understanding of the ligand-bound structure of the aptamer domain of the adenine riboswitches is based on crystal structure data and is well characterized, understanding of the structure and dynamics of the ligand-free aptamer is limited to indirect inferences from physicochemical probing experiments. Here we report the results of 15-nsec-long explicit-solvent molecular dynamics simulations of the add A-riboswitch crystal structure (1Y26), both in the adenine-bound (CLOSED) state and in the adenine-free (OPEN) state. Root-mean-square deviation, root-mean-square fluctuation, dynamic cross-correlation, and backbone torsion angle analyses are carried out on the two trajectories. These, along with solvent accessible surface area analysis of the two average structures, are benchmarked against available experimental data and are shown to constitute the basis for obtaining reliable insights into the molecular level details of the binding and switching mechanism. Our analysis reveals the interaction network responsible for, and conformational changes associated with, the communication between the binding pocket and the expression platform. It further highlights the significance of a, hitherto unreported, noncanonical W:H trans base pairing between A73 and A24, in the OPEN state, and also helps us to propose a possibly crucial role of U51 in the context of ligand binding and ligand discrimination.
Also flagged:transthyretinamyloid fibril formationsynthesisTTRamyloid diseasesbinding
Journal Article2009-07-21No SnippetsPalaninathan SK, Mohamedmohaideen NN, Orlandini E, Ortore G, Nencetti S, Lapucci A, Rossello A, Freundlich JS, Sacchettini JC.
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Transthyretin (TTR) is one of thirty non-homologous proteins whose misfolding, dissociation, aggregation, and deposition is linked to human amyloid diseases. Previous studies have identified that TTR amyloidogenesis can be inhibited through stabilization of the native tetramer state by small molecule binding to the thyroid hormone sites of TTR. We have evaluated a new series of beta-aminoxypropionic acids (compounds 5-21), with a single aromatic moiety (aryl or fluorenyl) linked through a flexible oxime tether to a carboxylic acid. These compounds are structurally distinct from the native ligand thyroxine and typical halogenated biaryl NSAID-like inhibitors to avoid off-target hormonal or anti-inflammatory activity. Based on an in vitro fibril formation assay, five of these compounds showed significant inhibition of TTR amyloidogenesis, with two fluorenyl compounds displaying inhibitor efficacy comparable to the well-known TTR inhibitor diflunisal. Fluorenyl 15 is the most potent compound in this series and importantly does not show off-target anti-inflammatory activity. Crystal structures of the TTR:inhibitor complexes, in agreement with molecular docking studies, revealed that the aromatic moiety, linked to the sp(2)-hybridized oxime carbon, specifically directed the ligand in either a forward or reverse binding mode. Compared to the aryl family members, the bulkier fluorenyl analogs achieved more extensive interactions with the binding pockets of TTR and demonstrated better inhibitory activity in the fibril formation assay. Preliminary optimization efforts are described that focused on replacement of the C-terminal acid in both the aryl and fluorenyl series (compounds 22-32). The compounds presented here constitute a new class of TTR inhibitors that may hold promise in treating amyloid diseases associated with TTR misfolding.
…The inappropriately low levels of Id1 and hepcidin mRNA observed at weaning further suggest that Hfe deficiency triggers iron overload by impairing hepatic Bmp/Smad signaling.…
Impaired regulation of hepcidin expression in response to iron loading appears to be the pathogenic mechanism for hereditary hemochromatosis. Iron normally induces expression of the BMP6 ligand, which, in turn, activates the BMP/Smad signaling cascade directing hepcidin expression. The molecular function of the HFE protein, involved in the most common form of hereditary hemochromatosis, is still unknown. We have used Hfe-deficient mice of different genetic backgrounds to test whether HFE has a role in the signaling cascade induced by BMP6. At 7 weeks of age, these mice have accumulated iron in their liver and have increased Bmp6 mRNA and protein. However, in contrast to mice with secondary iron overload, levels of phosphorylated Smads 1/5/8 and of Id1 mRNA, both indicators of BMP signaling, are not significantly higher in the liver of these mice than in wild-type livers. As a consequence, hepcidin mRNA levels in Hfe-deficient mice are similar or marginally reduced, compared with 7-week-old wild-type mice. The inappropriately low levels of Id1 and hepcidin mRNA observed at weaning further suggest that Hfe deficiency triggers iron overload by impairing hepatic Bmp/Smad signaling. HFE therefore appears to facilitate signal transduction induced by the BMP6 ligand.
The identification of genes influencing sensitivity to stimulants and opioids is important for determining their mechanism of action and may provide fundamental insights into the genetics of drug abuse. We used a panel of C57BL/6J (B6; recipient)x A/J (donor) chromosome substitution strains (CSSs) to identify quantitative trait loci (QTL) for both open field activity and sensitivity to the locomotor stimulant response to methamphetamine (MA). Mice were injected with saline (days 1 and 2) and MA (day 3; 2 mg/kg i.p.). We analyzed the total distance traveled in the open field for 30 min following each injection. CSS-8, -11 and -16 showed reduced MA-induced locomotor activity relative to B6, whereas CSS-10 and -12 showed increased MA-induced locomotor activity. Further analysis focused on CSS-11 because it was robustly different from B6 following MA injection, but did not differ in activity following saline injection and because it also showed reduced locomotor activity in response to the mu-opioid receptor agonist fentanyl (0.2 mg/kg i.p.). Thus, CSS-11 captures QTLs for the response to both psychostimulants and opioids. Using a B6 x CSS-11 F(2) intercross, we identified a dominant QTL for the MA response on chromosome 11. We used haplotype association mapping of cis expression QTLs and bioinformatic resources to parse among genes within the 95% confidence interval of the chromosome 11 QTL. Identification of the genes underlying QTLs for response to psychostimulants and opioids may provide insights about genetic factors that modulate sensitivity to drugs of abuse.
Also flagged:behavioralobesityAtxn2long-term potentiationWateranxiety disorders
Journal Article2009-07-20✓ 2 SnippetsHuynh DP, Maalouf M, Silva AJ, Schweizer FE, Pulst SM.
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Introduction)
…Atxn3 and huntingtin (htt) [16] – [18]…
Introduction)
…Althoughhttko mice were…
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Mouse models with physiological and behavioral differences attributable to differential plasticity of hippocampal and amygdalar neuronal networks are rare. We previously generated ataxin-2 (Atxn2) knockout mice and demonstrated that these animals lacked obvious anatomical abnormalities of the CNS, but showed marked obesity and reduced fertility. We now report on behavioral changes as a consequence of Atxn2-deficiency. Atxn2-deficiency was associated with impaired long-term potentiation (LTP) in the amygdala, but normal LTP in the hippocampus. Intact hippocampal plasticity was associated behaviorally with normal Morris Water maze testing. Impaired amygdala plasticity was associated with reduced cued and contextual fear conditioning. Conditioned taste aversion, however, was normal. In addition, knockout mice showed decreased innate fear in several tests and motor hyperactivity in open cage testing. Our results suggest that Atxn2-deficiency results in a specific set of behavioral and cellular disturbances that include motor hyperactivity and abnormal fear-related behaviors, but intact hippocampal function. This animal model may be useful for the study of anxiety disorders and should encourage studies of anxiety in patients with spinocerebellar ataxia type 2 (SCA2).
Also flagged:transcription factorsTFbindingmitochondrialMrpl15Msh6
Journal Article2009-07-20No SnippetsMason MJ, Fan G, Plath K, Zhou Q, Horvath S.
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<h4>Background</h4>Recent work has revealed that a core group of transcription factors (TFs) regulates the key characteristics of embryonic stem (ES) cells: pluripotency and self-renewal. Current efforts focus on identifying genes that play important roles in maintaining pluripotency and self-renewal in ES cells and aim to understand the interactions among these genes. To that end, we investigated the use of unsigned and signed network analysis to identify pluripotency and differentiation related genes.<h4>Results</h4>We show that signed networks provide a better systems level understanding of the regulatory mechanisms of ES cells than unsigned networks, using two independent murine ES cell expression data sets. Specifically, using signed weighted gene co-expression network analysis (WGCNA), we found a pluripotency module and a differentiation module, which are not identified in unsigned networks. We confirmed the importance of these modules by incorporating genome-wide TF binding data for key ES cell regulators. Interestingly, we find that the pluripotency module is enriched with genes related to DNA damage repair and mitochondrial function in addition to transcriptional regulation. Using a connectivity measure of module membership, we not only identify known regulators of ES cells but also show that Mrpl15, Msh6, Nrf1, Nup133, Ppif, Rbpj, Sh3gl2, and Zfp39, among other genes, have important roles in maintaining ES cell pluripotency and self-renewal. We also report highly significant relationships between module membership and epigenetic modifications (histone modifications and promoter CpG methylation status), which are known to play a role in controlling gene expression during ES cell self-renewal and differentiation.<h4>Conclusion</h4>Our systems biologic re-analysis of gene expression, transcription factor binding, epigenetic and gene ontology data provides a novel integrative view of ES cell biology.
Also flagged:nucleosidesugarnucleobaseglycosylbicyclohexane
Journal Article2009-07-20No SnippetsSaneyoshi H, Mazzini S, Aviñó A, Portella G, González C, Orozco M, Marquez VE, Eritja R.
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Modified thrombin-binding aptamers carrying 2'-deoxyguanine (dG) residues with locked North- or South-bicyclo[3.1.0]hexane pseudosugars were synthesized. Individual 2'-deoxyguanosines at positions dG5, dG10, dG14 and dG15 of the aptamer were replaced by these analogues where the North/anti and South/syn conformational states were confined. It was found that the global structure of the DNA aptamer was, for the most part, very accommodating. The substitution at positions 5, 10 and 14 with a locked South/syn-dG nucleoside produced aptamers with the same stability and global structure as the innate, unmodified one. Replacing position 15 with the same South/syn-dG nucleoside induced a strong destabilization of the aptamer, while the antipodal North/anti-dG nucleoside was less destabilizing. Remarkably, the insertion of a North/anti-dG nucleoside at position 14, where both pseudosugar conformation and glycosyl torsion angle are opposite with respect to the native structure, led to the complete disruption of the G-tetraplex structure as detected by NMR and confirmed by extensive molecular dynamics simulations. We conclude that conformationally locked bicyclo[3.1.0]hexane nucleosides appear to be excellent tools for studying the role of key conformational parameters that are critical for the formation of a stable, antiparallel G-tetrad DNA structures.
Also flagged:signal transductionretinoic acid hormoneinflammation responseMelatoninnucleuscircadian rhythms
Journal Article2009-07-19No SnippetsKlein DC, Bailey MJ, Carter DA, Kim JS, Shi Q, Ho AK, Chik CL, Gaildrat P, Morin F, Ganguly S, Rath MF, Møller M, Sugden D, Rangel ZG, Munson PJ, Weller JL, Coon SL.
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Microarray analysis has provided a new understanding of pineal function by identifying genes that are highly expressed in this tissue relative to other tissues and also by identifying over 600 genes that are expressed on a 24-h schedule. This effort has highlighted surprising similarity to the retina and has provided reason to explore new avenues of study including intracellular signaling, signal transduction, transcriptional cascades, thyroid/retinoic acid hormone signaling, metal biology, RNA splicing, and the role the pineal gland plays in the immune/inflammation response. The new foundation that microarray analysis has provided will broadly support future research on pineal function.
Journal Article2009-07-19✓ 5 SnippetsDoornbos B, Dijck-Brouwer DA, Kema IP, Tanke MA, van Goor SA, Muskiet FA, Korf J.
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Title)
…The development of peripartum depressive symptoms is associated with gene polymorphisms of MAOA, 5-HTT and COMT.…
Title)
…depressive symptoms is associated with gene polymorphisms of MAOA, 5-HTT and COMT…
Abstract)
…depressive symptoms in the course of pregnancy and polymorphisms in 5-HTT (p=0.019); MAOA (p=0.044) and COMT…
Abstract)
…depressive symptoms in the course of pregnancy and polymorphisms in 5-HTT (p=0.019); MAOA…
Title)
…polymorphisms of MAOA,5-HTTand COMT.…
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<h4>Background</h4>Polymorphisms of monoamine-related genes have been associated with depression following life events. The peripartum is a physiologically and psychologically challenging period, characterized by fluctuations in depressive symptoms, therefore facilitating prospective investigations in this gene x environment (G x E) interaction.<h4>Methods</h4>Eighty nine pregnant women filled in two Edinburgh Postpartum Depression Scale (EPDS) questionnaires during pregnancy and two in the postpartum period. MAOA, COMT and 5-HTT polymorphisms were analyzed.<h4>Results</h4>We found a significant interaction between the development of depressive symptoms in the course of pregnancy and polymorphisms in 5-HTT (p=0.019); MAOA (p=0.044) and COMT (p=0.026), and MAOA x COMT (p<0.001). Particularly, women carrying the combination of low activity variants of MAOA and COMT showed increased EPDS scores at week 36 of pregnancy and 6 weeks postpartum, but not during early pregnancy or 12 weeks postpartum.<h4>Conclusion</h4>We found that MAOA in combination with COMT appears to regulate not only the stress response in laboratory experiments, but also seems to influence the stress-evoked onset of mood during normal, mild, stressful events, such as experienced in the peripartum period. These findings support the GxE concept for depression, but they underline the complexity of this concept, as the cumulating effects of these polymorphic genes (i.e. MAOA+COMT) might be needed and the effects of these polymorphic genes becomes apparent in special environmental or physiological conditions (i.e. the peripartum period). We therefore suggest that G x E interactions become especially noticeable from longitudinal study designs in specific physiological or social challenging periods.
The administration of anti-CD3 antibodies, either unmodified or in bispecific formats, has been shown to kill tumors. However, their activity needs to be carefully controlled. We have approached this problem by inhibiting their anti-CD3 activity until it is required. Folated anti-human CD3 antibody bispecific conjugates were therefore synthesised in which the folate portion of the conjugates remained free to bind to folate receptor (FR) expressing cancer cells, whilst their anti-CD3 activity was reversibly inhibited. On irradiation with UV-A light, the T-cell binding activity of the anti-CD3 antibody can be restored only when and where it is required, i.e., adjacent to a tumor. Conjugate bound to FR expressed on normal tissues in other parts of the body remains inactive. This report describes the preclinical in vivo testing of these conjugates in transgenic mice whose T-cells express human CD3 molecules. When the 'cloaked' conjugates were reactivated in the region of the primary tumor, both primary tumor growth and liver metastasis were markedly reduced. That the deliberate targeting of T-cell activity locally to the primary tumor also resulted in reduced distant metastatic growth was a key finding. Light-activatable bispecific antibody conjugates similar to those described here offer a means to control T-cell targeting with a much higher degree of specificity to tumors because they minimize potentially dangerous and unwanted side effects in non-illuminated areas. The addition of light-specific targeting to the inherent tumor specific targeting of therapeutic antibody conjugates could result in the development of safer treatments for patients.
Also flagged:Lung cancergene expressioncancerMalignant pleural mesotheliomalung adenocarcinomatumors
Journal Article2009-07-18No SnippetsGuan P, Huang D, He M, Zhou B.
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<h4>Background</h4>A reliable and precise classification is essential for successful diagnosis and treatment of cancer. Gene expression microarrays have provided the high-throughput platform to discover genomic biomarkers for cancer diagnosis and prognosis. Rational use of the available bioinformation can not only effectively remove or suppress noise in gene chips, but also avoid one-sided results of separate experiment. However, only some studies have been aware of the importance of prior information in cancer classification.<h4>Methods</h4>Together with the application of support vector machine as the discriminant approach, we proposed one modified method that incorporated prior knowledge into cancer classification based on gene expression data to improve accuracy. A public well-known dataset, Malignant pleural mesothelioma and lung adenocarcinoma gene expression database, was used in this study. Prior knowledge is viewed here as a means of directing the classifier using known lung adenocarcinoma related genes. The procedures were performed by software R 2.80.<h4>Results</h4>The modified method performed better after incorporating prior knowledge. Accuracy of the modified method improved from 98.86% to 100% in training set and from 98.51% to 99.06% in test set. The standard deviations of the modified method decreased from 0.26% to 0 in training set and from 3.04% to 2.10% in test set.<h4>Conclusion</h4>The method that incorporates prior knowledge into discriminant analysis could effectively improve the capacity and reduce the impact of noise. This idea may have good future not only in practice but also in methodology.
Also flagged:hypertensionstrokekidney diseasesPMS1SLC24A4IPO7
Journal Article2009-07-17✓ 2 SnippetsAdeyemo A, Gerry N, Chen G, Herbert A, Doumatey A, Huang H, Zhou J, Lashley K, Chen Y, Christman M, Rotimi C.
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Results)
…As a case in point, the top scoring pathway – Development_Role of HDAC and calcium/clamodulin-dependent kinase (CaMK) in control of skeletal myogenesis- (Figure 3) contains the calcium-gated channels CACNA1E and CACNA1H, IGF-1, and AKT, each of which is known to play a role in mechanisms of BP regulation, hypertension and/or complications of hypertension (including left ventricular hypertrophy) [16]–[21].…
The evidence for the existence of genetic susceptibility variants for the common form of hypertension ("essential hypertension") remains weak and inconsistent. We sought genetic variants underlying blood pressure (BP) by conducting a genome-wide association study (GWAS) among African Americans, a population group in the United States that is disproportionately affected by hypertension and associated complications, including stroke and kidney diseases. Using a dense panel of over 800,000 SNPs in a discovery sample of 1,017 African Americans from the Washington, D.C., metropolitan region, we identified multiple SNPs reaching genome-wide significance for systolic BP in or near the genes: PMS1, SLC24A4, YWHA7, IPO7, and CACANA1H. Two of these genes, SLC24A4 (a sodium/potassium/calcium exchanger) and CACNA1H (a voltage-dependent calcium channel), are potential candidate genes for BP regulation and the latter is a drug target for a class of calcium channel blockers. No variant reached genome wide significance for association with diastolic BP (top scoring SNP rs1867226, p = 5.8 x 10(-7)) or with hypertension as a binary trait (top scoring SNP rs9791170, p = 5.1 x 10(-7)). We replicated some of the significant SNPs in a sample of West Africans. Pathway analysis revealed that genes harboring top-scoring variants cluster in pathways and networks of biologic relevance to hypertension and BP regulation. This is the first GWAS for hypertension and BP in an African American population. The findings suggests that, in addition to or in lieu of relying solely on replicated variants of moderate-to-large effect reaching genome-wide significance, pathway and network approaches may be useful in identifying and prioritizing candidate genes/loci for further experiments.
Also flagged:chromatinSteroid hormonesgene expressionkinasesbreast cancerBAF
Journal Article2009-07-17✓ 1 SnippetVicent GP, Zaurin R, Nacht AS, Li A, Font-Mateu J, Le Dily F, Vermeulen M, Mann M, Beato M.
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Discussion)
…possible role oflinker histoneshistones.…
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Steroid hormones regulate gene expression by interaction of their receptors with hormone responsive elements (HREs) and recruitment of kinases, chromatin remodeling complexes, and coregulators to their target promoters. Here we show that in breast cancer cells the BAF, but not the closely related PBAF complex, is required for progesterone induction of several target genes including MMTV, where it catalyzes localized displacement of histones H2A and H2B and subsequent NF1 binding. PCAF is also needed for induction of progesterone target genes and acetylates histone H3 at K14, an epigenetic mark that interacts with the BAF subunits by anchoring the complex to chromatin. In the absence of PCAF, full loading of target promoters with hormone receptors and BAF is precluded, and induction is compromised. Thus, activation of hormone-responsive promoters requires cooperation of at least two chromatin remodeling activities, BAF and PCAF.
Also flagged:CTIP1axondendriteinnervationEvi9zinc finger transcription factor
Journal Article2009-07-17✓ 4 SnippetsKuo TY, Hong CJ, Hsueh YP.
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Abstract)
…Finally, the expression of DCC and MAP1b, two molecules involved in direction and branching of axon outgrowth, is controlled by Bcl11A-L.…
Title)
…regulates expression ofDCCand MAP1b in…
Abstract)
…the expression ofDCCand MAP1b, two…
Abstract)
…controlled by Bcl11A-L.DCCoverexpression rescues the…
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The extension of axon branches is important for target innervation but how axon branching is regulated is currently not well understood. Here, we report that Bcl11A/CTIP1/Evi9, a zinc finger transcription factor, downregulates axon branching. Knockdown of Bcl11A induced axon branching and multi-axon formation, as well as dendrite outgrowth. Due to alternative splicing, a single Bcl11A gene encodes two protein products, Bcl11A-L and -S. Bcl11A-L was found to be the main Bcl11A player in regulation of neurite arborization; Bcl11A-S is an antagonist of Bcl11A-L. Time-lapse study further suggests that Bcl11A-L knockdown enhances axon dynamics and increases the duration of axon outgrowth. Finally, the expression of DCC and MAP1b, two molecules involved in direction and branching of axon outgrowth, is controlled by Bcl11A-L. DCC overexpression rescues the phenotype induced by Bcl11A-L knockdown. In conclusion, this report provides the first evidence that Bcl11A is important for neurite arborization.
Also flagged:heparindural venous sinus thrombosisSACintracranial hemorrhageheparin-induced thrombocytopeniaargatroban
Journal Article2009-07-17✓ 1 SnippetLa Barge DV, Bishop FS, Stevens EA, Eskandari R, Schmidt RH, Skalabrin EJ, Ng PP.
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…antithrombin-III…
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<h4>Background and purpose</h4>In this small series, local intrasinus catheter-directed heparin infusion with or without balloon thrombectomy was safe in the treatment of dural venous sinus thrombosis (DVST). Although systemic anticoagulation (SAC) is the treatment of choice, there is a lack of consensus regarding the best treatment should SAC fail or be contraindicated. We present our institutional experience with 16 patients in whom failure of, or contraindication to, SAC occurred and who subsequently underwent intrasinus catheter-directed heparin infusion with or without balloon thrombectomy.<h4>Materials and methods</h4>A retrospective review of 16 patients ranging in age from 14 days to 77 years who had intrasinus catheter-directed heparin infusion was undertaken with 9 male and 7 female patients identified. Of these 16 patients, 4 (25%) had a contraindication to SAC and SAC failed in 12 (75%). Technically successful intrasinus infusion catheter placement was achieved in all 16 patients (100%). Mean duration of infusion was 3.3 days (range, 1-6 days). Adjunctive balloon thrombectomy was performed in 9 (56.3%) of 16 patients. No procedure-related mortality occurred.<h4>Results</h4>Partial and complete sinus recanalization occurred in 10 (62.5%) of 16 patients and 1 (6.3%) of 16 patients, respectively. There were 3 deaths (18.8%) attributed to disease progression. At most recent clinical follow-up (mean, 9.3 months), 11 (84.6%) of 13 surviving patients were independent, with a modified Rankin Scale (mRS) score of 1 or less.<h4>Conclusions</h4>Local intrasinus catheter-directed heparin infusion with or without adjunctive balloon thrombectomy seems to be a safe and effective treatment of DVST in patients in whom SAC failed or in whom there was a contraindication to SAC. In addition, the risk for symptomatic intracranial hemorrhage may be significantly lower than intrasinus infusion of thrombolytics.
Also flagged:determinationpeptidesprotein synthesis-translationalgonad development
Journal Article2009-07-17No SnippetsEwen K, Baker M, Wilhelm D, Aitken RJ, Koopman P.
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The development of an embryo as male or female depends on differentiation of the gonads as either testes or ovaries. A number of genes are known to be important for gonadal differentiation, but our understanding of the regulatory networks underpinning sex determination remains fragmentary. To advance our understanding of sexual development beyond the transcriptome level, we performed the first global survey of the mouse gonad proteome at the time of sex determination by using two-dimensional nanoflow LC-MS/MS. The resulting data set contains a total of 1037 gene products (154 non-redundant and 883 redundant proteins) identified from 620 peptides. Functional classification and biological network construction suggested that the identified proteins primarily serve in RNA post-transcriptional modification and trafficking, protein synthesis and folding, and post-translational modification. The data set contains potential novel regulators of gonad development and sex determination not revealed previously by transcriptomics and proteomics studies and more than 60 proteins with potential links to human disorders of sexual development.
Also flagged:FOXO3aplasminogen activator inhibitor type 1Plasminogen activator inhibitor-1PAI-1fibrinolysistype 2 diabetes
Journal Article2009-07-16✓ 1 SnippetJag UR, Zavadil J, Stanley FM.
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…Fox C1…
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Plasminogen activator inhibitor-1 (PAI-1) is an important regulator of fibrinolysis. PAI-1 levels are elevated in type 2 diabetes, and this elevation correlates with macro- and microvascular complications of diabetes. However, the mechanistic link between insulin and up-regulation of PAI-1 is unclear. Here we demonstrate that overexpression of Forkhead-related transcription factor (Fox)O1, FoxO3a, and FoxC1 augment insulin's ability to activate the PAI-1 promoter. In addition, insulin treatment promotes the phosphorylation of nuclear and cytoplasmic Fox03a and an increase of cytoplasmic Fox03a. In contrast, insulin treatment led to the accumulation of phospho-Fox01 only in the cytoplasm. Furthermore, insulin also increased the ability of chimeric LexA-FoxO1, LexA-FoxO3a, and LexA-FoxC1 proteins to increase the activity of a LexA reporter, suggesting that the effect of insulin on FoxO3a was direct. Using small interfering RNA to specifically deplete each of the Fox transcription factors tested, we demonstrate that only reduction of FoxO3a inhibits insulin-increased PAI-1-Luc expression and PAI-1 mRNA accumulation. Finally, chromatin immunoprecipitation assays confirm the presence of FoxO3a on the PAI-1 promoter. These results suggest that FoxO3a mediates insulin-increased PAI-1 gene expression.
