Also flagged:breast cancer-menopausal breast cancerhormone receptortumorslactationiron
Journal Article2008-07-31✓ 1 SnippetLinos E, Willett WC, Cho E, Colditz G, Frazier LA.
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<h4>Background</h4>Adolescence may be a period of increased susceptibility to breast cancer due to regular division of undifferentiated cells that occurs between puberty and first birth. Red meat consumption during early adult life has been associated with breast cancer, but intake during adolescence has not been examined prospectively. We aimed to assess the relationship between red meat intake during adolescence and premenopausal breast cancer.<h4>Methods</h4>We examined the incidence of invasive premenopausal breast cancer prospectively within the Nurses' Health Study II. A total of 39,268 premenopausal women who completed a validated 124-item food frequency questionnaire on their diet during high school, were followed for 7 years, from 1998 to 2005. Cox proportional hazards regression was used to estimate relative risks (RR) and 95% confidence intervals (95% CI).<h4>Results</h4>455 cases of invasive premenopausal breast cancer were diagnosed between 1998 and 2005. Compared with women in the lowest quintile of red meat intake during high school, the multivariate-adjusted RR for the highest quintile of intake was 1.34 (95% CI, 0.94-1.89; P(trend) = 0.05). A significant linear association was observed with every additional 100 g of red meat consumed per day (RR, 1.20; 95% CI, 1.00-1.43; P = 0.05). This association was more pronounced in hormone receptor-positive tumors (RR, 1.36; 95% CI, 1.08-1.70; P = 0.008) and was not significant in hormone receptor-negative tumors (RR, 0.99; 95% CI, 0.61-1.61, P = 0.97).<h4>Conclusion</h4>Higher red meat intake in adolescence may increase the risk of premenopausal breast cancer.
Post-Golgi transport of peptide hormone-containing vesicles from the site of genesis at the trans-Golgi network to the release site at the plasma membrane is essential for activity-dependent hormone secretion to mediate various endocrinological functions. It is known that these vesicles are transported on microtubules to the proximity of the release site, and they are then loaded onto an actin/myosin system for distal transport through the actin cortex to just below the plasma membrane. The vesicles are then tethered to the plasma membrane, and a subpopulation of them are docked and primed to become the readily releasable pool. Cytoplasmic tails of vesicular transmembrane proteins, as well as many cytosolic proteins including adaptor proteins, motor proteins, and guanosine triphosphatases, are involved in vesicle budding, the anchoring of the vesicles, and the facilitation of movement along the transport systems. In addition, a set of cytosolic proteins is also necessary for tethering/docking of the vesicles to the plasma membrane. Many of these proteins have been identified from different types of (neuro)endocrine cells. Here, we summarize the proteins known to be involved in the mechanisms of sorting various cargo proteins into regulated secretory pathway hormone-containing vesicles, movement of these vesicles along microtubules and actin filaments, and their eventual tethering/docking to the plasma membrane for hormone secretion.
Huntington's disease is a dominant autosomal neurodegenerative disorder caused by an expansion of polyglutamines in the huntingtin (Htt) protein, whose cellular function remains controversial. To gain insight into Htt function, we purified epitope-tagged Htt and identified Argonaute as associated proteins. Colocalization studies demonstrated Htt and Ago2 to be present in P bodies, and depletion of Htt showed compromised RNA-mediated gene silencing. Mouse striatal cells expressing mutant Htt showed fewer P bodies and reduced reporter gene silencing activity compared with wild-type counterparts. These data suggest that the previously reported transcriptional deregulation in HD may be attributed in part to mutant Htt's role in post-transcriptional processes.
Also flagged:cancerhead and neck squamous cell carcinomaHNSCChead and neck canceralcoholoncogenes
Journal Article2008-07-31✓ 1 SnippetHa PK, Chang SS, Glazer CA, Califano JA, Sidransky D.
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It is well known that cellular DNA alterations can lead to the formation of cancer, and there has been much discovery in the pathways involved in the development of head and neck squamous cell carcinoma (HNSCC). With novel genome-wide molecular assays, our ability to detect these abnormalities has increased. We now have a better understanding of the molecular complexity of HNSCC, but there is still much research to be done. In this review, we discuss the well described genetic alterations and touch on the newer findings, as well as some of the future directions of head and neck cancer research.
An abundantly growing body of literature implicates conjugation of SUMO in the regulation of many proteins and processes, yet the regulation of SUMO pathways is poorly understood. To gain insight into the players in the SUMO1 pathway I have performed an in-silico co-expression meta-analysis of SUMO1, comparing many different multi-microarray studies of various normal and human tumour tissues, from the Oncomine database. This serves as a data-driven predictor of pathway partners of SUMO1. While the data obtained need to be confirmed by future independent experiments and can currently only be considered a hypothesis, results implicate defender against cell death (DAD1) and the anti-apoptotic DEK oncogene as new pathway partners of SUMO1.
Polyglutamine (polyQ)-expanded proteins are associated with cytotoxicity in some neurodegenerative disorders such as Huntington's disease. We have reported that the aggregation of the polyQ-expanded protein is partially suppressed by co-expression of either of two homologs of an AAA chaperone p97, CDC-48.1 or CDC-48.2, in Caenorhabditis elegans, but how p97 regulates the aggregation of polyQ-expanded proteins remains unclear. Here we present direct evidence that CDC-48.1 and CDC-48.2 suppress the aggregation of a huntingtin (Htt) exon1 fragment containing an expanded polyQ repeat in vitro. CDC-48.1 and CDC-48.2 bound the Htt exon1 fragment directly, and suppressed the formation of SDS-insoluble aggregates of Htt fragments containing 53 glutamine residues (HttQ53) independently of nucleotides. CDC-48.1 and CDC-48.2 also modulated the oligomeric states of HttQ53 during the aggregate formation. In the absence of CDC-48.1 and CDC-48.2, HttQ53 formed 70-150 kDa oligomers, whereas 300-500 kDa oligomers as well as 70-150 kDa oligomers accumulated in the presence of CDC-48.1 and CDC-48.2. Taken together, these results suggest that p97 plays a protective role in neurodegenerative disorders by directly suppressing the protein aggregation as a molecular chaperone.
Also flagged:Endothelial dysfunctioncardiovascular diseasediabetestype 2 diabetes mellitusadiponectinmyeloperoxidase
Journal Article2008-07-31✓ 5 SnippetsSchneider A, Neas L, Herbst MC, Case M, Williams RW, Cascio W, Hinderliter A, Holguin F, Buse JB, Dungan K, Styner M, Peters A, Devlin RB.
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…In addition, DNA analysis was performed with regard for the null polymorphism of glutathione S-transferase M1 (GSTM1) (chromosomal location 1p13.3), the valine-coding polymorphism (Ile105Val) of GSTP1 (chromosomal location 11q13), the aspartic acid-coding polymorphism H63D (His63Asp) of the HFE gene (chromosomal location 6p21.3), the tyrosine-coding polymorphism C282Y (Cys282Tyr) of the HFE gene, and the serine-coding polymorphism P149S (Pro149Ser) of the quinone oxidoreductase (NQ01) gene (chromosomal location 16q22.1).…
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…To identify susceptible subgroups, we also analyzed effect modification by genes of the antioxidant defense family and the hemochromatosis gene (HFE).…
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<h4>Background</h4>Exposure to fine airborne particulate matter [< or =2.5 microm in aerodynamic diameter (PM(2.5))] has been associated with cardiovascular and hematologic effects, especially in older people with cardiovascular disease. Some epidemiologic studies suggest that adults with diabetes also may be a particularly susceptible population.<h4>Objectives</h4>The purpose of this study was to analyze the short-term effects of ambient PM(2.5) on markers of endothelial function in diabetic volunteers.<h4>Methods</h4>We conducted a prospective panel study in 22 people with type 2 diabetes mellitus in Chapel Hill, North Carolina (USA), from November 2004 to December 2005. We acquired daily measurements of PM(2.5) and meteorologic data at central monitoring sites. On 4 consecutive days, we measured endothelial function by brachial artery ultrasound in all participants and by pulsewave measurements in a subgroup. Data were analyzed using additive mixed models with a random participant effect and adjusted for season, day of the week, and meteorology.<h4>Results</h4>Flow-mediated dilatation decreased in association with PM(2.5) during the first 24 hr, whereas small-artery elasticity index decreased with a delay of 1 and 3 days. These PM(2.5)-associated decrements in endothelial function were greater among participants with a high body mass index, high glycosylated hemoglobin A1c, low adiponectin, or the null polymorphism of glutathione S-transferase M1. However, high levels of myeloperoxidase on the examination day led to strongest effects on endothelial dysfunction.<h4>Conclusions</h4>These data demonstrate that PM(2.5) exposure may cause immediate endothelial dysfunction. Clinical characteristics associated with insulin resistance were associated with enhanced effects of PM on endothelial function. In addition, participants with greater oxidative potential seem to be more susceptible.
Also flagged:thalidomideangiogenesistumorbreast cancertumorsVEGF
Journal Article2008-07-30No SnippetsCyran CC, Sennino B, Chaopathomkul B, Fu Y, Rogut VS, Shames DM, Wendland MF, McDonald DM, Brasch RC.
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Thalidomide, which inhibits angiogenesis in certain tumor types, reduced extravasation of a macromolecular contrast medium (MMCM) in a human breast cancer model as assayed by MMCM-enhanced dynamic magnetic resonance imaging (MRI) and fluorescence microscopy in the same tumors. After a 1-week, three-dose course of thalidomide, the mean MRI-assayed endothelial transfer coefficient, K(PS), decreased significantly (p < 0.05) from 19.4 +/- 9.1 to 6.3 +/- 9.1 microl/min.100 cm(3). Correspondingly, microscopic measurements of extravasated MMCM, expressed as fractional area of streptavidin staining, were significantly (p < 0.05) lower in thalidomide-treated tumors (18.6 +/- 11.9%) than in control saline-treated tumors (50.2 +/- 2.3%). On a tumor-by-tumor basis, post-treatment K(PS) values correlated significantly (r(2) = 0.55, p < 0.05) with microscopic measures of MMCM extravasation. However, no significant differences were observed between saline- and thalidomide-treated tumors with respect to rate of growth, vascular richness, or amount of VEGF-containing cells. Because of its sensitivity to the detection of changes in vascular leakage in tumors, this MMCM-enhanced MRI assay could prove useful for monitoring the effects of thalidomide on an individual patient basis. The significant correlation between MRI and fluorescence microscopic measures of MMCM extravasation supports the utility of the non-invasive MRI approach for assessing the action of thalidomide on tumor blood vessels.
Acute tryptophan depletion (ATD) putatively results in a transient reduction in central serotonin transmission, and induces depressed mood in some un-medicated subjects with remitted major depressive disorder (MDD). The 5-HT transporter promoter region length polymorphism (5-HTTLPR) has been shown to influence behavioral and metabolic responses to ATD, as well as the risk for developing MDD within the context of stress. The current study investigates the relationships between 5-HTTLPR genotype, neurophysiologic response to ATD, and diagnostic phenotype (healthy control subjects versus MDD subjects differentiated by their depressive response to ATD) using (18)FDG-PET. Un-medicated subjects with remitted MDD and healthy controls were genotyped for the long (l) and short (s) alleles of the 5-HTTLPR polymorphism and categorized into one of three genotypes. On two separate occasions, subjects received either a placebo or an amino acid mixture designed to deplete plasma tryptophan, followed by (18)FDG-PET scanning. Depressive symptoms were rated to determine the diagnostic phenotype. Descriptive and predictive discriminant analyses were performed using brain regional metabolic data to classify according to phenotype and genotype. Overall, 79% of the cases were classified correctly by genotype, and 85% were classified correctly by phenotype. In a leave-one-out cross-validation, 72% of the subjects were classified correctly as carrying an s-allele, and 79% of the subjects were classified correctly by primary diagnosis. The robust nature of the classification results indicates that much of the variance in metabolic response to ATD is accounted for by genotypic and phenotypic category.
Also flagged:folatetumorbindingplatinumFolic acidfolate receptor
Journal Article2008-07-29No SnippetsDhar S, Liu Z, Thomale J, Dai H, Lippard SJ.
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Most low-molecular-weight platinum anticancer drugs have short blood circulation times that are reflected in their reduced tumor uptake and intracellular DNA binding. A platinum(IV) complex of the formula c, c, t-[Pt(NH 3) 2Cl 2(O 2CCH 2CH 2CO 2H)(O 2CCH 2CH 2CONH-PEG-FA)] ( 1), containing a folate derivative (FA) at an axial position, was prepared and characterized. Folic acid offers a means of targeting human cells that highly overexpress the folate receptor (FR). Compound 1 was attached to the surface of an amine-functionalized single-walled carbon nanotube (SWNT-PL-PEG-NH 2) through multiple amide linkages to use the SWNTs as a "longboat delivery system" for the platinum warhead, carrying it to the tumor cell and releasing cisplatin upon intracellular reduction of Pt(IV) to Pt(II). The ability of SWNT tethered 1 to destroy selectively FR(+) vs FR(-) cells demonstrated its ability to target tumor cells that overexpress the FR on their surface. That the SWNTs deliver the folate-bearing Pt(IV) cargos into FR(+) cancer cells by endocytosis was demonstrated by the localization of fluorophore-labeled SWNTs using fluorescence microscopy. Once inside the cell, cisplatin, formed upon reductive release from the longboat oars, enters the nucleus and reacts with its target nuclear DNA, as determined by platinum atomic absorption spectroscopy of cell extracts. Formation of the major cisplatin 1,2-intrastrand d(GpG) cross-links on the nuclear DNA was demonstrated by use of a monoclonal antibody specific for this adduct. The SWNT-tethered compound 1 is the first construct in which both the targeting and delivery moieties have been incorporated into the same molecule; it is also the first demonstration that intracellular reduction of a Pt(IV) prodrug leads to the cis-{Pt((NH 3) 2} 1,2-intrastrand d(GpG) cross-link in nuclear DNA.
Also flagged:heat shock proteinHSPHSP110HSPCHSP90HSP70
Journal Article2008-07-29No SnippetsKampinga HH, Hageman J, Vos MJ, Kubota H, Tanguay RM, Bruford EA, Cheetham ME, Chen B, Hightower LE.
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The expanding number of members in the various human heat shock protein (HSP) families and the inconsistencies in their nomenclature have often led to confusion. Here, we propose new guidelines for the nomenclature of the human HSP families, HSPH (HSP110), HSPC (HSP90), HSPA (HSP70), DNAJ (HSP40), and HSPB (small HSP) as well as for the human chaperonin families HSPD/E (HSP60/HSP10) and CCT (TRiC). The nomenclature is based largely on the more consistent nomenclature assigned by the HUGO Gene Nomenclature Committee and used in the National Center of Biotechnology Information Entrez Gene database for the heat shock genes. In addition to this nomenclature, we provide a list of the human Entrez Gene IDs and the corresponding Entrez Gene IDs for the mouse orthologs.
Journal Article2008-07-29✓ 1 SnippetRudel D, Tian H, Sommer RJ.
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Changes in organ morphology have been essential to the evolution of novel body forms and in permitting organisms to invade new ecological niches. Changes in the arrangement of cells and tissues and in the regulation of morphological movements are fundamental to evolutionary transitions of organ shape and function. However, little is known about the genetic and developmental control of these changes. We use interspecific differences in the migration and extension of the nematode hermaphrodite gonadal arms to study the generation of morphological novelty. We show that the extending Pristionchus pacificus gonadal arms display a ventral migration that is unique to the Diplogastridae in comparison to the Rhabditidae, including Caenorhabditis elegans, and other nematodes. This results in the distal gonad residing along the ventral side of the body in P. pacificus in contrast to lying on the dorsal side of the body as in C. elegans. We show that at the cellular level this morphogenetic movement is regulated by signals from the developing vulva and the sister gonadal arm. We further show that in P. pacificus Wnt signaling is essential for this regulation. We show genetic and molecular evidence that suggest the Wnt ligands Ppa-mom-2 and Ppa-cwn-2 are components of the signaling mechanism. Supporting these findings, the hermaphrodite gonad of Ppa-bar-1 mutant animals mimics the shape of the C. elegans hermaphrodite gonad; the arms fail to extend ventrally. Thus, this genetic analysis of gonad migration provides insight into the mechanisms underlying the generation of morphological novelty and organ shape.
Also flagged:Peroxiredoxin 6deathoxygenneurological disordersglaucomatransduction
Journal Article2008-07-29✓ 5 SnippetsFatma N, Kubo E, Sen M, Agarwal N, Thoreson WB, Camras CB, Singh DP.
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…A supply of PRDX6 protected RGCs from glutamate and TNF-alpha induced cytotoxicity by reducing ROS level and NF-kappaB activation, and limiting increased intracellular Ca2+ influx.…
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…PRDX6 for blocking ROS-mediated pathophysiology in glaucoma…
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…the presence ofPRDX6in RGCs, and…
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…an abundance ofPRDX6protein and mRNA.…
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…reduced expression ofPRDX6, and underwent apoptosis.…
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Higher expression of reactive oxygen species (ROS) is implicated in neurological disorders. A major event in glaucoma, the death of retinal ganglion cells (RGCs), has been associated with elevated levels of glutamate and TNF-alpha in the RGCs' local microenvironment. Herein we show that the transduction of Peroxiredoxin 6 (PRDX6) attenuates TNF-alpha- and glutamate-induced RGC death, by limiting ROS and maintaining Ca2+ homeostasis. Immunohistochemical staining of rat retina disclosed the presence of PRDX6 in RGCs, and Western and real-time PCR analysis revealed an abundance of PRDX6 protein and mRNA. RGCs treated with glutamate and/or TNF-alpha displayed elevated levels of ROS and reduced expression of PRDX6, and underwent apoptosis. A supply of PRDX6 protected RGCs from glutamate and TNF-alpha induced cytotoxicity by reducing ROS level and NF-kappaB activation, and limiting increased intracellular Ca2+ influx. Results provide a rationale for use of PRDX6 for blocking ROS-mediated pathophysiology in glaucoma and other neuronal disorders.
Journal Article2008-07-28No SnippetsGonzalez-Freire M, Santiago C, Verde Z, Lao JI, Oiivan J, Gómez-Gallego F, Lucia A, Lucia A.