Also flagged:ironiron regulatory hormonehereditary hemochromatosisanti-inflammatory cytokineinter-leukin-1 receptorIL-6
Journal Article2009-07-16✓ 5 Snippetsvan Deuren M, Kroot JJ, Swinkels DW.
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Abstract)
…In conclusion, this in vivo human model: i) supports the importance of an HFE-independent IL-6-hepcidin axis in the development of hypoferremia and anemia of inflammation; and ii) suggests that chronic inflammation protects patients with HFE-related hereditary hemochromatosis from iron accumulation.…
Abstract)
…In conclusion, this in vivo human model: i) supports the importance of an HFE-independent IL-6-hepcidin axis in …
Abstract)
…Here we describe the temporal relationship of serum hepcidin, serum iron and cytokines in a patient with HFE-related (C282Y homozygous) hereditary hemochromatosis who was treated for an auto-inflammatory condition, i.e. variant Schnitzler's syndrome, with the potent anti-inflammatory cytokine inter-leukin-1 receptor antagonist (IL-1ra, anakinra).…
Abstract)
…on an intactHFE-protein.…
Abstract)
…a patient withHFE-related (C282Y homozygous) he…
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It is currently unknown if the increase of the hepatic iron regulatory hormone hepcidin during inflammation in man depends on an intact HFE-protein. Here we describe the temporal relationship of serum hepcidin, serum iron and cytokines in a patient with HFE-related (C282Y homozygous) hereditary hemochromatosis who was treated for an auto-inflammatory condition, i.e. variant Schnitzler's syndrome, with the potent anti-inflammatory cytokine inter-leukin-1 receptor antagonist (IL-1ra, anakinra). The patient had bouts of fever with peaking serum IL-6 concentrations followed by peaking serum hepcidin levels, while serum iron was low. Upon treatment, these peaks disappeared and hepcidin levels became non-detectable, consistent with HFE deficiency. In conclusion, this in vivo human model: i) supports the importance of an HFE-independent IL-6-hepcidin axis in the development of hypoferremia and anemia of inflammation; and ii) suggests that chronic inflammation protects patients with HFE-related hereditary hemochromatosis from iron accumulation.
Also flagged:hexokinasephosphorylationglucoseHK1HKreverse transcriptase
Journal Article2009-07-16✓ 1 Snippetde Vooght KM, van Solinge WW, van Wesel AC, Kersting S, van Wijk R.
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…HFE…
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<h4>Background</h4>Hexokinase is one of the key enzymes of glycolysis and catalyzes the phosphorylation of glucose to glucose-6-phosphate. Red blood cell-specific hexokinase is transcribed from HK1 by use of an erythroid-specific promoter. The aim of this study was to investigate the molecular basis for hexokinase deficiency in a patient with chronic hemolysis.<h4>Design and methods</h4>Functional studies were performed using transient transfection of HK promoter constructs in human K562 erythroleukemia cells. The DNA-protein interaction at the promoter of hexokinase was studied using electrophoretic mobility shift assays with nuclear extracts from K562 cells. DNA analysis and reverse transcriptase polymerase chain reaction were performed according to standardized procedures.<h4>Results</h4>On the paternal allele we identified two novel mutations in cis in the erythroid-specific promoter of HKI: -373A>C and -193A>G. Transfection of promoter reporter constructs showed that the -193A>G mutation reduced promoter activity to 8%. Hence, -193A>G is the first mutation reported to affect red blood cell-specific hexokinase specific transcription. By electrophoretic mobility shift assays we showed that in vitro binding of c-jun to an AP-1 binding site was disrupted by this mutation. Subsequent chromatin-immunoprecipitation assays demonstrated that c-jun binds this region of the promoter in vivo. On the maternal allele we identified a novel missense mutation in exon 3: c.278G>A, encoding an arginine to glutamine substitution at residue 93, affecting both hexokinase-1 and red cell specific-hexokinase. In addition, this missense mutation was shown to compromise normal pre-mRNA processing.<h4>Conclusions</h4>We postulate that reduced erythroid transcription of HK1 together with aberrant splicing of both hexokinase-1 and red cell specific-hexokinase results in hexokinase deficiency and mild chronic hemolysis.
Also flagged:Caspaseneurodegenerative diseasesproteases
Journal Article2009-07-16No SnippetsBulat N, Widmann C.
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Apoptosis is induced by the cleavage of a subset of cellular proteins by proteases of the caspase family. Numerous (hundreds) caspase substrates have been described but only for a few of them is the function of their cleavage by caspases well understood. In this review, apoptosis and caspases will first be introduced. The main focus will then be directed to the caspase substrates, the actual "workers" doing the job of mediating and regulating the apoptotic process. The caspase substrates whose functions upon cleavage have been carefully investigated and those that are potentially involved in neurodegenerative diseases will be discussed in detail.
Also flagged:protocadherin-9protocadherin-17protocadherinsorganizationfertilizationphenyl
Journal Article2009-07-16✓ 1 SnippetLiu Q, Chen Y, Pan JJ, Murakami T.
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Abstract)
…Similar to Pcdh9 expression, Pcdh17 expression was found mainly in the anteroventral forebrain at 24 hpf, but its expression in the hindbrain and spinal cord, confined mainly to lateroventral regions of the hindbrain and anterior spinal cord, was more restricted than Pcdh9.…
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In this study we analyzed expression patterns of two delta-protocadherins, protocadherin-9 and protocadherin-17, in the developing zebrafish using in situ hybridization and RT-PCR methods. Both protocadherins were mainly detected in the embryonic central nervous system, but each showed a distinct expression pattern. Protocadherin-9 message (Pcdh9) was expressed after 10h post fertilization (hpf). It was found mainly in small clusters of cells in the anteroventral forebrain and ventrolateral hindbrain, and scattered cells throughout the spinal cord of young embryos (24 hpf). Pcdh9 expression in the hindbrain was segmental, reflecting a neuromeric organization, which became more evident at 34 hpf. As development proceeded, Pcdh9 expression increased throughout the brain, while its expression in the spinal cord was greatly reduced. Pcdh9 was also found in the developing retina and statoacoustic ganglion. Protocadherin-17 message (Pcdh17) expression began much earlier (1.5-2 hpf) than Pcdh9. Similar to Pcdh9 expression, Pcdh17 expression was found mainly in the anteroventral forebrain at 24 hpf, but its expression in the hindbrain and spinal cord, confined mainly to lateroventral regions of the hindbrain and anterior spinal cord, was more restricted than Pcdh9. As development proceeded, Pcdh17 expression was increased both in the brain and spinal cord: detected throughout the brain of two- and three-day old embryos, strongly expressed in the retina and in lateral regions of spinal cord in two-day old embryos. Its expression in the retina and spinal cord was reduced in three-day old embryos. Our results showed that expression of these two protocadherins was both spatially and temporally regulated.
Also flagged:ascorbateextracellulard-amphetaminedopaminebehavioralHD
Journal Article2009-07-16✓ 1 SnippetDorner JL, Miller BR, Klein EL, Murphy-Nakhnikian A, Andrews RL, Barton SJ, Rebec GV.
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A behavior-related deficit in the release of ascorbate (AA), an antioxidant vitamin, occurs in the striatum of R6/2 mice expressing the human mutation for Huntington's disease (HD), a dominantly inherited condition characterized by striatal dysfunction. To determine the role of corticostriatal fibers in AA release, we combined slow-scan voltammetry with electrical stimulation of cortical afferents to measure evoked fluctuations in extracellular AA in wild-type (WT) and R6/2 striatum. Although cortical stimulation evoked a rapid increase in AA release in both groups, the R6/2 response had a significantly shorter duration and smaller magnitude than WT. To determine if corticostriatal dysfunction also underlies the behavior-related AA deficit in R6/2s, we measured striatal AA release in separate groups of mice treated with d-amphetamine (5 mg/kg), a psychomotor stimulant known to release AA from corticostriatal terminals independently of dopamine. Relative to WT, both AA release and behavioral activation were diminished in R6/2 mice. Collectively, our results show that the corticostriatal pathway is directly involved in AA release and that this system is dysfunctional in HD. Moreover, because AA release requires glutamate uptake, a failure of striatal AA release in HD is consistent with an overactive glutamate system and diminished glutamate transport, both of which are thought to be central to HD pathogenesis.
Also flagged:tumorgliomasynthesisaminopeptidestumors
Journal Article2009-07-15No SnippetsShi J, Kim YS, Chakraborty S, Jia B, Wang F, Liu S.
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This report describes the synthesis of MAG(2)-PEG(4)-E[c(RGDfK)](2) (MAG(2)-P-RGD(2): MAG(2) = S-benzoylmercaptoacetylglycylglycyl; PEG(4) = 15-amino-4,7,10,13-tetraoxapentadecanoic acid) and MAG(2)-PEG(4)-E[PEG(4)-c(RGDfK)](2) (MAG(2)-3P-RGD(2)), and the evaluation of (99m)TcO(MAG(2)-P-RGD(2)) and (99m)TcO(MAG(2)-3P-RGD(2)) as new radiotracers for tumor imaging in the athymic nude mice bearing U87MG human glioma xenografts. We found that MAG(2) is such an efficient bifunctional chelating agent that (99m)TcO(MAG(2)-P-RGD(2)) and (99m)TcO(MAG(2)-3P-RGD(2)) coul d be prepared in high yield (>90%) with high specific activity (∼5 Ci/μmol) using a kit formulation. (99m)TcO(MAG(2)-P-RGD(2)) and (99m)TcO(MAG(2)-3P-RGD(2)) have very high solution stability in the kit matrix. Biodistribution data in athymic nude mice bearing U87MG human glioma xenografts indicated that replacing the highly charged [(99m)Tc(HYNIC = 6-hydrazinonicotinyl and TPPTS = trisodium triphenylphosphine-3,3',3''-trisulfonate) with smaller (99m)TcO(MAG(2)) resulted in a significant increase in the radiotracer uptake in the tumor and normal organs most likely due to the higher lipophilicity of (99m)TcO(MAG(2)-3P-RGD(2)) (log P = -3.15 ± 0.10) than that for [(99m)Tc(HYNIC-3P-RGD(2))(tricine)(TPPTS)] ((99m)Tc-3P-RGD(2): log P = -3.96 ± 0.05). Even though (99m)TcO(MAG(2)-3P-RGD(2)) has better tumor uptake (15.36 ± 2.17 %ID/g at 60 min postinjection (p.i.)) than (99m)Tc-3P-RGD(2) (9.15 ± 2.13 %ID/g at 60 min p.i.), its tumor-to-background (T/B) ratios (tumor/blood = 13.52 ± 4.57; tumor/liver = 4.25 ± 0.88; tumor/lung = 3.17 ± 0.60; and tumor/muscle = 8.34 ± 2.34) are not as good as those of (99m)Tc-3P-RGD(2) (tumor/blood = 36.0 ± 11.5; tumor/liver = 5.14 ± 1.46; tumor/lung = 4.36 ± 0.54; and tumor/muscle = 13.70 ± 2.21) at 60 min p.i. On the basis of these results, we believe that (99m)Tc-3P-RGD(2) remains a better radiotracer because of its higher T/B ratios.
Also flagged:FamilialAmyloid Neuropathyliver diseaseFAPAmyloid PolineuropathyFamilial Amyloid Polineuropathy
Journal Article2009-07-15✓ 1 SnippetTelles-Correia D, Cortez-Pinto H, Barbosa A, Mega I, Monteiro E.
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…Liver Disease; 1Hemochromatosis+ LC), unknown…
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<h4>Background</h4>It has been demonstrated in many studies that quality of life can be improved after liver transplantation in patients with liver disease. Nevertheless, quality of life improvement in specific groups of transplanted patients such as those with Familial Amyloid Polyneuropathy has not yet been explored. The present study aimed to compare the change in quality of life following liver transplantation between patients with Familial Amyloid Polyneuropathy (FAP) and patients with liver disease.<h4>Results</h4>Patient's mental quality of life showed an improvement in all liver disease patients, and a worsening in FAP patients, resulting in a significant difference between the two groups. Regarding physical quality of life, although a similar improvement was seen in both groups, FAP patients had significantly less improvement than the sub-group of decompensated liver disease (Child-Pugh B and C).<h4>Conclusion</h4>It is concluded that liver transplantation has a less beneficial impact in FAP patient's physical quality of life, probably because they are not so much disabled by their disease at the moment of liver transplantation. The lesser improvement in mental quality of life of FAP patients may be due to their particular psychological profile and greater expectations towards transplantation.
The dermal papilla comprises the specialised mesenchymal cells at the base of the hair follicle. Communication between dermal papilla cells and the overlying epithelium is essential for differentiation of the hair follicle lineages. We report that Sox2 is expressed in all dermal papillae at E16.5, but from E18.5 onwards expression is confined to a subset of dermal papillae. In postnatal skin, Sox2 is only expressed in the dermal papillae of guard/awl/auchene follicles, whereas CD133 is expressed both in guard/awl/auchene and in zigzag dermal papillae. Using transgenic mice that express GFP under the control of the Sox2 promoter, we isolated Sox2(+) (GFP(+)) CD133(+) cells and compared them with Sox2(-) (GFP(-)) CD133(+) dermal papilla cells. In addition to the 'core' dermal papilla gene signature, each subpopulation expressed distinct sets of genes. GFP(+) CD133(+) cells had upregulated Wnt, FGF and BMP pathways and expressed neural crest markers. In GFP(-) CD133(+) cells, the hedgehog, IGF, Notch and integrin pathways were prominent. In skin reconstitution assays, hair follicles failed to form when dermis was depleted of both GFP(+) CD133(+) and GFP(-) CD133(+) cells. In the absence of GFP(+) CD133(+) cells, awl/auchene hairs failed to form and only zigzag hairs were found. We have thus demonstrated a previously unrecognised heterogeneity in dermal papilla cells and shown that Sox2-positive cells specify particular hair follicle types.
Also flagged:neurogenesisneurodegenerative diseasestrokeVEGFdeathaging
Journal Article2009-07-15No SnippetsWhitman MC, Greer CA.
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Though initially described in the early 1960s, it is only within the past decade that the concept of continuing adult neurogenesis has gained widespread acceptance. Neuroblasts from the subventricular zone (SVZ) migrate along the rostral migratory stream (RMS) into the olfactory bulb, where they differentiate into interneurons. Neuroblasts from the subgranular zone (SGZ) of the hippocampal formation show relatively little migratory behavior, and differentiate into dentate gyrus granule cells. In sharp contrast to embryonic and perinatal development, these newly differentiated neurons must integrate into a fully functional circuit, without disrupting ongoing performance. Here, after a brief historical overview and introduction to olfactory circuitry, we review recent advances in the biology of neural stem cells, mechanisms of migration in the RMS and olfactory bulb, differentiation and survival of new neurons, and finally mechanisms of synaptic integration. Our primary focus is on the olfactory system, but we also contrast the events occurring there with those in the hippocampal formation. Although both SVZ and SGZ neurogenesis are involved in some types of learning, their full functional significance remains unclear. Since both systems offer models of integration of new neuroblasts, there is immense interest in using neural stem cells to replace neurons lost in injury or disease. Though many questions remain unanswered, new insights appear daily about adult neurogenesis, regulatory mechanisms, and the fates of the progeny. We discuss here some of the central features of these advances, as well as speculate on future research directions.
Also flagged:antibodylipopeptideRetinoic acidretinolRAtetanus toxin
Journal Article2009-07-14No SnippetsWatson DS, Huang Z, Szoka FC.
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Retinoic acid (RA), the bioactive metabolite of retinol, is essential for robust humoral immunity in animals and humans. Recent interest in RA as a vaccine adjuvant has been encouraged by reports showing cooperative enhancement of antibody responses to tetanus toxin in rodents by all-trans RA (ATRA) and a Toll-like receptor-3 agonist. We hypothesized that RA would augment the antibody response to a co-delivered lipopeptide immunogen derived from the membrane proximal region (MPR) of HIV-1 gp41. The MPR is weakly immunogenic and could benefit from potent new humoral adjuvants. When co-formulated in liposomes and administered to BALB/C mice, ATRA alone did not elicit serum anti-peptide antibodies to an MPR-derived lipopeptide. However, addition of ATRA, but not 13-cis RA, to a liposomal formulation containing the Toll-like receptor-4 agonist monophosphoryl lipid A resulted in a fourfold enhancement of serum anti-peptide IgG titers as compared with a formulation containing lipid A alone (P=0.00039). The difference did not arise from biophysical changes in the liposome formulation, including vesicle size, vesicle charge and liposome association of antigen. Thus, ATRA warrants further study as a vaccine adjuvant.
Also flagged:p53cisplatingastric carcinomagastric cancertumors5-fluorouracil
Journal Article2009-07-14✓ 1 SnippetYashiro M, Inoue T, Nishioka N, Matsuoka T, Boland CR, Hirakawa K.
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…DCC…
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<h4>Background</h4>Combined treatment with 5-fluorouracil and cisplatin (FP chemotherapy) is an effective neoadjuvant regimen for gastric carcinoma. However, it is ineffective in half of all patients. This study tests the hypothesis that genetic markers might identify those patients with gastric cancer who would respond to neoadjuvant FP chemotherapy.<h4>Materials and methods</h4>A total of 23 patients with gastric carcinoma were treated with neoadjuvant chemotherapy. Pretreatment biopsy specimens before neoadjuvant chemotherapy were obtained from 15 of 23 patients, and resected tumors were obtained from all 23. Genetic studies were performed to detect allelic imbalance (AI), microsatellite instability (MSI), and K-ras mutation.<h4>Results</h4>A clinical response was observed in 13 of 23 patients. Kaplan-Meier survival curve showed that clinical responder group had a significantly higher likelihood of overall survival (P = 0.0165), compared with nonresponder group. In 23 resection specimens, 10 of 23 tumors presented AI at the p53 locus and/or MSI; 8 of the 10 tumors were nonresponders, while 12 of 13 tumors without p53 AI or MSI were responders (P = 0.0007). In 15 pretreatment biopsy specimens, 8 tumors had p53 AI and/or MSI; 7 of the 8 tumors were nonresponders, while 6 of 7 tumors without p53 AI or MSI were responders to preoperative chemotherapy (P = 0.008). Tumors with AI at the p53 locus and/or MSI were significantly more resistant to neoadjuvant chemotherapy. No relationship was found between K-ras mutations and responses.<h4>Conclusions</h4>Analysis for p53 AI and MSI might represent a clinically useful approach to predicting the response to neoadjuvant FP chemotherapy in gastric carcinoma.
Also flagged:Plerixaforgranulocyte colony-stimulating factorG-CSFgene expressionB-cell acute lymphocytic leukemiaCD34
Journal Article2009-07-14No SnippetsDonahue RE, Jin P, Bonifacino AC, Metzger ME, Ren J, Wang E, Stroncek DF.
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Plerixafor (AMD3100) and granulocyte colony-stimulating factor (G-CSF) mobilize peripheral blood stem cells by different mechanisms. A rhesus macaque model was used to compare plerixafor and G-CSF-mobilized CD34(+) cells. Three peripheral blood stem cell concentrates were collected from 3 macaques treated with G-CSF, plerixafor, or plerixafor plus G-CSF. CD34(+) cells were isolated by immunoselection and were analyzed by global gene and microRNA (miR) expression microarrays. Unsupervised hierarchical clustering of the gene expression data separated the CD34(+) cells into 3 groups based on mobilization regimen. Plerixafor-mobilized cells were enriched for B cells, T cells, and mast cell genes, and G-CSF-mobilized cells were enriched for neutrophils and mononuclear phagocyte genes. Genes up-regulated in plerixafor plus G-CSF-mobilized CD34(+) cells included many that were not up-regulated by either agent alone. Two hematopoietic progenitor cell miR, miR-10 and miR-126, and a dendritic cell miR, miR-155, were up-regulated in G-CSF-mobilized CD34(+) cells. A pre-B-cell acute lymphocytic leukemia miR, miR-143-3p, and a T-cell miR, miR-143-5p, were up-regulated in plerixafor plus G-CSF-mobilized cells. The composition of CD34(+) cells is dependent on the mobilization protocol. Plerixafor-mobilized CD34(+) cells include more B-, T-, and mast cell precursors, whereas G-CSF-mobilized cells have more neutrophil and mononuclear phagocyte precursors.
Also flagged:ironhepatic fibrosischronic hepatitis C
Journal Article2009-07-14✓ 5 SnippetsWon JE, Jeong SH, Chung JI, Lee JH, Hwang SH, Kim JW, Lee SH, Kim N, Park YS, Lee DH, Kim H.
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…indices , and HFE gene mutation . …
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…HFE mutation, and hepatic fibrosis…
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…fibrosis were assessed by appropriate pathological scoring systems, clinical data including serum iron indices, and HFE…
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…HFE mutation, and hepatic fibrosis in chronic hepatitis C…
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…HFE gene mutations in Korean patients with chronic hepatitis C…
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<h4>Objectives</h4>We studied the status of hepatic iron deposition and its relationship with blood iron indices, liver histology, and HFE gene mutations in Korean patients with chronic hepatitis C (CH-C).<h4>Methods</h4>105 patients with CH-C who underwent pretreatment liver biopsy were consecutively enrolled. The hepatic iron deposition, histological activity and fibrosis were assessed by appropriate pathological scoring systems, clinical data including serum iron indices, and HFE gene mutation.<h4>Results</h4>Hepatic iron deposition was found in 37 patients (35%), which was not significantly associated with degree of hepatic fibrosis or steatosis. The serum ferritin level was elevated in 27% of the patients and was an independent factor associated with hepatic iron deposition by logistic regression; however, it was not significantly associated with hepatic fibrosis either. Only H63D heterozygote was found in 6 out of 48 patients (12.5%), which was not different from the prevalence of H63D mutation in the Korean population (8.5%).<h4>Conclusions</h4>Hepatic iron deposition was uncommon and mild in Korean CH-C. Neither hepatic iron deposition nor serum ferritin were significantly related to the severity of hepatic fibrosis, which does not support the significant role of iron in the progression of hepatic fibrosis.
Journal Article2009-07-14No SnippetsJacob K, Albrecht S, Sollier C, Faury D, Sader E, Montpetit A, Serre D, Hauser P, Garami M, Bognar L, Hanzely Z, Montes JL, Atkinson J, Farmer JP, Bouffet E, Hawkins C, Tabori U, Jabado N.
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<h4>Background</h4>Juvenile pilocytic astrocytomas (JPA), a subgroup of low-grade astrocytomas (LGA), are common, heterogeneous and poorly understood subset of brain tumours in children. Chromosomal 7q34 duplication leading to fusion genes formed between KIAA1549 and BRAF and subsequent constitutive activation of BRAF was recently identified in a proportion of LGA, and may be involved in their pathogenesis. Our aim was to investigate additional chromosomal unbalances in LGA and whether incidence of 7q34 duplication is associated with tumour type or location.<h4>Methods and results</h4>Using Illumina-Human-Hap300-Duo and 610-Quad high-resolution-SNP-based arrays and quantitative PCR on genes of interest, we investigated 84 paediatric LGA. We demonstrate that 7q34 duplication is specific to sporadic JPA (35 of 53 - 66%) and does not occur in other LGA subtypes (0 of 27) or NF1-associated-JPA (0 of 4). We also establish that it is site specific as it occurs in the majority of cerebellar JPA (24 of 30 - 80%) followed by brainstem, hypothalamic/optic pathway JPA (10 of 16 - 62.5%) and is rare in hemispheric JPA (1 of 7 - 14%). The MAP-kinase pathway, assessed through ERK phosphorylation, was active in all tumours regardless of 7q34 duplication. Gain of function studies performed on hTERT-immortalised astrocytes show that overexpression of wild-type BRAF does not increase cell proliferation or baseline MAPK signalling even if it sensitises cells to EGFR stimulation.<h4>Conclusions and interpretation</h4>Our results suggest that variants of JPA might arise from a unique site-restricted progenitor cell where 7q34 duplication, a hallmark of this tumour-type in association to MAPK-kinase pathway activation, potentially plays a site-specific role in their pathogenesis. Importantly, gain of function abnormalities in components of MAP-Kinase signalling are potentially present in all JPA making this tumour amenable to therapeutic targeting of this pathway.
…tested interactions of htt amino acids 1-89 with 20Q…
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…Htt associates with membranes and polyglutamine expansion in htt may alter membrane function in Huntington disease through a mechanism that is not known.…
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…We prepared synthetic lipid vesicles composed of phosphatidylcholine and phosphatidylethanolamine and tested interactions of htt amino acids 1-89 with 20Q, 32Q or 53Q with the vesicles.…
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…(>37Q) in huntingtin (htt) causes Huntington disease.…
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An expanded polyglutamine (Q) tract (>37Q) in huntingtin (htt) causes Huntington disease. Htt associates with membranes and polyglutamine expansion in htt may alter membrane function in Huntington disease through a mechanism that is not known. Here we used differential scanning calorimetry to examine the effects of polyQ expansion in htt on its insertion into lipid bilayers. We prepared synthetic lipid vesicles composed of phosphatidylcholine and phosphatidylethanolamine and tested interactions of htt amino acids 1-89 with 20Q, 32Q or 53Q with the vesicles. GST-htt1-89 with 53Q inserted into synthetic lipid vesicles significantly more than GST-htt1-89 with 20Q or 32Q. We speculate that by inserting more into cell membranes, mutant huntingtin could increase disorder within the lipid bilayer and thereby disturb cellular membrane function.
…We examined the prevalence of the S65C mutation of the hemochromatosis gene in Brazilians with clinical suspicion of hereditary hemochromatosis.…
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…mutation in thehemochromatosisgene in Brazil.…
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…mutations in thehemochromatosisgene.…
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…mutation of thehemochromatosisgene in Brazilians…
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…suspicion of hereditaryhemochromatosis, using the polymerase…
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Development of hereditary hemochromatosis is associated with the C282Y, H63D or S65C mutations in the hemochromatosis gene. Though there is extensive knowledge about the former two, there is little information on the mechanism of action and the allelic frequency of the S65C mutation. We examined the prevalence of the S65C mutation of the hemochromatosis gene in Brazilians with clinical suspicion of hereditary hemochromatosis. Genotyping for this mutation was carried out in 633 individuals with clinical suspicion of hereditary hemochromatosis, using the polymerase chain reaction, followed by enzymatic digestion. The sample comprised 77.1% men and 22.9% women, giving a ratio of approximately 3:1; the mean age was 48.8 +/- 13.8 years. More than half (57.3%) of the individuals in the sample were 41 to 60 years old. The frequency of heterozygotes for this mutation was 0.016; no homozygous mutant patients were found. This is the first analysis of the S65C mutation in individuals suspected of having hereditary hemochromatosis in Brazil.
Also flagged:CytokineglobinhistonetranslationalhemoglobinopathiesSignal transduction
Journal Article2009-07-13✓ 2 SnippetsSripichai O, Kiefer CM, Bhanu NV, Tanno T, Noh SJ, Goh SH, Russell JE, Rognerud CL, Ou CN, Oneal PA, Meier ER, Gantt NM, Byrnes C, Lee YT, Dean A, Miller JL.
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…(MAFF, ID2, HHEX,SOX6, and EGR1).…
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…SOX6…
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Therapeutic regulation of globin genes is a primary goal of translational research aimed toward hemoglobinopathies. Signal transduction was used to identify chromatin modifications and transcription factor expression patterns that are associated with globin gene regulation. Histone modification and transcriptome profiling were performed using adult primary CD34(+) cells cultured with cytokine combinations that produced low versus high levels of gamma-globin mRNA and fetal hemoglobin (HbF). Embryonic, fetal, and adult globin transcript and protein expression patterns were determined for comparison. Chromatin immunoprecipitation assays revealed RNA polymerase II occupancy and histone tail modifications consistent with transcriptional activation only in the high-HbF culture condition. Transcriptome profiling studies demonstrated reproducible changes in expression of nuclear transcription factors associated with high HbF. Among the 13 genes that demonstrated differential transcript levels, 8 demonstrated nuclear protein expression levels that were significantly changed by cytokine signal transduction. Five of the 8 genes are recognized regulators of erythropoiesis or globin genes (MAFF, ID2, HHEX, SOX6, and EGR1). Thus, cytokine-mediated signal transduction in adult erythroid cells causes significant changes in the pattern of globin gene and protein expression that are associated with distinct histone modifications as well as nuclear reprogramming of erythroid transcription factors.
Also flagged:cyclic peptidescyclic peptideCyclicPeptidesα-SynucleinParkinson
Journal Article2009-07-13✓ 5 SnippetsKritzer JA, Hamamichi S, McCaffery JM, Santagata S, Naumann TA, Caldwell KA, Caldwell GA, Lindquist S.
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…Second, the constructs were transformed into a yeast disease model that uses the GAL1 promoter for the inducible expression of a toxic polypeptide unrelated to α-syn, exon 1 of human huntingtin with 103 glutamine residues (Htt-103Q)14,15.…
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…103 glutamine residues (Htt-103Q) 14 , 15…
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…both α-syn andHtt-103Q toxicity could be…
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…constructs that preventedHtt-103Q toxicity also reduced…
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…assay or onHtt-103Q toxicity, and thus…
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Phage display has demonstrated the utility of cyclic peptides as general protein ligands but cannot access proteins inside eukaryotic cells. Expanding a new chemical genetics tool, we describe the first expressed library of head-to-tail cyclic peptides in yeast (Saccharomyces cerevisiae). We applied the library to selections in a yeast model of alpha-synuclein toxicity that recapitulates much of the cellular pathology of Parkinson's disease. From a pool of 5 million transformants, we isolated two related cyclic peptide constructs that specifically reduced the toxicity of human alpha-synuclein. These expressed cyclic peptide constructs also prevented dopaminergic neuron loss in an established Caenorhabditis elegans Parkinson's model. This work highlights the speed and efficiency of using libraries of expressed cyclic peptides for forward chemical genetics in cellular models of human disease.
Also flagged:Tyrosinasecoumarinresveratrolumbelliferonecoppermelanins
Journal Article2009-07-13No SnippetsFais A, Corda M, Era B, Fadda MB, Matos MJ, Quezada E, Santana L, Picciau C, Podda G, Delogu G.
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In the present work we report on the contribution of the coumarin moiety to tyrosinase inhibition. Coumarin-resveratrol hybrids 1-8 have been resynthesized to investigate the structure-activity relationships and the IC(50) values of these compounds were measured. The results showed that these compounds exhibited tyrosinase inhibitory activity. Compound 3-(3',4',5'-trihydroxyphenyl)-6,8-dihydroxycoumarin (8)is the most potentcompound (0.27 mM), more so than umbelliferone (0.42 mM), used as reference compound. The kinetic studies revealed that compound 8 caused non-competitive tyrosinase inhibition.
Also flagged:liver diseaseAlpha-1 antitrypsinserine proteaseneutrophil elastaseendoplasmic reticulumlung disease
Journal Article2009-07-13No SnippetsMcLean C, Greene CM, McElvaney NG.
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Alpha-1 antitrypsin (A1AT) is a 52 kDa serine protease inhibitor that is synthesized in and secreted from the liver. Although it is present in all tissues in the body the present consensus is that its main role is to inhibit neutrophil elastase in the lung. A1AT deficiency occurs due to mutations of the A1AT gene that reduce serum A1AT levels to <35% of normal. The most clinically significant form of A1AT deficiency is caused by the Z mutation (Glu342Lys). ZA1AT polymerizes in the endoplasmic reticulum of liver cells and the resulting accumulation of the mutant protein can lead to liver disease, while the reduction in circulating A1AT can result in lung disease including early onset emphysema. There is currently no available treatment for the liver disease other than transplantation and therapies for the lung manifestations of the disease remain limited. Gene therapy is an evolving field which may be of use as a treatment for A1AT deficiency. As the liver disease associated with A1AT deficiency may represent a gain of function possible gene therapies for this condition include the use of ribozymes, peptide nucleic acids (PNAs) and RNA interference (RNAi), which by decreasing the amount of aberrant protein in cells may impact on the pathogenesis of the condition.
Also flagged:Netrinaxon guidanceextracellularlocalizationdendriteUNC-5-receptor
Journal Article2009-07-12✓ 3 SnippetsKilleen MT.
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…DCC/Fra…
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…Working through the UNC-40/DCC/Fra receptor, UNC-6/Netrin pr…
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…and axons expressing UNC-40/DCC/Fra and repel those…
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The extracellular cue UNC-6/Netrin is a well-known axon guidance molecule and recently it has also been shown to be involved with localization of pre-synaptic complexes. Working through the UNC-40/DCC/Fra receptor, UNC-6/Netrin promotes the formation of pre-synaptic terminals between the pre-synaptic AIY interneuron and its post-synaptic partner, the RIA interneuron. In the DA9 motor neuron, UNC-6/Netrin has an alternate role promoting the exclusion of pre-synaptic components from the dendrite via its UNC-5-receptor. Surprisingly, the requirement for UNC-5 persists even after DA9 axon migration is complete, because synapses become mis-localized after it is depleted. This observation provides at least a partial explanation for the persistence of UNC-6/Netrin and UNC-5 in the adult nervous system. These activities parallel the previously known bi-functional axon guidance effects of UNC-6/Netrin, since it can attract cells and axons expressing UNC-40/DCC/Fra and repel those expressing UNC-5 alone or in combination with UNC-40. UNC-6/Netrin cooperates with the Wnt family members to exclude synapses from compartments within the DA9 axon, so that they only occur in regions free of the influence of both UNC-6/Netrin and the Wnts. Regulation of both axon guidance and synapse formation by axon guidance cues permits coordination in circuit assembly between pre- and post-synaptic cells.
Also flagged:cancerprostate tumorsBCRABL1TMPRSS2ERG
Journal Article2009-07-10✓ 1 SnippetMaher CA, Palanisamy N, Brenner JC, Cao X, Kalyana-Sundaram S, Luo S, Khrebtukova I, Barrette TR, Grasso C, Yu J, Lonigro RJ, Schroth G, Kumar-Sinha C, Chinnaiyan AM.
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I A O 0000326)
…ARFGEF2…
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Recurrent gene fusions are a prevalent class of mutations arising from the juxtaposition of 2 distinct regions, which can generate novel functional transcripts that could serve as valuable therapeutic targets in cancer. Therefore, we aim to establish a sensitive, high-throughput methodology to comprehensively catalog functional gene fusions in cancer by evaluating a paired-end transcriptome sequencing strategy. Not only did a paired-end approach provide a greater dynamic range in comparison with single read based approaches, but it clearly distinguished the high-level "driving" gene fusions, such as BCR-ABL1 and TMPRSS2-ERG, from potential lower level "passenger" gene fusions. Also, the comprehensiveness of a paired-end approach enabled the discovery of 12 previously undescribed gene fusions in 4 commonly used cell lines that eluded previous approaches. Using the paired-end transcriptome sequencing approach, we observed read-through mRNA chimeras, tissue-type restricted chimeras, converging transcripts, diverging transcripts, and overlapping mRNA transcripts. Last, we successfully used paired-end transcriptome sequencing to detect previously undescribed ETS gene fusions in prostate tumors. Together, this study establishes a highly specific and sensitive approach for accurately and comprehensively cataloguing chimeras within a sample using paired-end transcriptome sequencing.
A third signal that can be provided by IL-12 or type I IFN is required for differentiation of naive CD8 T cells responding to Ag and costimulation. The cytokines program development of function and memory within 3 days of initial stimulation, and we show here that programming involves regulation of a common set of approximately 355 genes including T-bet and eomesodermin. Much of the gene regulation program is initiated in response to Ag and costimulation within 24 h but is then extinguished unless a cytokine signal is available. Histone deacetylase inhibitors mimic the effects of IL-12 or type I IFN signaling, indicating that the cytokines relieve repression and allow continued gene expression by promoting increased histone acetylation. In support of this, increased association of acetylated histones with the promoter loci of granzyme B and eomesodermin is shown to occur in response to IL-12, IFN-alpha, or histone deacetylase inhibitors. Thus, IL-12 and IFN-alpha/beta enforce in common a complex gene regulation program that involves, at least in part, chromatin remodeling to allow sustained expression of a large number of genes critical for CD8 T cell function and memory.
Also flagged:methylationpeptidecytosinenucleotideCytosincancer
Journal Article2009-07-10No SnippetsVogel N, Schiebel K, Humeny A.
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With the decipherment of the human genome, new questions have moved into the focus of today's research. One key aspect represents the discovery of DNA variations capable to influence gene transcription, RNA splicing, or regulating processes, and their link to pathology. Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS) is a powerful tool for the qualitative investigation and relative quantification of variations like single nucleotide polymorphisms, DNA methylation, microsatellite instability, or loss of heterozygosity. After its introduction into proteomics, efforts were made to adopt this technique to DNA analysis. Initially intended for peptide/protein analysis, it held several difficulties for application to nucleic acids. Today, MALDI-TOF-MS has reached worldwide acceptance and application in nucleic acid research, with a wide spectrum of methods being available. One of the most versatile approaches relies on primer extension to genotype single alleles, microsatellite repeat lengths or the methylation status of a given cytosine. Optimized methods comprising intelligent primer design and proper nucleotide selection for primer extension enabled multiplexing of reactions, rendering the analysis more economic due to parallel genotyping of several alleles in a single experiment. Laboratories equipped with MALDI-TOF-MS possess a universal technical platform for the analysis of a large variety of different molecules.
Also flagged:degradationrho kinaseproteasomemacroautophagypolyglutamine-related disordersHuntington disease
Journal Article2009-07-09No SnippetsBauer PO, Nukina N.
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Enhancing the degradation of mutant protein is one of the most investigated approaches in experimental therapy of the polyglutamine-related disorders such as Huntington disease (HD). Inhibition of rho-associated kinases (ROCKs) reduced the aggregation and levels of mutant huntingtin in cellular models of HD via activation of the ubiquitin proteasome system (UPS) and macroautophagy. This unique effect makes the Rho/ROCK pathway and its downstream effectors attractive therapeutic targets for polyglutamine-related diseases.
Also flagged:mitochondrial leucoencephalopathymultiple sclerosisLeucoencephalopathylactateataxiamitochondrial aspartyl-tRNA synthetase
Journal Article2009-07-09✓ 5 SnippetsIsohanni P, Linnankivi T, Buzkova J, Lönnqvist T, Pihko H, Valanne L, Tienari PJ, Elovaara I, Pirttilä T, Reunanen M, Koivisto K, Marjavaara S, Suomalainen A.
In-Text Gene Mentions
Abstract)
…DARS2 mutations cause childhood-to-adolescence onset leucoencephalopathy, but they do not seem to be associated with MS.…
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…DARS2 mutations in mitochondrial leucoencephalopathy and multiple sclerosis.…
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…The signs and symptoms show some overlap with the most common leucoencephalopathy of young adults, multiple sclerosis (MS).<h4>Objective</h4>To clarify the molecular background of LBSL patients in Finland, and to look for DARS2 mutations in a group of MS patients.<h4>Methods</h4>Clinical evaluation of LBSL patients, DARS2 sequencing and haplotype analysis, and carrier frequency determination in Finland.<h4>Results</h4>All eight LBSL patients were compound heterozygotes for DARS2 mutations: all carried R76SfsX5 change, seven had M134_K165del, and one had C152F change.…
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…Mutations in DARS2, encoding mitochondrial aspartyl-tRNA synthetase, were recently shown to cause LBSL.…
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…No enrichment of the two common DARS2 mutations was found in 321 MS patients.<h4>Conclusion</h4>All LBSL patients were compound heterozygotes, which suggests that DARS2 mutation homozygosity may be lethal or manifest as a different phenotype.…
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<h4>Background</h4>Leucoencephalopathy with brain stem and spinal cord involvement and high brain lactate (LBSL) was first defined by characteristic magnetic resonance imaging and spectroscopic findings. The clinical features include childhood or juvenile onset slowly progressive ataxia, spasticity, and dorsal column dysfunction, occasionally accompanied by learning difficulties. Mutations in DARS2, encoding mitochondrial aspartyl-tRNA synthetase, were recently shown to cause LBSL. The signs and symptoms show some overlap with the most common leucoencephalopathy of young adults, multiple sclerosis (MS).<h4>Objective</h4>To clarify the molecular background of LBSL patients in Finland, and to look for DARS2 mutations in a group of MS patients.<h4>Methods</h4>Clinical evaluation of LBSL patients, DARS2 sequencing and haplotype analysis, and carrier frequency determination in Finland.<h4>Results</h4>All eight LBSL patients were compound heterozygotes for DARS2 mutations: all carried R76SfsX5 change, seven had M134_K165del, and one had C152F change. Axonal neuropathy was found in five of the eight patients. The carrier frequencies of the R76SfsX5 and M134_K165del mutations were 1:95 and 1:380, respectively. All patients shared common European haplotypes, suggestive of common European LBSL ancestors. No enrichment of the two common DARS2 mutations was found in 321 MS patients.<h4>Conclusion</h4>All LBSL patients were compound heterozygotes, which suggests that DARS2 mutation homozygosity may be lethal or manifest as a different phenotype. The authors show here that despite identical mutations the clinical picture was quite variable in the patients. Axonal neuropathy was an important feature of LBSL. DARS2 mutations cause childhood-to-adolescence onset leucoencephalopathy, but they do not seem to be associated with MS.
<h4>Purpose</h4>Elevated levels of dietary histidine have previously been shown to prevent or mitigate cataract formation in farmed Atlantic salmon (Salmo salar L). The aim of this study was to shed light on the mechanisms by which histidine acts. Applying microarray analysis to the lens transcriptome, we screened for differentially expressed genes in search for a model explaining cataract development in Atlantic salmon and possible markers for early cataract diagnosis.<h4>Methods</h4>Adult Atlantic salmon (1.7 kg) were fed three standard commercial salmon diets only differing in the histidine content (9, 13, and 17 g histidine/kg diet) for four months. Individual cataract scores for both eyes were assessed by slit-lamp biomicroscopy. Lens N-acetyl histidine contents were measured by high performance liquid chromatography (HPLC). Total RNA extracted from whole lenses was analyzed using the GRASP 16K salmonid microarray. The microarray data were analyzed using J-Express Pro 2.7 and validated by quantitative real-time polymerase chain reaction (qRT-PCR).<h4>Results</h4>Fish developed cataracts with different severity in response to dietary histidine levels. Lens N-acetyl histidine contents reflected the dietary histidine levels and were negatively correlated to cataract scores. Significance analysis of microarrays (SAM) revealed 248 significantly up-regulated transcripts and 266 significantly down-regulated transcripts in fish that were fed a low level of histidine compared to fish fed a higher histidine level. Among the differentially expressed transcripts were metallothionein A and B as well as transcripts involved in lipid metabolism, carbohydrate metabolism, regulation of ion homeostasis, and protein degradation. Hierarchical clustering and correspondence analysis plot confirmed differences in gene expression between the feeding groups. The differentially expressed genes could be categorized as "early" and "late" responsive according to their expression pattern relative to progression in cataract formation.<h4>Conclusions</h4>Dietary histidine regimes affected cataract formation and lens gene expression in adult Atlantic salmon. Regulated transcripts selected from the results of this genome-wide transcription analysis might be used as possible biological markers for cataract development in Atlantic salmon.
…The following mouse models were used: control FVB/N [50] with 7 glutamines in mouse endogenous htt homologue and HD transgenic YAC (yeast artificial chromosome) model expressing full-length human HD cDNA containing 72 polyglutamines (HD72) [19].…
Introduction)
…In HD, unstable CAG expansion within the coding region of the IT15 gene is translated into an abnormally long polyglutamine tract near the N-terminus of the protein called huntingtin (htt) [1-3].…
Results)
…Indeed, transfection of neuronal cultures from control mice with GFP-HD82, a truncated form of human htt (amino acid 1–221) with pathologic 82 polyglutamine repeats, leads to rapid formation of visible aggregates in both primary striatal neurons and glial cells within 2–10 hours post transfection (Figure 3A, a, &3A, b ).…
I A O 0000606)
…(HD): Huntington's disease; (htt): huntingtin; (mhtt): mutant huntingtin; (TP): tricyclic pyrone; (APP): amyloid β protein precursor; (AD): Alzheimer's disease; (LacCer): lactosylceramide; (IBs): inclusion bodies; (NINDS): National Institute of Neurological Disorders and Stroke; (CREB): cAMP-response element binding protein; (HAP1): huntingtin-associated protein-1; (HIP1): huntingtin interacting protein-1; (Sp1): specificity protein 1; (GFP): green fluorescent protein; (DIC): days in culture; (Tfn): transferrin; (ACAT): acyl-CoA:cholesterol acyltransferase; (NB): neurobasal; (cav-1): caveolin-1; (HMPA): hexamethylphosphoramide; (LDA): lithium diisopropylamide; (THF): tetrahydrofuran; (TFA): trifluoroacetic acid; (Ac2O): acetic anhydride; (MsCl): methanesulfonyl chloride.…
Introduction)
…protein called huntingtin (htt) [ 1 -…
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<h4>Background</h4>Huntington's disease (HD) is a progressive neurodegenerative disorder caused by a CAG repeat expansion mutation in the coding region of a novel gene. The mechanism of HD is unknown. Most data suggest that polyglutamine-mediated aggregation associated with expression of mutant huntingtin protein (mhtt) contributes to the pathology. However, recent studies have identified early cellular dysfunctions that preclude aggregate formation. Suppression of aggregation is accepted as one of the markers of successful therapeutic approaches. Previously, we demonstrated that tricyclic pyrone (TP) compounds efficiently inhibited formation of amyloid-beta (Abeta) aggregates in cell and mouse models representing Alzheimer's Disease (AD). In the present study, we aimed to determine whether TP compounds could prevent aggregation and restore early cellular defects in primary embryonic striatal neurons from animal model representing HD.<h4>Results</h4>TP compounds effectively inhibit aggregation caused by mhtt in neurons and glial cells. Treatment with TP compounds also alleviated cholesterol accumulation and restored clathrin-independent endocytosis in HD neurons.<h4>Conclusion</h4>We have found that TP compounds not only blocked mhtt-induced aggregation, but also alleviated early cellular dysfunctions that preclude aggregate formation. Our data suggest TP molecules may be used as lead compounds for prevention or treatment of multiple neurodegenerative diseases including HD and AD.
Also flagged:mitochondrialHuntington's diseasemitochondriaHuntington'sdiseasepathogenesis
Journal Article2009-07-08✓ 1 SnippetLi XJ, Orr AL, Li S.
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Impaired mitochondrial function has been well documented in Huntington's disease. Mutant huntingtin is found to affect mitochondria via various mechanisms including the dysregulation of gene transcription and impairment of mitochondrial function or trafficking. The lengthy and highly branched neuronal processes constitute complex neural networks in which there is a large demand for mitochondria-generated energy. Thus, the impaired mitochondrial trafficking in neuronal cells may play an important role in the selective neuropathology of Huntington's disease. Here we discuss the evidence for the effect of the Huntington's disease protein huntingtin on the intracellular trafficking of mitochondria and the involvement of this defective trafficking in the pathogenesis of Huntington's disease.
Also flagged:Y-27632Huntington diseaseHDneurodegenerative diseasepolyglutamineRho-associated kinase
Journal Article2009-07-08✓ 5 SnippetsLi M, Huang Y, Ma AA, Lin E, Diamond MI.
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Abstract)
…However, Y-27632 treatment improved rotarod performance significantly, and also reduced soluble brain Htt levels.…
Abstract)
…We then initiated a trial in R6/2 mice, which express Htt exon 1, administering 100 mg/kg/day of Y-27632 in drinking water.…
Abstract)
…of the huntingtin (Htt) protein.…
Abstract)
…kinase ROCK, reducesHttaggregation in cultured…
Abstract)
…cultured cells andHtt-induced neurodegeneration in …
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Huntington disease (HD) is a devastating, untreatable, dominantly inherited neurodegenerative disease. It is caused by an expanded CAG codon repeat that leads to an elongated polyglutamine tract in the N-terminus of the huntingtin (Htt) protein. Few mechanism-based therapeutic leads have been developed. Y-27632, an inhibitor of the Rho-associated kinase ROCK, reduces Htt aggregation in cultured cells and Htt-induced neurodegeneration in Drosophila, but its effect in mice is unknown. We determined that Y-27632 is bioavailable in brain, with a half-life of 60-90 min. We then initiated a trial in R6/2 mice, which express Htt exon 1, administering 100 mg/kg/day of Y-27632 in drinking water. We did not observe a significant effect on brain weight, inclusion number or size, striatal medium spiny neuron number, clasping behavior, or lifespan. However, Y-27632 treatment improved rotarod performance significantly, and also reduced soluble brain Htt levels. The ROCK signaling pathway thus remains a promising therapeutic target for HD, and more potent inhibitors may prove useful.