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The cross-country world championship is one of the best models to study characteristics needed to achieve top-level endurance athletic capacity. We report the genotype combination of a recent cross-country champion (12 km race) in polymorphisms of seven genes that are candidates to influence endurance phenotype traits (ACTN3, ACE, PPARGC1A, AMPD1, CKMM, GDF8 (myostatin) and HFE). His data were compared with those of eight other runners (world-class but not world champions). The only athlete with the genotype theoretically more suited to attaining world-class endurance running performance was the case study subject. A favourable genetic endowment, together with exceptional environmental factors (years of altitude living and training in this case), seems to be necessary to attain the highest possible level of running endurance performance.
Also flagged:bisphosphonatebone metastasistetraacetic acidBP
Journal Article2008-07-27No SnippetsLiu W, Hajibeigi A, Lin M, Rostollan CL, Kovacs Z, Oz OK, Sun X.
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A hybrid compound (DO3A-BP) featuring a radiometal bifunctional chelator (1,4,7,10-tetraazacyclotetradecane-N,N',N'',N'''-tetraacetic acid, DOTA) and an osteoclast-targeting moiety (bisphosphonate) was designed and synthesized. The (111)In-labeled complex of DO3A-BP showed significantly elevated uptake in osteoclasts compared to the undifferentiated adherent bone marrow derived cells. Biodistribution studies revealed a favorable tissue distribution profile in normal mice with high bone uptake and long retention, and low or negligible accumulation in non-target organs.
<h4>Summary</h4>In 87 patients with hereditary hemochromatosis, osteoporosis was detected in 25%, and osteopenia in 41%. Bone mineral density was independently associated with BMI, ALP levels, hypogonadism/menopause, and the amount of iron removed to reach depletion, but not with cirrhosis. Osteoporosis is influenced by iron overload in hemochromatosis.<h4>Introduction</h4>To analyze prevalence, clinical characteristics and genetic background associated with osteoporosis in a retrospective study in Italian patients with hereditary hemochromatosis (HHC).<h4>Methods</h4>In 87 consecutive patients with HHC, bone mineral density was systematically evaluated by dual energy x-ray absorptiometry of the lumbar spine (n = 87) and femoral neck (n = 66).<h4>Results</h4>Osteoporosis was detected in 22 (25.3%), and osteopenia in 36 (41.4%) patients. Mean Z scores were -0.92 +/- 1.42 at lumbar spine and -0.35 +/- 1.41 at femoral neck. Lumbar spine T-score was independently associated with total ALP (p = 0.002), hypogonadism/menopause (p = 0.026), and iron overload (p = 0.033 for ferritin and p = 0.017 for iron removed). We observed a borderline significance for BMI (p = 0.069) and smoking status (p = 0.086). Lumbar spine osteoporosis was independently associated with lower BMI (OR 0.73, 95% CI 0.54-0.94), total ALP (OR 1.17, 95% CI 1-1.39 per 10 unit increase) and the amount of iron removed (OR 1.53, 95% CI 1-2.5 per 5 g increase). HFE genotypes did not differ between patients with and without osteoporosis.<h4>Conclusions</h4>Osteoporosis is observed in a quarter of unselected patients with HHC, independently of the genetic background, and is associated with ALP, hypogonadism, body weight, and severity of iron overload.
Also flagged:APCFen-1tumorsbase excision repairflap endonuclease 1cytoplasm
Journal Article2008-07-26✓ 1 SnippetJaiswal AS, Narayan S.
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Prevailing literature suggests diversified cellular functions for the adenomatous polyposis coli (APC) gene. Among them a recently discovered unique role of APC is in DNA repair. The APC gene can modulate the base excision repair (BER) pathway through an interaction with DNA polymerase beta (Pol-beta) and flap endonuclease 1 (Fen-1). Taken together with the transcriptional activation of APC gene by alkylating agents and modulation of BER activity, APC may play an important role in carcinogenesis and chemotherapy by determining whether cells with DNA damage survive or undergo apoptosis. In this review, we summarize the evidence supporting this novel concept and suggest that these results will have implications for the development of more effective strategies for chemoprevention, prognosis and chemotherapy of certain types of tumors.
Also flagged:cancercell growthdipeptidefloxuridineDipeptide monoestermetabolism
Journal Article2008-07-25No SnippetsTsume Y, Hilfinger JM, Amidon GL.
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Dipeptide monoester prodrugs of floxuridine were synthesized, and their chemical stability in buffers, resistance to glycosidic bond metabolism, affinity for PEPT1, enzymatic activation and permeability in cancer cells were determined and compared to those of mono amino acid monoester floxuridine prodrugs. Prodrugs containing glycyl moieties were the least stable in pH 7.4 buffer ( t 1/2 < 100 min). The activation of all floxuridine prodrugs was 2- to 30-fold faster in cell homogenates than their hydrolysis in buffer, suggesting enzymatic action. The enzymatic activation of dipeptide monoester prodrugs containing aromatic promoieties in cell homogenates was 5- to 20-fold slower than that of other dipeptide and most mono amino acid monoester prodrugs ( t 1/2 approximately 40 to 100 min). All prodrugs exhibited enhanced resistance to glycosidic bond metabolism by thymidine phosphorylase compared to parent floxuridine. In general, the 5'-O-dipeptide monoester floxuridine prodrugs exhibited higher affinity for PEPT1 than the corresponding 5'-O-mono amino acid ester prodrugs. The permeability of dipeptide monoester prodrugs across Caco-2 and Capan-2 monolayers was 2- to 4-fold higher than the corresponding mono amino acid ester prodrug. Cell proliferation assays in AsPC-1 and Capan-2 pancreatic ductal cell lines indicated that the dipeptide monoester prodrugs were equally as potent as mono amino acid prodrugs. The transport and enzymatic profiles of 5'- l-phenylalanyl- l-tyrosyl-floxuridine, 5'- l-phenylalanyl- l-glycyl-floxuridine, and 5'- l-isoleucyl- l-glycyl-floxuridine suggest their potential for increased oral uptake, delayed enzymatic bioconversion and enhanced resistance to metabolism to 5-fluorouracil, as well as enhanced uptake and cytotoxic activity in cancer cells, attributes that would facilitate prolonged systemic circulation for enhanced therapeutic action.
A number of lines of evidence suggest that senescence of normal human diploid fibroblasts (HDFs) in culture is relevant to the process of aging in vivo. Using normal human skin diploid fibroblasts, we examine the changes in genes and proteins following treatment with a mild dose of H2O2, which induces premature senescence. Multidimensional Protein Identification Technology (MudPIT) in combination with mass spectrometry analyses of whole cell lysates from HDFs detected 65 proteins in control group, 48 proteins in H2O2-treated cells and 109 proteins common in both groups. In contrast, cDNA microarray analyses show 173 genes up-regulated and 179 genes down-regulated upon H2O2 treatment. Both MudPIT and cDNA microarray analyses indicate that H2O2 treatment caused elevated levels of thioredoxin reductase 1. Semi-quantitative RT-PCR and Western-blot were able to verify the finding. Out of a large number of genes or proteins detected, only a small fraction shows the overlap between the outcomes of microarray versus proteomics. The low overlap suggests the importance of considering proteins instead of transcripts when investigating the gene expression profile altered by oxidative stress.
Also flagged:chromatinnucleosomegene expressionnucleosomeshistonebinding
Journal Article2008-07-25✓ 1 SnippetStehr R, Kepper N, Rippe K, Wedemann G.
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The folding of the nucleosome chain into a chromatin fiber modulates DNA accessibility and is therefore an important factor for the control of gene expression. The fiber conformation depends crucially on the interaction between individual nucleosomes. However, this parameter has not been accurately determined experimentally, and it is affected by posttranslational histone modifications and binding of chromosomal proteins. Here, the effect of different internucleosomal interaction strengths on the fiber conformation was investigated by Monte Carlo computer simulations. The fiber geometry was modeled to fit that of chicken erythrocyte chromatin, which has been examined in numerous experimental studies. In the Monte Carlo simulation, the nucleosome shape was described as an oblate spherocylinder, and a replica exchange protocol was developed to reach thermal equilibrium for a broad range of internucleosomal interaction energies. The simulations revealed the large impact of the nucleosome geometry and the nucleosome repeat length on the compaction of the chromatin fiber. At high internucleosomal interaction energies, a lateral self-association of distant fiber parts and an interdigitation of nucleosomes were apparent. These results identify key factors for the control of the compaction and higher order folding of the chromatin fiber.
Also flagged:lipid AdisaccharideaminoTLR2TLR4cytokine
Journal Article2008-07-25No SnippetsZhang Y, Gaekwad J, Wolfert MA, Boons GJ.
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Tetra-acylated lipid As derived from Porphyromonas gingivalis LPS have been synthesized using a key disaccharide intermediate functionalized with levulinate (Lev), allyloxycarbonate (Alloc) and anomeric dimethylthexylsilyl (TDS) as orthogonal protecting groups and 9-fluorenylmethoxycarbamate (Fmoc) and azido as amino protecting groups. Furthermore, an efficient cross-metathesis has been employed for the preparation of the unusual branched R-(3)-hydroxy-13-methyltetradecanic acid and (R)-3-hexadecanoyloxy-15-methylhexadecanoic acid of P. gingivalis lipid A. Biological studies have shown that the synthetic lipid As cannot activate human and mouse TLR2 and TLR4 to produce cytokines. However, it has been found that the compounds are potent antagonist of cytokine secretion by human monocytic cells induced by enteric LPS.
Also flagged:lamivudinechronic hepatitisliver cirrhosis type Bliver cirrhosishemosiderosisLAM
Journal Article2008-07-25✓ 1 SnippetOhkoshi S, Yoshimura A, Yamamoto S, Yano M, Kurita S, Yamazaki K, Aoki YH, Yamagiwa S, Wakabayashi H, Sugiyama M, Takahashi T, Ishikawa T, Matsuda Y, Ichida T, Kamimura T, Aoyagi Y.
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I A O 0000613)
…mutations of theHFEgene using DNA…
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<h4>Purpose</h4>To study the changes in serum ferritin levels in lamivudine (LAM)-treated patients with chronic hepatitis and liver cirrhosis type B and determine whether successful treatment with LAM results in a reduction of serum ferritin levels.<h4>Methods</h4>Thirty patients with chronic hepatitis B virus (HBV) infection were followed prospectively during their treatment with LAM for 12 months. Serum HBV DNA, ferritin levels, and emergence of YMDD mutants were monitored. A case of severe liver cirrhosis with hepatic hemosiderosis that was treated successfully with LAM also is shown as a representative case.<h4>Results</h4>Serum alanine aminotransferase and ferritin levels decreased significantly more in the patients treated with LAM without YMDD mutants (n = 23) than those with mutants (n = 7). Hepatic hemosiderosis along with serum iron markers improved greatly in the representative patient.<h4>Conclusion</h4>Successful treatment with LAM may reduce serum ferritin levels and improve hepatic siderosis in a subset of patients with chronic HBV infection.
Also flagged:endoplasmic reticulumphosphatidylinositolSec16inositol-requiring protein 1PI4-kinase IIIαPI4K-IIIα
Journal Article2008-07-24✓ 1 SnippetFarhan H, Weiss M, Tani K, Kaufman RJ, Hauri HP.
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The biogenesis of endoplasmic reticulum (ER) exit sites (ERES) involves the formation of phosphatidylinositol-4 phosphate (PI4) and Sec16, but it is entirely unknown how ERES adapt to variations in cargo load. Here, we studied acute and chronic adaptive responses of ERES to an increase in cargo load for ER export. The acute response (within minutes) to increased cargo load stimulated ERES fusion events, leading to larger but less ERES. Silencing either PI4-kinase IIIalpha (PI4K-IIIalpha) or Sec16 inhibited the acute response. Overexpression of secretory cargo for 24 h induced the unfolded protein response (UPR), upregulated COPII, and the cells formed more ERES. This chronic response was insensitive to silencing PI4K-IIIalpha, but was abrogated by silencing Sec16. The UPR was required as the chronic response was absent in cells lacking inositol-requiring protein 1. Mathematical model simulations further support the notion that increasing ERES number together with COPII levels is an efficient way to enhance the secretory flux. These results indicate that chronic and acute increases in cargo load are handled differentially by ERES and are regulated by different factors.
Also flagged:linoleic acidestrogen receptor alphafatty acidcancerbreast cancerestrogen
Journal Article2008-07-24✓ 2 SnippetsWang LS, Huang YW, Liu S, Yan P, Lin YC.
In-Text Gene Mentions
I A O 0000606)
…CLA: conjugated linoleic acid; E2: 17β-estradiol; ERα(+): estrogen receptor α positive; ERα(-): estrogen receptor α negative; ERE: estrogen responsive element; VEGF: vascular endothelial growth factor; PTPγ: protein tyrosine phosphatase γ; ATAC: Arimidex, Tamoxifen, Alone or in Combination; ASCO: American Society of Clinical Oncology; DCC: Dextran-Coated Charcoal; FBS: fetal bovine serum; NEC: primary cultured non-cancerous human breast epithelial cells; NSC: primary cultured non-cancerous human breast stromal cells; CAEC: primary cultured cancerous human breast epithelial cells; CASC: primary cultured cancerous human breast stromal cells; Tam: 4-Hydroxytamoxifen.…
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…medium with theDCC-treated FBS.…
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<h4>Background</h4>Conjugated linoleic acid (CLA), a naturally occurring fatty acid found in ruminant products such as milk and beef, has been shown to possess anti-cancer activities in in vivo animal models and in vitro cell culture systems. In human breast cancer, the overall duration of estrogen exposure is the most important risk factor for developing estrogen-responsive breast cancer. Accordingly, it has been suggested that estrogen exposure reduces apoptosis through the up-regulation of the anti-apoptosis protein, Bcl-2. Bcl-2, an anti-apoptotic protein, regulates apoptosis and plays a crucial role in the development and growth regulation of normal and cancerous cells. Our research interest is to examine the effects of CLA on the induction of apoptosis in human breast tissues.<h4>Methods</h4>The localization of Bcl-2 in both normal and cancerous human breast tissues was determined by immunohistochemical staining and the Bcl-2 protein expression was tested by western blot analysis. Co-culture of epithelial cells and stromal cells was carried out in the presence or absence of CLA to evaluate apoptosis in the context of a cell-cell interaction.<h4>Results</h4>The results showed that both normal and cancerous breast tissues were positive for Bcl-2 staining, which was higher overall in mammary ducts but very low in the surrounding stromal compartment. Interestingly, by quantifying the western blot data, basal Bcl-2 protein levels were higher in normal breast epithelial cells than in cancerous epithelial cells. Furthermore, treatment with 17beta-estradiol (E2) stimulated growth and up-regulated Bcl-2 expression in estrogen responsive breast epithelial cells; however, these carcinogenic effects were diminished by either CLA or 4-Hydroxytamoxifen (Tam) and were suppressed further by the combination of CLA and Tam. In both one cell type cultured and co-culture systems, CLA induced cell apoptosis in ERalpha transfected MDA-MB-231 cells but not in the wild type MDA-MB-231 cells.<h4>Conclusion</h4>These data, therefore, demonstrate that ERalpha plays important roles in CLA induced apoptosis in human breast tissues.
Also flagged:cancerantibodiesovarian cancercomplement factorsEMILIN2Von Willebrand factor
Journal Article2008-07-24✓ 5 SnippetsScholler N, Gross JA, Garvik B, Wells L, Liu Y, Loch CM, Ramirez AB, McIntosh MW, Lampe PD, Urban N.
In-Text Gene Mentions
Abstract)
…PEBP1 was detected in 29 out of 30 ascites samples and discriminated ovarian cancer sera from controls (p = 0.02).…
I A O 0000615)
…In conclusion, using a novel type of biotinylated recombinant antibodies that we call biobodies, we identified complement catabolitic products, EMILIN2, Von Willebrand factor and PEBP1 or a related protein, as candidate markers for ovarian carcinoma.…
Results)
…Anti-PEBP1 center pAb ranked 17 out of 338 full length antibodies and performed better than 4 out of 8 anti-CA125 mAbs [3] in preferential binding to the serum of individual cancer patients, suggesting that PEBP1 is a marker for ovarian cancer.…
…PEBP1 detection in ascites cells, normal and tumor tissues, and tumor cell lines.…
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<h4>Background</h4>Strategies to discover circulating protein markers of ovarian cancer are urgently needed. We developed a novel technology that permits us to isolate recombinant antibodies directed against the potential serum biomarkers, to facilitate the further development of affinity reagents necessary to construct diagnostic tests.<h4>Methods</h4>This study presents a novel discovery approach based on serum immunoprecipitation with cancer-specific in vivo biotinylated recombinant antibodies (biobodies) derived from differentially selected yeast-display scFv, and analysis of the eluted serum proteins by electrophoresis and/or mass spectrometry.<h4>Results</h4>Using this strategy we identified catabolic fragments of complement factors, EMILIN2, Von Willebrand factor and phosphatidylethanolamine-binding protein 1 (PEBP1 or RKIP) in patient sera. To our knowledge, this is the first report of a soluble form of PEBP1 in human. Independent evidence for ovarian cancer-specific expression of PEBP1 in patient sera was found by ELISA assays and antibody arrays with anti-PEBP1 antibodies. PEBP1 was detected in 29 out of 30 ascites samples and discriminated ovarian cancer sera from controls (p = 0.02). Finally, we confirmed by western blots the presence of a 21-23 kDa fragment corresponding to the expected size of PEBP1 but we also showed additional bands of 38 kDa and 50-52 kDa in various tissues and cell lines.<h4>Conclusion</h4>We conclude that the novel strategy described here allows the identification of candidate biomarkers that can be variants of normally expressed proteins or that display cancer-specific post-translational modifications.
Also flagged:Rhomembranenetrin 1axonsgrowth coneRho GTPases
Journal Article2008-07-24✓ 5 SnippetsMoore SW, Correia JP, Lai Wing Sun K, Pool M, Fournier AE, Kennedy TE.