…The later is clinically significant as the 5-HTT is a popular target of pharmaceutical agents, such as selective serotonin reuptake inhibitors (SSRIs), used for the management of major depressive disorder and other affective conditions.…
Abstract)
…the 5-HT transporter (5-HTT) has significant skeletal…
Abstract)
…significant as the5-HTTis a popular…
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Novel molecular pathways obligatory for bone health are being rapidly identified. One pathway recently revealed involves gut-derived 5-hydroxytryptamine (5-HT) mediation of the complete skeletal effects of low-density lipoprotein receptor-related protein 5 (LRP5). Mounting evidence supports 5-HT as an important regulatory compound in bone with previous evidence demonstrating that bone cells possess functional pathways for responding to 5-HT. In addition, there is growing evidence that potentiation of 5-HT signaling via inhibition of the 5-HT transporter (5-HTT) has significant skeletal effects. The later is clinically significant as the 5-HTT is a popular target of pharmaceutical agents, such as selective serotonin reuptake inhibitors (SSRIs), used for the management of major depressive disorder and other affective conditions. The observation that 5-HT mediates the complete skeletal effects of LRP5 represents a significant paradigm shift from the traditional view that LRP5 located on the cell surface membrane of osteoblasts exerts direct skeletal effects via Wnt/beta-catenin signaling. This paper discusses the mounting evidence for skeletal effects of 5-HT and the ability of gut-derived 5-HT to satisfactorily explain the skeletal effects of LRP5.
Also flagged:2-aminobenzamidesangiogenesisSynthesisquinazolinedionessugarcyclization
Journal Article2009-07-08No SnippetsHuang C, Meng X, Cui J, Li Z.
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A series of novel 3-N-sugar-substituted quinazolinediones were synthesizedthrough the cyclization of the intermediate 2-aminobenzamides using triphosgene as the condensing reagent. Their anti-angiogenesis activities were investigated. The compound 3-(2'-aminoglucosyl)-2,4-(1H,3H)-quinazolinedione, (5d) showed good anti-angiogenesis activity.
Also flagged:Mitomycinscancertumourssynthesismitomycinmitomycin C
Journal Article2009-07-08No SnippetsAndrez JC.
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Mitomycins are a class of very potent antibacterial and anti-cancer compounds having a broad activity against a range of tumours. They have been used in clinics since the 1960's, and the challenges represented by their total synthesis have challenged generations of chemists. Despite these chemical and medicinal features, these compounds, in racemic form, have succumbed to total synthesis only four times over the last 30 years.
Also flagged:phytoestrogenestradiolrisedronatesecretionmenopausebone resorption
Journal Article2009-07-07✓ 1 SnippetWeaver CM, Martin BR, Jackson GS, McCabe GP, Nolan JR, McCabe LD, Barnes S, Reinwald S, Boris ME, Peacock M.
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<h4>Introduction</h4>Reduction of ovarian estrogen secretion at menopause increases net bone resorption and leads to bone loss. Isoflavones have been reported to protect bone from estrogen deficiency, but their modest effects on bone resorption have been difficult to measure with traditional analytical methods.<h4>Methods</h4>In this randomized-order, crossover, blinded trial in 11 healthy postmenopausal women, we compared four commercial sources of isoflavones from soy cotyledon, soy germ, kudzu, and red clover and a positive control of oral 1 mg estradiol combined with 2.5 mg medroxyprogesterone or 5 mg/d oral risedronate (Actonel) for their antiresorptive effects on bone using novel (41)Ca methodology.<h4>Results</h4>Risedronate and estrogen plus progesterone decreased net bone resorption measured by urinary (41)Ca by 22 and 24%, respectively (P < 0.0001). Despite serum isoflavone profiles indicating bioavailability of the phytoestrogens, only soy isoflavones from the cotyledon and germ significantly decreased net bone resorption by 9% (P = 0.0002) and 5% (P = 0.03), respectively. Calcium absorption and biochemical markers of bone turnover were not influenced by interventions.<h4>Conclusions</h4>Dietary supplements containing genistein-like isoflavones demonstrated a significant but modest ability to suppress net bone resorption in postmenopausal women at the doses supplied in this study over a 50-d intervention period.
Also flagged:gene silencingtyrosine hydroxylaseTHdeathvesicular monoamine transporter-2VMAT2
Journal Article2009-07-07✓ 1 SnippetUlusoy A, Sahin G, Björklund T, Aebischer P, Kirik D.
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Short-hairpin RNA (shRNA)-mediated gene knockdown is a powerful tool for targeted gene silencing and an emerging novel therapeutic strategy. Recent publications, however, reported unexpected toxicity after utilizing viral-mediated shRNA knockdown in vivo. Thus, it is currently unclear whether shRNA-mediated knockdown strategy can be used as a safe and efficient tool for gene silencing. In this study, we have generated rAAV vectors expressing shRNAs targeting the rat tyrosine hydroxylase (TH) mRNA (shTH) for testing the efficacy of in vivo TH knockdown in the nigral dopaminergic neurons. At high titers, not only the shTH vectors but also the scrambled and green fluorescence protein (GFP)-only controls caused cell death. In a dose-response study, we identified a dose window leading to >60% decrease in TH(+) neurons without any change in vesicular monoamine transporter-2 (VMAT2) expression. Moreover, using the safe and efficient dose, we showed that dopamine (DA) synthesis rate was significantly reduced and this lead to emergence of motor deficits in the shTH-expressing rats. Interestingly, these animals showed very robust and long-lasting recovery after a single systemic L-3,4-dihydroxyphenylalanine (L-DOPA) administration beyond what can be achieved in 6-hydroxydopamine (6-OHDA)-lesioned rats. Our results have implications for both mechanistic and therapeutic studies utilizing long-term shRNA-mediated gene silencing in the nigrostriatal projection system.
<h4>Background and aims</h4>Mutations in HFE are the most common cause of the iron-overload disorder hereditary hemochromatosis. Levels of the main iron regulatory hormone, hepcidin, are inappropriately low in hereditary hemochromatosis mouse models and patients with HFE mutations, indicating that HFE regulates hepcidin. The bone morphogenetic protein 6 (BMP6)-SMAD signaling pathway is an important endogenous regulator of hepcidin expression. We investigated whether HFE is involved in BMP6-SMAD regulation of hepcidin expression.<h4>Methods</h4>The BMP6-SMAD pathway was examined in Hfe knockout (KO) mice and in wild-type (WT) mice as controls. Mice were placed on diets of varying iron content. Hepcidin induction by BMP6 was examined in primary hepatocytes from Hfe KO mice; data were compared with those of WT mice.<h4>Results</h4>Liver levels of Bmp6 messenger RNA (mRNA) were higher in Hfe KO mice; these were appropriate for the increased hepatic levels of iron in these mice, compared with WT mice. However, levels of hepatic phosphorylated Smad 1/5/8 protein (an intracellular mediator of Bmp6 signaling) and Id1 mRNA (a target gene of Bmp6) were inappropriately low for the body iron burden and Bmp6 mRNA levels in Hfe KO, compared with WT mice. BMP6 induction of hepcidin expression was reduced in Hfe KO hepatocytes compared with WT hepatocytes.<h4>Conclusions</h4>HFE is not involved in regulation of BMP6 by iron, but does regulate the downstream signals of BMP6 that are triggered by iron.
Also flagged:Huntington's diseasediabetes mellitusHDneurodegenerative disorderglucoseinsulin
Journal Article2009-07-07✓ 2 SnippetsBoesgaard TW, Nielsen TT, Josefsen K, Hansen T, Jørgensen T, Pedersen O, Nørremølle A, Nielsen JE, Hasholt L.
In-Text Gene Mentions
Abstract)
…These data indicate that insulin release from beta-cells expressing mutant huntingtin appears to be polyglutamine length-dependent, and that polyglutamine lengths within the range normally found in adult onset HD do not influence insulin release.…
Abstract)
…However, the glucose-stimulated induction of insulin release was significantly reduced in the insulinoma-cell line expressing highly expanded huntingtin compared to cells expressing huntingtin with modestly elongated polyglutamine stretches.…
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Huntington's disease (HD) is an autosomal, dominantly inherited, neurodegenerative disorder characterised by neurological, cognitive and psychiatric symptoms. HD has been associated with diabetes mellitus, which is, to some extent, supported by studies in transgenic HD mice. In transgenic mice, the severity of the diabetic phenotype appears to correlate with the length of a polyglutamine expansion in the protein huntingtin. In the present study, we investigated the association between diabetes mellitus and HD by performing an oral glucose-tolerance test (OGTT) to evaluate the glucose-tolerance status and OGTT-related insulin release in 14 HD patients. Furthermore, we expressed N-terminal huntingtin fragments with different polyglutamine lengths in an insulinoma-cell line (INS-1E) to investigate how mutant huntingtin influences glucose-stimulated insulin release in vitro. We found no difference between a group of early- and middle-stage HD patients and a large group of control individuals in any of the assessed variables. However, the glucose-stimulated induction of insulin release was significantly reduced in the insulinoma-cell line expressing highly expanded huntingtin compared to cells expressing huntingtin with modestly elongated polyglutamine stretches. These data indicate that insulin release from beta-cells expressing mutant huntingtin appears to be polyglutamine length-dependent, and that polyglutamine lengths within the range normally found in adult onset HD do not influence insulin release. This challenges the assumption of an increased risk of diabetes among HD patients, although our results do not exclude a changed glucose tolerance in end-stage HD patients or in patients with juvenile onset HD. It also raises the question of which extent transgenic mice models reflect the pathology of human HD in this regard.
<h4>Background</h4>As gene expression signatures may serve as biomarkers, there is a need to develop technologies based on mRNA expression patterns that are adaptable for translational research. Xceed Molecular has recently developed a Ziplex technology, that can assay for gene expression of a discrete number of genes as a focused array. The present study has evaluated the reproducibility of the Ziplex system as applied to ovarian cancer research of genes shown to exhibit distinct expression profiles initially assessed by Affymetrix GeneChip analyses.<h4>Methods</h4>The new chemiluminescence-based Ziplex gene expression array technology was evaluated for the expression of 93 genes selected based on their Affymetrix GeneChip profiles as applied to ovarian cancer research. Probe design was based on the Affymetrix target sequence that favors the 3' UTR of transcripts in order to maximize reproducibility across platforms. Gene expression analysis was performed using the Ziplex Automated Workstation. Statistical analyses were performed to evaluate reproducibility of both the magnitude of expression and differences between normal and tumor samples by correlation analyses, fold change differences and statistical significance testing.<h4>Results</h4>Expressions of 82 of 93 (88.2%) genes were highly correlated (p < 0.01) in a comparison of the two platforms. Overall, 75 of 93 (80.6%) genes exhibited consistent results in normal versus tumor tissue comparisons for both platforms (p < 0.001). The fold change differences were concordant for 87 of 93 (94%) genes, where there was agreement between the platforms regarding statistical significance for 71 (76%) of 87 genes. There was a strong agreement between the two platforms as shown by comparisons of log2 fold differences of gene expression between tumor versus normal samples (R = 0.93) and by Bland-Altman analysis, where greater than 90% of expression values fell within the 95% limits of agreement.<h4>Conclusion</h4>Overall concordance of gene expression patterns based on correlations, statistical significance between tumor and normal ovary data, and fold changes was consistent between the Ziplex and Affymetrix platforms. The reproducibility and ease-of-use of the technology suggests that the Ziplex array is a suitable platform for translational research.
Recent studies have demonstrated extensive transcriptional activity across the human genome, a substantial fraction of which is not associated with any functional annotation. However, very little is known regarding the post-transcriptional processes that operate within the different classes of RNA molecules. To characterize the post-transcriptional properties of expressed sequences from human chromosome 21 (HSA21), we separated RNA molecules from three cell lines (GM06990, HeLa S3, and SK-N-AS) according to their ribosome content by sucrose gradient fractionation. Polyribosomal-associated RNA and total RNA were subsequently hybridized to genomic tiling arrays. We found that approximately 50% of the transcriptional signals were located outside of annotated exons and were considered as TARs (transcriptionally active regions). Although TARs were observed among polysome-associated RNAs, RT-PCR and RACE experiments revealed that approximately 40% were likely to represent nonspecific cross-hybridization artifacts. Bioinformatics discrimination of TARs according to conservation and sequence complexity allowed us to identify a set of high-confidence TARs. This set of TARs was significantly depleted in the polysomes, suggesting that it was not likely to be involved in translation. Analysis of polysome representation of RefSeq exons showed that at least 15% of RefSeq transcripts undergo significant post-transcriptional regulation in at least two of the three cell lines tested. Among the regulated transcripts, enrichment analysis revealed an over-representation of genes involved in Alzheimer's disease (AD), including APP and the BACE1 protease that cleaves APP to produce the pathogenic beta 42 peptide. We demonstrate that the combination of RNA fractionation and tiling arrays is a powerful method to assess the transcriptional and post-transcriptional properties of genomic regions.
<h4>Background</h4>Behavior genetic methods can help to elucidate gene-environment (G-E) interplay in the development of internalizing (INT) disorders (i.e., major depression and anxiety disorders). To date, however, no study has conducted a comprehensive analysis examining multiple environmental risk factors with the purpose of delineating general mechanisms of G-E influence in the development of INT disorders.<h4>Methods</h4>The sample consisted of 1315 male and female twin pairs participating in the age 17 assessment of the Minnesota Twin Family Study. Quantitative G-E interplay models were used to examine how genetic and environmental risk for INT disorders changes as a function of environmental context. Multiple measures and informants were employed to construct composite measures of INT disorders and six environmental risk factors including: stressful life events, mother-child and father-child relationship problems, antisocial and prosocial peer affiliation, and academic achievement and engagement.<h4>Results</h4>Significant moderation effects were detected between each environmental risk factor and INT such that in the context of greater environmental adversity, nonshared environmental factors became more important in the etiology of INT symptoms.<h4>Conclusion</h4>Our results are consistent with the interpretation that environmental stressors have a causative effect on the emergence of INT disorders. The consistency of our results suggests a general mechanism of environmental influence on INT disorders regardless of the specific form of environmental risk.
Also flagged:ironmetabolismγ-globinextracellulartransferrin receptor-1TfR1
Journal Article2009-07-06No SnippetsWandzik K, Zahn C, Dassler K, Fuchs H.
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We investigated the remodeling of iron metabolism during megakaryocytic development of K562 cells. Differentiation was successfully verified by increase of the megakaryocytic marker CD61 and concomitant decrease of the erythroid marker γ-globin. The reduction of erythroid properties was accompanied by changes in the cellular iron content and in the expression of proteins regulating cellular iron homeostasis. Independent of available inorganic or transferrin-bound extracellular iron, total intracellular iron increases while the iron-to-protein ratio decreases. The iron exporter ferroportin is downregulated within 1-6 h, followed by downregulation of transferrin receptor-1 (TfR1) and ferritin heavy chain (H-ferritin) mainly after 24-48 h. The hemochromatosis protein-1, a ligand of TfR1, peaked after 24 h. All effects were independent of iron supply with the exception of H-ferritin, which was restored by excess iron. While alterations of CD61, TfR1 and ferritin expression were revoked by a protein kinase C inhibitor, downregulation of ferroportin remained unaffected.
Drug combinations are a promising strategy to overcome the compensatory mechanisms and unwanted off-target effects that limit the utility of many potential drugs. However, enthusiasm for this approach is tempered by concerns that the therapeutic synergy of a combination will be accompanied by synergistic side effects. Using large scale simulations of bacterial metabolism and 94,110 multi-dose experiments relevant to diverse diseases, we provide evidence that synergistic drug combinations are generally more specific to particular cellular contexts than are single agent activities. We highlight six combinations whose selective synergy depends on multitarget drug activity. For one anti-inflammatory example, we show how such selectivity is achieved through differential expression of the drugs' targets in cell types associated with therapeutic, but not toxic, effects and validate its therapeutic relevance in a rat model of asthma. The context specificity of synergistic combinations creates many opportunities for therapeutically relevant selectivity and enables improved control of complex biological systems.
Also flagged:SynthesisamidebindingNR2BNMDA receptorNMDA receptors
Journal Article2009-07-05No SnippetsMosley CA, Myers SJ, Murray EE, Santangelo R, Tahirovic YA, Kurtkaya N, Mullasseril P, Yuan H, Lyuboslavsky P, Le P, Wilson LJ, Yepes M, Dingledine R, Traynelis SF, Liotta DC.
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The synthesis and structure-activity relationship analysis of a novel class of amide-based biaryl NR2B-selective NMDA receptor antagonists are presented. Some of the studied compounds are potent, selective, non-competitive, and voltage-independent antagonists of NR2B-containing NMDA receptors. Like the founding member of this class of antagonists (ifenprodil), several interesting compounds of the series bind to the amino terminal domain of the NR2B subunit to inhibit function. Analogue potency is modulated by linker length, flexibility, and hydrogen bonding opportunities. However, unlike previously described classes of NR2B-selective NMDA antagonists that exhibit off-target activity at a variety of monoamine receptors, the compounds described herein show much diminished effects against the hERG channel and alpha(1)-adrenergic receptors. Selections of the compounds discussed have acceptable half-lives in vivo and are predicted to permeate the blood-brain barrier. These data together suggest that masking charged atoms on the linker region of NR2B-selective antagonists can decrease undesirable side effects while still maintaining on-target potency.
Also flagged:neurodegenerative disorderspolyglutaminepolyQ diseasesnucleuspathogenesisUPS
Journal Article2009-07-03✓ 5 SnippetsHavel LS, Li S, Li XJ.
In-Text Gene Mentions
S I O 001029)
…For example, in Huntington's disease the polyQ domain is in the N-terminal region of the HD protein, huntingtin (htt), and its expansion to more than 37 glutamines leads to the neurological symptoms of HD.…
S I O 001029)
…Although immunocytochemistry studies show that some normal htt can localize to the nucleus [39], nuclear fractionation of HD mouse brains clearly indicates that the majority of full-length mutant htt is cytoplasmic and that smaller N-terminal htt fragments are enriched in the nucleus [13,14,40].…
S I O 001029)
…Despite these unanswered questions, we know that the presence of N-terminal htt fragments in HD mouse brains can be detected as early as two months prior to the obvious neurological phenotype, which does not appear until the age of four to five months, indicating that the generation and accumulation of N-terminal htt precede neurological symptoms [13].…
S I O 001029)
…Examination of the brains of HD patients indicates that only truncated N-terminal htt fragments with an expanded polyQ tract are capable of forming nuclear inclusions, as these nuclear inclusions can only be labeled by antibodies against the N-terminal, but not the internal or C-terminal, region of htt [3,4].…
I A O 0000615)
…In the case of HD, we have yet to determine which N-terminal htt fragments are generated and enter the neuronal nuclei in the brain and whether posttranslational modifications influence their nuclear accumulation.…
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There are nine inherited neurodegenerative disorders caused by polyglutamine (polyQ) expansion in various disease proteins. Although these polyglutamine proteins have different functions and are localized in different subcellular regions, all the polyQ diseases share a common pathological feature: the nuclear accumulation of polyQ disease proteins and the formation of inclusions. The nuclear accumulation of polyQ proteins in turn leads to gene transcriptional dysregulation and neuropathology. Here we will discuss potential mechanisms behind the nuclear accumulation of mutant polyQ proteins, since an understanding of how polyQ proteins accumulate in the nucleus could help elucidate the pathogenesis of these diseases and develop their treatment.
Haemochromatoses encompass a variety of genetic iron overload diseases. The most frequent entity remains HFE-related haemochromatosis. The other syndromes include diseases related to mutations of the hemojuvelin, hepcidin, transferrin receptor 2 and ferroportin genes. Iron excess is due to deficiencies in either hepcidin or ferroportin, the two key regulatory proteins of iron metabolism. Diagnosis rests essentially upon non invasive clinical, biological and imaging criteria. The mainstay of iron overload treatment is venesection therapy in case of hepcidin deficiency, the therapeutic approach for the future being hepcidin supplementation. In ferroportin deficiency, oral chelation is an interesting orientation. The recent creation in France of a reference center and of several competence centers for rare genetic iron overload diseases represents a valuable organization for improving both the understanding of the diseases and the management of the patients.
Also flagged:type 2 diabetesobesitychromosomediabetesZfp69zinc finger domain transcription factor 69
Journal Article2009-07-03No SnippetsScherneck S, Nestler M, Vogel H, Blüher M, Block MD, Berriel Diaz M, Herzig S, Schulz N, Teichert M, Tischer S, Al-Hasani H, Kluge R, Schürmann A, Joost HG.
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Polygenic type 2 diabetes in mouse models is associated with obesity and results from a combination of adipogenic and diabetogenic alleles. Here we report the identification of a candidate gene for the diabetogenic effect of a QTL (Nidd/SJL, Nidd1) contributed by the SJL, NON, and NZB strains in outcross populations with New Zealand Obese (NZO) mice. A critical interval of distal chromosome 4 (2.1 Mbp) conferring the diabetic phenotype was identified by interval-specific congenic introgression of SJL into diabetes-resistant C57BL/6J, and subsequent reporter cross with NZO. Analysis of the 10 genes in the critical interval by sequencing, qRT-PCR, and RACE-PCR revealed a striking allelic variance of Zfp69 encoding zinc finger domain transcription factor 69. In NZO and C57BL/6J, a retrotransposon (IAPLTR1a) in intron 3 disrupted the gene by formation of a truncated mRNA that lacked the coding sequence for the KRAB (Krüppel-associated box) and Znf-C2H2 domains of Zfp69, whereas the diabetogenic SJL, NON, and NZB alleles generated a normal mRNA. When combined with the B6.V-Lep(ob) background, the diabetogenic Zfp69(SJL) allele produced hyperglycaemia, reduced gonadal fat, and increased plasma and liver triglycerides. mRNA levels of the human orthologue of Zfp69, ZNF642, were significantly increased in adipose tissue from patients with type 2 diabetes. We conclude that Zfp69 is the most likely candidate for the diabetogenic effect of Nidd/SJL, and that retrotransposon IAPLTR1a contributes substantially to the genetic heterogeneity of mouse strains. Expression of the transcription factor in adipose tissue may play a role in the pathogenesis of type 2 diabetes.
Also flagged:breast cancertumorcancerERBB2gene expressionbreast tumors
Journal Article2009-07-03No SnippetsKao J, Salari K, Bocanegra M, Choi YL, Girard L, Gandhi J, Kwei KA, Hernandez-Boussard T, Wang P, Gazdar AF, Minna JD, Pollack JR.
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<h4>Background</h4>Breast cancer cell lines have been used widely to investigate breast cancer pathobiology and new therapies. Breast cancer is a molecularly heterogeneous disease, and it is important to understand how well and which cell lines best model that diversity. In particular, microarray studies have identified molecular subtypes-luminal A, luminal B, ERBB2-associated, basal-like and normal-like-with characteristic gene-expression patterns and underlying DNA copy number alterations (CNAs). Here, we studied a collection of breast cancer cell lines to catalog molecular profiles and to assess their relation to breast cancer subtypes.<h4>Methods</h4>Whole-genome DNA microarrays were used to profile gene expression and CNAs in a collection of 52 widely-used breast cancer cell lines, and comparisons were made to existing profiles of primary breast tumors. Hierarchical clustering was used to identify gene-expression subtypes, and Gene Set Enrichment Analysis (GSEA) to discover biological features of those subtypes. Genomic and transcriptional profiles were integrated to discover within high-amplitude CNAs candidate cancer genes with coordinately altered gene copy number and expression.<h4>Findings</h4>Transcriptional profiling of breast cancer cell lines identified one luminal and two basal-like (A and B) subtypes. Luminal lines displayed an estrogen receptor (ER) signature and resembled luminal-A/B tumors, basal-A lines were associated with ETS-pathway and BRCA1 signatures and resembled basal-like tumors, and basal-B lines displayed mesenchymal and stem/progenitor-cell characteristics. Compared to tumors, cell lines exhibited similar patterns of CNA, but an overall higher complexity of CNA (genetically simple luminal-A tumors were not represented), and only partial conservation of subtype-specific CNAs. We identified 80 high-level DNA amplifications and 13 multi-copy deletions, and the resident genes with concomitantly altered gene-expression, highlighting known and novel candidate breast cancer genes.<h4>Conclusions</h4>Overall, breast cancer cell lines were genetically more complex than tumors, but retained expression patterns with relevance to the luminal-basal subtype distinction. The compendium of molecular profiles defines cell lines suitable for investigations of subtype-specific pathobiology, cancer stem cell biology, biomarkers and therapies, and provides a resource for discovery of new breast cancer genes.
Also flagged:axonsNetrin-1SHHbindingRobo receptorsRobo1
Journal Article2009-07-02No SnippetsReeber SL, Kaprielian Z.
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In the developing nervous system, pathfinding axons navigate through a series of intermediate targets in order to form synaptic connections. Vertebrate spinal commissural axons extend toward and across the floor plate (FP), a key intermediate target located at the ventral midline (VM). Subsequently, post-crossing commissural axons grow either alongside or significant distances away from the floor plate (FP), but never re-cross the VM. Consistent with this behavior, post-crossing commissural axons lose responsiveness to the FP-associated chemoattractants, Netrin-1 and SHH, and gain responsiveness to Slits, which are potent midline repellents, in vitro. In addition, the results of several in vivo studies suggest that the upregulation of Slit-binding repulsive Robo receptors, Robo1/2, alters the responsiveness of decussated commissural axons to midline guidance cues. Nevertheless, in vertebrates, it is unclear whether Robo1/2 are the sole or major repellent receptors responsible for driving these commissural axons away from the VM and preventing their re-entry into the FP. We recently re-visited these issues in the chick spinal cord by assessing the consequences of manipulating Robo expression on commissural axons in ovo. Our findings suggest that, at least in chick embryos, the upregulation of repulsive Robos on post-crossing axons alters the responsiveness of these axons to midline repellents and facilitates their expulsion from, but is not likely to have a significant role in preventing their re-entry into the VM.