In-Text Gene Mentions
Abstract)
…Here, we show that netrin 1, through its receptor DCC, inhibits RhoA in embryonic spinal commissural neurons.…
Title)
…Rho inhibition recruitsDCCto the neuronal…
Abstract)
…through its receptorDCC, inhibits RhoA in…
Abstract)
…the netrin receptorDCCto the plasma…
Abstract)
…increased plasma membraneDCCand adhesion to…
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Molecular cues, such as netrin 1, guide axons by influencing growth cone motility. Rho GTPases are a family of intracellular proteins that regulate the cytoskeleton, substrate adhesion and vesicle trafficking. Activation of the RhoA subfamily of Rho GTPases is essential for chemorepellent axon guidance; however, their role during axonal chemoattraction is unclear. Here, we show that netrin 1, through its receptor DCC, inhibits RhoA in embryonic spinal commissural neurons. To determine whether netrin 1-mediated chemoattraction requires Rho function, we inhibited Rho signaling and assayed axon outgrowth and turning towards netrin 1. Additionally, we examined two important mechanisms that influence the guidance of axons to netrin 1: substrate adhesion and transport of the netrin receptor DCC to the plasma membrane. We found that inhibiting Rho signaling increased plasma membrane DCC and adhesion to substrate-bound netrin 1, and also enhanced netrin 1-mediated axon outgrowth and chemoattractive axon turning. Conversely, overexpression of RhoA or constitutively active RhoA inhibited axonal responses to netrin 1. These findings provide evidence that Rho signaling reduces axonal chemoattraction to netrin 1 by limiting the amount of plasma membrane DCC at the growth cone, and suggest that netrin 1-mediated inhibition of RhoA activates a positive-feedback mechanism that facilitates chemoattraction to netrin 1. Notably, these findings also have relevance for CNS regeneration research. Inhibiting RhoA promotes axon regeneration by disrupting inhibitory responses to myelin and the glial scar. By contrast, we demonstrate that axon chemoattraction to netrin 1 is not only maintained but enhanced, suggesting that this might facilitate directing regenerating axons to appropriate targets.
Also flagged:papillaechromosomeschromosomefungiform papillaenebulin-related anchoring proteinactin-binding LIM protein 1
Journal Article2008-07-24✓ 1 SnippetReiner DJ, Jan TA, Boughter JD, Li CX, Lu L, Williams RW, Waters RS.
In-Text Gene Mentions
Text
…Sox6…
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Quantitative trait loci (QTLs) analysis has been used to examine natural variation of phenotypes in the mouse somatosensory cortex, hippocampus, cerebellum, and amygdala. QTL analysis has also been utilized to map and identify genes underlying anatomical features such as muscle, organ, and body weights. However, this methodology has not been previously applied to identification of anatomical structures related to gustatory phenotypes. In this study, we used QTL analysis to map and characterize genes underlying tongue size, papillae number, and papillae area. In a set of 43 BXD recombinant inbred (RI) mice (n = 111) and 2 parental strains (C57BL/6J and DBA/2J; n = 7), we measured tongue length, width, and weight. In a subset of 23 BXD RI mice and the parental mice, we measured filiform and fungiform papillae number and fungiform papillae area. Using QTL linkage analysis (through WebQTL), we detected 2 significant and noninteracting QTLs influencing tongue length on chromosomes 5 and 7. We also found a significant QTL on chromosome 19 underlying fungiform papillae area and a suggestive QTL on chromosome 2 linked to fungiform papillae number. From these QTLs, we identified a number of candidate genes within the QTL intervals that include SRY-box containing gene, nebulin-related anchoring protein, and actin-binding LIM protein 1. This study is an important first step in identifying genetic factors underlying tongue size, papillae size, and papillae number using QTL analysis.
Also flagged:coat proteincapsidPf1glycineglutaminevirion
Journal Article2008-07-24No SnippetsLorieau JL, Day LA, McDermott AE.
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This study has examined the atomic-level dynamics of the protein in the capsid of filamentous phage Pf1. This capsid consists of approximately 7,300 small subunits of only 46 aa in a helical array around a highly extended, circular single-stranded DNA molecule of 7,349 nt. Measurements were made of site-specific, solid-state NMR order parameters, S, the values which are dimensionless quantities between 0 (mobile) and 1 (static) that characterize the amplitudes of molecular bond angular motions that are faster than microseconds. It was found that the protein subunit backbone is very static, and of particular interest, it appears to be static at residues glycine 15 and glutamine 16 where it had been previously thought to be mobile. In contrast to the backbone, several side chains display large-amplitude angular motions. Side chains on the virion exterior that interact with solvent are highly mobile, but surprisingly, the side chains of residues arginine 44 and lysine 45 near the DNA deep in the interior of the virion are also highly mobile. The large-amplitude dynamic motion of these positively charged side chains in their interactions with the DNA were not previously expected. The results reveal a highly dynamic aspect of a DNA-protein interface within a virus.
…However, superdonors heterozygous for the H63D mutation in HFE had significantly decreased hepcidin : ferritin ratios demonstrating for the first time that the heterozygous state for HFE mutations is associated with alterations in hepcidin expression.…
Abstract)
…Mutations in HFE associated with hemochromatosis were present in superdonors at the same frequency as the normal population.…
<h4>Background</h4>Individuals donating whole blood 13 times in a 2-year period without development of iron deficiency anemia (superdonors) are a self-selected population that is deferred for low hematocrit (Hct) level less frequently than other donors.<h4>Study design and methods</h4>Iron metabolism was assessed in 138 superdonors through a questionnaire and measurement of Hct, serum ferritin, serum hepcidin, and serum growth differentiation factor 15 (GDF15). Genetic testing for HFE and JAK-2 mutations was also performed.<h4>Results and conclusions</h4>Iron deficiency (ferritin level, <30 microg/L) is present in more than 60 percent of superdonors. Behaviors altering iron status included casual use of iron supplements in males, but not in females, and cigarette smoking that produced increased Hct associated with decreased ferritin. The striking biochemical characteristic of superdonors is greatly decreased serum hepcidin, consistent with their need to absorb maximal amounts of dietary iron to replace that lost from blood donation. GDF15 is normal in most superdonors, indicating that GDF15 overexpression arising from the expanded erythroid pool necessary to replace donated red cells is not the biochemical mechanism for the decreased serum hepcidin. Mutations in JAK-2 were not found, indicating that undiagnosed polycythemia vera is not a common cause for successful repeated blood donation by superdonors. Mutations in HFE associated with hemochromatosis were present in superdonors at the same frequency as the normal population. However, superdonors heterozygous for the H63D mutation in HFE had significantly decreased hepcidin : ferritin ratios demonstrating for the first time that the heterozygous state for HFE mutations is associated with alterations in hepcidin expression.
Also flagged:schizophreniabehavioral disturbancesadult-onset disordersbehavioralcognitionschizophreniform disorder
Journal Article2008-07-24✓ 1 SnippetWelham J, Isohanni M, Jones P, McGrath J.
In-Text Gene Mentions
Text
…5-HTT…
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<h4>Background</h4>Birth cohort (BC) studies demonstrate that individuals who develop schizophrenia differ from the general population on a range of developmental indices. The aims of this article were to summarize key findings from BC studies in order to identify areas of convergence and to outline areas requiring further research.<h4>Method</h4>We define BC studies as studies based on general population BCs where data are collected prospectively from birth or childhood and which identify schizophrenia or related disorders as an outcome. To identify such studies, we searched various electronic databases using the search parameters (schizo* OR psych*) AND (birth cohort). We also checked the references of relevant articles and previous reviews.<h4>Results</h4>We identified 11 BCs from 7 countries that have examined schizophrenia as an outcome in adulthood. There is relatively consistent evidence that, as a group, children who later develop schizophrenia have behavioral disturbances and psychopathology, intellectual and language deficits, and early motor delays. Evidence with respect to alterations in language, educational performance, and physical growth has also been identified in some studies. BC studies have also contributed evidence about a wide range of putative risk factors for schizophrenia.<h4>Conclusions</h4>BC studies have provided important, convergent insights into how the developmental trajectory of individuals who develop schizophrenia differs from their peers. The combination of new paradigms and larger cohorts, with the tools of modern epidemiology and biomedical science, is advancing our understanding of the developmental pathways to schizophrenia.
Also flagged:acid-sensing ion channel 1Huntington's diseaseubiquitinproteasomeHDneurodegenerative disorder
Journal Article2008-07-24✓ 4 SnippetsWong HK, Bauer PO, Kurosawa M, Goswami A, Washizu C, Machida Y, Tosaki A, Yamada M, Knöpfel T, Nakamura T, Nukina N.
In-Text Gene Mentions
Abstract)
…Ben markedly reduced the huntingtin-polyglutamine (htt-polyQ) aggregation in an inducible cellular system, and the therapeutic value of Ben was successfully recapitulated in the R6/2 animal model of HD.…
Abstract)
…the huntingtin-polyglutamine (htt-polyQ) aggregation in an…
Abstract)
…degradation of solublehtt-polyQ specifically in its…
Abstract)
…blockade also decreasedhtt-polyQ aggregation in the…
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Huntington's disease (HD) is a fatal neurodegenerative disorder. Despite a tremendous effort to develop therapeutic tools in several HD models, there is no effective cure at present. Acidosis has been observed previously in cellular and in in vivo models as well as in the brains of HD patients. Here we challenged HD models with amiloride (Ami) derivative benzamil (Ben), a chemical agent used to rescue acid-sensing ion channel (ASIC)-dependent acidotoxicity, to examine whether chronic acidosis is an important part of the HD pathomechanism and whether these drugs could be used as novel therapeutic agents. Ben markedly reduced the huntingtin-polyglutamine (htt-polyQ) aggregation in an inducible cellular system, and the therapeutic value of Ben was successfully recapitulated in the R6/2 animal model of HD. To reveal the mechanism of action, Ben was found to be able to alleviate the inhibition of the ubiquitin-proteasome system (UPS) activity, resulting in enhanced degradation of soluble htt-polyQ specifically in its pathological range. More importantly, we were able to demonstrate that blocking the expression of a specific isoform of ASIC (asic1a), one of the many molecular targets of Ben, led to an enhancement of UPS activity and this blockade also decreased htt-polyQ aggregation in the striatum of R6/2 mice. In conclusion, we believe that chemical compounds that target ASIC1a or pharmacological alleviation of UPS inhibition would be an effective and promising approach to combat HD and other polyQ-related disorders.
Also flagged:Nod2Nucleotide oligomerisation domain 2innate immunitygastroenteritisadenolymphitissepticaemia
Journal Article2008-07-23✓ 1 SnippetMeinzer U, Esmiol-Welterlin S, Barreau F, Berrebi D, Dussaillant M, Bonacorsi S, Chareyre F, Niwa-Kawakita M, Alberti C, Sterkers G, Villard C, Lesuffleur T, Peuchmaur M, Karin M, Eckmann L, Giovannini M, Ollendorff V, Wolf-Watz H, Hugot JP.
In-Text Gene Mentions
Introduction)
…in patients withhemochromatosis, however, enteric Yersinia…
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Nucleotide oligomerisation domain 2 (NOD2) is a component of the innate immunity known to be involved in the homeostasis of Peyer patches (PPs) in mice. However, little is known about its role during gut infection in vivo. Yersinia pseudotuberculosis is an enteropathogen causing gastroenteritis, adenolymphitis and septicaemia which is able to invade its host through PPs. We investigated the role of Nod2 during Y. pseudotuberculosis infection. Death was delayed in Nod2 deleted and Crohn's disease associated Nod2 mutated mice orogastrically inoculated with Y. pseudotuberculosis. In PPs, the local immune response was characterized by a higher KC level and a more intense infiltration by neutrophils and macrophages. The apoptotic and bacterial cell counts were decreased. Finally, Nod2 deleted mice had a lower systemic bacterial dissemination and less damage of the haematopoeitic organs. This resistance phenotype was lost in case of intraperitoneal infection. We concluded that Nod2 contributes to the susceptibility to Y. pseudotuberculosis in mice.
Also flagged:viral infectioninfectionvirionamantadineinfluenza infectionprimary infection
Journal Article2008-07-23No SnippetsBeauchemin CA, McSharry JJ, Drusano GL, Nguyen JT, Went GT, Ribeiro RM, Perelson AS.
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We analyzed the dynamics of an influenza A/Albany/1/98 (H3N2) viral infection, using a set of mathematical models highlighting the differences between in vivo and in vitro infection. For example, we found that including virion loss due to cell entry was critical for the in vitro model but not for the in vivo model. Experiments were performed on influenza virus-infected MDCK cells in vitro inside a hollow-fiber (HF) system, which was used to continuously deliver the drug amantadine. The HF system captures the dynamics of an influenza infection, and is a controlled environment for producing experimental data which lend themselves well to mathematical modeling. The parameter estimates obtained from fitting our mathematical models to the HF experimental data are consistent with those obtained earlier for a primary infection in a human model. We found that influenza A/Albany/1/98 (H3N2) virions under normal experimental conditions at 37 degrees C rapidly lose infectivity with a half-life of approximately 6.6+/-0.2 h, and that the lifespan of productively infected MDCK cells is approximately 13 h. Finally, using our models we estimated that the maximum efficacy of amantadine in blocking viral infection is approximately 74%, and showed that this low maximum efficacy is likely due to the rapid development of drug resistance.
The thiazolidinone 3-[(3-trifluoromethyl)phenyl]-5-[(4-carboxyphenyl)methylene]-2-thioxo-4-thiazolidinone (CFTR(inh)-172) inhibits cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel conductance with submicromolar affinity and blocks cholera toxin-induced intestinal fluid secretion. Fifty-eight CFTR(inh)-172 analogs were synthesized to identify CFTR inhibitors with improved water solubility, exploring modifications in its two phenyl rings, thiazolidinone core, and core-phenyl connectors. Greatest CFTR inhibition potency was found for 3-CF(3) and polar group-substituted-phenyl rings, and a thiazolidinone core. Two compounds with approximately 1muM CFTR inhibition potency and solubility >180 microM (>10-fold more than CFTR(inh)-172) were identified: Tetrazolo-172, containing 4-tetrazolophenyl in place of 4-carboxyphenyl, and Oxo-172, containing thiazolidinedione in place of the thiazolidinone core. These water soluble thiazolidinone analogs had low cellular toxicity. The improved water solubility of Tetrazolo- and Oxo-172 make them potential lead candidates for therapy of secretory diarrheas and polycystic kidney disease.
…These results are comparable to the behavioral data of the 5-HTT null mutant mice, which demonstrated a range of behavioral and neurophysiological abnormalities that resemble symptoms of mood and anxiety disorders [31].…
Introduction)
…SSRIs, like fluoxetine and fluvoxamine, inhibit the reuptake of serotonin (5-hydroxytryptamine or 5-HT) into the presynaptic neuron by binding to the serotonin transporter (5-HTT), which results in an increase of synaptic serotonin levels.…
Results)
…No statistical significant reductions of 5-HTT binding in the raphe nucleus were observed after prenatal fluvoxamine exposure at either P20 (N = 6) or adult (N = 6).…
Introduction)
…the serotonin transporter (5-HTT), which results in…
Results)
…specifically to the5-HTT, 5-HTT levels may…
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<h4>Background</h4>Women are at great risk for mood and anxiety disorders during their childbearing years and may become pregnant while taking antidepressant drugs. In the treatment of depression and anxiety disorders, selective serotonin reuptake inhibitors (SSRIs) are the most frequently prescribed drugs, while it is largely unknown whether this medication affects the development of the central nervous system of the fetus. The possible effects are the product of placental transfer efficiency, time of administration and dose of the respective SSRI.<h4>Methodology/principal findings</h4>In order to attain this information we have setup a study in which these parameters were measured and the consequences in terms of physiology and behavior are mapped. The placental transfer of fluoxetine and fluvoxamine, two commonly used SSRIs, was similar between mouse and human, indicating that the fetal exposure of these SSRIs in mice is comparable with the human situation. Fluvoxamine displayed a relatively low placental transfer, while fluoxetine showed a relatively high placental transfer. Using clinical doses of fluoxetine the mortality of the offspring increased dramatically, whereas the mortality was unaffected after fluvoxamine exposure. The majority of the fluoxetine-exposed offspring died postnatally of severe heart failure caused by dilated cardiomyopathy. Molecular analysis of fluoxetine-exposed offspring showed long-term alterations in serotonin transporter levels in the raphe nucleus. Furthermore, prenatal fluoxetine exposure resulted in depressive- and anxiety-related behavior in adult mice. In contrast, fluvoxamine-exposed mice did not show alterations in behavior and serotonin transporter levels. Decreasing the dose of fluoxetine resulted in higher survival rates and less dramatic effects on the long-term behavior in the offspring.<h4>Conclusions</h4>These results indicate that prenatal fluoxetine exposure affects fetal development, resulting in cardiomyopathy and a higher vulnerability to affective disorders in a dose-dependent manner.
Also flagged:methylated cytosinechromatinMBDbindingdinucleotidemethyl
Journal Article2008-07-22✓ 1 SnippetDhasarathy A, Wade PA.
In-Text Gene Mentions
Text
…linker histones…
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A family of proteins conserved throughout the eukaryotic lineage is characterized by the presence of a common sequence motif-the methyl-CpG-binding domain, or MBD. This sequence motif corresponds to a structural domain which, in some but not all cases, confers the ability to bind methylated cytosine residues in the context of the dinucleotide 5' CG 3'. Mammals have five well-characterized members of this family, each with unique biological characteristics. Recently, much progress has been made in defining the biochemical properties of one member of this family, MeCP2. This protein has a very high affinity for chromatin and considerable insight has been gained into its interactions with naked DNA and with chromatin fibers. Previous models have proposed that several members of the MBD family contribute to establishment and/or maintenance of transcriptional repression by recruiting enzymes that locally modify histones. Surprisingly, recent data indicate that MeCP2 is likely to contribute to chromatin properties through an architectural role, participating in higher order chromatin structures that facilitate both gene repression as well as gene activation. These observations suggest that existing models probably do not explain the entire gamut of biological functions performed by this very interesting protein family.
Also flagged:serotonin transporterpsychiatric disordersactivitySLC6A45
Journal Article2008-07-22✓ 3 SnippetsNoskova T, Pivac N, Nedic G, Kazantseva A, Gaysina D, Faskhutdinova G, Gareeva A, Khalilova Z, Khusnutdinova E, Kovacic DK, Kovacic Z, Jokic M, Seler DM.