Also flagged:nucleussynapticsynapsesaxonsextracellularlidocaine
Journal Article2009-07-02No SnippetsShao J, Lai D, Meyer U, Luksch H, Wessel R.
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Avian nucleus isthmi pars parvocellularis (Ipc) neurons are reciprocally connected with the layer 10 (L10) neurons in the optic tectum and respond with oscillatory bursts to visual stimulation. Our in vitro experiments show that both neuron types respond with regular spiking to somatic current injection and that the feedforward and feedback synaptic connections are excitatory, but of different strength and time course. To elucidate mechanisms of oscillatory bursting in this network of regularly spiking neurons, we investigated an experimentally constrained model of coupled leaky integrate-and-fire neurons with spike-rate adaptation. The model reproduces the observed Ipc oscillatory bursting in response to simulated visual stimulation. A scan through the model parameter volume reveals that Ipc oscillatory burst generation can be caused by strong and brief feedforward synaptic conductance changes. The mechanism is sensitive to the parameter values of spike-rate adaptation. In conclusion, we show that a network of regular-spiking neurons with feedforward excitation and spike-rate adaptation can generate oscillatory bursting in response to a constant input.
Also flagged:COMTBDNFNRG1DTNBP1psychosispsychotic disorders
Journal Article2009-07-02✓ 5 SnippetsDutt A, McDonald C, Dempster E, Prata D, Shaikh M, Williams I, Schulze K, Marshall N, Walshe M, Walshe M, Allin M, Collier D, Murray R, Bramon E.
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Abstract)
…Abnormal hippocampal and lateral ventricular volumes are among the most replicated endophenotypes for psychosis; however, the influences of COMT, BDNF, 5-HTT, NRG1 and DTNBP1 genes on these key brain regions must be very subtle if at all present.…
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…The effect of COMT, BDNF, 5-HTT, NRG1 and DTNBP1 genes on hippocampal and lateral ventricular volume in psychosis.…
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…Neither was there any effect of the BDNF, 5-HTTLPR, NRG1 and DTNBP1 genotypes on these regional brain volumes.<h4>Conclusions</h4>Abnormal hippocampal and lateral ventricular volumes are among the most replicated endophenotypes for psychosis; however, the influences of COMT, BDNF, 5-HTT, NRG1 and DTNBP1 genes on these key brain regions must be very subtle if at all present.…
Abstract)
…Genetic epidemiological studies support an overlap between schizophrenia and bipolar disorder, and COMT, BDNF, 5-HTT, NRG1 and DTNBP1 genes have been implicated in the aetiology of both these disorders.…
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…of COMT, BDNF,5-HTT, NRG1 and DTNBP1…
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<h4>Background</h4>Morphometric endophenotypes which have been proposed for psychotic disorders include lateral ventricular enlargement and hippocampal volume reductions. Genetic epidemiological studies support an overlap between schizophrenia and bipolar disorder, and COMT, BDNF, 5-HTT, NRG1 and DTNBP1 genes have been implicated in the aetiology of both these disorders. This study examined associations between these candidate genes and morphometric endophenotypes for psychosis.<h4>Method</h4>A total of 383 subjects (128 patients with psychosis, 194 of their unaffected relatives and 61 healthy controls) from the Maudsley Family Psychosis Study underwent structural magnetic resonance imaging and genotyping. The effect of candidate genes on brain morphometry was examined using linear regression models adjusting for clinical group, age, sex and correlations between members of the same family.<h4>Results</h4>The results showed no evidence of association between variation in COMT genotype and lateral ventricular, and left or right hippocampal volumes. Neither was there any effect of the BDNF, 5-HTTLPR, NRG1 and DTNBP1 genotypes on these regional brain volumes.<h4>Conclusions</h4>Abnormal hippocampal and lateral ventricular volumes are among the most replicated endophenotypes for psychosis; however, the influences of COMT, BDNF, 5-HTT, NRG1 and DTNBP1 genes on these key brain regions must be very subtle if at all present.
It is likely that multiple genes contribute to immunoglobulin (Ig)E production. Co-stimulatory molecules are crucial for the cross-talk between antigen presenting cells and T-lymphocytes which drives the IgE response. We evaluated gene-gene interactions of haplotype tagging polymorphisms in a pathway of 24 co-stimulatory genes in relation to serum IgE levels. We assessed this at ages 1-2 yrs and 6-8 yrs in 3,062 Dutch children from a pooled data set of three birth cohorts: PIAMA (Prevention and Incidence Asthma and Mite Allergy), PREVASC (Prevention of Asthma in Children) and KOALA (Child, parents and health: lifestyle and genetic constitution). Single- and multi-locus associations with serum IgE levels (3rd versus 1st tertile) were evaluated by Chi-squared tests and the multifactor dimensionality reduction (MDR) method in the following co-stimulatory genes: VTCN1, TNFRSF4, TNFRSF18, TNFRSF14, TNFSF18, TNFSF4, CD28, CTLA4, ICOS, PDCD1, BTLA, CD80, CD86, HLA-G, CD274, PDCD1LG2, CD276, LILRA4, LILRB1, LILRB2, LILRB4, CD40, ICOSLG, and CD40LG. We found multiple statistically significant single-locus ((S)) and multi-locus ((M)) associations for the genes VTCN1(SM), TNFSF18(SM), TNFSF4(S), CD28(S), CTLA4(M), ICOS(S), BTLA(M), CD80(M), CD86(SM), CD274(SM), PDCD1LG2(M), LILRA4(SM), LILRB4(M), and CD40(SM) with serum IgE. Two-locus interactions of CD86 with VTCN1 and CD274 with LILRA4 were confirmed by logistic regression. In conclusion, serum IgE levels are regulated by multiple gene-gene interaction effects in the co-stimulatory pathway. We suggest using research strategies that model multiple gene-gene interactions in genetic studies.
Also flagged:aryl hydrocarbon receptorestrogen receptor alphaAHRchromatinTranscription factorbinding
Journal Article2009-07-02✓ 1 SnippetAhmed S, Valen E, Sandelin A, Matthews J.
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Recent studies have shown that activated aryl hydrocarbon receptor (AHR) induced the recruitment of estrogen receptor-alpha (ERalpha) to AHR-regulated genes and that AHR is recruited to ERalpha-regulated genes. However, these findings were limited to a small number of well-characterized AHR- or ERalpha-responsive genes with little knowledge of what was occurring at other genomic regions. In this study, we showed using chromatin immunoprecipitation followed by hybridization to promoter focused microarrays (ChIP-chip) that 2,3,7,8-tetrachlorodibenzo-p-dioxin treatment significantly increased the overlap of genomic regions bound by both AHR and ERalpha. Conventional and sequential ChIPs confirmed the recruitment of AHR and ERalpha to many of the identified regions. Transcription factor binding site analysis revealed an overrepresentation of aryl hydrocarbon receptor response elements in regions bound by both AHR and ERalpha, suggesting that AHR was the important factor determining the recruitment of ERalpha to these regions. RNA interference-mediated knockdown of AHR confirmed its requirement for the recruitment of ERalpha to some, but not all, of the shared regions. Our findings demonstrate not only that dioxin induces the recruitment of ERalpha to AHR target genes but also that AHR is recruited to estrogen-responsive regions in a gene-specific manner, suggesting that AHR utilizes both of these mechanisms to modulate estrogen-dependent signaling.
Also flagged:maternal depressionserotonin transporteremotional disordersDepressionpostnatal depressionanxiety
Journal Article2009-07-01No SnippetsAraya R, Hu X, Heron J, Enoch MA, Evans J, Lewis G, Nutt D, Goldman D.
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There has been a large but inconsistent literature on interactions between the 5-HTTLPR polymorphism of the serotonin transporter gene and adversity on emotional disorders. We investigated these interactions in 4,334 children from a birth longitudinal cohort: the Avon Longitudinal Study of Parents and Children (ALSPAC). We measured emotional symptoms at 7 years with the Strengths and Difficulties Questionnaire. Mothers rated stressful life events between ages 5 and 7 years. Maternal depression was defined as a score > or =12 on the Edinburgh Postnatal Depression Scale at 2 or 8 months postnatally. Triallelic genoptyping of the 5-HTTLPR polymorphism was performed. We found strong associations between stressful life events (OR 1.19; 1.12-1.26; P < 0.01) and maternal postnatal depression (OR 1.91; 1.63-2.24; P < 0.01) with emotional symptoms in the children. There were no main 5-HTTLPR genotype effects or significant interactions between genotype and life events or maternal postnatal depression on emotional symptoms. There was marginal evidence (P = 0.08) for an interaction between stressful life events and genotype in boys only, with those in the low and high 5-HTTLPR expression groups showing stronger associations. In these 7-year-old children, we did not replicate previously reported G x E interactions between 5-HTTLPR and life events for emotional symptoms. Gene by environment interactions may be developmentally dependent and show variation depending on the type and levels of exposure and sex. Young cohorts are essential to improve our understanding of the impact of development on gene and environment interactions.
Also flagged:ethylene glycolmineralizationalkaline phosphatasecalciumhydroxyapatitesynthesis
Journal Article2009-07-01No SnippetsKeskar V, Marion NW, Mao JJ, Gemeinhart RA.
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Hydrogels have gained acceptance as biomaterials in a wide range of applications, including pharmaceutical formulations, drug delivery, and tissue sealants. However, exploiting the potential of hydrogels as scaffolds for cell transplantation, tissue engineering, and regenerative medicine still remains a challenge due to, in part, scaffold design limitations. Here, we describe a highly interconnected, macroporous poly(ethylene glycol) diacrylate hydrogel scaffold, with pores ranging from 100 to 600 microm. The scaffold exhibits rapid cell uptake and cell seeding without the need of any external force or device with high incorporation efficiency. When human mesenchymal stem cells are seeded within the porous scaffolds, the scaffolds were found to promote long-term stem cell viability, and on exposure to osteogenic medium, elicit an mineralization response as evaluated by an increased alkaline phosphatase activity (per cell) and calcium and phosphate content within the constructs. The atomic composition of the mineralized matrix was further determined by energy dispersive spectroscopy and found to be similar to calcium-deficient hydroxyapatite, the amorphous biological precursor of bone. The macroporous design of the hydrogel appears advantageous over similar porous hydrogel scaffolds with respect to ease of synthesis, ease of stem cell seeding, and its ability to support long-term stem cell survival and possible differentiation.
Also flagged:serotonin transporterbindingdepressiontransportersmajor depressive disordermajor depressive episode
Journal Article2009-07-01✓ 5 SnippetsMiller JM, Kinnally EL, Ogden RT, Oquendo MA, Mann JJ, Parsey RV.
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Abstract)
…Lower 5-HTT BP(P) may represent a biological pathway through which early life stress predisposes to the development of subsequent psychiatric illness, including major depressive disorder.…
Abstract)
…brain 5-HTT BP(P) was measured using positron emission tomography (PET) with [(11)C]McN 5652 and a metabolite-corrected arterial input function in 43 healthy volunteers and 23 subjects in a major depressive episode…
<h4>Background</h4>Physical or psychological adversity in childhood is associated with a higher risk for depression in adulthood, and with persistent serotonergic abnormalities in humans and in animal models. We hypothesized that reported childhood abuse would be associated with lower brain serotonin transporter (5-HTT) binding potential (BP(P), proportional to the number of available transporters) in adults. We examined healthy volunteers and subjects with major depressive disorder, a sample enriched for childhood abuse.<h4>Methods</h4>Regional brain 5-HTT BP(P) was measured using positron emission tomography (PET) with [(11)C]McN 5652 and a metabolite-corrected arterial input function in 43 healthy volunteers and 23 subjects in a major depressive episode, ten of whom reported a history of sexual and/or physical abuse before age 15, and 13 of whom did not. As only two healthy volunteers reported childhood abuse, primary analyses were restricted to the depressed sample, with healthy controls presented as comparators.<h4>Results</h4>Depressed subjects reporting childhood abuse had lower 5-HTT BP(P) than nonabused depressed subjects across all brain regions examined (P = 0.017). The groups did not differ in relevant demographic or clinical variables. Genotype frequencies of a functional polymorphism in the 5-HTT gene promoter (5-HTTLPR) did not differ between the groups.<h4>Conclusions</h4>Reported childhood abuse is associated with lower 5-HTT BP(P) in this sample of subjects with major depression, consistent with other reports that childhood adversity can lower serotonergic function permanently. Lower 5-HTT BP(P) may represent a biological pathway through which early life stress predisposes to the development of subsequent psychiatric illness, including major depressive disorder.
…In the Australian sample only, women had a significantly reduced risk of developing CRC when compared with men (hazard ratio = 0.58, p = 0.012) independent of HFE genotype for either single nucleotide polymorphisms.…
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…Haemochromatosis HFE gene polymorphisms as potential modifiers of hereditary nonpolyposis colorectal cancer risk and onset age.…
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…To understand the relationship between HNPCC disease phenotype and polymorphisms of the HFE gene, a total of 362 individuals from Australia and Poland with confirmed causative MMR gene mutations were genotyped for the HFE C282Y and H63D polymorphisms.…
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…HaemochromatosisHFEgene polymorphisms as…
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…Polymorphisms of theHFEgene, which cause…
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Hereditary nonpolyposis colorectal cancer (HNPCC) is characterized by germline mutations in DNA mismatch repair genes; however, variation in disease expression suggests that there are potential modifying factors. Polymorphisms of the HFE gene, which cause the iron overload disorder hereditary haemochromatosis, have been proposed as potential risk factors for the development of colorectal cancer (CRC). To understand the relationship between HNPCC disease phenotype and polymorphisms of the HFE gene, a total of 362 individuals from Australia and Poland with confirmed causative MMR gene mutations were genotyped for the HFE C282Y and H63D polymorphisms. A significantly increased risk of developing CRC was observed for H63D homozygotes when compared with combined wild-type homozygotes and heterozygotes (hazard ratio = 2.93, p = 0.007). Evidence for earlier CRC onset was also observed in H63D homozygotes with a median age of onset 6 years earlier than wild type or heterozygous participants (44 vs. 50 years of age). This effect was significant by all tests used (log-rank test p = 0.026, Wilcoxon p = 0.044, Tarone-Ware p = 0.035). No association was identified for heterozygosity of either polymorphism and limitations on power-prevented investigation of C282Y homozygosity or compound C282Y/H63D heterozygosity. In the Australian sample only, women had a significantly reduced risk of developing CRC when compared with men (hazard ratio = 0.58, p = 0.012) independent of HFE genotype for either single nucleotide polymorphisms. In conclusion, homozygosity for the HFE H63D polymorphism seems to be a genetic modifier of disease expression in HNPCC. Understanding the mechanisms by which HFE interrelates with colorectal malignancies could lead to reduction of disease risk in HNPCC.
Also flagged:Sudden infant death syndromeunexplaineddeathserotonin transporterlocalizationSIDS
Journal Article2009-07-01✓ 4 SnippetsLavezzi AM, Casale V, Oneda R, Weese-Mayer DE, Matturri L.
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Abstract)
…Furthermore, a significant correlation among 5-HTT Long (L) allele, hypoplasia of the raphé nuclei, and maternal smoking in pregnancy was observed in sudden fetal and infant deaths.…
Abstract)
…This study, besides to delineate the cytoarchitecture and the localization in the brainstem of the human raphé nuclei, aims to evaluate the correlation between neuropathological raphé defects and serotonin transporter gene (5-HTT) promoter region polymorphisms in a cohort of 28 SIDS victims, 12 sudden intrauterine unexplained deaths (SIUD), and 17 controls.…
Abstract)
…serotonin transporter gene (5-HTT) promoter region polymorphism…
This study, besides to delineate the cytoarchitecture and the localization in the brainstem of the human raphé nuclei, aims to evaluate the correlation between neuropathological raphé defects and serotonin transporter gene (5-HTT) promoter region polymorphisms in a cohort of 28 SIDS victims, 12 sudden intrauterine unexplained deaths (SIUD), and 17 controls. Hypoplasia of one or more nuclei of both the rostral and caudal raphé groups was found in 57% of SIDS, in 67% of SIUD, and only in 12% of controls. Furthermore, a significant correlation among 5-HTT Long (L) allele, hypoplasia of the raphé nuclei, and maternal smoking in pregnancy was observed in sudden fetal and infant deaths. The presence of the L allele represents a predisposing factor for sudden fetal and infant death in association with morphologic developmental defects of the raphé nuclei and prenatal smoke exposure. A further consideration of the authors is that SIUD should not be regarded as a separate entity from SIDS, given the potentially shared neuropathological and genetic bases.
Also flagged:ironsteatosischronic hepatitisliver diseasehepatic fibrosisfibrosis
Journal Article2009-07-01✓ 5 SnippetsCheng R, Barton JC, Morrison ED, Phatak PD, Krawitt EL, Gordon SC, Kowdley KV.
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Abstract)
…In a logistic regression analysis using age, sex, HFE genotype, log10 ferritin, and log10 HIC as independent variables, log10 serum ferritin (P=0.0008), male sex (P=0.0086), and log10 HIC (P=0.047), but not HFE genotype (P=0.0554) were independently associated with presence or absence of advanced hepatic fibrosis.…
Abstract)
…The goal of this study was to compare hepatic histopathologic features and hepatic iron concentration (HIC) among patients with phenotypic hemochromatosis and different HFE genotypes.…
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…C282Y/H63D compound heterozygotes and patients with HFE genotypes other than C282Y/C282Y were more likely to have stainable Kupffer cell iron (31.1% vs. 9.5%; P=0.02), portal or lobular inflammation (28.9% vs. 15.6%; P=0.03), and steatosis (33.3% vs. 10.2%; P<0.01) on liver biopsy than C282Y homozygotes.…
Abstract)
…HFE genotypes other than C282Y/C282Y were more likely to have stainable Kupffer cell iron (31.1% vs. 9.5%; P=0.02), portal or lobular inflammation…
Abstract)
…hepatic fibrosis, pattern of iron deposition, presence of steatosis or necroinflammation, and HIC were compared among different HFE…
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<h4>Objective</h4>There are limited data comparing hepatic phenotype among hemochromatosis patients with different HFE genotypes. The goal of this study was to compare hepatic histopathologic features and hepatic iron concentration (HIC) among patients with phenotypic hemochromatosis and different HFE genotypes.<h4>Methods</h4>We studied 182 US patients with phenotypic hemochromatosis. Degree of hepatic fibrosis, pattern of iron deposition, presence of steatosis or necroinflammation, and HIC were compared among different HFE genotypes.<h4>Results</h4>C282Y/H63D compound heterozygotes and patients with HFE genotypes other than C282Y/C282Y were more likely to have stainable Kupffer cell iron (31.1% vs. 9.5%; P=0.02), portal or lobular inflammation (28.9% vs. 15.6%; P=0.03), and steatosis (33.3% vs. 10.2%; P<0.01) on liver biopsy than C282Y homozygotes. Mean log10 HIC (P<0.05) and log10 ferritin (P<0.05) were higher among C282Y homozygotes than in patients with other HFE genotypes. In a logistic regression analysis using age, sex, HFE genotype, log10 ferritin, and log10 HIC as independent variables, log10 serum ferritin (P=0.0008), male sex (P=0.0086), and log10 HIC (P=0.047), but not HFE genotype (P=0.0554) were independently associated with presence or absence of advanced hepatic fibrosis.<h4>Conclusions</h4>C282Y/H63D compound heterozygotes and other non-C282Y homozygotes which express the hepatic hemochromatosis phenotype frequently have evidence of steatosis or chronic hepatitis and lower body iron stores than C282Y homozygotes. These data suggest that presence of concomitant liver disease may explain expression of the hemochromatosis phenotype among non-C282Y homozygotes. Increased age, HIC, and ferritin are associated with advanced hepatic fibrosis, regardless of HFE genotype.
Also flagged:Alzheimer's diseaseADprotein kinase CPKCamyloid precursor proteinAPP
Journal Article2009-07-01No SnippetsKozikowski AP, Chen Y, Subhasish T, Lewin NE, Blumberg PM, Zhong Z, D'Annibale MA, Wang WL, Shen Y, Langley B.
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A series of benzolactam compounds were synthesized, some of which caused a concentration-dependent increase in sAPPalpha and decrease in Abeta production in the concentration range of 0.1-10 microM. Moreover, some compounds showed neuroprotective effects in the 10-20 microM range in the HCA cortical neuron model of oxidative stress and no toxicity in measurements of neuron viability by MTT assay, even at the highest concentrations tested (20 microM). Alzheimer's disease (AD) is a well-studied neurodegenerative process characterized by the presence of amyloid plaques and neurofibrillary tangles. In this study, a series of protein kinase C (PKC) activators were investigated, some of which also exhibit histone deacetylase (HDAC) inhibitory activity, under the hypothesis that such compounds might provide a new path forward in the discovery of drugs for the treatment of AD. The PKC-activating properties of these drugs were expected to enhance the alpha-secretase pathway in the processing of amyloid precursor protein (APP), while their HDAC inhibition was anticipated to confer neuroprotective activity. We found that benzolactams 9 and 11-14 caused a concentration-dependent increase in sAPPalpha and decrease in beta-amyloid (Abeta) production in the concentration range of 0.1-10 microM, consistent with a shift of APP metabolism toward the alpha-secretase-processing pathway. Moreover, compounds 9-14 showed neuroprotective effects in the 10-20 microM range in the homocysteate (HCA) cortical neuron model of oxidative stress. In parallel, we found that the most neuroprotective compounds caused increased levels of histone acetylation (H4), thus indicating their likely ability to inhibit HDAC activity. As the majority of the compounds studied also show nanomolar binding affinities for PKC, we conclude that it is possible to design, de novo, agents that combine both PKC-activating properties along with HDAC inhibitory properties. Such agents would be capable of modulating amyloid processing while showing neuroprotection. These findings may offer a new approach to therapies that exhibit disease-modifying effects, as opposed to symptomatic relief, in the treatment of AD.
Also flagged:pathogenesispsoriatic arthritisnail diseasepsoriasispsoriatic nail diseaseautoimmune disorders
Journal Article2009-07-01✓ 1 SnippetMcGonagle D, Benjamin M, Tan AL.
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…Althoughtype 1 psoriasis1 psoriasis is…
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<h4>Purpose of review</h4>Both psoriasis and psoriatic arthritis (PsA), and by implication psoriatic nail disease, have been considered as autoimmune disorders. This was based on the assumption that T-cell-directed responses against common skin and synovial antigens led to shared immunopathological mechanisms at these different sites, which was indirectly supported by the human leucocyte antigen-Cw6 disease association. This study draws on recent microanatomical and genetic studies of PsA, psoriasis and psoriatic-associated nail disease to show how the prevailing autoimmunity concepts for psoriatic disease need to be redrawn, especially in the case of joint and nail disease.<h4>Recent findings</h4>Recent microanatomical studies confirm that normal tendon and ligament insertion points to bone (entheses), the key territory for the inflammatory reaction associated with PsA, being subject to microdamage that strongly points to a role for microtrauma in the joints, which is reminiscent of Koebner responses in the skin. Furthermore, the nail is functionally integrated with entheses associated with the distal phalanx that provides anchorage to the skin and joint. Although type 1 psoriasis is strongly linked to the human leucocyte antigen-Cw6, recent genetic studies have suggested that both joint and nail disease do not share this association.<h4>Summary</h4>These microanatomical and genetic insights have important implications for a better understanding of PsA and nail disease and for an improved understanding of the psoriatic disease spectrum.
Also flagged:plasmid replication initiator proteinDNA helicasePcrA HelicasePlasmid Replicationoligonucleotideheparin
Journal Article2009-07-01✓ 2 SnippetsSlatter AF, Thomas CD, Webb MR.
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…DCC-SSB and MDCC-PBP were…
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…duplex, rather thanDCC-SSB binding.…
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The plasmid replication initiator protein, RepD, greatly stimulates the ability of the DNA helicase, PcrA, to unwind plasmid lengths of DNA. Unwinding begins at oriD, the double-stranded origin of replication that RepD recognizes and covalently binds to initiate replication. Using a combination of plasmids containing oriD and oligonucleotide structures that mimic parts of oriD, the kinetics of DNA nicking and separation have been determined, along with the coupling ratio between base separation and ATP hydrolysis. At 30 degrees C, the rate of nicking is 1.0 s(-1), and translocation is approximately 30 bp s(-1). During translocation, the coupling ratio is one ATP hydrolyzed per base pair separated, the same as the value previously reported for ATP hydrolyzed per base moved by PcrA along single-stranded DNA. The data suggest that processivity is high, such that several thousand base-pair plasmids are unwound by a single molecule of PcrA. In the absence of RepD, a single PcrA is unable to separate even short lengths (10 to 40 bp) of double stranded DNA.
Journal Article2009-07-01No SnippetsPaganetti P, Weiss A, Trapp M, Hammerl I, Bleckmann D, Bodner RA, Coven-Easter S, Housman DE, Parker CN.