In-Text Gene Mentions
Abstract)
…The serotonin transporter (5-HTT) is a protein…
Abstract)
…activity of the5-HTTgene (5-HTT or…
Abstract)
…the 5-HTT gene (5-HTTor SLC6A4) is…
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The serotonin transporter (5-HTT) is a protein that has a major role in divergent psychiatric disorders, personality traits and behaviors, by regulating serotonergic synaptic function. Transcriptional activity of the 5-HTT gene (5-HTT or SLC6A4) is modulated by a polymorphic repetitive element (5-HTT gene-linked polymorphic region, 5-HTTLPR), which consists of a 44-base pairs insertion-deletion in the promoter region, creating a short (S) allele and a long (L) allele. Ethnic differences in the allele frequencies of the 5-HTTLPR exist between Caucasian and Asian populations. This study investigated ethnic differences in 5-HTTLPR in 1804 healthy Caucasian subjects from several European populations living in Croatia and the Russian Federation. The genotype and allele frequency of the 5-HTTLPR differed significantly (P<0.001) between male and female Croats, Russians, Tatars and Bashkirs, due to the lower frequency of the S allele (38% and 37%) and S/S genotype (14% and 15%) in Croat men and women compared to other studied groups. When male and female data were collapsed, Russians had marginally different allele and genotype distribution compared to Bashkirs and Tatars. Bashkirs and Tatars had similar allele and genotype frequency. The higher frequency of the S/S genotype was found in Tatars and Bashkirs compared to Croats and Russians. Gender related differences occurred only in the allele distribution within Bashkir population. These ethnic differences might be responsible for the inconsistent findings in the studies of the association between various psychiatric disorders, personality traits, behaviors and 5-HTTLPR across different ethnicities, and should be controlled to enable the generalization of results across various population groups.
Also flagged:P2Y nucleotide receptorsnucleotidealkaline phosphatasenucleoside triphosphate diphosphohydrolasesP2Y 1 receptorNTPDase1
Journal Article2008-07-22No SnippetsEliahu SE, Camden J, Lecka J, Weisman GA, Sévigny J, Gélinas S, Fischer B.
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P2Y nucleotide receptors (P2YRs) are attractive pharmaceutical targets. Most P2YR agonists proposed as drugs consist of a nucleotide scaffold, but their use is limited due to their chemical and enzymatic instabilities. To identify drug candidates, we developed non-hydrolyzable P2YR agonists. We synthesized ATP-beta,gamma-CH(2) analogues 2-4, and evaluated their chemical and metabolic stabilities and activities at P2Y(1,2,4,6) receptors. Analogues 2-4 exhibited t(1/2) values of 14.5-65 h in gastric juice pH. They were completely resistant to alkaline phosphatase for 30 min at 37 degrees C and slowly hydrolyzed in human blood serum (t(1/2) 12.7-71.9 h). In comparison to ATP, analogues 2-4 were barely hydrolyzed by nucleoside triphosphate diphosphohydrolases, NTPDase1,2,3,8 (< 8% hydrolysis), and nucleotide pyrophosphatases, NPP1,3 (< or = 10% hydrolysis). Analogues 2 and 4B were selective agonists of the P2Y(1)R with EC(50)s of 0.08 and 17.2 microM, respectively. These features make analogues 2 and 4B potential therapeutic agents for health disorders involving the P2Y(1)R.
Also flagged:tumourbreast cancertumourscancercell cyclecell proliferation
Journal Article2008-07-21No SnippetsUbezio P, Cameron D.
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<h4>Background</h4>Despite the recent development of technologies giving detailed images of tumours in vivo, direct or indirect ways to measure how many cells are actually killed by a treatment or are resistant to it are still beyond our reach.<h4>Methods</h4>We designed a simple model of tumour progression during treatment, based on descriptions of the key phenomena of proliferation, quiescence, cell killing and resistance, and giving as output the macroscopically measurable tumour volume and growth fraction. The model was applied to a database of the time course of volumes of breast cancer in patients undergoing pre-operative chemotherapy, for which the initial estimate of proliferating cells by the measure of the percentage of Ki67-positive cells was available.<h4>Results</h4>The analysis recognises different patterns of response to treatment. In one subgroup of patients the fitting implied drug resistance. In another subgroup there was a shift to higher sensitivity during the therapy. In the subgroup of patients where killing of cycling cells had the highest score, the drugs showed variable efficacy against quiescent cells.<h4>Conclusion</h4>The approach was feasible, providing items of information not otherwise available. Additional data, particularly sequential Ki67 measures, could be added to the system, potentially reducing uncertainty in estimates of parameter values.
Also flagged:Breast cancercell proliferationestrogen receptorestrogenERβ(ER) α
Journal Article2008-07-21✓ 1 SnippetSotoca AM, van den Berg H, Vervoort J, van der Saag P, Ström A, Gustafsson JA, Rietjens I, Murk AJ.
In-Text Gene Mentions
Methods)
…Cultured U2OS cells were washed with PBS, trypsinized, and seeded in transparent 96-well plates (Greiner) at 100 μl/well at a density of 10 × 104 cells/ml (U2OS-ERα) or 7.5 × 104 cells/ml (U2OS-ERβ) in a 1:1 mixture of DMEM and Ham's F12 medium without phenol red, buffered with 1260 mg/l NaHCO3, and supplemented with 5% DCC-FCS and 0.5% nonessential amino acids.…
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Breast cancer cells show overexpression of estrogen receptor (ER) alpha relative to ERbeta compared to normal breast tissues. This observation has lead to the hypothesis that ERbeta may modulate the proliferative effect of ERalpha. This study investigated how variable cellular expression ratios of the ERalpha and ERbeta modulate the effects on cell proliferation induced by ERalpha or ERbeta agonists, respectively. Using human osteosarcoma (U2OS) ERalpha or ERbeta reporter cells, propyl-pyrazole-triol (PPT) was shown to be a selective ERalpha and diarylpropionitrile (DPN) a preferential ERbeta modulator. The effects of these selective estrogen receptor modulators (SERMs) and of the model compound E2 on the proliferation of T47D human breast cancer cells with tetracycline-dependent expression of ERbeta (T47D-ERbeta) were characterized. E2-induced cell proliferation of cells in which ERbeta expression was inhibited was similar to that of the T47D wild-type cells, whereas this E2-induced cell proliferation was no longer observed when ERbeta expression in the T47D-ERbeta cells was increased. In the T47D-ERbeta cell line, DPN also appeared to be able to suppress cell proliferation when levels of ERbeta expression were high. In the T47D-ERbeta cell line, PPT was unable to suppress cell proliferation at all ratios of ERalpha/ERbeta expression, reflecting its ability to activate only ERalpha and not ERbeta. It is concluded that effects of estrogen-like compounds on cell proliferation are dependent on the actual ERalpha/ERbeta expression levels in these cells or tissues and the potential of the estrogen agonists to activate ERalpha and/or ERbeta.
Also flagged:Tir8SigirrlupusToll-like receptorTLRinterleukin 1 receptor
Journal Article2008-07-21✓ 1 SnippetLech M, Kulkarni OP, Pfeiffer S, Savarese E, Krug A, Garlanda C, Mantovani A, Anders HJ.
In-Text Gene Mentions
S I O 001029)
…Recently, systematic genome-wide studies on multiple multiethnical cohorts of lupus patients have identified genetic variants in genes like IRF5, BANK1, ITGAM, TNFSF4, and STAT4 by mapping genomic regions associated with human systemic LE (SLE) (6–11).…
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The Sigirr gene (also known as Tir8) encodes for an orphan receptor of the Toll-like receptor (TLR)/interleukin 1 receptor family that inhibits TLR-mediated pathogen recognition in dendritic cells. Here, we show that Sigirr also inhibits the activation of dendritic cells and B cells upon exposure to RNA and DNA lupus autoantigens. To evaluate the functional role of Sigirr in the pathogenesis of systemic lupus erythematosus (SLE), we generated Sigirr-deficient C57BL/6-lpr/lpr mice. These mice developed a progressive lymphoproliferative syndrome followed by severe autoimmune lung disease and lupus nephritis within 6 mo of age as compared with the minor abnormalities observed in C57BL/6-lpr/lpr mice. Lack of Sigirr was associated with enhanced activation of dendritic cells and increased expression of multiple proinflammatory and antiapoptotic mediators. In the absence of Sigirr, CD4 T cell numbers were increased and CD4(+)CD25(+) T cell numbers were reduced. Furthermore, lack of Sigirr enhanced the activation and proliferation of B cells, including the production of autoantibodies against multiple nuclear lupus autoantigens. These data identify Sigirr as a novel SLE susceptibility gene in mice.
We identified a unique family with autosomal dominant heart disease variably expressed as restrictive cardiomyopathy (RCM), hypertrophic cardiomyopathy (HCM), and dilated cardiomyopathy (DCM), and sought to identify the molecular defect that triggered divergent remodeling pathways. Polymorphic DNA markers for nine sarcomeric genes for DCM and/or HCM were tested for segregation with disease. Linkage to eight genes was excluded, but a cardiac troponin T (TNNT2) marker cosegregated with the disease phenotype. Sequencing of TNNT2 identified a heterozygous missense mutation resulting in an I79N substitution, inherited by all nine affected family members but by none of the six unaffected relatives. Mutation carriers were diagnosed with RCM (n = 2), non-obstructive HCM (n = 3), DCM (n = 2), mixed cardiomyopathy (n = 1), and mild concentric left ventricular hypertrophy (n = 1). Endomyocardial biopsy in the proband revealed non-specific fibrosis, myocyte hypertrophy, and no myofibrillar disarray. Restrictive Doppler filling patterns, atrial enlargement, and pulmonary hypertension were observed among family members regardless of cardiomyopathy subtype. Mutation of a sarcomeric protein gene can cause RCM, HCM, and DCM within the same family, underscoring the necessity of comprehensive morphological and physiological cardiac assessment in familial cardiomyopathy screening.
Also flagged:Hdac1gene expressionchromatin remodellingtranscriptional repressorHistone deacetylase 1organogenesis
Journal Article2008-07-21✓ 2 SnippetsNoël ES, Casal-Sueiro A, Busch-Nentwich E, Verkade H, Dong PD, Stemple DL, Ober EA.
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…Glucose-regulated interactions between Hdac1/2, Pdx1 and/or Sox6 have been suggested to control insulin gene expression in mouse insulinoma cell lines (Iguchi et al., 2007; Mosley and Ozcan, 2004).…
Discussion)
…Hdac1/2, Pdx1 and/orSox6have been suggested…
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Liver, pancreas and lung originate from the presumptive foregut in temporal and spatial proximity. This requires precisely orchestrated transcriptional activation and repression of organ-specific gene expression within the same cell. Here, we show distinct roles for the chromatin remodelling factor and transcriptional repressor Histone deacetylase 1 (Hdac1) in endodermal organogenesis in zebrafish. Loss of Hdac1 causes defects in timely liver specification and in subsequent differentiation. Mosaic analyses reveal a cell-autonomous requirement for hdac1 within the hepatic endoderm. Our studies further reveal specific functions for Hdac1 in pancreas development. Loss of hdac1 causes the formation of ectopic endocrine clusters anteriorly to the main islet, as well as defects in exocrine pancreas specification and differentiation. In addition, we observe defects in extrahepatopancreatic duct formation and morphogenesis. Finally, loss of hdac1 results in an expansion of the foregut endoderm in the domain from which the liver and pancreas originate. Our genetic studies demonstrate that Hdac1 is crucial for regulating distinct steps in endodermal organogenesis. This suggests a model in which Hdac1 may directly or indirectly restrict foregut fates while promoting hepatic and exocrine pancreatic specification and differentiation, as well as pancreatic endocrine islet morphogenesis. These findings establish zebrafish as a tractable system to investigate chromatin remodelling factor functions in controlling gene expression programmes in vertebrate endodermal organogenesis.
Also flagged:gene expressionenoxacindegradationRNA-binding proteinpenicillinstreptomycin
Journal Article2008-07-20No SnippetsShan G, Li Y, Zhang J, Li W, Szulwach KE, Duan R, Faghihi MA, Khalil AM, Lu L, Paroo Z, Chan AW, Shi Z, Liu Q, Wahlestedt C, He C, Jin P.
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Small interfering RNAs (siRNAs) and microRNAs (miRNAs) are sequence-specific post-transcriptional regulators of gene expression. Although major components of the RNA interference (RNAi) pathway have been identified, regulatory mechanisms for this pathway remain largely unknown. Here we demonstrate that the RNAi pathway can be modulated intracellularly by small molecules. We have developed a cell-based assay to monitor the activity of the RNAi pathway and find that the small-molecule enoxacin (Penetrex) enhances siRNA-mediated mRNA degradation and promotes the biogenesis of endogenous miRNAs. We show that this RNAi-enhancing activity depends on the trans-activation-responsive region RNA-binding protein. Our results provide a proof-of-principle demonstration that small molecules can be used to modulate the activity of the RNAi pathway. RNAi enhancers may be useful in the development of research tools and therapeutics.
…Autophagy is a major clearance pathway for the removal of mutant huntingtin associated with HD, and many other disease-causing, cytoplasmic, aggregate-prone proteins.…
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The formation of intra-neuronal mutant protein aggregates is a characteristic of several human neurodegenerative disorders, like Alzheimer's disease, Parkinson's disease (PD) and polyglutamine disorders, including Huntington's disease (HD). Autophagy is a major clearance pathway for the removal of mutant huntingtin associated with HD, and many other disease-causing, cytoplasmic, aggregate-prone proteins. Autophagy is negatively regulated by the mammalian target of rapamycin (mTOR) and can be induced in all mammalian cell types by the mTOR inhibitor rapamycin. It can also be induced by a recently described cyclical mTOR-independent pathway, which has multiple drug targets, involving links between Ca(2+)-calpain-G(salpha) and cAMP-Epac-PLC-epsilon-IP(3) signalling. Both pathways enhance the clearance of mutant huntingtin fragments and attenuate polyglutamine toxicity in cell and animal models. The protective effects of rapamycin in vivo are autophagy-dependent. In Drosophila models of various diseases, the benefits of rapamycin are lost when the expression of different autophagy genes is reduced, implicating that its effects are not mediated by autophagy-independent processes (like mild translation suppression). Also, the mTOR-independent autophagy enhancers have no effects on mutant protein clearance in autophagy-deficient cells. In this review, we describe various drugs and pathways inducing autophagy, which may be potential therapeutic approaches for HD and related conditions.
Also flagged:RosiglitazonePPARtranscription factorsinsulin-dependent diabetesmitochondrialHuntington disease
Journal Article2008-07-18No SnippetsQuintanilla RA, Jin YN, Fuenzalida K, Bronfman M, Johnson GVW.
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Peroxisome proliferator-activated receptor-gamma (PPARgamma) is a member of the PPAR family of transcription factors. Synthetic PPARgamma agonists are used as oral anti-hyperglycemic drugs for the treatment of non-insulin-dependent diabetes. However, emerging evidence indicates that PPARgamma activators can also prevent or attenuate neurodegeneration. Given these previous findings, the focus of this report is on the potential neuroprotective role of PPARgamma activation in preventing the loss of mitochondrial function in Huntington disease (HD). For these studies we used striatal cells that express wild-type (STHdh(Q7/Q7)) or mutant (STHdh(Q111/Q111)) huntingtin protein at physiological levels. Treatment of mutant cells with thapsigargin resulted in a significant decrease in mitochondrial calcium uptake, an increase in reactive oxygen species production, and a significant decrease in mitochondrial membrane potential. PPARgamma activation by rosiglitazone prevented the mitochondrial dysfunction and oxidative stress that occurred when mutant striatal cells were challenged with pathological increases in calcium. The beneficial effects of rosiglitazone were likely mediated by activation of PPARgamma, as all protective effects were prevented by the PPARgamma antagonist GW9662. Additionally, the PPARgamma signaling pathway was significantly impaired in the mutant striatal cells with decreases in PPARgamma expression and reduced PPARgamma transcriptional activity. Treatment with rosiglitazone increased mitochondrial mass levels, suggesting a role for the PPARgamma pathway in mitochondrial function in striatal cells. Altogether, this evidence indicates that PPARgamma activation by rosiglitazone attenuates mitochondrial dysfunction in mutant huntingtin-expressing striatal cells, and this could be an important therapeutic avenue to ameliorate the mitochondrial dysfunction that occurs in HD.
Also flagged:neurodegenerative disordersADPDneurodegenerative diseasespathogenesisAlzheimer's
Journal Article2008-07-18✓ 1 SnippetSowell RA, Owen JB, Butterfield DA.
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The risk of developing neurodegenerative disorders such as Alzheimer's disease (AD) and Parkinson's disease (PD) increases with age. AD and PD are the two most common neurodegenerative diseases that currently affect millions of persons within the United States population. While many clues about the mechanisms of these disorders have been uncovered, to date, the molecular mechanisms associated with the cause of these diseases are not completely understood. Furthermore, there are no available cures or preventive treatments for either disorder. Animal models of AD and PD, though not perfect, offer a means to gain knowledge of the basic biochemistry associated with these disorders and with drug efficacy. The field of proteomics which focuses on identifying the dynamic nature of the protein content expressed within a particular cell, tissue, or organism, has provided many insights into these disturbing disorders. Proteomic studies have revealed many pathways that are associated with disease pathogenesis and that may lead to the development of potential therapeutic targets. This review provides a discussion of key findings from AD and PD proteomics-based studies in various animal models of disease.
Also flagged:mitoticmitosischromosomespindleorganizationkinetochore
Journal Article2008-07-18✓ 1 SnippetSomma MP, Ceprani F, Bucciarelli E, Naim V, De Arcangelis V, Piergentili R, Palena A, Ciapponi L, Giansanti MG, Pellacani C, Petrucci R, Cenci G, Vernì F, Fasulo B, Goldberg ML, Di Cunto F, Gatti M.