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The quantification of cellular proteins is essential for the study of many different biological processes. This study describes an assay for the detection of the intracellular mutant huntingtin, the causative agent of Huntington's disease, with a method that may be generally applicable to other cellular proteins. A small recombinant protein tag that is recognized by a pair of readily available, high-affinity monoclonal antibodies was designed. This tag was then added to an inducible fragment of the mutant huntingtin protein by genetic engineering. We show that it is possible to use time-resolved FRET to detect low intracellular levels of huntingtin by a simple lysis and detection procedure. This assay was then adapted into a homogeneous, miniaturized format suitable for screening in 1536-well plates. The use of time-resolved FRET also permits the assay to be multiplexed with a standard readout of cell toxicity, thus allowing the identification of conditions causing reduction of protein levels simply due to cytotoxicity. The screening results demonstrated that the assay is able to identify compounds that modulate the levels of huntingtin both positively and negatively and that represent valuable starting points for drug discovery programs.
Also flagged:cell migrationtyrosine kinase receptorsaxonsangiogenesisEph receptorscytoplasmic
Journal Article2009-07-01✓ 1 SnippetHu T, Shi G, Larose L, Rivera GM, Mayer BJ, Zhou R.
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The Eph family of tyrosine kinase receptors and their ligands, the ephrins, participates in the regulation of a wide variety of biological functions under normal and pathological conditions. During embryonic development, interactions between the ligands and receptors define tissue boundaries, guide migrating axons, and regulate angiogenesis, as well as bone morphogenesis. These molecules have also been shown to modify neural activity in the adult nervous system and influence tumor progression. However, the molecular mechanisms underlying these diverse functions are not completely understood. In this study, we conducted a yeast two-hybrid screen to identify molecules that physically interact with Eph receptors using the cytoplasmic domain of EphA3 as "bait". This study identified Nck1 as a strong binding partner of EphA3 as assayed using both GST fusion protein pull down and co-immunoprecipitation techniques. The interaction is mediated through binding of the Nck1 SH2 domain to the phosphotyrosine residue at position 602 (Y602) of the EphA3 receptor. The removal of the SH2 domain or the mutation of the Y602 residue abolishes the interaction. We further demonstrated that EphA3 activation inhibits cell migration and process outgrowth, and these inhibiting effects are partially alleviated by dominant-negative Nck1 mutants that lack functional SH2 or SH3 domains, but not by the wild-type Nck1 gene. These results suggest that Nck1 interacts with EphA3 to regulate cell migration and process retraction.
Also flagged:lysinedipeptidesphosphoniumpolyunsaturated fatty acidsascorbatefuran
Journal Article2009-07-01No SnippetsZhu X, Anderson VE, Sayre LM.
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The alpha-amino groups of histidine and lysine were derivatized with p-carboxylbenzyltriphenylphosphonium to form the pseudo dipeptides, PHis and PLys, which can be sensitively detected by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) due to the fixed positive charge of the phosphonium group. Detection limits of PHis and PLys by MALDI-TOFMS were both 30 fmol with a signal-to-noise ratio of 5:1. These pseudo dipeptides were excellent surrogates for His- or Lys-containing peptides in model reactions mimicking proteins with reactive electrophiles, prominently those generated by peroxidation of polyunsaturated fatty acids including 4-hydroxy-2(E)-nonenal (HNE), 4-oxo-2(E)-nonenal (ONE), 2(E)-octenal, and 2(E)-heptenal. An air-saturated solution of linoleic acid (d0:d5 = 1:1) was incubated in the presence of Fe(II) and ascorbate with these two pseudo dipeptides, and the reaction products were characterized by MALDI-TOFMS and liquid chromatography/electrospray ionization mass spectrometry (LC/ESI-MS). By using PHis and PLys, the previously reported ONE-derived His-furan adduct was detected along with evidence for a cyclic alpha,beta-unsaturated ketone. A dimer formed from ONE was found to react with PHis through Michael addition. Alkenals were found to form two novel adducts with PLys. 2(E)-Octenoic acid-His Michael adduct and N(epsilon)-pentanoyllysine were identified as potential protein side-chain adducts modified by products of linoleic acid peroxidation. In addition, when PHis or PLys and AcHis or BocLys were exposed to the linoleic acid peroxidation, an epoxy-keto-ocatadecenoic acid mediated His-His cross-link was detected, along with the observation of a His-ONE/9,12-dioxo-10-dodecenoic acid-Lys derived pyrrole cross-link.
Also flagged:nanobinscholesterolacrylic aciddoxorubicinconjugationazide
Journal Article2009-07-01No SnippetsLee SM, Chen H, O'Halloran TV, Nguyen ST.
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Modularly clickable polymer-caged nanobins (PCNs) were prepared from liposome templates using a drop-in cholesterol-modified poly(acrylic acid) reagent followed by cross-linking with alkyne-functionalized diamine linker that allows for the conjugation of azide-modified targeting ligands via click ligation. These PCNs possess pH-responsive characteristics that can be used to trigger the release of encapsulated doxorubicin (DXR) payload inside the liposomal core under mild acidic conditions. After click-conjugation with azide-modified folate as an active targeting ligand, the resulting folate-conjugated, DXR-loaded PCNs (f-PCN(DXR)) demonstrated enhanced potency to folate receptor (FR)-positive tumor cells such as KB and OvCa432 over FR-negative MCF7 cells. f-PCN(DXR) can readily discriminate FR-positive tumor cells as a function of the level of cellular FR-expression, showing different degrees of potentiation in each cell. With both targeting functionalities and pH-sensitive drug-releasing triggers, f-PCN(DXR) was fifty-times more potent than the untargeted agent toward cancer cells that overexpress the folate target receptors.
Journal Article2009-07-01✓ 1 SnippetTaouli B, Ehman RL, Reeder SB.
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…hemochromatosis…
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<h4>Objective</h4>With recent advances in technology, advanced MRI methods such as diffusion-weighted and perfusion-weighted MRI, MR elastography, chemical shift-based fat-water separation, and MR spectroscopy can now be applied to liver imaging. We will review the respective roles of these techniques for assessment of chronic liver disease.<h4>Conclusion</h4>MRI plays an increasingly important role in assessment of patients with chronic liver disease because of the lack of ionizing radiation and the possibility of performing multiparametric imaging.
Also flagged:phosphatidylethanolamine-binding proteinbacterial infectionPEBPimmunity-related proteinsmetabolism
Journal Article2009-07-01✓ 3 SnippetsReumer A, Bogaerts A, Van Loy T, Husson SJ, Temmerman L, Choi C, Clynen E, Hassan B, Schoofs L.
In-Text Gene Mentions
Abstract)
…We demonstrate that transgenic flies overexpressing PEBP1 are highly protected against bacterial infection due to the release of immunity-related proteins in their hemolymph.…
This study addresses the biological function of CG18594, a Drosophila melanogaster phosphatidylethanolamine-binding protein (PEBP) that we named PEBP1, by combining fly genetics, survival experiments and differential proteomics. We demonstrate that transgenic flies overexpressing PEBP1 are highly protected against bacterial infection due to the release of immunity-related proteins in their hemolymph. Apart from proteins that have been reported earlier to participate in insect immunity, we also identify proteins involved in metabolism and signaling, and, in addition, twelve (hypothetical) proteins with unknown function. This is the first report demonstrating an immune function for a Drosophila PEBP protein.
Journal Article2009-07-01No SnippetsRuth-Sahd LA, Schneider M, Haagen B.
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Critical care nurses must be able to recognize the signs of symptoms of diabulimia-a potentially life-threatening disorder. Skipping insulin is used as a means of weight control in some persons with diabetes, particularly in young women. This article focuses on the assessment, pathophysiology, critical care nursing interventions, and psychosocial initiatives of interest to critical care nurses in the care of patients with diabulimia.
…iron indices andhemochromatosis-related morbidity for compoun…
Abstract)
…were genotyped forHFEC282Y and H63D.…
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<h4>Unlabelled</h4>The risk of hemochromatosis-related morbidity is unknown among HFE compound heterozygotes (C282Y/H63D). We used a prospective population-based cohort study to estimate the prevalence of elevated iron indices and hemochromatosis-related morbidity for compound heterozygotes. In all, 31,192 subjects of northern European descent were genotyped for HFE C282Y and H63D. An HFE-genotype stratified random sample of 1,438 subjects, followed for an average of 12 years to a mean age of 65 years, completed questionnaires and gave blood. Clinical examinations were blinded to HFE genotype. A total of 180 (84 males) clinically examined C282Y/H63D participants were compared with 330 (149 males) controls with neither HFE mutation; 132 (65 males) and 270 (122 males), respectively, had serum iron measures at both timepoints. Mean serum ferritin (SF) and transferrin saturation (TS) were significantly greater for male and female compound heterozygotes than for wild-types at baseline and follow-up (all P < 0.02) except for females who were premenopausal at baseline, where SF was similar in both genotype groups. For subjects with serum measures from both baseline and follow-up, mean SF and TS levels did not change significantly for men or for postmenopausal women, but for premenopausal women SF levels increased from 43 to 109 microg/L for compound heterozygotes and from 35 to 64 microg/L for wild-types (both P < 0.001). Male and female compound heterozygotes had a similar prevalence of hemochromatosis-related morbidity to wild-types. One of 82 males and zero of 95 females had documented iron overload-related disease.<h4>Conclusion</h4>For male compound heterozygotes, mean iron indices do not change during middle age but for female compound heterozygotes menopause results in increased mean SF. Although compound heterozygotes might maintain elevated iron indices during middle age, documented iron overload-related disease is rare.
Also flagged:serotonin transporterserotoninmetabolismRemifentanildrug abuse5-HT1 receptors
Journal Article2009-07-01✓ 5 SnippetsKosek E, Jensen KB, Lonsdorf TB, Schalling M, Ingvar M.
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Abstract)
…Previously the 5-HTTLPR s-allele has been associated with higher risk of developing chronic pain conditions but in this study we show that the genotype coding for low 5-HTT expression is associated with a better analgesic effect of an opioid.…
Discussion)
…Individuals with a genotype coding for low 5-HTT expression (SA/SA or SA/LG) responded with more pain relief to Remifentanil than individuals with a genotype coding for high (LA/LA) 5-HTT expression.…
Introduction)
…Drugs inhibiting the 5-HTT and the norepinephrine transporter (NET) (i.e. serotonin and norepinephrine re-uptake inhibitors (SNRIs)) have antidepressive and anxiolytic effects, but also have antinociceptive effects [18-22].…
Discussion)
…Subjects with a genotype coding for low 5-HTT expression (SA/SA and SA/LG) rated the heat stimuli as significantly less painful following Remifentanil compared to individuals with high expression (LA/LA) and those with an intermediate expression showed an intermediate response.…
Introduction)
…The serotonin transporter (5-HTT) is a key regulator of serotonin metabolism.…
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<h4>Background</h4>There is evidence from animal studies that serotonin (5-HT) can influence the antinociceptive effects of opioids at the spinal cord level. Therefore, there could be an influence of genetic polymorphisms in the serotonin system on individual variability in response to opioid treatment of pain. The serotonin transporter (5-HTT) is a key regulator of serotonin metabolism and availability and its gene harbors several known polymorphisms that are known to affect 5-HTT expression (e.g. 5-HTTLPR, rs25531). The aim of this study was to investigate if the triallelic 5-HTTLPR influences pain sensitivity or the analgesic effect of opioids in humans. 43 healthy volunteers (12 men, 31 women, mean age 26 years) underwent heat pain stimulations before and after intravenous injection of Remifentanil; a rapid and potent opioid drug acting on micro-type receptors. Subjects rated their perceived pain on a visual analogue scale (VAS). All participants were genotyped for the 5-HTTLPR and the rs25531 polymorphism. We recruited by advertising, with no history of drug abuse, chronic pain or psychiatric disorders.<h4>Results</h4>At baseline, there was no difference in pain ratings for the different triallelic 5-HTTLPR genotype groups. However, the opiod drug had a differential analgesic effect depending on the triallelic 5-HTTLPR genotype. Remifentanil had a significantly better analgesic effect in individuals with a genotype coding for low 5-HTT expression (SA/SA and SA/LG) as compared to those with high expression(LA/LA), p < 0.02. The analgesic effect for the three different genotype groups was linear to degree of 5-HTT expression.<h4>Conclusion</h4>This is the first report showing an influence of the triallelic 5-HTTLPR on pain sensitivity or the analgesic effect of opioids in humans. Previously the 5-HTTLPR s-allele has been associated with higher risk of developing chronic pain conditions but in this study we show that the genotype coding for low 5-HTT expression is associated with a better analgesic effect of an opioid. The s-allele has been associated with downregulation of 5-HT1 receptors and we suggest that individuals with a desensitization of 5-HT1 receptors have an increased analgesic response to opioids during acute pain stimuli, but may still be at increased risk of developing chronic pain conditions.
Also flagged:cancerimmune responseshereditary colon canceradenomatous polypsIL-17polyp
Journal Article2009-07-01No SnippetsGounaris E, Blatner NR, Dennis K, Magnusson F, Gurish MF, Strom TB, Beckhove P, Gounari F, Khazaie K.
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T-regulatory (Treg) cells play a major role in cancer by suppressing protective antitumor immune responses. A series of observations (from a single laboratory) suggest that Treg cells are protective in cancer by virtue of their ability to control cancer-associated inflammation in an interleukin (IL)-10-dependent manner. Here, we report that the ability of Treg cells to produce IL-10 and control inflammation is lost in the course of progressive disease in a mouse model of hereditary colon cancer. Treg cells that expand in adenomatous polyps no longer produce IL-10 and instead switch to production of IL-17. Aberrant Treg cells from polyp-ridden mice promote rather than suppress focal mastocytosis, a critical tumor-promoting inflammatory response. The cells, however, maintain other Treg characteristics, including their inability to produce IL-2 and ability to suppress proliferation of stimulated CD4 T cells. By promoting inflammation and suppressing T-helper functions, these cells act as a double-edged knife propagating tumor growth.
Also flagged:Mineralsilicacarbon dioxideapatiteamideAmino acid
Journal Article2009-07-01No SnippetsManning PL, Morris PM, McMahon A, Jones E, Gize A, Macquaker JH, Wolff G, Thompson A, Marshall J, Taylor KG, Lyson T, Gaskell S, Reamtong O, Sellers WI, van Dongen BE, Buckley M, Wogelius RA.
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An extremely well-preserved dinosaur (Cf. Edmontosaurus sp.) found in the Hell Creek Formation (Upper Cretaceous, North Dakota) retains soft-tissue replacement structures and associated organic compounds. Mineral cements precipitated in the skin apparently follow original cell boundaries, partially preserving epidermis microstructure. Infrared and electron microprobe images of ossified tendon clearly show preserved mineral zonation, with silica and trapped carbon dioxide forming thin linings on Haversian canals within apatite. Furthermore, Fourier transform infrared spectroscopy (FTIR) of materials recovered from the skin and terminal ungual phalanx suggests the presence of compounds containing amide groups. Amino acid composition analyses of the mineralized skin envelope clearly differ from the surrounding matrix; however, intact proteins could not be obtained using protein mass spectrometry. The presence of endogenously derived organics from the skin was further demonstrated by pyrolysis gas chromatography mass spectrometry (Py-GCMS), indicating survival and presence of macromolecules that were in part aliphatic (see the electronic supplementary material).
The 2001 foot-and-mouth disease epidemic was controlled by culling of infectious premises and pre-emptive culling intended to limit the spread of disease. Of the control strategies adopted, routine culling of farms that were contiguous to infected premises caused the most controversy. Here we perform a retrospective analysis of the culling of contiguous premises as performed in 2001 and a simulation study of the effects of this policy on reducing the number of farms affected by disease. Our simulation results support previous studies and show that a national policy of contiguous premises (CPs) culling leads to fewer farms losing livestock. The optimal national policy for controlling the 2001 epidemic is found to be the targeting of all contiguous premises, whereas for localized outbreaks in high animal density regions, more extensive fixed radius ring culling is optimal. Analysis of the 2001 data suggests that the lowest-risk CPs were generally prioritized for culling, however, even in this case, the policy is predicted to be effective. A sensitivity analysis and the development of a spatially heterogeneous policy show that the optimal culling level depends upon the basic reproductive ratio of the infection and the width of the dispersal kernel. These analyses highlight an important and probably quite general result: optimal control is highly dependent upon the distance over which the pathogen can be transmitted, the transmission rate of infection and local demography where the disease is introduced.
…Common variants on chromosome 6p22.1 are associated with schizophrenia.…
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Schizophrenia, a devastating psychiatric disorder, has a prevalence of 0.5-1%, with high heritability (80-85%) and complex transmission. Recent studies implicate rare, large, high-penetrance copy number variants in some cases, but the genes or biological mechanisms that underlie susceptibility are not known. Here we show that schizophrenia is significantly associated with single nucleotide polymorphisms (SNPs) in the extended major histocompatibility complex region on chromosome 6. We carried out a genome-wide association study of common SNPs in the Molecular Genetics of Schizophrenia (MGS) case-control sample, and then a meta-analysis of data from the MGS, International Schizophrenia Consortium and SGENE data sets. No MGS finding achieved genome-wide statistical significance. In the meta-analysis of European-ancestry subjects (8,008 cases, 19,077 controls), significant association with schizophrenia was observed in a region of linkage disequilibrium on chromosome 6p22.1 (P = 9.54 x 10(-9)). This region includes a histone gene cluster and several immunity-related genes--possibly implicating aetiological mechanisms involving chromatin modification, transcriptional regulation, autoimmunity and/or infection. These results demonstrate that common schizophrenia susceptibility alleles can be detected. The characterization of these signals will suggest important directions for research on susceptibility mechanisms.
Also flagged:PRDX) 6MMP2glaucomaTGFβperoxiredoxin(
Journal Article2009-07-01✓ 5 SnippetsFatma N, Kubo E, Toris CB, Stamer WD, Camras CB, Singh DP.
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Abstract)
…PRDX6 attenuates oxidative stress- and TGFbeta-induced abnormalities of human trabecular meshwork cells.…
Abstract)
…The data provide evidence that o…
Title)
…PRDX6attenuates oxidative stress-…
Abstract)
…reduced expression ofPRDX6mRNA and protein.…
Abstract)
…related to reducedPRDX6expression, and provide…
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Oxidative stress and TGFbeta-induced disturbance of cells and tissues are implicated in initiation and progression of pathophysiology of cells/tissues. Using primary human trabecular meshwork (TM) cells from normal and glaucomatous subjects, this study demonstrated that peroxiredoxin (PRDX) 6, an antioxidant, offsets the deleterious effects of oxidative stress on TM cells by optimizing ROS and TGFbeta levels. An analysis of glaucomatous TM cells revealed a reduced expression of PRDX6 mRNA and protein. Biochemical assays disclosed enhanced levels of ROS, as well as high levels of TGFbetas and these cells expressed elevated extracellular matrix (ECM) and Tsp1 proteins with reduced MMP2; conditions implicated in the pathophysiology of glaucoma. Non-glaucomatous TM cells exposed to TGFbetas/ROS showed similar features as in glaucomatous cells. The abnormalities induced were reversed by delivery of PRDX6. The data provide evidence that oxidative stress-induced abnormality in TM may be related to reduced PRDX6 expression and provide a foundation for antioxidant-based therapeutics for treating glaucoma.
Also flagged:ironParkinson'sAlzheimer'sHuntington's diseasescirrhosisthalassaemia
Journal Article2009-07-01✓ 1 SnippetHocq A, Brouette N, Saussez S, Luhmer M, Gillis P, Gossuin Y.
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Abstract)
…spleen of cirrhosis,hemochromatosisand thalassaemia patients.…
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Excess iron is found in brain nuclei from neurodegenerative patients (with Parkinson's, Alzheimer's and Huntington's diseases) and also in the liver and spleen of cirrhosis, hemochromatosis and thalassaemia patients. Ferritin, the iron-storing protein of mammals, is known to darken T(2)-weighted MR images. Understanding NMR tissue behavior may make it possible to detect those diseases, to follow their evolution and finally to establish a protocol for non-invasive measurement of an organ's iron content using MRI methods. In this preliminary work, the MR relaxation properties of embalmed iron-containing tissues were studied as well as their potential correlation with the iron content of these tissues. Relaxometric measurements (T(1) and T(2)) of embalmed samples of brain nuclei (caudate nucleus, dentate nucleus, globus pallidus, putamen, red nucleus and substantia nigra), liver and spleen from six donors were made at different magnetic fields (0.00023-14 T). The influence of the inter-echo time on transverse relaxation was also studied. Moreover, iron content of tissues was determined by inductively coupled plasma atomic emission spectroscopy. In brain nuclei, 1/T(2) increases quadratically with the field and depends on the inter-echo time in CPMG sequences at high fields, both features compatible with an outer sphere relaxation theory. In liver and spleen, 1/T(2) increases linearly with the field and depends on the inter-echo time at all fields. In our study, a correlation between 1/T(2) and iron concentration is observed. Explaining the relaxation mechanism for these tissues is likely to require a combination of several models. The value of 1/T(2) at high field could be used to evaluate iron accumulation in vivo. In the future, confirmation of those features is expected to be achieved from measurements of fresh (not embalmed) human tissues.
Also flagged:IL10IL6FamilialLymphoid Malignanciesimmune responsechronic lymphocytic leukemia
Journal Article2009-07-01No SnippetsLiang XS, Caporaso N, McMaster ML, Ng D, Landgren O, Yeager M, Chanock S, Goldin LR.
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Familial aggregation, linkage and case-control studies support the role of germline genes in the aetiology of lymphoid malignancies. To further examine the role of genetic variation underlying susceptibility, we analysed 1536 single nucleotide polymorphisms in 152 genes involved in apoptosis, DNA repair, immune response and oxidative stress pathways among a unique sample of 165 unrelated familial cases including patients with chronic lymphocytic leukaemia (CLL), Waldenström macroglobulinaemia (WM) and Hodgkin lymphoma (HL), and 107 spouse controls. We confirmed previous studies showing a polymorphism in the IL10 promoter (rs1800890/-3575T>A) to be associated with non-Hodgkin lymphoma, as this allele was found to be associated with both CLL and WM. We also confirmed the role of IL6 variation to be associated with HL. Polymorphisms in TNFSF10 were associated with both CLL and WM. Future replication and functional studies are needed to clarify the role of these genetic variants. Finally, our data further support the close association of WM and CLL.
Also flagged:HuntingtonHuntington diseaseHDneurodegenerative disorderpolymeraseReverse transcription
Journal Article2009-07-01✓ 1 SnippetNiclis J, Trounson AO, Dottori M, Ellisdon A, Bottomley SP, Verlinsky Y, Cram D.
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Abstract)
…the HD gene (HTT).…
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Huntington disease (HD) is an incurable late-onset neurodegenerative disorder caused by a CAG repeat expansion in exon 1 of the HD gene (HTT). The major hallmark of disease pathology is neurodegeneration in the brain. Currently, there are no useful in-vitro human models of HD. Recently, two human embryonic stem cell (hESC) lines carrying partial (CAG(37)) and fully (CAG(51)) penetrant mutant alleles have been derived from affected IVF embryos identified following preimplantation genetic diagnosis (PGD). Fluorescence polymerase chain reaction (F-PCR) and Genescan analysis confirmed the original embryonic HD genotypes. Reverse transcription PCR (RT-PCR) analysis confirmed the expression of mutant transcripts and western blot analysis demonstrated expression of mutant huntingtin protein (HTT). After treatment with noggin, HD hESC formed neurospheres, which could be further differentiated into cells susceptible to neurodegeneration in HD, namely primary neurones and astrocytes. Small pool PCR analysis of neurosphere cells revealed instability of disease-length CAG repeats following differentiation. The presence of active HTT genes, neural differentiation capabilities and evidence of CAG repeat instability indicates these HD hESC lines may serve as valuable in-vitro human models of HD to better understand the mechanisms of neurodegeneration in patients, and for drug screening to identify new therapies for human clinical trials.
Also flagged:pathogenesisAcute hepatic failurehepatic encephalopathyacetaminophengalactosaminethioacetamide
Journal Article2009-07-01✓ 1 SnippetTuñón MJ, Alvarez M, Culebras JM, González-Gallego J.
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Text
…hemochromatosis…
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Acute hepatic failure (AHF) is a severe liver injury accompanied by hepatic encephalopathy which causes multiorgan failure with an extremely high mortality rate, even if intensive care is provided. Management of severe AHF continues to be one of the most challenging problems in clinical medicine. Liver transplantation has been shown to be the most effective therapy, but the procedure is limited by shortage of donor organs. Although a number of clinical trials testing different liver assist devices are under way, these systems alone have no significant effect on patient survival and are only regarded as a useful approach to bridge patients with AHF to liver transplantation. As a result, reproducible experimental animal models resembling the clinical conditions are still needed. The three main approaches used to create an animal model for AHF are: surgical procedures, toxic liver injury and infective procedures. Most common models are based on surgical techniques (total/partial hepatectomy, complete/transient devascularization) or the use of hepatotoxic drugs (acetaminophen, galactosamine, thioacetamide, and others), and very few satisfactory viral models are available. We have recently developed a viral model of AHF by means of the inoculation of rabbits with the virus of rabbit hemorrhagic disease. This model displays biochemical and histological characteristics, and clinical features that resemble those in human AHF. In the present article an overview is given of the most widely used animal models of AHF, and their main advantages and disadvantages are reviewed.