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S I O 001029)
…Main phenotypic traits: NDC no dividing cells; CAB chromosome aberrations; ACC abnormal chromosome condensation; PCS precocious sister chromatid separation; DCC defective chromosome congression at metaphase; HCC hypercontracted chromosomes; LFA, low relative frequency of anaphases; DCS defective chromosome segregation following sister chromatid separation; NSS no sister chromatid separation with scattered chromosomes; NSC no sister chromatid separation with chromosomes at the center of the cell; CBA chromatin bridges at anaphase; DDA, chromosome decondensation during anatelophase; LTS long anatelophase spindles; MPS monopolar spindles; DSP defective spindle poles (defective asters and/or broad poles); SSP short spindles; LMD, spindles with low MT density; OSD other spindle defects; BIN binucleated cells (cytokinesis failure); OMD, other mitotic defects.…
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RNAi screens have, to date, identified many genes required for mitotic divisions of Drosophila tissue culture cells. However, the inventory of such genes remains incomplete. We have combined the powers of bioinformatics and RNAi technology to detect novel mitotic genes. We found that Drosophila genes involved in mitosis tend to be transcriptionally co-expressed. We thus constructed a co-expression-based list of 1,000 genes that are highly enriched in mitotic functions, and we performed RNAi for each of these genes. By limiting the number of genes to be examined, we were able to perform a very detailed phenotypic analysis of RNAi cells. We examined dsRNA-treated cells for possible abnormalities in both chromosome structure and spindle organization. This analysis allowed the identification of 142 mitotic genes, which were subdivided into 18 phenoclusters. Seventy of these genes have not previously been associated with mitotic defects; 30 of them are required for spindle assembly and/or chromosome segregation, and 40 are required to prevent spontaneous chromosome breakage. We note that the latter type of genes has never been detected in previous RNAi screens in any system. Finally, we found that RNAi against genes encoding kinetochore components or highly conserved splicing factors results in identical defects in chromosome segregation, highlighting an unanticipated role of splicing factors in centromere function. These findings indicate that our co-expression-based method for the detection of mitotic functions works remarkably well. We can foresee that elaboration of co-expression lists using genes in the same phenocluster will provide many candidate genes for small-scale RNAi screens aimed at completing the inventory of mitotic proteins.
Also flagged:obesityGSTM1GSTT1GSTP1Glutathione S -TransferaseGST
Journal Article2008-07-18✓ 1 SnippetProbst-Hensch NM, Imboden M, Felber Dietrich D, Barthélemy JC, Ackermann-Liebrich U, Berger W, Gaspoz JM, Schwartz J.
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S I O 001029)
…We have demonstrated that the acute effect of particulate matter (PM) air pollution on HRV is modified by polymorphisms in the glutathione S-transferase (GST) gene GSTM1 (Schwartz et al. 2005) and the hemochromatosis gene HFE (Park et al. 2006), both exhibiting antioxidative properties (Forsberg et al. 2001; Hayes and Strange 2000; Park et al. 2006).…
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<h4>Background</h4>Disturbances of heart rate variability (HRV) may represent one pathway by which second-hand smoke (SHS) and air pollutants affect cardiovascular morbidity and mortality. The mechanisms are poorly understood.<h4>Objectives</h4>We investigated the hypothesis that oxidative stress alters cardiac autonomic control. We studied the association of polymorphisms in oxidant-scavenging glutathione S-transferase (GST) genes and their interactions with SHS and obesity with HRV.<h4>Methods</h4>A total of 1,133 nonsmokers > 50 years of age from a population-based Swiss cohort underwent ambulatory 24-hr electrocardiogram monitoring and reported on lifestyle and medical history. We genotyped GSTM1 and GSTT1 gene deletions and a GSTP1 (Ile105Val) single nucleotide polymorphism and analyzed genotype-HRV associations by multiple linear regressions.<h4>Results</h4>Homozygous GSTT1 null genotypes exhibited an average 10% decrease in total power (TP) and low-frequency-domain HRV parameters. All three polymorphisms modified the cross-sectional associations of HRV with SHS and obesity. Homozygous GSTM1 null genotypes with > 2 hr/day of SHS exposure exhibited a 26% lower TP [95% confidence interval (CI), 11 to 39%], versus a reduction of -5% (95% CI, -22 to 17%) in subjects with the gene and the same SHS exposure compared with GSTM1 carriers without SHS exposure. Similarly, obese GSTM1 null genotypes had, on average, a 22% (95% CI, 12 to 31%) lower TP, whereas with the gene present obesity was associated with only a 3% decline (95% CI, -15% to 10%) compared with nonobese GSTM1 carriers.<h4>Conclusions</h4>GST deficiency is associated with significant HRV alterations in the general population. Its interaction with SHS and obesity in reducing HRV is consistent with an impact of oxidative stress on the autonomous nervous system.
Also flagged:antibodylipoprotein lipaseP66LPLAntithrombin IIIantibodies
Journal Article2008-07-17✓ 2 SnippetsCasanovas A, Carrascal M, Abián J, López-Tejero MD, Llobera M.
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…Antithrombin III (ATIII) was identified as…
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…designed to eliminateATIII, here we demonstrate…
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Specific antibodies are essential tools for studying proteins. P66 is a chicken polyclonal antibody raised against bovine lipoprotein lipase (LPL) that has been used in earlier studies. Here, we developed a two-dimensional (2D) Western blot with reducing gels, using commercial bovine LPL (53 kDa) as a standard and P66 for detection. Our results revealed incomplete purification of commercial LPL and nonspecificity of P66, both undetectable in one-dimensional analysis. Antithrombin III (ATIII) was identified as both a major contaminant in commercial LPL and a cross-reacting protein with P66. Although LPL purification methods were presumably designed to eliminate ATIII, here we demonstrate that some procedures fell short of this objective and thus led to the production of a nonspecific antibody. Our results define 2D electrophoresis/Western blot and mass spectrometric protein identification as the most reliable procedure for validating LPL purity and the specificity of antibodies against this enzyme.
Also flagged:synphilin 1polypeptidesproteasomedegradationcytosolmicrotubules
Journal Article2008-07-17No SnippetsZaarur N, Meriin AB, Gabai VL, Sherman MY.
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Abnormal polypeptides that escape proteasome-dependent degradation and aggregate in cytosol can be transported via microtubules to an aggresome, a recently discovered organelle where aggregated proteins are stored or degraded by autophagy. We used synphilin 1, a protein implicated in Parkinson disease, as a model to study mechanisms of aggresome formation. When expressed in naïve HEK293 cells, synphilin 1 forms multiple small highly mobile aggregates. However, proteasome or Hsp90 inhibition rapidly triggered their translocation into the aggresome, and surprisingly, this response was independent on the expression level of synphilin 1. Therefore, aggresome formation, but not aggregation of synphilin 1, represents a special cellular response to a failure of the proteasome/chaperone machinery. Importantly, translocation to aggresomes required a special aggresome-targeting signal within the sequence of synphilin 1, an ankyrin-like repeat domain. On the other hand, formation of multiple small aggregates required an entirely different segment within synphilin 1, indicating that aggregation and aggresome formation determinants can be separated genetically. Furthermore, substitution of the ankyrin-like repeat in synphilin 1 with an aggresome-targeting signal from huntingtin was sufficient for aggresome formation upon inhibition of the proteasome. Analogously, attachment of the ankyrin-like repeat to a huntingtin fragment lacking its aggresome-targeting signal promoted its transport to aggresomes. These findings indicate the existence of transferable signals that target aggregation-prone polypeptides to aggresomes.
Also flagged:mitochondrial complex IIHuntington's diseaseHDproteasomebrain-derived neurotrophic factorBDNF
Journal Article2008-07-17✓ 1 SnippetSeo H, Kim W, Isacson O.
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…However, this discrepancy with HD patient tissue was not apparent in the mutant CAG repeat huntingtin full-length HD (YAC72) transgenic mouse model during post-symptomatic and late-stage pathology, which then also showed UPS inhibition similar to HD patients' brains.…
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Intraneuronal protein aggregates of the mutated huntingtin in Huntington's disease (HD) brains suggest an overload and/or dysfunction of the ubiquitin-proteasome system (UPS). There is a general inhibition of the UPS in many brain regions (cerebellum, cortex, substantia nigra and caudate-putamen) and skin fibroblasts from HD patients. In the current experiment, the widely used mutant huntingtin-exon 1 CAG repeat HD transgenic mice model (R6/2) (with 144 CAG repeat and exon 1) during late-stage pathology, had increases in proteasome activity in the striatum. However, this discrepancy with HD patient tissue was not apparent in the mutant CAG repeat huntingtin full-length HD (YAC72) transgenic mouse model during post-symptomatic and late-stage pathology, which then also showed UPS inhibition similar to HD patients' brains. In both types of HD model mice, we determined biochemical changes, including expression of brain-derived neurotrophic factor (BDNF) and mitochondrial complex II/III (MCII/III) activities related to HD pathology. We found increases of both BDNF expression, and MCII/III activities in YAC72 transgenic mice, and no change of BDNF expression in R6/2 mice. Our data show that extreme CAG repeat lengths in R6/2 mice is paradoxically associated with increased proteasome activity, probably as a cellular compensatory biochemical change in response to the underlying mutation. Changes in HD patients for UPS function, BDNF expression and MCII/III activity are only partially modeled in R6/2 and YAC72 mice, with the latter at 16 months of age being most congruent with the human disease.
We synthesized several hydrophobic esters and ethers of butorphanol and assessed their affinities at opioid receptors in CHO cell membranes. Tested compounds displayed moderate to high affinities to the mu and kappa receptors. The findings accord with previous evidence of a lipophilic binding pocket in the opioid receptors that can be accessed to afford good binding affinity without the need for a phenolic hydrogen-bond donor group. The most potent (K(i)=61 pM at mu and 48 pM at kappa) novel agent was (-)-N-cyclobutylmethylmorphinan-3-yl-14-ol phenoxyacetate (4d).
Also flagged:FDironFpnmembranecell surfaceerythropoiesis
Journal Article2008-07-17✓ 5 SnippetsGirelli D, De Domenico I, Bozzini C, Campostrini N, Busti F, Castagna A, Soriani N, Cremonesi L, Ferrari M, Colombari R, McVey Ward D, Kaplan J, Corrocher R.
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Abstract)
…Two unrelated probands with "non-HFE" hemochromatosis were screened for Fpn mutations.…
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…This appears to reflect functional heterogeneity of Fpn mutants, with loss-of-function generally resulting in the M type.<h4>Methods</h4>Two unrelated probands with "non-HFE" hemochromatosis were screened for Fpn mutations.…
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…probands with “non-HFE”hemochromatosiswere screened for…
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<h4>Background/aims</h4>Clinico-pathological manifestations of ferroportin (Fpn) disease (FD) are heterogeneous, with some patients presenting with iron overload predominantly in macrophages ("M" phenotype), others predominantly in hepatocytes ("H" phenotype). This appears to reflect functional heterogeneity of Fpn mutants, with loss-of-function generally resulting in the M type.<h4>Methods</h4>Two unrelated probands with "non-HFE" hemochromatosis were screened for Fpn mutations. Mutants were functionally characterized by immunofluorescence microscopy, evaluation of their ability to bind hepcidin and export iron, and by expressing them in zebrafish.<h4>Results</h4>Two novel Fpn mutations were identified: I152F in patient-1, presenting with typical M phenotype; and L233P in patient-2, presenting with ambiguous features (massive overload in both macrophages and hepatocytes). Molecular studies suggested loss of function in both cases. The I152F, normally localized on cell membrane and internalized by hepcidin, showed a unique "primary" deficit of iron export capability. The L233P did not appropriately traffic to cell surface. Loss of function was confirmed by expressing both mutants in vivo in zebrafish, resulting in iron limited erythropoiesis. Clinical manifestations were likely enhanced in both patients by non-genetic factors (HCV, alcohol).<h4>Conclusions</h4>The combination of careful review of clinico-pathological data with molecular studies can yield compelling explanations for phenotype heterogeneity in FD.
<h4>Background</h4>Receptor interacting protein 140 (RIP140) is a versatile transcriptional co-repressor that plays roles in diverse metabolic processes including fat accumulation in adipocytes. Previously we identified three methylated arginine residues in RIP140, which rendered its export to the cytoplasm; but it was unclear what triggered RIP140 arginine methylation.<h4>Methodology/principal findings</h4>In this study, we determined the activated PKCepsilon as the specific trigger for RIP140 arginine methylation and its subsequent export. We identified two PKCepsilon-phosphorylated residues of RIP140, Ser-102 and Ser-1003, which synergistically stimulated direct binding of RIP140 by 14-3-3 that recruited protein arginine methyl transferase 1 to methylate RIP140. The methylated RIP140 then preferentially recruited exportin 1 for nuclear export. As a result, the nuclear gene-repressive activity of RIP140 was reduced. In RIP140 null adipocyte cultures, the defect in fat accumulation was effectively rescued by the phosphorylation-deficient mutant RIP140 that resided predominantly in the nucleus, but less so by the phospho-mimetic RIP140 that was exported to the cytoplasm.<h4>Conclusions/significance</h4>This study uncovers a novel means, via a cascade of protein modifications, to inactivate, or suppress, the nuclear action of an important transcription coregulator RIP140, and delineates the first specific phosphorylation-arginine methylation cascade that could alter protein subcellular distribution and biological activity.
Also flagged:breast cancermethylationhypermethylationcancerinvasivePITX2
Journal Article2008-07-16✓ 1 SnippetWidschwendter M, Apostolidou S, Raum E, Rothenbacher D, Fiegl H, Menon U, Stegmaier C, Jacobs IJ, Brenner H.
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…, MYOD1 ,DCC).…
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<h4>Background</h4>Epigenetic changes are emerging as one of the most important events in carcinogenesis. Two alterations in the pattern of DNA methylation in breast cancer (BC) have been previously reported; active estrogen receptor-alpha (ER-alpha) is associated with decreased methylation of ER-alpha target (ERT) genes, and polycomb group target (PCGT) genes are more likely than other genes to have promoter DNA hypermethylation in cancer. However, whether DNA methylation in normal unrelated cells is associated with BC risk and whether these imprints can be related to factors which can be modified by the environment, is unclear.<h4>Methodology/principal findings</h4>Using quantitative methylation analysis in a case-control study (n = 1,083) we found that DNA methylation of peripheral blood cell DNA provides good prediction of BC risk. We also report that invasive ductal and invasive lobular BC is characterized by two different sets of genes, the latter particular by genes involved in the differentiation of the mesenchyme (PITX2, TITF1, GDNF and MYOD1). Finally we demonstrate that only ERT genes predict ER positive BC; lack of peripheral blood cell DNA methylation of ZNF217 predicted BC independent of age and family history (odds ratio 1.49; 95% confidence interval 1.12-1.97; P = 0.006) and was associated with ER-alpha bioactivity in the corresponding serum.<h4>Conclusion/significance</h4>This first large-scale epigenotyping study demonstrates that DNA methylation may serve as a link between the environment and the genome. Factors that can be modulated by the environment (like estrogens) leave an imprint in the DNA of cells that are unrelated to the target organ and indicate the predisposition to develop a cancer. Further research will need to demonstrate whether DNA methylation profiles will be able to serve as a new tool to predict the risk of developing chronic diseases with sufficient accuracy to guide preventive measures.
Also flagged:Parkinson's diseasePDaxon guidanceaxonneurodegenerative diseaseAlzheimer's disease
Journal Article2008-07-16No SnippetsLi Y, Rowland C, Xiromerisiou G, Lagier RJ, Schrodi SJ, Dradiotis E, Ross D, Bui N, Catanese J, Aggelakis K, Grupe A, Hadjigeorgiou G.
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Susceptibility to sporadic Parkinson's disease (PD) is thought to be influenced by both genetic and environmental factors and their interaction with each other. Statistical models including multiple variants in axon guidance pathway genes have recently been purported to be capable of predicting PD risk, survival free of the disease and age at disease onset; however the specific models have not undergone independent validation. Here we tested the best proposed risk panel of 23 single nucleotide polymorphisms (SNPs) in two PD sample sets, with a total of 525 cases and 518 controls. By single marker analysis, only one marker was significantly associated with PD risk in one of our sample sets (rs6692804: P = 0.03). Multi-marker analysis using the reported model found a mild association in one sample set (two sided P = 0.049, odds ratio for each score change = 1.07) but no significance in the other (two sided P = 0.98, odds ratio = 1), a stark contrast to the reported strong association with PD risk (P = 4.64x10(-38), odds ratio as high as 90.8). Following a procedure similar to that used to build the reported model, simulated multi-marker models containing SNPs from randomly chosen genes in a genome wide PD dataset produced P-values that were highly significant and indistinguishable from similar models where disease status was permuted (3.13x10(-23) to 4.90x10(-64)), demonstrating the potential for overfitting in the model building process. Together, these results challenge the robustness of the reported panel of genetic markers to predict PD risk in particular and a role of the axon guidance pathway in PD genetics in general.
…of thalassemia andhemochromatosispatients are not…
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Assays for the detection of the iron regulatory hormone hepcidin in plasma or urine have not yet been widely available, whereas quantitative comparisons between hepcidin levels in these different matrices were thus far even impossible due to technical restrictions. To circumvent these limitations, we here describe several advances in time-of flight mass spectrometry (TOF MS), the most important of which concerned spiking of a synthetic hepcidin analogue as internal standard into serum and urine samples. This serves both as a control for experimental variation, such as recovery and matrix-dependent ionization and ion suppression, and at the same time allows value assignment to the measured hepcidin peak intensities. The assay improvements were clinically evaluated using samples from various patients groups and its relevance was further underscored by the significant correlation of serum hepcidin levels with serum iron indices in healthy individuals. Most importantly, this approach allowed kinetic studies as illustrated by the paired analyses of serum and urine samples, showing that more than 97% of the freely filtered serum hepcidin can be reabsorbed in the kidney. Thus, the here reported advances in TOF MS-based hepcidin measurements represent critical steps in the accurate quantification of hepcidin in various body fluids and pave the way for clinical studies on the kinetic behavior of hepcidin in both healthy and diseased states.
Blushing is considered to be one of the prime pathophysiological markers of social anxiety disorder, potentially mediated by serotonergic function. Therefore, in the present study 62 patients with social anxiety disorder and 62 age- and sex-matched healthy controls were investigated for the influence of serotonin transporter (5-HTT) gene variation (5-HTTLPR, rs25531) on blushing propensity as measured by the blushing propensity scale (BPS). The less active 5-HTTLPR genotypes were nominally significantly associated with increased blushing propensity in patients with social anxiety disorder as compared to controls with an equidirectional trend for the less active 5-HTTLPR/rs25531 haplotypes. Even when statistically controlled for influence of depression, this association remained significant. In summary, the present pilot study suggests a potential role of functional serotonin transporter gene variation in blushing propensity warranting replication and encouraging genetic analyses of further intermediate phenotypes of social anxiety disorder.
Also flagged:DIXDC1retinoic acidDishevelled-AxinWntCcd1embryonic carcinoma
Journal Article2008-07-16✓ 1 SnippetJing XT, Wu HT, Wu Y, Ma X, Liu SH, Wu YR, Ding XF, Peng XZ, Qiang BQ, Yuan JG, Fan WH, Fan M.
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Human DIXDC1 is a member of Dishevelled-Axin (DIX) domain containing gene family which plays important roles in Wnt signaling and neural development. In this report, we first confirmed that expression of Ccd1, a mouse homologous gene of DIXDC1, was up-regulated in embryonic developing nervous system. Further studies showed that Ccd1 was expressed specifically in neurons and colocalized with early neuronal marker Tuj1. During the aggregation induced by RA and neuronal differentiation of embryonic carcinoma P19 cells, expressions of Ccd1 as well as Wnt-1 and N-cadherin were dramatically increased. Stable overexpression of DIXDC1 in P19 cells promoted the neuronal differentiation. P19 cells overexpressing DIXDC1 but not the control P19 cells could differentiate into Tuj1 positive cells with RA induction for only 2 days. Meanwhile, we also found that overexpression of DIXDC1 facilitated the expression of Wnt1 and bHLHs during aggregation and differentiation, respectively, while inhibited gliogenesis by down-regulating the expression of GFAP in P19 cells. Thus, our finding suggested that DIXDC1 might play an important role during neurogenesis, overexpression of DIXDC1 in embryonic carcinoma P19 cells promoted neuronal differentiation, and inhibited gliogenesis induced by retinoic acid.
Also flagged:Heat shock transcription factor 1polyglutaminechaperonesneurodegenerative diseasespolyglutamine (polyQ) diseasespolyQ diseases
Journal Article2008-07-16✓ 1 SnippetFujikake N, Nagai Y, Popiel HA, Okamoto Y, Yamaguchi M, Toda T.
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Many neurodegenerative diseases including Alzheimer, Parkinson, and polyglutamine (polyQ) diseases are thought to be caused by protein misfolding. The polyQ diseases, including Huntington disease and spinocerebellar ataxias (SCAs), are caused by abnormal expansions of the polyQ stretch in disease-causing proteins, which trigger misfolding of these proteins, resulting in their deposition as inclusion bodies in affected neurons. Although genetic expression of molecular chaperones has been shown to suppress polyQ protein misfolding and neurodegeneration, toward developing a therapy, it is ideal to induce endogenous molecular chaperones by chemical administration. In this study, we assessed the therapeutic effects of heat shock transcription factor 1 (HSF1)-activating compounds, which induce multiple molecular chaperones, on polyQ-induced neurodegeneration in vivo. We found that oral administration of 17-(allylamino)-17-demethoxygeldanamycin (17-AAG) markedly suppresses compound eye degeneration and inclusion body formation in a Drosophila model of SCA. 17-AAG also dramatically rescued the lethality of the SCA model (74.1% rescue) and suppressed neurodegeneration in a Huntington disease model (46.3% rescue), indicating that 17-AAG is widely effective against various polyQ diseases. 17-AAG induced Hsp70, Hsp40, and Hsp90 expression in a dose-dependent manner, and the expression levels correlated with its therapeutic effects. Furthermore, knockdown of HSF1 abolished the induction of molecular chaperones and the therapeutic effect of 17-AAG, indicating that its therapeutic effects depend on HSF1 activation. Our study indicates that induction of multiple molecular chaperones by 17-AAG treatment is a promising therapeutic approach for a wide range of polyQ diseases and possibly other neurodegenerative diseases.
…Huntington's disease (HD) is an autosomal-dominant neurodegenerative disease caused by an expanded polyglutamine tract in the ubiquitously expressed huntingtin protein.…
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Huntington's disease (HD) is an autosomal-dominant neurodegenerative disease caused by an expanded polyglutamine tract in the ubiquitously expressed huntingtin protein. Clinically, HD is characterized by motor, cognitive and psychiatric deficits. Striking degeneration of the striatum is observed in HD with the medium spiny neurons (MSNs) being the most severely affected neuronal subtype. Dysfunction of MSNs is marked by characteristic changes in gene expression which precede neuronal death. The ubiquitous expression of the huntingtin protein raises the question as to whether the selective vulnerability of the MSN is cell-autonomous, non-cell-autonomous, or a combination thereof. In particular, growing evidence suggests that abnormalities of the cortex and corticostriatal projections may be primary causes of striatal vulnerability. To examine this issue, we developed transgenic mice that, within the forebrain, selectively express a pathogenic huntingtin species in the MSNs, specifically excluding the neocortex. These mice develop a number of abnormalities characteristic of pan-cellular HD mouse models, including intranuclear inclusion bodies, motor impairment, and changes in striatal gene expression. As this phenotype develops in the presence of normal levels of brain-derived neurotrophic factor and its major striatal receptor, tropomyosin-related kinase B, these data represent the first demonstration of in vivo cell-autonomous transcriptional dysregulation in an HD mouse model. Furthermore, our findings suggest that therapies targeted directly to the striatum may be efficacious at reversing some of the molecular abnormalities present in HD.
Also flagged:MN1hematopoiesisoncoproteinmeningioma 1acute myeloid leukemiaAML
Journal Article2008-07-16✓ 1 SnippetMeester-Smoor MA, Janssen MJ, Grosveld GC, de Klein A, van IJcken WF, Douben H, Zwarthoff EC.
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The oncoprotein meningioma 1 (MN1) is overexpressed in several subtypes of acute myeloid leukemia (AML) and overexpression was associated with a poor response to chemotherapy. MN1 is a cofactor of retinoic acid receptor/retinoic x receptor (RAR/RXR)-mediated transcription and this study identified genes in the promonocytic cell line U937 that were regulated by MN1. We found that MN1 can both stimulate and inhibit transcription. Combining MN1 expression with all-trans retinoic acid (ATRA), the ligand of the RAR/RXR dimer, showed that MN1 could both enhance and repress ATRA effects. Many of the identified genes are key players in hematopoiesis and leukemogenesis (e.g. MEIS1 and BMI1). Another interesting target is DHRS9. DHRS9 is involved in the synthesis of ATRA from vitamin A. MN1 inhibited DHRS9 expression and completely abolished its induction by ATRA. MN1 is also the target of a rare AML-causing translocation encoding the MN1-TEL protein. MN1-TEL induces expression of only a few genes and its most pronounced effect is inhibition of a large group of ATRA-induced genes including DHRS9. In conclusion, both MN1 and MN1-TEL interfere with the ATRA pathway and this might explain the differentiation block in leukemias in which these genes are involved.
Human hepatocellular carcinoma (HCC) is one of the commonest causes of mortality among solid organ malignancies. The incidence of HCC in the United States is rising. Few proteomic biomarker studies have been done in U.S. populations. Tumor and nonmalignant tissue from three American patients with hepatitis and non-hepatitis-associated HCC were analyzed to find common differences in protein expression. Proteins were separated by 2D electrophoresis (isoelectric focusing followed by 10% SDS-PAGE). Gels were fixed and then stained with Coomassie brilliant blue. Digitization and processing were performed using the PDQuest software. The Student's t-test was used to detect quantitative protein changes between tumor and nonmalignant liver consistent in all sample pairs with a cutoff made at P < 0.01. This yielded a total of 20 spots with significant (>2 fold) abundance changes. Matrix-assisted laser desorption ionization mass spectrometry analysis was performed using Waters Micomass M@LDI SYSTEM. The proteins were then identified using manual ProFound. Among the 20 spots, 10 showed overexpression and 10 showed underexpression in tumor. Overexpressed proteins included beta-5-tubulin, beta-actin, vimentin, hypermethylated in cancer 2 protein, heat-shock 70-kDa protein 9B, serum albumin, 39S ribosomal protein L45, butyrophilin, autoimmune regulator, and transcription factor ETV7. Underexpressed proteins included BiP protein, superoxide dismutase, peroxiredoxin 2, inoraganic pyrophosphatase, keratin 8, carbonic anhydrase 1, repulsive guidance molecule, catalase, C-1-tetrahydrofolate synthase, and hemoglobin alpha-2. Of particular interest, the protein autoimmune regulator was expressed 14-fold higher in tumor tissue, suggesting it may have a role in HCC. Validation and further investigation of these protein changes may lead to the discovery of new molecular targets for therapy, biomarkers for early detection, and new endpoints for therapeutic efficacy and toxicity.
Also flagged:succinic anhydridedextrinZidovudinenucleosidereverse transcriptaseacquired immunodeficiency syndrome
Journal Article2008-07-15No SnippetsWannachaiyasit S, Chanvorachote P, Nimmannit U.
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The aim of this study was to investigate a newly synthesized dextrin-zidovudine (AZT) conjugate designed as a sustained release prodrug of AZT for parenteral administration. AZT was first reacted with succinic anhydride to form a succinoylated AZT which was subsequently coupled with dextrin to yield the dextrin-AZT conjugate. The structure of the conjugate was characterized by FT-IR and (1)H-NMR spectroscopy. The drug content of the conjugate was 18.9 wt.%. The release in vitro of free AZT and succinoylated AZT was investigated in buffer solutions at pH 5.5 and 7.4 and in human plasma. AZT and succinoylated AZT release from the conjugate was 1.4% (pH 5.5), 41.7% (pH 7.4) and 78.4% in human plasma after 24 h. Release was complete in human plasma after 48 h. A pharmacokinetic study in rats following intravenous administration of the conjugate showed prolonged plasma levels of AZT compared to free AZT. The use of the conjugate extended the plasma half-life of AZT from 1.3 to 19.3 h and the mean residence time from 0.4 to 23.6 h. Furthermore, the conjugate provided a significant greater area under the plasma concentration-time curve and reduced the systemic clearance of AZT. This study suggested the potential of this novel dextrin-AZT conjugate as a new intravenous preparation of AZT.
Also flagged:Prothrombinvenous thrombotic diseasearterial thrombotic diseasemyocardial infarctionstrokearterial disease
Journal Article2008-07-15✓ 2 SnippetsDi Micco P, Di Fiore R, Niglio A, Quaranta S, Angiolillo A, Cardillo G, Castaldo G.
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I A O 0000613)
…normal activity ofATIII, PC and PS,…
I A O 0000613)
…PC, PS orATIIIdeficiencies, FVL or…
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Prothrombin G20210A gene variant (FII G20210A) is a risk factor for venous thrombotic disease while conflicting results have been reported for the risk of arterial thrombotic events. However, vascular episodes were absent in up to 40% of the 67 homozygotes for the G20210A described so far, which indicates that the clinical expression depends on additional risk/trigger factors. We describe six homozygotes for the G20210A variant, among which the first pair of siblings (cases n. 3 and 4) reported so far that displayed a strongly heterogeneous clinical outcome. Case 1, a female of 27 years, developed a full thrombosis of common femoral, superficial and popliteal veins. She assumed oral contraceptives in the last two years. Case n. 2, 34 years old, suffered of recurrent pregnancy loss in absence of any causative alteration. Cases n. 3 and n. 5 experienced arterial thrombotic disease, i.e., juvenile myocardial infarction (40 years old) and stroke (48 years old), respectively, in absence of other risk factors. Finally, cases n. 4 and 6 identified as homozygotes for the FII G20210A variant being consanguineous of symptomatic subjects bearing the variant, did not experience any episode of venous nor arterial disease. Both of them have chronic liver disease with an impairement of the prothrombin time INR. Thus, homozygotes for the G20210A are at risk for arterial (in addition to venous) thromobotic events; chronic liver disease might modulate this risk.
<h4>Objective</h4>Genetic linkage studies in schizophrenia (SZ) have primarily focused on the phenotype of disease susceptibility. A limited number of studies, however, have reported suggestive linkage to specific SZ symptom domains including regions on chromosomes 6, 8, and 20. We examined these chromosomal regions for association to positive, negative, and disorganized symptom clusters, using a dense set of single-nucleotide polymorphisms (SNPs).<h4>Methods</h4>We ascertained 178 Caucasian patients with SZ for lifetime severity of clinical symptomatology using a structured diagnostic interview. The cohort was genotyped with the Affymetrix 500K microarray, from which we selected, a priori, 4833 intragenic SNPs located within chromosomal regions previously linked to specific SZ symptom clusters. Parametric tests, corrected for multiple testing, were used to compare the effects of allelic variation within these SNPs to the lifetime severity of the specific symptom domain that had been implicated by prior linkage studies.<h4>Results</h4>We were able to extend previous reports of linkage between chromosome 6q and both positive and disorganized symptoms. Lifetime severity of positive symptoms was significantly (P = 2.50 x 10(-5)) associated with a SNP within the origin recognition complex subunit 3-like (ORC3L) gene, a gene implicated in synaptic plasticity. Level of disorganized symptoms was significantly (P < 6.00 x 10(-5)) associated 2 SNPs within the brain-specific angiogenesis inhibitor 3 (BAI3) gene, which is highly expressed in brain during development.<h4>Conclusions</h4>These data point toward specific candidate genes located within previously implicated linkage peaks for clinical symptomatology. Identification of functional variants within these regions and a characterization of the effect of these risk genotypes on the treatment of specific clinical symptoms are needed.
Also flagged:Cdk5axondendritic spinesKalirinRho GDP/exchange factors
Journal Article2008-07-15No SnippetsXin X, Wang Y, Ma XM, Rompolas P, Keutmann HT, Mains RE, Eipper BA.
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Kalirin, one of the few Rho guanine nucleotide exchange factors (GEFs) that contains spectrin-like repeats, plays a critical role in axon extension and maintenance of dendritic spines. PC12 cells were used to determine whether Cdk5, a critical participant in both processes, regulates the action of Kalirin. Expression of Kalirin-7 in nondifferentiated PC12 cells caused GEF-activity-dependent extension of broad cytoplasmic protrusions; coexpression of dominant-negative Cdk5 largely eliminated this response. The spectrin-like repeat region of Kalirin plays an essential role in this response, which is not mimicked by the GEF domain alone. Thr1590, which follows the first GEF domain of Kalirin, is the only Cdk5 phosphorylation site in Kalirin-7. Although mutant Kalirin-7 with Ala1590 retains GEF activity, it is unable to cause extension of protrusions. Kalirin-7 with an Asp1590 mutation has slightly increased GEF activity and dominant-negative Cdk5 fails to block its ability to cause extension of protrusions. Phosphorylation of Thr1590 causes a slight increase in GEF activity and Kalirin-7 solubility. Dendritic spines formed by cortical neurons in response to the expression of Kalirin-7 with Ala1590 differ in shape from those formed in response to wild-type Kalirin-7 or Kalirin-7 containing Asp1590. The presence of Thr1590 in each major Kalirin isoform would allow Cdk5 to regulate Kalirin function throughout development.
UL18 is a human cytomegalovirus class I MHC (MHCI) homolog that binds the host inhibitory receptor LIR-1 and the only known viral MHC homolog that presents peptides. The 2.2-A structure of a LIR-1/UL18/peptide complex reveals increased contacts and optimal surface complementarity in the LIR-1/UL18 interface compared with LIR/MHCI interfaces, resulting in a >1,000-fold higher affinity. Despite sharing only approximately 25% sequence identity, UL18's structure and peptide binding are surprisingly similar to host MHCI. The crystal structure suggests that most of the UL18 surface, except where LIR-1 and the host-derived light chain bind, is covered by carbohydrates attached to 13 potential N-glycosylation sites, thereby preventing access to bound peptide and association with most MHCI-binding proteins. The LIR-1/UL18 structure demonstrates how a viral protein evolves from its host ancestor to impede unwanted interactions while preserving and improving its receptor-binding site.
The enormous dynamic range of human bodily fluid proteomes poses a significant challenge for current MS-based proteomics technologies as it makes it especially difficult to detect low abundance proteins in human biofluids such as blood plasma, which is an essential aspect for successful biomarker discovery efforts. Here we present a novel tandem IgY12-SuperMix immunoaffinity separation system for enhanced detection of low abundance proteins in human plasma. The tandem IgY12-SuperMix system separates approximately 60 abundant proteins from the low abundance proteins in plasma, allowing for significant enrichment of low abundance plasma proteins in the SuperMix flow-through fraction. High reproducibility of the tandem separations was observed in terms of both sample processing recovery and LC-MS/MS identification results based on spectral count data. The ability to quantitatively measure differential protein abundances following application of the tandem separations was demonstrated by spiking six non-human standard proteins at three different levels into plasma. A side-by-side comparison between the SuperMix flow-through and IgY12 flow-through samples analyzed by both one- and two-dimensional LC-MS/MS revealed a 60-80% increase in proteome coverage as a result of the SuperMix separations, suggesting significantly enhanced detection of low abundance proteins. A total of 695 plasma proteins were confidently identified in a single analysis (with a minimum of two peptides per protein) by coupling the tandem separation strategy with two-dimensional LC-MS/MS, including 42 proteins with reported normal concentrations of approximately 100 pg/ml to 100 ng/ml. The concentrations of two selected proteins, macrophage colony-stimulating factor 1 and matrix metalloproteinase-8, were independently validated by ELISA as 202 pg/ml and 12.4 ng/ml, respectively. Evaluation of binding efficiency revealed that 45 medium abundance proteins were efficiently captured by the SuperMix column with >90% retention. Taken together, these results illustrate the potential broad utilities of this tandem IgY12-SuperMix strategy for proteomics applications involving human biofluids where effectively addressing the dynamic range challenge of the specimen is imperative.
Also flagged:Huntington's diseasehuntingtin-interacting protein 1HIP-1HIPPIHuntingtinHD
Journal Article2008-07-15✓ 5 SnippetsBhattacharyya NP, Banerjee M, Majumder P.
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Abstract)
…Huntingtin protein (Htt), whose mutation causes Huntington's disease (HD), interacts with large numbers of proteins that participate in diverse cellular pathways.…
Abstract)
…In the present review, we present evidence that Htt-interacting protein 1 (HIP-1), an endocytic protein, together with its interacting partner HIPPI, regulates apoptosis and gene expression, both processes being implicated in HD.…
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…This observation indicates that wild-type Htt is involved in various cellular processes and that the mutated Htt alters these processes in HD.…
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…Huntingtin protein (Htt), whose mutation causes…
Abstract)
…indicates that wild-typeHttis involved in…
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Huntingtin protein (Htt), whose mutation causes Huntington's disease (HD), interacts with large numbers of proteins that participate in diverse cellular pathways. This observation indicates that wild-type Htt is involved in various cellular processes and that the mutated Htt alters these processes in HD. The roles of these interacting proteins in HD pathogenesis remain largely unknown. In the present review, we present evidence that Htt-interacting protein 1 (HIP-1), an endocytic protein, together with its interacting partner HIPPI, regulates apoptosis and gene expression, both processes being implicated in HD. Further studies are necessary to establish whether the HIPPI-HIP-1 complex or other interacting partners of HIPPI regulate apoptosis and gene expression that are relevant to HD.