Also flagged:Ron receptor tyrosine kinasebreast cancersRonbreast cancertyrosine kinaseestrogen
Journal Article2009-07-01No SnippetsMeyer SE, Zinser GM, Stuart WD, Pathrose P, Waltz SE.
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The Ron receptor tyrosine kinase is expressed in normal breast tissue and is overexpressed in approximately 50% of human breast cancers. Despite the recent studies on Ron in breast cancer, nothing is known about the importance of this protein during breast development. To investigate the functional significance of Ron in the normal mammary gland, we compared mammary gland development in wild-type mice to mice containing a targeted ablation of the tyrosine kinase (TK) signaling domain of Ron (TK-/-). Mammary glands from RonTK-/- mice exhibited accelerated pubertal development including significantly increased ductal extension and branching morphogenesis. While circulating levels of estrogen, progesterone, and overall rates of epithelial cell turnover were unchanged, significant increases in phosphorylated MAPK, which predominantly localized to the epithelium, were associated with increased branching morphogenesis. Additionally, purified RonTK-/- epithelial cells cultured ex vivo exhibited enhanced branching morphogenesis, which was reduced upon MAPK inhibition. Microarray analysis of pubertal RonTK-/- glands revealed 393 genes temporally impacted by Ron expression with significant changes observed in signaling networks regulating development, morphogenesis, differentiation, cell motility, and adhesion. In total, these studies represent the first evidence of a role for the Ron receptor tyrosine kinase as a critical negative regulator of mammary development.
Also flagged:colorectal canceradenomascarcinomascolorectal tumorscolorectal tumorTP53
Journal Article2009-07-01✓ 1 SnippetLea IA, Jackson MA, Dunnick JK.
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…DCC…
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The colorectal cancer paradigm explains how genetic and histological changes lead normal epithelial cell to transform into pre-malignant adenomas then progress to malignant carcinomas. Using the Genetic Alterations in Cancer Knowledge System intragenic allele loss and gene mutation data from approximately 9000 colorectal tumors were compared to the model of colorectal tumor development. The distribution of mutations along the TP53 codons as a function of tumorigenesis also was analyzed. Alterations of APC, KRAS and TP53 were observed in a higher percentage of adenocarcinomas compared to adenomas (P<0.05) indicating that the alterations accumulated with malignancy. Alterations in BRAF, CTNNB, HRAS and NRAS were infrequent regardless of morphology. Differences were observed in the distribution of TP53 mutations with tumorigenesis. Mutations (single base substitutions) occurred most frequently at codons 175 and 273 in both tumor types; however, in adenocarcinomas the mutation incidence at codon 248 was approximately three times that reported in adenomas. It is proposed that the higher incidence of mutation at codon 248 is a later event in colorectal tumorigenesis that occurs as the tumors become malignant.
Also flagged:netrin-1axonsextracellulargrowth conegrowth conesaxon
Journal Article2009-07-01No SnippetsMoore SW, Biais N, Sheetz MP.
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During embryonic development, axons are guided to their target by patterning proteins encountered along their trajectory. These cues can be linked to the cells that produce them or secreted into the extracellular matrix. Whether secreted cues, like netrin-1, provide traction for the growth cone when they become attached to the extracellular matrix is unclear. Advancing spinal commissural neuron growth cones were shown to generate local forces of 4 to 15 piconewtons but, when confronted with immobilized netrin-1, generated traction forces in excess of 63 piconewtons on netrin-1 that can redirect the trajectory of the axon.
Also flagged:nucleosomeshistonehistonescentromeresminichromosomekinetochore
Journal Article2009-07-01✓ 1 SnippetFuruyama T, Henikoff S.
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…Condensin…
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Centromeres of higher eukaryotes are epigenetically maintained; however, the mechanism that underlies centromere inheritance is unknown. Centromere identity and inheritance require the assembly of nucleosomes containing the CenH3 histone variant in place of canonical H3. Although H3 nucleosomes wrap DNA in a left-handed manner and induce negative supercoils, we show here that CenH3 nucleosomes reconstituted from Drosophila histones induce positive supercoils. Furthermore, we show that CenH3 likewise induces positive supercoils in functional centromeres in vivo, using a budding yeast minichromosome system and temperature-sensitive mutations in kinetochore proteins. The right-handed wrapping of DNA around the histone core implied by positive supercoiling indicates that centromere nucleosomes are unlikely to be octameric and that the exposed surfaces holding the nucleosome together would be available for kinetochore protein recruitment. The mutual incompatibility of nucleosomes with opposite topologies could explain how centromeres are efficiently maintained as unique loci on chromosomes.
Also flagged:brain atrophystrokedementialeukoaraiosisautosomeschromosomes
Journal Article2009-07-01No SnippetsTurner ST, Fornage M, Jack CR, Mosley TH, Knopman DS, Kardia SL, Boerwinkle E, de Andrade M.
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<h4>Objective</h4>To localize susceptibility genes for alterations in brain structure associated with risk of stroke and dementia. We conducted genomewide linkage analyses for magnetic resonance imaging (MRI) measures of brain atrophy, ventricular, and subcortical white matter hyperintensity (leukoaraiosis) in 689 non-Hispanic white (673 sibling pairs; median age, 61 years) and 544 non-Hispanic black participants (503 sibling pairs; median age, 64 years) from sibships with at least 2 members with essential hypertension.<h4>Design, setting, and patients</h4>We determined brain, ventricular, and leukoaraiosis volumes from axial fluid-attenuated inversion recovery MRI; we calculated brain atrophy as the difference between total intracranial and brain volumes. Microsatellite markers (n = 451) distributed across the 22 autosomes were genotyped, and we used variance components methods to estimate heritability and assess evidence of genetic linkage for each MRI measure.<h4>Main outcome measures</h4>Brain atrophy ventricular volume, and leukoaraiosis determined from fluid-attenuated inversion recovery MRI.<h4>Results</h4>In both races, the heritability of each MRI measure was statistically greater than 0 (P < .001), ranging in magnitude from 0.42 (for ventricular volume in blacks) to 0.69 (for brain atrophy in blacks). Based on multipoint logarithm of odds scores (MLS), the strongest evidence of genetic linkage was observed for brain atrophy on chromosomes 1 (MLS, 3.49 at 161 cM; P < .001) and 17 (MLS, 3.08 at 18 cM; P < .001) in whites; for ventricular volume on chromosome 12 (MLS, 3.67 at 49 cM; P < .001) in blacks and chromosome 10 (MLS, 2.47 at 110 cM; P < .001) in whites; and for leukoaraiosis on chromosome 11 (MLS, 2.21 at 118 cM; P < .001) in whites and chromosome 22 (MLS, 2.02 at 36 cM; P = .001) in blacks.<h4>Conclusions</h4>The MRI measures of structural brain injury are heritable in non-Hispanic black and white sibships ascertained through hypertensive sibling pairs. The susceptibility loci for brain atrophy, ventricular volume, and leukoaraiosis identified by linkage analyses differ among MRI measures and between races.
Also flagged:Hepatocellular carcinomacancerdeathtumourliver cancerscirrhosis
Journal Article2009-07-01✓ 1 SnippetRampone B, Schiavone B, Martino A, Viviano C, Confuorto G.
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…hemochromatosis…
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Hepatocellular carcinoma (HCC) still remains a considerable challenge for surgeons. Surgery, including liver transplantation, is the most important therapeutic approach for patients with this disease. HCC is frequently diagnosed at advanced stages and has a poor prognosis with a high mortality rate even when surgical resection has been considered potentially curative. This brief report summarizes the current status of the management of this malignancy and includes a short description of new pharmacological approaches in HCC treatment.
Also flagged:NetrincancerNetDeleted in Colorectal Cancercancerscell growth
Journal Article2009-07-01✓ 5 SnippetsDuman-Scheel M.
In-Text Gene Mentions
Abstract)
…Here, the roles of Net-DCC in the regulation of these cellular processes in tumors and developing neurons are discussed.…
Abstract)
…The advantages of using Drosophila to study the function of Net-DCC and other axon guidance molecules in these cellular processes, as well as the potential for cancer therapeutics targeting Net-DCC are highlighted.…
Abstract)
…In recent years, a number of axon guidance genes, including Netrin (Net) and Deleted in Colorectal Cancer (DCC), have been implicated in human cancers.…
Title)
…Netrin and DCC: axon guidance regulators at the intersection of nervous system development and cancer.…
Title)
…Netrin andDCC: axon guidance regulators…
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In recent years, a number of axon guidance genes, including Netrin (Net) and Deleted in Colorectal Cancer (DCC), have been implicated in human cancers. Many of the hallmarks of human cancer, such as cell growth, invasion, evasion of apoptosis, and formation of a blood supply to the tumor, involve cellular processes that are critical during nervous system development. Here, the roles of Net-DCC in the regulation of these cellular processes in tumors and developing neurons are discussed. The advantages of using Drosophila to study the function of Net-DCC and other axon guidance molecules in these cellular processes, as well as the potential for cancer therapeutics targeting Net-DCC are highlighted.
Also flagged:gene expressionregulation of gene expressionimmune responsesinterleukin-2IL-2TNF-β
Journal Article2009-07-01No SnippetsHughes AL, Friedman R.
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The evolution of multicellular organisms involved the evolution of specialized cell types performing distinct functions; and specialized cell types presumably arose from more generalized ancestral cell types as a result of mutational event, such as gene duplication and changes in gene expression. We used characters based on gene expression data to reconstruct evolutionary relationships among 11 types of lymphocytes by the maximum parsimony method. The resulting phylogenetic tree showed expected patterns including separation of the lymphoid and myeloid lineages; clustering together of granulocyte types; and pairing of phenotypically similar cell types such as T-helper cells type 1 and T-helper cells type 2 (Th1 and Th2). We used phylogenetic analyses of sequence data to determine the time of origin of genes showing significant expression difference between Th1 and Th2 cells. Many such genes, particularly those involved in the regulation of gene expression or activation of proteins, were of ancient origin, having arisen by gene duplication before the most recent common ancestor (MRCA) of tetrapods and teleosts. However, certain other genes with significant expression difference between Th1 and Th2 arose after the tetrapod-teleost MRCA, and some of the latter were specific to eutherian (placental) mammals. This evolutionary pattern is consistent with previous evidence that, while bony fishes possess Th1 and Th2 cells, the latter differ phenotypically in important respects from the corresponding cells of mammals. Our results support a gradualistic model of the evolution of distinctive cellular phenotypes whereby the unique characteristics of a given cell type arise as a result of numerous independent mutational changes over hundreds of millions of years.
Also flagged:NetrinRobo-Slitheparan sulfateproteoglycansaxonsaxon
Journal Article2009-07-01✓ 5 SnippetsKastenhuber E, Kern U, Bonkowsky JL, Chien CB, Driever W, Schweitzer J.
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…Robo2/Slit function, DA axons are attracted toward the midline by DCC (deleted in colorectal cancer…
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…DCC (deleted in colorectal cancer…
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…Netrin-DCC, Robo-Slit, and heparan…
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…the midline byDCC(deleted in colorectal…
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Longitudinal axons provide connectivity between remote areas of the nervous system. Although the molecular determinants driving commissural pathway formation have been well characterized, mechanisms specifying the formation of longitudinal axon tracts in the vertebrate nervous system are largely unknown. Here, we study axon guidance mechanisms of the longitudinal dopaminergic (DA) diencephalospinal tract. This tract is established by DA neurons located in the ventral diencephalon and is thought to be involved in modulating locomotor activity. Using mutant analysis as well as gain of function and loss of function experiments, we demonstrate that longitudinal DA axons navigate by integrating long-range signaling of midline-derived cues. Repulsive Robo2/Slit signaling keeps longitudinal DA axons away from the midline. In the absence of repulsive Robo2/Slit function, DA axons are attracted toward the midline by DCC (deleted in colorectal cancer)/Netrin1 signaling. Thus, Slit-based repulsion counteracts Netrin-mediated attraction to specify lateral positions of the DA diencephalospinal tract. We further identified heparan sulfate proteglycans as essential modulators of DA diencephalospinal guidance mechanisms. Our findings provide insight into the complexity of positioning far-projecting longitudinal axons and allow us to provide a model for DA diencephalospinal pathfinding. Simultaneous integrations of repulsive and attractive long-range cues from the midline act in a concerted manner to define lateral positions of DA longitudinal axon tracts.
Also flagged:membraneNGFNHE1growth conesgrowth conefilopodia
Journal Article2009-07-01✓ 1 SnippetSin WC, Moniz DM, Ozog MA, Tyler JE, Numata M, Church J.
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…DCC…
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The ubiquitously expressed Na(+)/H(+) exchanger NHE1 plays an important role in regulating polarized membrane protrusion and directional motility in non-neuronal cells. Using NGF-differentiated PC12 cells and murine neocortical neurons in vitro, we now show that NHE1 plays a role in regulating early neurite morphogenesis. NHE1 was expressed in growth cones in which it gave rise to an elevated intracellular pH in actively extending neurites. The NHE1 inhibitor cariporide reversibly reduced growth cone filopodia number and the formation and elongation of neurites, especially branches, whereas the transient overexpression of full-length NHE1, but not NHE1 mutants deficient in either ion translocation activity or actin cytoskeletal anchoring, elicited opposite effects. In addition, compared with neocortical neurons obtained from wild-type littermates, neurons isolated from NHE1-null mice exhibited reductions in early neurite outgrowth, an effect that was rescued by overexpression of full-length NHE1 but not NHE1 mutants. Finally, the growth-promoting effects of netrin-1, but not BDNF or IGF-1, were markedly reduced by cariporide in wild-type neocortical neurons and were not observed in NHE1-null neurons. Although netrin-1 failed to increase growth cone intracellular pH or Na(+)/H(+) exchange activity, netrin-1-induced increases in early neurite outgrowth were restored in NHE1-null neurons transfected with full-length NHE1 but not an ion translocation-deficient mutant. Collectively, the results indicate that NHE1 participates in the regulation of early neurite morphogenesis and identify a novel role for NHE1 in the promotion of early neurite outgrowth by netrin-1.
…Thus, endogenous Hsp70s are a critical component of the cellular defense against the toxic effects of misfolded htt protein in neurons, but buffer toxicity by mechanisms independent of the deposition of fibrillar aggregates.…
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…toxic effects of misfolded htt protein in neurons ,…
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…Huntington's disease (HD) is a fatal neurodegenerative disorder caused by an expansion of a polyglutamine (polyQ) tract in the protein huntingtin (htt), which leads to its aggregation and accumulation in inclusion bodies.…
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…the protein huntingtin (htt), which leads to…
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…formed by mutanthttexon 1, but…
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Endogenous protein quality control machinery has long been suspected of influencing the onset and progression of neurodegenerative diseases characterized by accumulation of misfolded proteins. Huntington's disease (HD) is a fatal neurodegenerative disorder caused by an expansion of a polyglutamine (polyQ) tract in the protein huntingtin (htt), which leads to its aggregation and accumulation in inclusion bodies. Here, we demonstrate in a mouse model of HD that deletion of the molecular chaperones Hsp70.1 and Hsp70.3 significantly exacerbated numerous physical, behavioral and neuropathological outcome measures, including survival, body weight, tremor, limb clasping and open field activities. Deletion of Hsp70.1 and Hsp70.3 significantly increased the size of inclusion bodies formed by mutant htt exon 1, but surprisingly did not affect the levels of fibrillar aggregates. Moreover, the lack of Hsp70s significantly decreased levels of the calcium regulated protein c-Fos, a marker for neuronal activity. In contrast, deletion of Hsp70s did not accelerate disease in a mouse model of infectious prion-mediated neurodegeneration, ruling out the possibility that the Hsp70.1/70.3 mice are nonspecifically sensitized to all protein misfolding disorders. Thus, endogenous Hsp70s are a critical component of the cellular defense against the toxic effects of misfolded htt protein in neurons, but buffer toxicity by mechanisms independent of the deposition of fibrillar aggregates.
Also flagged:gastroenteritisacute gastroenteritisReverse transcriptionreverse transcriptaseagaroseNucleotide
Journal Article2009-07-01No SnippetsChanit W, Thongprachum A, Khamrin P, Okitsu S, Mizuguchi M, Ushijima H.
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We investigated the incidence of sapovirus (SaV)-associated gastroenteritis in infants and children in Japan during 2007-2008 and characterized the diversity of SaV-positive strains. SaV was detected in 19 (4%) of 477 fecal specimens. The leading genogroup (79%, 15 cases) comprised intergenogroup recombinant SaVs (GII/GIV).
Also flagged:axonsinnervationpsychiatric disordersprotocadherinscadherincytoplasmic region
Journal Article2009-07-01✓ 1 SnippetKatori S, Hamada S, Noguchi Y, Fukuda E, Yamamoto T, Yamamoto H, Hasegawa S, Yagi T.
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Serotonergic axons from the raphe nuclei in the brainstem project to every region of the brain, where they make connections through their extensive terminal arborizations. This serotonergic innervation contributes to various normal behaviors and psychiatric disorders. The protocadherin-alpha (Pcdha) family of clustered protocadherins consists of 14 cadherin-related molecules generated from a single gene cluster. We found that the Pcdhas were strongly expressed in the serotonergic neurons. To elucidate their roles, we examined serotonergic fibers in a mouse mutant (Pcdha(Delta CR/Delta CR)) lacking the Pcdha cytoplasmic region-encoding exons, which are common to the gene cluster. In the first week after birth, the distribution pattern of serotonergic fibers in Pcdha(Delta CR/Delta CR) mice was similar to wild-type, but by 3 weeks of age, when the serotonergic axonal termini complete their arborizations, the distribution of the projections was abnormal. In some target regions, notably the globus pallidus and substantia nigra, the normally even distribution of serotonin axonal terminals was, in the mutants, dense at the periphery of each region, but sparse in the center. In the stratum lacunosum-molecular of the hippocampus, the mutants showed denser serotonergic innervation than in wild-type, and in the dentate gyrus of the hippocampus and the caudate-putamen, the innervation was sparser. Together, the abnormalities suggested that Pcdha proteins are important in the late-stage maturation of serotonergic projections. Further examination of alternatively spliced exons encoding the cytoplasmic tail showed that the A-type (but not the B-type) cytoplasmic tail was essential for the normal development of serotonergic projections.
Also flagged:calciumSpinocerebellar ataxia type 2SCA2neurodegenerative diseasepolyglutamineataxin-2
Journal Article2009-07-01✓ 1 SnippetLiu J, Tang TS, Tu H, Nelson O, Herndon E, Huynh DP, Pulst SM, Bezprozvanny I.
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…Htt…
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Spinocerebellar ataxia type 2 (SCA2) is an autosomal dominantly inherited, neurodegenerative disease caused by an expansion of polyglutamine tracts in the cytosolic protein ataxin-2 (Atx2). Cerebellar Purkinje cells (PCs) are predominantly affected in SCA2. The cause of PC degeneration in SCA2 is unknown. Here we demonstrate that mutant Atx2-58Q, but not wild-type (WT) Atx2-22Q, specifically associates with the cytosolic C-terminal region of type 1 inositol 1,4,5-trisphosphate receptor (InsP(3)R1), an intracellular calcium (Ca(2+)) release channel. Association with Atx2-58Q increased the sensitivity of InsP(3)R1 to activation by InsP(3) in planar lipid bilayer reconstitution experiments. To validate physiological significance of these findings, we performed a series of experiments with an SCA2-58Q transgenic mouse model that expresses human full-length Atx2-58Q protein under the control of a PC-specific promoter. In Ca(2+) imaging experiments, we demonstrated that stimulation with 3,5-dihydroxyphenylglycine (DHPG) resulted in higher Ca(2+) responses in 58Q PC cultures than in WT PC cultures. DHPG-induced Ca(2+) responses in 58Q PC cultures were blocked by the addition of ryanodine, an inhibitor of the ryanodine receptor (RyanR). We further demonstrated that application of glutamate induced more pronounced cell death in 58Q PC cultures than in WT PC cultures. Glutamate-induced cell death of 58Q PC cultures was attenuated by dantrolene, a clinically relevant RyanR inhibitor and Ca(2+) stabilizer. In whole animal experiments, we demonstrated that long-term feeding of SCA1-58Q mice with dantrolene alleviated age-dependent motor deficits (quantified in beam-walk and rotarod assays) and reduced PC loss observed in untreated SCA2-58Q mice by 12 months of age (quantified by stereology). Results of our studies indicate that disturbed neuronal Ca(2+) signaling may play an important role in SCA2 pathology and also suggest that the RyanR constitutes a potential therapeutic target for treatment of SCA2 patients.
Also flagged:Alcoholic liver diseasehepatitis Cinfectionliver diseaseliver cirrhosishepatocellular carcinoma
Journal Article2009-07-01✓ 1 SnippetMueller S, Millonig G, Seitz HK.
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Alcoholic liver disease (ALD) and hepatitis C virus (HCV) infection represent, either alone or in combination, more than two thirds of all patients with liver disease in the Western world. This review discusses the epidemiology and combined impact of ALD and HCV on the progression of liver disease. ALD and HCV affect the progression of liver disease to liver cirrhosis and hepatocellular carcinoma (HCC) in a synergistic manner. Thus, the risk for HCC increases five times with a daily alcohol consumption of 80 g; in the presence of HCV it is increased 20-fold, and a combination of both risk factors leads to a more than 100-fold risk for HCC development. Alcohol consumption also decreases the response to interferon treatment which is probably due to a lack of compliance than a direct effect on HCV replication. Several molecular mechanisms are discussed that could explain the synergistic interaction of alcohol and HCV on disease progression. They include modulation of the immune response and apoptosis, increased oxidative stress via induction of CYP2E1 and the hepatic accumulation of iron. Thus, both HCV and alcohol independently cause hepatic iron accumulation in > 50% of patients probably due to suppression of the liver-secreted systemic iron hormone hepcidin. A better understanding of hepcidin regulation could help in developing novel therapeutic approaches to treat the chronic disease in the future. For now, it can be generally concluded that HCV-infected patients should abstain from alcohol and alcoholics should be encouraged to participate in detoxification programs.
Also flagged:polyacrylamidepropylene oxideCopolymerpolymershomopolymers-
Journal Article2009-07-01No SnippetsWan F, He W, Zhang J, Chu B.
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High viscosity is an inherent problem of sequencing matrices made of hydrophilic polymers. This problem is amplified in separations using microchips where the channels are even smaller. A novel thermal-associating graft copolymer, using linear polyacrylamide (LPA) as the backbone and poly(propylene oxide) (PPO) as the graft side chain was synthesized. The injection problem could be resolved by introducing PPO side chains that can be assembled by using temperature changes but without an obvious detrimental effect on the sieving ability of the LPA. Viscosity measurement showed that these LPA-g-PPO copolymers had a transition temperature of approximately 40 degrees C, above which a significant increase in viscosity was observed. The sequencing performance depended on the thermal association properties of PPO and related parameters. Without optimization, a read length of 1000 bases with a single base resolution of 0.3 was achieved within an hour on an ABI 310 analyzer, using 1.8 wt% LPA-g-PPO (1.8 MDa, PPO, 0.2%). This novel thermal reversible copolymer solution can be a promising candidate as a viable matrix for DNA sequencing in CE, and even more so in microchip electrophoresis.
Also flagged:deathvenous thromboembolismdeep vein thrombosispulmonary embolusobstructive sleep apneaobesity
Journal Article2009-07-01No SnippetsLongitudinal Assessment of Bariatric Surgery (LABS) Consortium, Flum DR, Belle SH, King WC, Wahed AS, Berk P, Chapman W, Pories W, Courcoulas A, McCloskey C, Mitchell J, Patterson E, Pomp A, Staten MA, Yanovski SZ, Thirlby R, Wolfe B.
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<h4>Background</h4>To improve decision making in the treatment of extreme obesity, the risks of bariatric surgical procedures require further characterization.<h4>Methods</h4>We performed a prospective, multicenter, observational study of 30-day outcomes in consecutive patients undergoing bariatric surgical procedures at 10 clinical sites in the United States from 2005 through 2007. A composite end point of 30-day major adverse outcomes (including death; venous thromboembolism; percutaneous, endoscopic, or operative reintervention; and failure to be discharged from the hospital) was evaluated among patients undergoing first-time bariatric surgery.<h4>Results</h4>There were 4776 patients who had a first-time bariatric procedure (mean age, 44.5 years; 21.1% men; 10.9% nonwhite; median body-mass index [the weight in kilograms divided by the square of the height in meters], 46.5). More than half had at least two coexisting conditions. A Roux-en-Y gastric bypass was performed in 3412 patients (with 87.2% of the procedures performed laparoscopically), and laparoscopic adjustable gastric banding was performed in 1198 patients; 166 patients underwent other procedures and were not included in the analysis. The 30-day rate of death among patients who underwent a Roux-en-Y gastric bypass or laparoscopic adjustable gastric banding was 0.3%; a total of 4.3% of patients had at least one major adverse outcome. A history of deep-vein thrombosis or pulmonary embolus, a diagnosis of obstructive sleep apnea, and impaired functional status were each independently associated with an increased risk of the composite end point. Extreme values of body-mass index were significantly associated with an increased risk of the composite end point, whereas age, sex, race, ethnic group, and other coexisting conditions were not.<h4>Conclusions</h4>The overall risk of death and other adverse outcomes after bariatric surgery was low and varied considerably according to patient characteristics. In helping patients make appropriate choices, short-term safety should be considered in conjunction with both the long-term effects of bariatric surgery and the risks associated with being extremely obese. (ClinicalTrials.gov number, NCT00433810.)