<h4>Background</h4>Systems biology refers to multidisciplinary approaches designed to uncover emergent properties of biological systems. Stem cells are an attractive target for this analysis, due to their broad therapeutic potential. A central theme of systems biology is the use of computational modeling to reconstruct complex systems from a wealth of reductionist, molecular data (e.g., gene/protein expression, signal transduction activity, metabolic activity, etc.). A number of deterministic, probabilistic, and statistical learning models are used to understand sophisticated cellular behaviors such as protein expression during cellular differentiation and the activity of signaling networks. However, many of these models are bimodal i.e., they only consider row-column relationships. In contrast, multiway modeling techniques (also known as tensor models) can analyze multimodal data, which capture much more information about complex behaviors such as cell differentiation. In particular, tensors can be very powerful tools for modeling the dynamic activity of biological networks over time. Here, we review the application of systems biology to stem cells and illustrate application of tensor analysis to model collagen-induced osteogenic differentiation of human mesenchymal stem cells.<h4>Results</h4>We applied Tucker1, Tucker3, and Parallel Factor Analysis (PARAFAC) models to identify protein/gene expression patterns during extracellular matrix-induced osteogenic differentiation of human mesenchymal stem cells. In one case, we organized our data into a tensor of type protein/gene locus link x gene ontology category x osteogenic stimulant, and found that our cells expressed two distinct, stimulus-dependent sets of functionally related genes as they underwent osteogenic differentiation. In a second case, we organized DNA microarray data in a three-way tensor of gene IDs x osteogenic stimulus x replicates, and found that application of tensile strain to a collagen I substrate accelerated the osteogenic differentiation induced by a static collagen I substrate.<h4>Conclusion</h4>Our results suggest gene- and protein-level models whereby stem cells undergo transdifferentiation to osteoblasts, and lay the foundation for mechanistic, hypothesis-driven studies. Our analysis methods are applicable to a wide range of stem cell differentiation models.
Also flagged:PKATNFR1vesicle55-kDa TNFR1type I tumor necrosis factor receptorextracellular space
Journal Article2008-07-14✓ 1 SnippetIslam A, Jones H, Hiroi T, Lam J, Zhang J, Moss J, Vaughan M, Levine SJ.
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The 55-kDa TNFR1 (type I tumor necrosis factor receptor) can be released to the extracellular space by two mechanisms, the proteolytic cleavage and shedding of soluble receptor ectodomains and the release of full-length receptors within exosome-like vesicles. We have shown that the brefeldin A-inhibited guanine nucleotide exchange protein BIG2 associates with TNFR1 and selectively modulates the release of TNFR1 exosome-like vesicles via an ARF1- and ARF3-dependent mechanism. Here, we assessed the role of BIG2 A kinase-anchoring protein (AKAP) domains in the regulation of TNFR1 exosome-like vesicle release from human vascular endothelial cells. We show that 8-bromo-cyclic AMP induced the release of full-length, 55-kDa TNFR1 within exosome-like vesicles via a protein kinase A (PKA)-dependent mechanism. Using RNA interference to decrease specifically the levels of individual PKA regulatory subunits, we demonstrate that RIIbeta modulates both the constitutive and cAMP-induced release of TNFR1 exosome-like vesicles. Consistent with its AKAP function, BIG2 was required for the cAMP-induced PKA-dependent release of TNFR1 exosome-like vesicles via a mechanism that involved the binding of RIIbeta to BIG2 AKAP domains B and C. We conclude that both the constitutive and cAMP-induced release of TNFR1 exosome-like vesicles occur via PKA-dependent pathways that are regulated by the anchoring of RIIbeta to BIG2 via AKAP domains B and C. Thus, BIG2 regulates TNFR1 exosome-like vesicle release by two distinct mechanisms, as a guanine nucleotide exchange protein that activates class I ADP-ribosylation factors and as an AKAP for RIIbeta that localizes PKA signaling within cellular TNFR1 trafficking pathways.
Journal Article2008-07-14✓ 1 SnippetBjörkqvist M, Wild EJ, Thiele J, Silvestroni A, Andre R, Lahiri N, Raibon E, Lee RV, Benn CL, Soulet D, Magnusson A, Woodman B, Landles C, Pouladi MA, Hayden MR, Khalili-Shirazi A, Lowdell MW, Brundin P, Bates GP, Leavitt BR, Möller T, Tabrizi SJ.
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Abstract)
…Monocytes from HD subjects expressed mutant huntingtin and were pathologically hyperactive in response to stimulation, suggesting that the mutant protein triggers a cell-autonomous immune activation.…
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Huntington's disease (HD) is an inherited neurodegenerative disorder characterized by both neurological and systemic abnormalities. We examined the peripheral immune system and found widespread evidence of innate immune activation detectable in plasma throughout the course of HD. Interleukin 6 levels were increased in HD gene carriers with a mean of 16 years before the predicted onset of clinical symptoms. To our knowledge, this is the earliest plasma abnormality identified in HD. Monocytes from HD subjects expressed mutant huntingtin and were pathologically hyperactive in response to stimulation, suggesting that the mutant protein triggers a cell-autonomous immune activation. A similar pattern was seen in macrophages and microglia from HD mouse models, and the cerebrospinal fluid and striatum of HD patients exhibited abnormal immune activation, suggesting that immune dysfunction plays a role in brain pathology. Collectively, our data suggest parallel central nervous system and peripheral pathogenic pathways of immune activation in HD.
…heterozygotes for theHFE hemochromatosishemochromatosis-related allele…
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…, F7, andHFEhaving no independent…
Discussion)
…mechanism for thehemochromatosis-associated A allele.…
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…existing literature onHFEdoes not show…
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<h4>Background</h4>Many candidate genes have been reported to be risk factors for acute coronary syndrome (ACS), but their impact on clinical prognosis following ACS is unknown.<h4>Methods</h4>We examined the association of putative genetic risk factors with 3-year post-ACS mortality in 811 ACS survivors at university-affiliated hospitals in Kansas City, Missouri. Through a systematic literature search, we first identified genetic variants reported as susceptibility factors for atherosclerosis or ACS. Restricting our analysis to whites, so as to avoid confounding from racial admixture, we genotyped ACS cases for 89 genetic variants in 72 genes, and performed individual Kaplan-Meier survival analyses. We then performed Cox regression to create multivariate risk prediction models that further minimized potential confounding.<h4>Results</h4>Of 89 variants tested, 16 were potentially associated with mortality (P < 0.1 for all), of which 6 were significantly associated (P < 0.05) with mortality following ACS. While these findings are not more than what would be expected by chance (P = 0.28), even after Bonferroni correction and adjustment for traditional cardiac risk factors, the IRS1 972Arg variant association (P = 0.001) retained borderline statistical significance (P < 0.1).<h4>Conclusion</h4>With the possible exception of IRS1, we conclude that multiple candidate genes were not associated with post-ACS mortality in our patient cohort. Because of power limitations, the 16 gene variants with P values < 0.1 may warrant further study. Our data do not support the hypothesis that the remaining 73 genes have substantial, clinically significant association with mortality after an ACS.
Also flagged:OX40acute coronary syndromeOX40 ligandOX40Ltumor necrosis factor superfamily member 4pathogenesis
Journal Article2008-07-12✓ 2 SnippetsLiu DM, Yan JC, Wang CP, Chen GH, Ding S, Liu PJ, Du RZ.
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Abstract)
…<h4>Background</h4>Increasing evidence show that OX40 ligand (OX40L), also known as tumor necrosis factor superfamily member 4 (TNFSF4), plays an important role in the pathogenesis of atherosclerosis.…
Abstract)
…superfamily member 4 (TNFSF4), plays an important…
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<h4>Background</h4>Increasing evidence show that OX40 ligand (OX40L), also known as tumor necrosis factor superfamily member 4 (TNFSF4), plays an important role in the pathogenesis of atherosclerosis. We investigated whether expression levels of soluble OX40L in serum and of membrane OX40L on platelets were related to serum concentrations of matrix metalloproteinases (MMPs) and stability of coronary atherosclerotic plaque in patients with acute coronary syndrome (ACS).<h4>Methods</h4>We included healthy controls (n=30), patients with stable angina (SA) (n=40) and patients with ACS, including unstable angina (UA) (n=70) and acute myocardial infarction (AMI) (n=40). The expression of OX40L on platelets (pOX40L) was analyzed with flow cytometry whereas serum concentrations of soluble OX40L (sOX40L), MMP-9 and MMP-3 were determined with ELISA. All coronary stenoses with >or=30% diameter reduction were assessed by angiographic coronary stenosis morphology.<h4>Results</h4>The expression of OX40L on platelets were significantly higher in patients with ACS (61.5+/-11.5) compared with healthy controls (28.9+/-7.4) or with the group of patients with SA (31.2+/-8.1) (mean fluorescence intensity+/-SD) (p<0.001). Similarly, we observed higher sOX40L concentrations in patients with ACS (34.6+/-9.3) compared with controls (10.2+/-4.7) or patients with SA (11.4+/-5.8) (ng/ml+/-SD) (p<0.001). Serum MMP-3 and MMP-9 levels in patients were two times greater than those in the control group. A positive correlation was observed between OX40L expression on platelets and MMP-9 and MMP-3 serum concentrations. OX40L expression on platelets were furthermore correlated with soluble OX40L in serum and with complex coronary stenoses (r1=0.61, r2=0.57, p<0.001).<h4>Conclusion</h4>Patients with ACS show increased OX40L system (pOX40L and sOX40L) expression which may create a proinflammatory milieu for aggravating the development of atherosclerosis, and may be a valuable marker for predicting the severity of ACS.
Also flagged:halogenated) aromatic hydrocarbonsaryl hydrocarbon receptorAHRestrogen receptorERgene expression
Journal Article2008-07-11✓ 1 SnippetLam SH, Mathavan S, Tong Y, Li H, Karuturi RK, Wu Y, Vega VB, Liu ET, Gong Z.
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Results)
…cascade (FGB, SERPINA1,SERPINC1) for EC gene…
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The ability to perform large-scale, expression-based chemogenomics on whole adult organisms, as in invertebrate models (worm and fly), is highly desirable for a vertebrate model but its feasibility and potential has not been demonstrated. We performed expression-based chemogenomics on the whole adult organism of a vertebrate model, the zebrafish, and demonstrated its potential for large-scale predictive and discovery chemical biology. Focusing on two classes of compounds with wide implications to human health, polycyclic (halogenated) aromatic hydrocarbons [P(H)AHs] and estrogenic compounds (ECs), we generated robust prediction models that can discriminate compounds of the same class from those of different classes in two large independent experiments. The robust expression signatures led to the identification of biomarkers for potent aryl hydrocarbon receptor (AHR) and estrogen receptor (ER) agonists, respectively, and were validated in multiple targeted tissues. Knowledge-based data mining of human homologs of zebrafish genes revealed highly conserved chemical-induced biological responses/effects, health risks, and novel biological insights associated with AHR and ER that could be inferred to humans. Thus, our study presents an effective, high-throughput strategy of capturing molecular snapshots of chemical-induced biological states of a whole adult vertebrate that provides information on biomarkers of effects, deregulated signaling pathways, and possible affected biological functions, perturbed physiological systems, and increased health risks. These findings place zebrafish in a strategic position to bridge the wide gap between cell-based and rodent models in chemogenomics research and applications, especially in preclinical drug discovery and toxicology.
Also flagged:gliomaslowchromosomeprimary tumorschromosomestumor
Journal Article2008-07-11✓ 1 SnippetIdbaih A, Carvalho Silva R, Crinière E, Marie Y, Carpentier C, Boisselier B, Taillibert S, Rousseau A, Mokhtari K, Ducray F, Thillet J, Sanson M, Hoang-Xuan K, Delattre JY.
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Abstract)
…ETS1, ACACA, andCSE1L.…
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Using a one-megabase BAC-based array comparative genomic hybridization technique (aCGH), we have investigated a series of 16 low-grade gliomas (LGGs) and their subsequent progression to higher-grade malignancies. The most frequent chromosome imbalances in primary tumors were gains of chromosomes 7q, 8q, and 22q, and losses of chromosomes 1p, 13q, and 19q. In tumor progression, gains of chromosomes 11q, 7q, 20q, and 21q, and losses of chromosomes 9p, including CDKN2A locus, 19q, 14q, 1p, and 6q were the most frequent genomic disequilibria. Progressive tumors were more imbalanced than primary tumors in terms of altered chromosomal arms (3.8 vs. 6.6 in mean abnormal chromosomal arm) and altered BACs (17 vs. 21%). Interestingly, putative novel candidate genes associated with glioma progression were identified, in particular DOCK8, PTPRD, CER1, TPHO, DHFR, MSH3, ETS1, ACACA, and CSE1L.
Also flagged:amino acidNKLhomeoboxhomeodomainPRDPax4
Journal Article2008-07-11✓ 1 SnippetFonseca NA, Vieira CP, Holland PW, Vieira J.
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Results)
…are POU1F1, POU3F1,POU3F2, POU3F3, and POU3F4.…
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<h4>Background</h4>Although homeobox genes have been the subject of many studies, little is known about the main amino acid changes that occurred early in the evolution of genes belonging to different classes.<h4>Results</h4>In this study, we report a method for the fast and efficient retrieval of sequences belonging to the ANTP (HOXL and NKL) and PRD classes. Furthermore, we look for diagnostic amino acid residues that can be used to distinguish HOXL, NKL and PRD genes.<h4>Conclusion</h4>The reported protein features will facilitate the robust classification of homeobox genes from newly sequenced bilaterian genomes. Nevertheless, in non-bilaterian genomes our findings must be cautiously applied. In principle, as long as a good manually curated data set is available the approach here described can be applied to non-bilaterian organisms as well. Our results help focus experimental studies onto investigating the biochemical functions of key homeodomain residues in different gene classes.
Also flagged:Phospholipase Dserotoninmitogen-activated proteinRhophosphoinositide-3 (PI3) kinasesPLD
Journal Article2008-07-11✓ 1 SnippetLiu Y, Fanburg BL.
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We have previously reported the participation of mitogen-activated protein, Rho, and phosphoinositide-3 (PI3) kinases in separate pathways in serotonin (5-HT)-induced proliferation of pulmonary artery smooth muscle cells (SMCs). In this study, we investigated the possible participation of phospholipase D (PLD) and phosphatidic acid (PA) in this growth process. 5-HT stimulated a time-dependent increase in [(3)H]phosphatidylbutanol and PA generation. Exposure of SMCs to 1-butanol or overexpression of an inactive mutant of human PLD1R898R blocked 5-HT-induced proliferation. Furthermore, 1-butanol inhibited 5-HT activation of S6K1 and S6 protein, downstream effectors of mammalian target of rapamycin (mTOR), by 80 and 72%, respectively, and partially blocked activation of extracellular signal-regulated kinase (ERK) by 30% but had no effect on other associated signaling pathways. Exogenous PA caused cellular proliferation and revitalized cyclin D1 expression by 5-HT of the 1-butanol-treated cells. PA also reproduced activations by 5-HT of mTOR, S6K1, and ERK. Transfection with inactive human PLD1 reduced 5-HT-induced activation of S6K1 by approximately 50%. Inhibition of 5-HT receptor 2A (R 2A) with ketaserin blocked PLD activation by 5-HT. Inhibition with PI3-kinase inhibitor failed to block either activation of PLD by 5-HT or PA-dependent S6K1 phosphorylation. Taken together, these results indicate that ligation of the 5-HTR 2A by 5-HT initiates PLD activation in SMCs, and that its product, PA, is an early signaling molecule in 5-HT-induced pulmonary artery SMC proliferation. Signaling by PA produces its downstream effects primarily through the mTOR/S6K1 pathway and to a lesser extent through the ERK pathway. Hydrolysis of cell membrane lipid may be important in vascular effects of 5-HT.
Also flagged:ironPDdeathLewy bodiesmetabolismneurodegenerative disorder
Journal Article2008-07-11✓ 2 SnippetsRhodes SL, Ritz B.
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Parkinson's disease (PD) is acknowledged as the second most common neurodegenerative disorder after Alzheimer's Disease. Older age may be the only unequivocal risk factor for PD although the male to female ratio is consistently greater than 1 in populations of European ancestry. Characteristic features of PD include dopaminergic neuron death in the substantia nigra (SN) pars compacta, accumulation of alpha-synuclein inclusions known as Lewy bodies in the SN, and brain iron accumulation beyond that observed in non-PD brains of a similar age. In this review article, we will provide an overview of human and animal studies investigating the contributions of iron in PD, a summary of human studies of iron-related genes in PD, a review of the literature on the genetics of iron metabolism, and some hypotheses on possible roles for iron in the pathogenic processes of PD including potential interactions between iron and other factors associated with Parkinson's disease.
Also flagged:cell adhesion moleculesNeph1NephrinbindingIgsynapse
Journal Article2008-07-11✓ 1 SnippetChao DL, Shen K.
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…DCC…
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Cell adhesion molecules of the Immunoglobulin superfamily (IgCAMs) play diverse functions during neural development. Previously, we have identified SYG-1/Neph1 and SYG-2/Nephrin, IgCAMs necessary for synaptic specificity in Caenorhabditis elegans. Here, we conduct an in vivo structure-function analysis of SYG-1 and SYG-2 to identify domains of SYG-1 and SYG-2 necessary for heterophilic binding as well as synaptic specificity. We find the first Ig domain of SYG-1 and the first 5 Ig domains of SYG-2 are necessary and sufficient for their binding in vivo, as well as for synapse formation. We also find the SYG-2 cytoplasmic domain is required for SYG-2 subcellular trafficking, while the intracellular region of SYG-1 is required for synaptic function at earlier developmental stages, but is dispensable for later stages. This study defines the domain requirements for SYG-1/SYG-2 heterophilic binding and suggests that unknown SYG-1 extracellular interactors may play a role in SYG-1-mediated synaptic specificity.
Also flagged:Huntingtinphosphorylationvesiclesmolecular motorskinesinsdynein
Journal Article2008-07-10✓ 1 SnippetColin E, Zala D, Liot G, Rangone H, Borrell-Pagès M, Li XJ, Saudou F, Humbert S.