Quorum sensing is a process of bacterial communication involving production and detection of secreted molecules called autoinducers. Gram-negative bacteria use acyl-homoserine lactone (AHL) autoinducers, which are detected by one of two receptor types. First, cytoplasmic LuxR-type receptors bind accumulated intracellular AHLs. AHL-LuxR complexes bind DNA and alter gene expression. Second, membrane-bound LuxN-type receptors bind accumulated extracellular AHLs. AHL-LuxN complexes relay information internally by phosphorylation cascades that direct gene expression changes. Here, we show that a small molecule, previously identified as an antagonist of LuxN-type receptors, is also a potent antagonist of the LuxR family, despite differences in receptor structure, localization, AHL specificity, and signaling mechanism. Derivatives were synthesized and optimized for potency, and in each case, we characterized the mode of action of antagonism. The most potent antagonist protects Caenorhabditis elegans from quorum-sensing-mediated killing by Chromobacterium violaceum, validating the notion that targeting quorum sensing has potential for antimicrobial drug development.
Also flagged:ironmetabolismHereditary HemochromatosisHHiron overload syndromecirrhosis
Journal Article2009-07-01✓ 4 SnippetsRossetti MV, Méndez M, Afonso S, Gerez E, Batlle A, Muñoz A, Parera V.
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…We investigate the prevalence of C282Y, H63D and S65C mutations in 95 individuals (77 males, 18 females) bearing iron metabolism alterations to establish an early diagnosis of HH.…
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…HFEgene mutations in…
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…of mutations inHFEgene.…
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…mutations in theHFEgene (45 males,…
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Hereditary Hemochromatosis (HH) is an iron overload syndrome caused by increased duodenal iron absorption, which leads to excessive iron deposition in parenchymal cells of the liver and mayor organs, causing cirrhosis, diabetes, cardiac failure, endocrine complications and arthritis. There are 6 types of HH related to mutations in the genes that encode proteins of iron metabolism. HH Type I is inherited as an autosomal recessive trait of mutations in HFE gene. We investigate the prevalence of C282Y, H63D and S65C mutations in 95 individuals (77 males, 18 females) bearing iron metabolism alterations to establish an early diagnosis of HH. Among this population, 58% carried mutations in the HFE gene (45 males, 10 females). H63D mutation was found in 32.6% of the subjects (29.5% in heterozygocity, 3.15% in homozygocity). S65C mutation was only detected in the heterozygous form (5.3% of the patients), 2 of them carried also H63D mutation. C282Y in heterozygocity was found in 15.8% of the individuals; but only 4.15% carried this mutation in homozygocity. Our findings are in agreement with the prevalence of the Mediterranean origin of most of our patients, where C282Y mutation is not as common as H63D mutation.
Also flagged:uroporphyrinogen decarboxylaseURO-DexcretionuroporphyrinporphyrinPorphyria cutanea tarda
Journal Article2009-07-01✓ 2 SnippetsWarby CA, Phillips JD, Bergonia HA, Whitby FG, Hill CP, Kushner JP.
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Porphyria cutanea tarda (PCT) is caused by inhibition of uroporphyrinogen decarboxylase (URO-D) activity in hepatocytes. Subnormal URO-D activity results in accumulation and urinary excretion of uroporphyrin and heptacarboxyl porphyrin. Heterozygosity for mutations in the URO-D gene is found in the familial form of PCT (F-PCT). Over 70 mutations of URO-D have been described but very few have been characterized structurally. Here we characterize 3 mutations in the URO-D gene found in patients with F-PCT, G318R, K297N, and D306Y. Expression of the D306Y mutation results in an insoluble recombinant protein. G318R and K297N have little effect on the structure or activity of recombinant URO-D, but the proteins display reduced stability in vitro.
Also flagged:porphyria cutanea tardaironcytochrome P450sporphyrinUrodporphyrins
Journal Article2009-07-01✓ 3 SnippetsArch DD, Bergeron M, Hathaway L, Kushner JP, Phillips JD, Franklin MR.
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…Urod mutation and homozygous for null Hfe alleles spontaneously develop major increases in hepatic and urinary porphyrins several months after weaning but the high % uroporphyrin signature of PCT…
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…Hfe alleles spontaneously develop major increases in hepatic and urinary porphyrins several months after weaning but the high % uroporphyrin signature of PCT…
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…homozygous for nullHfealleles spontaneously develop…
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Most rodent models of porphyria cutanea tarda (PCT) share in common the administration of iron and agents that induce transcription of cytochrome P450s. Dissection of changes related to porphyrin accumulation required generation of a genetic model free from exogenous precipitants. Mice heterozygous for a null Urod mutation and homozygous for null Hfe alleles spontaneously develop major increases in hepatic and urinary porphyrins several months after weaning but the high % uroporphyrin signature of PCT is established earlier, before total hepatic and urinary porphyrins rise. Total porphyrin levels eventually plateau at higher levels in females than in males. Porphyrinogens were the dominant tetrapyrroles accumulating in hepatocytes. Hepatic Urod activity is markedly reduced but total hepatic heme content does not diminish. Microsomal heme, however, is reduced and in vitro metabolism of prototype substrates showed that some but not all cytochrome P450 activities are reduced. High hepatic levels of uroporphyrinogen are also associated with increased glutathione S-transferase activity and elevated mRNA of 2 transporters, Abcc1 and Abcc4. This murine model of familial PCT affords the opportunity to study changes in porphyrinogen and porphyrin accumulation and transport in the absence of exogenous factors that alter P450 activity and transmembrane transporters.
Also flagged:hepatitis C virus infectionironhepatocarcinomabacterial infectionsinfectionHCV infection
Journal Article2009-07-01✓ 5 SnippetsRamírez E, Pacho A, Morales JM, De Castro I, Paz-Artal E, Morales P.
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…The aim of this study was to describe the frequencies of HFE mutations among a kidney transplant population with versus without hepatitis C virus (HCV) infection, and its influence on liver and kidney status parameters.…
Mutations in hemochromatosis gene cause an inappropriately high absorption of iron that induces iron overload and deposition in several tissues, such as liver, pancreas, and heart. Iron overload in the liver has been associated with a high risk of hepatocarcinoma and susceptibility to viral and bacterial infections. The aim of this study was to describe the frequencies of HFE mutations among a kidney transplant population with versus without hepatitis C virus (HCV) infection, and its influence on liver and kidney status parameters. We selected 3 populations: 2 groups of kidney transplant recipients-59 with and 60 without HCV infection-and a third control group of 50 healthy subjects. We collected clinical data concerning liver and kidney status, such as iron, ferritin, albumin, creatinine, gamma GGT, GOT, proteinuria, %prothrombin, and Bilirubin. HFE mutations among patients and controls were determined by polymerase chain reaction-restriction fragment length polymorphism using DNA from the peripheral blood. We observed no significant difference with respect to the frequencies of HFE mutations between controls and patients with versus without HCV infection. Finally comparison of HFE positive versus negative mutation carriers in both groups suggest that any clinical parameter is associated with HFE mutations.
Also flagged:conduct disorderdevelopmental psychopathologyconduct disorderedMAOAchromosomeserotonin
Journal Article2009-07-01No SnippetsDodge KA.
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The gene-environment interaction effect in the development of conduct disorder is one of the most important discoveries of the past decade, but the mechanisms through which this effect operates remain elusive. I propose a model of these processes that focuses on the individual's response to a threatening stimulus in ongoing social interaction. The individual's response coordinates three interrelated systems: neural, autonomic, and information-processing. In each system, adaptive, evolutionarily selected response patterns characterize normal responding, but in psychopathology these patterns have gone awry. Antecedents of individual differences in these response patterns arise from genetic polymorphisms, adverse environmental experiences early in life, and their interaction. Programs of research are proposed to test hypotheses in the model through longitudinal, experimental, and clinical intervention methods. This model can serve as a template for inquiry in other forms of developmental psychopathology.
Using flow-cytometric method the frequency of lymphocytes beaming mutations at T-cell receptor (TCR) locus was assessed in women residing in radiation polluted regions of Bryansk and Tula Districts. Simultaneously genotyping of the 8 polymorph loci for genes involved in detoxication of xenobiotics and oestrogen metabolism was carried out. The increased TCR-mutant cell frequency was found to be characteristic of homozygotes of the low activity appropriated enzymes for 3 loci (HFE187, GSTM1 and MTHFR) at least. This tendency was statistically significant in case of deletion polymorphism of the GSTM1 gene: TCR-mutant cell frequency of the homozygous carriers of a deletion at the GSTM1 locus was (4.63 +/- 0.18) x 10(-4) while it was (4.05 +/- 0.15) x 10(-4) in other groups of persons. The greatest mutant cell frequency was observed in carriers of the minor allele 4889G of the locus CYP1A. More often the increased values of the TCR-mutant cells (outside range "3sigma") were determined in women with genotypes A/G or G/G of the locus CYP1A1 (25%) than in carries of the normal genotype A/A (1.6%) (OR = 20.6; p = 0.0002). The comparison of the groups of women with reproductive system diseases reveals significant elevation in the mean TCR-mutant cell frequency in inhabitants of the most radiation polluted region among others.
Also flagged:rheumatoid arthritisosteoarthritisRAOANetrin-1Neogenin
Journal Article2009-07-01✓ 1 SnippetSchubert T, Denk A, Mägdefrau U, Kaufmann S, Bastone P, Lowin T, Schedel J, Bosserhoff AK.
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…-3, -4, Neogenin,DCC, UNC5A-D. The influence…
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Changes in the expression of repellent factors, i.e., Netrins and their receptors, may be responsible for the invasive behavior of the synovial tissue cells in patients with rheumatoid arthritis (RA) and osteoarthritis (OA). This study was carried out to analyze the expression of Netrins and their receptors in synovial cells of patients with RA, OA, and control subjects without synovial inflammation. Quantitative RT-PCR was performed to measure the expression of Netrin-1, -3, -4, Neogenin, DCC, UNC5A-D. The influence of Netrin-1 on synovial fibroblasts (SF) was analyzed by determining proliferation, migration, and their ability to organize collagen. SF expressed all repellent factors of the Netrin family. When comparing SF of healthy donors to patients with RA and OA, a stronger expression of UNC5B (4 fold) and UNC5C (769 fold) in RA and OA was found, whereas expression of the other molecules revealed no significant differences. Treating the SF-cells with recombinant Netrin-1 resulted in inhibition of migration of RA- and OA-SFs whereas control cells were not affected. The stronger expression of UNC5B and UNC5C receptors might contribute to the disordered phenotype of RA- and OA-SFs. Addition of Netrin-1 reduces the migratory ability of SFs, potentially by repulsion, as seen in neuronal cells in embryonic development. Due to its function, Netrin-1 may constitute a novel target in the treatment of OA and RA.
Also flagged:hydroxyapatitebeta-tricalcium phosphatebeta-tricalciumbone formationporeankylosing spondylitis
Journal Article2009-07-01No SnippetsBansal S, Chauhan V, Sharma S, Maheshwari R, Juyal A, Raghuvanshi S.
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<h4>Background</h4>Autologous cancellous bone is the most effective biological graft material. However, harvest of autologous bone is associated with significant morbidity. Since porous hydroxyapatite and beta-tricalcium phosphate are biodegradable materials and can be replaced by bone tissue, but it lacks osteogenic property. We conducted a study to assess their use as a scaffold and combine them with bone marrow aspirate for bone regeneration using its osteogenic property for posterolateral spinal fusion on one side and autologous bone graft on the other side and compare them radiologically in terms of graft incorporation and fusion.<h4>Materials and methods</h4>Thirty patients with unstable dorsal and lumbar spinal injuries who needed posterior stabilization and fusion were evaluated in this prospective study from October 2005 to March 2008. The posterior stabilization was done using pedicle screw and rod assembly, and fusion was done using hydroxyapatite and beta-tricalcium phosphate mixed with bone marrow aspirate as a bone graft substitute over one side of spine and autologous bone graft obtained from iliac crest over other side of spine. The patients were followed up to a minimum of 12 months. Serial radiographs were done at an interval of 3, 6, and 12 months and CT scan was done at one year follow-up. Graft incorporation and fusion were assessed at each follow-up. The study was subjected to statistical analysis using chi-square and kappa test to assess graft incorporation and fusion.<h4>Results</h4>At the end of the study, radiological graft incorporation and fusion was evident in all the patients on the bone graft substitute side and in 29 patients on the autologous bone graft side of the spine (P > 0.05). One patient showed lucency and breakage of distal pedicle screw in autologous bone graft side. The interobserver agreement (kappa) had an average of 0.72 for graft incorporation, 0.75 for fusion on radiographs, and 0.88 for the CT scan findings.<h4>Conclusion</h4>Hydroxyapatite and beta-tricalcium phosphate mixed with bone marrow aspirate seems to be a promising alternative to conventional autologous iliac bone graft for posterolateral spinal fusion.
Also flagged:thrombipulmonary embolismPEthromboembolicheparinMassive pulmonary embolism
Journal Article2009-07-01✓ 1 SnippetVogiatzis I, Dapcevic I, Sachpekidis V, Stafylas P, Sidiropoulos A, Pittas S, Tsangaris V.
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…Antithrombin-III…
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Right sided heart thrombi may develop within the right heart chambers or they may be peripheral venous clots that on their way to the lungs, accidentally lodge in a patent foramen ovale, tricuspid chordae or Chiaris network. Type A thrombi have a worm-like shape and are extremely mobile. These pleomorphic thrombi are mainly localized in the right atrium, frequently move back and forth through the tricuspid orifice and may cause cardiovascular collapse when entrapment occurs. Type B thrombi attach to the atrial or ventricular wall indicating that they are probably of local origin. We describe the case of a middle age man (48 years old) with no cardiovascular history and a massive pulmonary embolism where transthoracic echocardiography revealed many type A thrombi in both right atrium and ventricle. He presented with acute dyspnea, diaphoresis and hemodynamical instability. He was treated with thrombolysis and after three hours was greatly improved and the thrombi were disappeared. After ten days of hospitalization he was discharged. Thrombi were originated in the popliteal region of the inferior vena cava of both legs and were totally treated.
New glycyrrhizic acid (GA) conjugates were synthesized with the use of tert-butyl esters of amino acids or benzyl esters of dipeptides; they contained two residues of L-amino acids (Met, Phe, Pro, and Ile or dipeptides Gly-Leu and Gly-Phe). Activation of GA carboxy groups was carried out with the help of N-hydroxysuccinimide, N,N'-dicyclohexylcarbodiimide, or N-hydroxybenzotriazole with dicyclohexylcarbodiimide. A proline-containing GA derivative is a low-toxic substance; it raises the level of agglutinins by 3.7 times in the blood of mice and 3 times that of hemolysins compared with the control. Dipeptide GA derivatives possess an expressed anti-HIV-1 activity in cultures of MT-4 cells and are 90-70 times less cytotoxic than azidothymidine. The selectivity index of the compounds exceeds those of GA by 110 and 34 times, respectively.
Also flagged:tryptophan hydroxylaseserotonin transporteressential hypertensionTPH5-hydroxytryptamine transporterpolymerase
Journal Article2009-07-01✓ 3 SnippetsXia DS, Lu CZ, Guo QY, Song YQ, Li C, Xu JQ, Zhang F.
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…To investigate the relationship between tryptophan hydroxylase (TPH) gene A218C in intron 7 and 5-hydroxytryptamine transporter (5-HTT) gene variable number tandem repeat (VNTR) in intron 2 and gene-linked polymorphic region (LPR) deletion/insertion polymorphism and essential hypertension (EH) in Chinese northern Han population.…
Abstract)
…TPH) gene A218C in intron 7 and 5-hydroxytryptamine transporter (5-HTT) gene variable number tandem repeat (VNTR) in intron 2 and gene-linked polymorphic region (LPR) deletion/insertion polymorphism and essential hypertension…
<h4>Objective</h4>To investigate the relationship between tryptophan hydroxylase (TPH) gene A218C in intron 7 and 5-hydroxytryptamine transporter (5-HTT) gene variable number tandem repeat (VNTR) in intron 2 and gene-linked polymorphic region (LPR) deletion/insertion polymorphism and essential hypertension (EH) in Chinese northern Han population.<h4>Methods</h4>A total of 280 EH patients and 200 normotensive controls were genotyped using polymerase chain reaction-restriction fragment length polymorphism technique.<h4>Results</h4>There were no significant differences in the frequencies of the genotypes and alleles of TPH gene A218C and 5-HTTVNTR between EH patents and controls (all P > 0.05). The genotype frequencies of SS, LS and LL in the 5-HTTLPR polymorphism was 68%, 29% and 3% in EH patients, 53%, 37% and 10% in the controls respectively (P < 0.01). The frequencies of allele S and L of the 5-HTTLPR were 82% and 18% in EH patients, 72% and 28% in the controls respectively (P < 0.01). Compared with the carriers of L allele (LS + LL), the EH risk was significantly higher in the SS homozygote (OR = 1.90, 95%CI = 1.31 - 2.77, P = 0.001). After adjustment of age, gender, body mass index, blood lipids, fasting blood glucose and blood uric acid level, the binary logistic regression analysis demonstrated that SS genotype in the 5-HTTLPR polymorphism was significantly related to occurrence of EH (OR = 1.47, 95%CI = 1.06 - 2.04, P = 0.021).<h4>Conclusions</h4>The SS genotype of the 5-HTTLPR might be a susceptible gene to EH, while the TPH gene A218C and 5-HTTVNTR polymorphism is not associated with EH in Chinese northern Han population.
Also flagged:Transglutaminasecalciumtransglutaminasesneurodegenerative disordersAlzheimer's diseaseParkinson's disease
Journal Article2009-07-01✓ 1 SnippetJeitner TM, Muma NA, Battaile KP, Cooper AJ.
In-Text Gene Mentions
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The following review examines the role of calcium in promoting the in vitro and in vivo activation of transglutaminases in neurodegenerative disorders. Diseases such as Alzheimer's disease, Parkinson's disease and Huntington's disease exhibit increased transglutaminase activity and rises in intracellular calcium concentrations, which may be related. The aberrant activation of transglutaminase by calcium is thought to give rise to a variety of pathological moieties in these diseases, and the inhibition has been shown to have therapeutic benefit in animal and cellular models of neurodegeneration. Given the potential clinical relevance of transglutaminase inhibitors, we have also reviewed the recent development of such compounds.
Also flagged:Huntington diseaseHuntington's diseaseHuntingtinpolyglutamine diseasesHD
Journal Article2009-07-01✓ 2 SnippetsMazdeh M, Pour-Jafari H, Ghaleiha A, Pour-Jafari B.
In-Text Gene Mentions
Abstract)
…Huntington's disease is caused by a trinucleotide repeat expansion (CAG)n in the gene coding for Huntingtin (Htt) and is one of the several polyglutamine diseases.…
Abstract)
…coding for Huntingtin (Htt) and is one…
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Huntington's disease is caused by a trinucleotide repeat expansion (CAG)n in the gene coding for Huntingtin (Htt) and is one of the several polyglutamine diseases. Its physical symptoms occur in a large range of ages, with a mean occurrence in a person's late 40's and early 50's. Almost all references indicated that if the age of onset is below 20 years then it is known as juvenile HD. Our case was an Iranian family with 4 affected siblings (2 sisters and 2 brothers). In addition to 4 affected children, they had 5 normal male progenies. There was no any other case in their family history. The onset age of the disease in our case family was 20 to 25 years. Their parents were unaffected and nonconsanguineous. Analysis of the pathogenic (CAG)n repeat region of the HD gene for the affected members have showed an expansion allele with 46, 50, 46, and 44 repeats in 4 affected siblings. Our results indicated that the age of 20 years maybe is not a stable limit point for all cases of juvenile HD, and perhaps onset ages are related with the CAG repeat sizes in such individuals.
Also flagged:oesophageal varicesviral infectionsparasitic infectionscancerliver enzymesalbumin
Journal Article2009-07-01✓ 1 SnippetBahlas S.
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…hemochromatosis…
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<h4>Objectives</h4>The objective of this study is to reach a model defining factors precipitating short survival in patients with oesophageal varices and improving the understanding of such factors. Models would help to prioritize the clinical goals and intervention for saving the lives of patients.<h4>Methods</h4>Retrospective analysis of all patients admitted to King Abdul Aziz University Hospital who had been diagnosed with oesophageal varices. The patients' demographics, disease history, physical examination, viral infections, parasitic infections, blood pictures, cancer biomarkers, liver enzymes and bleeding details were collected, tested for correlation with mortality to formulate a model.<h4>Results</h4>A total of 148 patients were included in this study. 37 clinical variables were studied only 15 factors were found to have a statistical significance. These factors were PT (RC=0.17338 P-value 0.00011), APTT (RC=0.07916, P-value 0.00002), haemoglobin level (RC=-0.44748, P-value <0.0001), WBC (RC = 0.22255, P-value 0.00001), serum albumin level (RC=-0.12953, P-value 0.00001), serum creatinine (RC=0.01483, P-value 0.00002), at least one incidence of encephalopathy (RC=1.80500, P-value 0.00014), total bilirubin (RC=0.01371, P-value 0.00016), direct bilirubin (RC=0.01298, P-value 0.00357, serum AST (RC=0.00914, P-value 0.00462), presence of at least bleeding event (RC=1.03373, P-value 0.00613), ascites grade I (RC=-1.57435, P-value 0.00967), SBP (RC=1.47216, P-value 0.01581), platelets count (RC=0.00398, P-value 0.03476) and oesophageal varices (RC = -1.42139, P-value 0.03673). Only 5 factors were likely to affect the mortality status. These factors were encephalopathy, spontaneous SBP, bleeding, ascites and grade of oesophageal varices. Six models were then formulated.<h4>Conclusion</h4>These models should be retested in larger study groups to test their reliability in order to use them as surrogate end point in future clinical studies.
Also flagged:ontogenesismitosismembranecytoplasmMitoticspindle
Journal Article2009-07-01✓ 2 SnippetsTerskikh VV, Vorotelyak YA, Vasiliev AV.
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S I O 001029)
…For example, the mutant protein Huntingtin (Htt), which characterizes for Huntington's disease, contains a polyglutamine fragment which assists aggresome formation.…
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…A recombinant Drosophila was created in which the N-end fragment of the human Htt protein was expressed; this human protein contained 128 glutamine repeats (Htt-Q128).…
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Asymmetric division is one of the most fundamental characteristics of adult stem cells , which ensures one daughter cell maintains stem cell status and the other daughter cell becomes committed to differentiation. New data emerged recently that allow us to conclude that asymmetric division has another important aspect: it enables self-maintenance of stem cells.
Also flagged:Cu/Zn superoxide dismutaseSuperoxide dismutaseCu/Zn SODchloroplastsSODChloroplastic SOD
Journal Article2009-07-01No SnippetsSundaram S, Khanna S, Khanna-Chopra R.
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Superoxide dismutase is the first line of defense against oxidative stress and thus helps in maintaining the cellular integrity. Chenopodium murale, a weed species adapted to widely varying climatic conditions faces extremes of temperatures ranging from 4 °C to 45 °C (Tmax) during growth and development. From this plant, we have purified a thermostable chloroplastic Cu/Zn superoxide dismutase (Chl Cu/Zn SOD) to homogeneity using minimal steps. Incubation of lysed chloroplasts at 70 °C for 1h reduced the interference of cytosolic SOD isoforms and reduced the protein content by 75 %. Chloroplastic SOD was purified from the heat stable fraction by gel filtration chromatography. The purified enzyme had a native molecular weight of 24 kDa, a half-life of 47.9 min at 80 °C and showed a single band at 24 kDa on SDS-PAGE. The N-terminus contained the conserved amino acids of chl Cu-Zn SOD. The Chl Cu/Zn SOD protein and its activity were enhanced under very high temperatures, high light intensities and in water stress/recovered C. murale plants under controlled environment conditions. Chl Cu/Zn SOD was also one of the predominant isoforms throughout growing period in field grown plants and declined during senescence. The Chl Cu/Zn SOD activity increased with the increase in ambient temperature and peaked in April with a 45 °C Tmax. These results clearly indicate that the chloroplastic Cu/Zn SOD is stably expressed at extreme environmental conditions. The presence of stable monomeric chloroplastic Cu/Zn SOD might help the plants to maintain the cellular homeostatis against adverse environmental conditions.