In-Text Gene Mentions
I A O 0000326)
…htt…
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The transport of vesicles in neurons is a highly regulated process, with vesicles moving either anterogradely or retrogradely depending on the nature of the molecular motors, kinesins and dynein, respectively, which propel vesicles along microtubules (MTs). However, the mechanisms that determine the directionality of transport remain unclear. Huntingtin, the protein mutated in Huntington's disease, is a positive regulatory factor for vesicular transport. Huntingtin is phosphorylated at serine 421 by the kinase Akt but the role of this modification is unknown. Here, we demonstrate that phosphorylation of wild-type huntingtin at S421 is crucial to control the direction of vesicles in neurons. When phosphorylated, huntingtin recruits kinesin-1 to the dynactin complex on vesicles and MTs. Using brain-derived neurotrophic factor as a marker of vesicular transport, we demonstrate that huntingtin phosphorylation promotes anterograde transport. Conversely, when huntingtin is not phosphorylated, kinesin-1 detaches and vesicles are more likely to undergo retrograde transport. This also applies to other vesicles suggesting an essential role for huntingtin in the control of vesicular directionality in neurons.
Also flagged:RP2daDendritedendritesecdysone receptorecdysone
Journal Article2008-07-10✓ 1 SnippetOu Y, Chwalla B, Landgraf M, van Meyel DJ.
In-Text Gene Mentions
Results)
…Robo2, Robo3 and Frazzled/DCC) have also been…
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<h4>Background</h4>Developing neurons form dendritic trees with cell type-specific patterns of growth, branching and targeting. Dendrites of Drosophila peripheral sensory neurons have emerged as a premier genetic model, though the molecular mechanisms that underlie and regulate their morphogenesis remain incompletely understood. Still less is known about this process in central neurons and the extent to which central and peripheral dendrites share common organisational principles and molecular features. To address these issues, we have carried out two comparable gain-of-function screens for genes that influence dendrite morphologies in peripheral dendritic arborisation (da) neurons and central RP2 motor neurons.<h4>Results</h4>We found 35 unique loci that influenced da neuron dendrites, including five previously shown as required for da dendrite patterning. Several phenotypes were class-specific and many resembled those of known mutants, suggesting that genes identified in this study may converge with and extend known molecular pathways for dendrite development in da neurons. The second screen used a novel technique for cell-autonomous gene misexpression in RP2 motor neurons. We found 51 unique loci affecting RP2 dendrite morphology, 84% expressed in the central nervous system. The phenotypic classes from both screens demonstrate that gene misexpression can affect specific aspects of dendritic development, such as growth, branching and targeting. We demonstrate that these processes are genetically separable. Targeting phenotypes were specific to the RP2 screen, and we propose that dendrites in the central nervous system are targeted to territories defined by Cartesian co-ordinates along the antero-posterior and the medio-lateral axes of the central neuropile. Comparisons between the screens suggest that the dendrites of peripheral da and central RP2 neurons are shaped by regulatory programs that only partially overlap. We focused on one common candidate pathway controlled by the ecdysone receptor, and found that it promotes branching and growth of developing da neuron dendrites, but a role in RP2 dendrite development during embryonic and early larval stages was not apparent.<h4>Conclusion</h4>We identified commonalities (for example, growth and branching) and distinctions (for example, targeting and ecdysone response) in the molecular and organizational framework that underlies dendrite development of peripheral and central neurons.
Also flagged:LeukoencephalopathylactateLBSLmitochondrial aspartyl-tRNA synthetaseProtonN-acetylaspartate
Journal Article2008-07-10✓ 4 SnippetsUluc K, Baskan O, Yildirim KA, Ozsahin S, Koseoglu M, Isak B, Scheper GC, Gunal DI, van der Knaap MS.
In-Text Gene Mentions
Abstract)
…In LBSL, distinct MRI findings should lead to the diagnosis, which can be confirmed by the analysis of the disease gene DARS2.…
Abstract)
…mutations in theDARS2gene, which encodes…
Abstract)
…two mutations inDARS2.…
Abstract)
…the disease geneDARS2.…
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Leukoencephalopathy with brainstem and spinal cord involvement and lactate elevation (LBSL) is a recently described disorder with autosomal recessive mode of inheritance. Lately, mutations in the DARS2 gene, which encodes mitochondrial aspartyl-tRNA synthetase, have been found as the underlying defect. We report a 19-year-old male patient with cerebellar, pyramidal and dorsal column dysfunctions and specific magnetic resonance imaging (MRI) and characteristic magnetic resonance spectroscopy (MRS) abnormalities. The patient was compound-heterozygous for two mutations in DARS2. MRI showed selective involvement of cerebral and cerebellar white matter and superior and inferior cerebellar peduncles, without contrast enhancement. The U-fibers were spared. The sensory and the pyramidal tracts were affected over their entire length. Involvement of the intraparenchymal trajectories of the trigeminal nerves and mesencephalic trigeminal tracts was demonstrated. In the spinal cord, signal abnormalities were identified in the dorsal columns and the lateral corticospinal tracts. Proton-MRS of the frontal and cerebellar white matter showed elevated lactate, reduced N-acetylaspartate, increased myoinositol and mildly elevated choline. In LBSL, distinct MRI findings should lead to the diagnosis, which can be confirmed by the analysis of the disease gene DARS2.
Also flagged:synthesisglucosaminesheparansulfatehydroxylglucosamine
Journal Article2008-07-09No SnippetsLiu R, Chanthamontri C, Han H, Hernández-Torres JM, Wood KV, McLuckey SA, Wei A.
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Sulfated epitopes of alpha-glucosamine (GlcN sulfoforms) were prepared by solid-phase synthesis as models of internal glucosamines within heparan sulfate. An orthogonally protected 2'-hydroxyethyl GlcN derivative was immobilized on a trityl resin support and subjected to regioselective deprotection and sulfonation conditions, which were optimized with the aid of on-resin infrared or Raman analysis. The sulfoforms were cleaved from the resin under mild Lewis acid conditions without affecting the O- or N-sulfate groups and purified by reversed-phase high-performance liquid chromatography (HPLC). The alpha-GlcN sulfoforms and their 4- O-benzyl ethers were examined by electrospray ionization tandem mass spectrometry (ESI-MS/MS), with product ion spectra produced by collision-induced dissociation (CID). ESI-MS/MS revealed significant differences in parent ion stabilities and fragmentation rates as a function of sulfate position. Ion fragmentation by CID resulted in characteristic mass losses with strong correlation to the positions of both free hydroxyl groups and sulfate ions. Most of these fragmentation patterns are consonant with elimination pathways, and suggest possible strategies for elucidating the structures of glucosamine-derived sulfoforms with identical m/ z ratios. In particular, fragmentation analysis can easily distinguish GlcN sulfoforms bearing the relatively rare 3- O-sulfate from isomers with the more common 6- O-sulfate.
Also flagged:synthesis2,3-dihydroquinazolinoneheterocycletubulinbindingcancer
Journal Article2008-07-09No SnippetsChinigo GM, Paige M, Grindrod S, Hamel E, Dakshanamurthy S, Chruszcz M, Minor W, Brown ML.
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For several decades the 2,3-dihydroquinazolinone (DHQZ) heterocycle has been known to possess a variety of important biological and medicinal properties. Despite the many interesting facets of these molecules, synthetic access to nonracemic DHQZ analogues has remained elusive. Herein, we disclose a synthetic route that allows access to either enantiomer of a variety of DHQZ derivatives. We illustrate the utility of this chemistry with the asymmetric preparation and biological evaluation of a new chiral fluorescent tubulin binding agent with extremely potent antiproliferative properties against human cancer cells. A computational rationale for the increased potency of the (S)-enantiomer over the (R)-enantiomer is given, based on the crystal structure of alpha,beta-tubulin complexed with colchicine. Taking advantage of the inherent fluorescence of these molecules, confocal images of GMC-5-193 (compound 7) in the cytoplasm of human melanoma cells (MDA-MB-435) cells are presented.
Also flagged:porphyrinicorganizationvesiclemembranezincvesicles
Journal Article2008-07-09No SnippetsDuncan TV, Ghoroghchian PP, Rubtsov IV, Hammer DA, Therien MJ.
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Formed through cooperative self-assembly of amphiphilic diblock copolymers and electronically conjugated porphyrinic near-infrared (NIR) fluorophores (NIRFs), NIR-emissive polymersomes (50 nm to 50 microm diameter polymer vesicles) define a family of organic-based, soft-matter structures that are ideally suited for deep-tissue optical imaging and sensitive diagnostic applications. Here, we describe magic angle and polarized pump-probe spectroscopic experiments that: (i) probe polymersome structure and NIRF organization and (ii) connect emitter structural properties and NIRF loading with vesicle emissive output at the nanoscale. Within polymersome membrane environments, long polymer chains constrain ethyne-bridged oligo(porphinato)zinc(II) based supermolecular fluorophore (PZn n ) conformeric populations and disperse these PZn n species within the hydrophobic bilayer. Ultrafast excited-state transient absorption and anisotropy dynamical studies of NIR-emissive polymersomes, in which the PZn n fluorophore loading per nanoscale vesicle is varied between 0.1-10 mol %, enable the exploration of concentration-dependent mechanisms for nonradiative excited-state decay. These experiments correlate fluorophore structure with its gross spatial arrangement within specific nanodomains of these nanoparticles and reveal how compartmentalization of fluorophores within reduced effective dispersion volumes impacts bulk photophysical properties. As these factors play key roles in determining the energy transfer dynamics between dispersed fluorophores, this work underscores that strategies that modulate fluorophore and polymer structure to optimize dispersion volume in bilayered nanoscale vesicular environments will further enhance the emissive properties of these sensitive nanoscale probes.
Also flagged:cell proliferation3,4-methylenedioxymethamphetaminenucleus5-HT1A receptoripsapirone5-HT1A
Journal Article2008-07-09✓ 4 SnippetsRenoir T, Païzanis E, El Yacoubi M, Saurini F, Hanoun N, Melfort M, Lesch KP, Hamon M, Lanfumey L.
In-Text Gene Mentions
Title)
…cell proliferation in5-HTTknock-out vs. wild-type…
Abstract)
…approaches in both5-HTTwild-type and knock-out…
Abstract)
…were abolished in5-HTT-/- knock-out mice.…
Abstract)
…These5-HTT-dependent effects, opposite t…
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Although numerous studies investigated the mechanisms underlying 3,4-methylenedioxymethamphetamine (MDMA)-induced neurotoxicity, little is known about its long-term functional consequences on 5-HT neurotransmission in mice. This led us to evaluate the delayed effects of MDMA exposure on the 5-HT system, using in-vitro and in-vivo approaches in both 5-HTT wild-type and knock-out mice. Acute MDMA in-vitro application on slices of the dorsal raphe nucleus (DRN) induced concentration-dependent 5-HT release and 5-HT cell firing inhibition. Four weeks after MDMA administration (20 mg/kg b.i.d for 4 d), a 2-fold increase in the potency of the 5-HT1A receptor agonist ipsapirone to inhibit the discharge of DRN 5-HT neurons and a larger hypothermic response to 8-OH-DPAT were observed in MDMA- compared to saline-treated mice. This adaptive 5-HT1A autoreceptor supersensitivity was associated with decreases in 5-HT levels but no changes of [3H]citalopram binding in brain. Long-term MDMA treatment also induced a 30% decrease in BrdU labelling of proliferating hippocampal cells and an increased immobility duration in the forced swim test suggesting a depressive-like behaviour induced by MDMA treatment. All these effects were abolished in 5-HTT-/- knock-out mice. These data indicated that, in mice, MDMA administration induced a delayed adaptive supersensitivity of 5-HT1A autoreceptors in the DRN, a deficit in hippocampal cell proliferation and a depressive-like behaviour. These 5-HTT-dependent effects, opposite to those of antidepressants, might contribute to MDMA-induced mood disorders.
…Specifically, the downregulation of VRK1/VRK2 protein levels, as a consequence of p53 accumulation, is thus dependent on the levels of the p300/CBP protein available for transcriptional complexes, since in this context this cofactor functions as a repressor of the effect.…
Results)
…For this experiment cells were transfected with a fixed amount of p53 that induces an almost complete downregulation of both VRK2 isoforms, and the effect of an increasing concentration of chloroquine was determined.…
Results)
…The human VRK2 gene generates by alternative splicing two isoforms of VRK2 of 508 (VRK2A) and 397 (VRK2B) aminoacids respectively [31].…
S I O 001029)
…p53 also induces downregulation of VRK2 isoforms that is protected by p300 and is sensitive to chloroquine.…
Discussion)
…This downregulation of VRK1, or VRK2, induced by p53 requires transcriptional activation of an intermediate gene that is responsible for targeting VRK proteins to enter the endocytic-lysosomal pathway [12], as shown by its sensitivity to chloroquine.…
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<h4>Background</h4>The vaccinia-related kinase 1 (VRK1) protein, an activator of p53, can be proteolytically downregulated by an indirect mechanism, which requires p53-dependent transcription.<h4>Principal findings</h4>In this work we have biochemically characterized the contribution of several p53 transcriptional cofactors with acetyl transferase activity to the induction of VRK1 downregulation that was used as a functional assay. Downregulation of VRK1 induced by p53 is prevented in a dose dependent manner by either p300 or CBP, but not by PCAF, used as transcriptional co-activators, suggesting that p53 has a different specificity depending on the relative level of these transcriptional cofactors. This inhibition does not require p53 acetylation, since a p53 acetylation mutant also induces VRK1 downregulation. PCAF can not revert the VRK1 protection effect of p300, indicating that these two proteins do not compete for a common factor needed to induce VRK1 downregulation. The protective effect is also induced by the C/H3 domain of p300, a region implicated in binding to several transcription factors and SV40 large T antigen; but the protective effect is lost when a mutant C/H3Del33 is used. The protective effect is a consequence of direct binding of the C/H3 domain to the transactivation domain of p53. A similar downregulatory effect can also be detected with VRK2 protein.<h4>Conclusions/significance</h4>Specific p53-dependent effects are determined by the availability and ratios of its transcriptional cofactors. Specifically, the downregulation of VRK1/VRK2 protein levels, as a consequence of p53 accumulation, is thus dependent on the levels of the p300/CBP protein available for transcriptional complexes, since in this context this cofactor functions as a repressor of the effect. These observations point to the relevance of knowing the cofactor levels in order to determine one effect or another.
Neonatal injection of recombinant adeno-associated virus serotype 8 (rAAV8) vectors results in widespread transduction in multiple organs and therefore holds promise in neonatal gene therapy. On the other hand, insertional mutagenesis causing liver cancer has been implicated in rAAV-mediated neonatal gene transfer. Here, to better understand rAAV integration in neonatal livers, we investigated the frequency and spectrum of genomic integration of rAAV8 vectors in the liver following intraperitoneal injection of 2.0 x 10(11) vector genomes at birth. This dose was sufficient to transduce a majority of hepatocytes in the neonatal period. In the first approach, we injected mice with a beta-galactosidase-expressing vector at birth and quantified rAAV integration events by taking advantage of liver regeneration in a chronic hepatitis animal model and following partial hepatectomy. In the second approach, we performed a new, quantitative rAAV vector genome rescue assay by which we identified rAAV integration sites and quantified integrations. As a result, we find that at least approximately 0.05% of hepatocytes contained rAAV integration, while the average copy number of integrated double-stranded vector genome per cell in the liver was approximately 0.2, suggesting concatemer integration. Twenty-three of 34 integrations (68%) occurred in genes, but none of them were near the mir-341 locus, the common rAAV integration site found in mouse hepatocellular carcinoma. Thus, rAAV8 vector integration occurs preferentially in genes at a frequency of 1 in approximately 10(3) hepatocytes when a majority of hepatocytes are once transduced in the neonatal period. Further studies are warranted to elucidate the relationship between vector dose and integration frequency or spectrum.
Also flagged:VRK1vaccinia-related kinase(VRK) 1serine-threonine kinasetranscription factors
Journal Article2008-07-09✓ 5 SnippetsSanz-García M, López-Sánchez I, Lazo PA.
In-Text Gene Mentions
S I O 001029)
…In HEK293T cells there was a strong overlap between the cytosolic signal of VRK2 and Ran (Fig. 4E),…
S I O 001029)
…In VRK2 the overlapping region corresponds to residues 256–320 (Fig. 5, C and D).…
Abstract)
…Ran is a novel negative regulator of nuclear VRK1 and VRK2 kinase activity, which may vary in different subcellular localizations generating an asymmetric intracellular distribution of kinase activity depending on local protein interactions.…
Results)
…Because VRK proteins, particularly VRK2 and VRK1, have a highly conserved amino-terminal region with their catalytic domain (397 amino acids), whether the kinase activity of both VRK2 isoforms was also inhibited by Ran was also determined (Fig. 7E).…
Results)
…For this aim HEK293T cells were transfected with mammalian plasmids expressing fusion proteins GST-VRK1 or GST-VRK2B (the nuclear isoform of VRK2) (8) that are identical and differ only in the last amino acid (8) and with the empty vector expressing GST.…
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Human vaccinia-related kinase (VRK) 1 is a novel serine-threonine kinase that regulates several transcription factors, nuclear envelope assembly, and chromatin condensation and is also required for cell cycle progression. The regulation of this kinase family is unknown. Mass spectrometry has permitted the identification of Ran as an interacting and regulatory protein of the VRK serine-threonine kinase activities. The stable interaction has been validated by pulldown of endogenous proteins as well as by reciprocal immunoprecipitations. The three members of the VRK family stably interact with Ran, and the interaction was not affected by the bound nucleotide, GDP or GTP. The interaction was stronger with the RanT24N that is locked in its inactive conformation and cannot bind nucleotides. None of the kinases phosphorylated Ran or RCC1. VRK1 does not directly interact with RCC1, but if Ran is present they can be isolated as a complex. The main effect of the interaction of inactive RanGDP with VRK1 is the inhibition of its kinase activity, which was detected by a reduction in VRK1 autophosphorylation and a reduction in phosphorylation of histone H3 in residues Thr-3 and Ser-10. The kinase activity inhibition can be relieved by the interaction with the constitutively active RanGTP or RanL43E, which locks Ran in its GTP-bound active conformation. In this complex, the interaction with VRK proteins does not alter the effect of its guanine exchange factor, RCC1. Ran is a novel negative regulator of nuclear VRK1 and VRK2 kinase activity, which may vary in different subcellular localizations generating an asymmetric intracellular distribution of kinase activity depending on local protein interactions.
Also flagged:ironFerritinbindingendocytosisG-proteinsucrose
Journal Article2008-07-07✓ 1 SnippetKalgaonkar S, Lönnerdal B.
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…HFE…
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Ferritin (Ft) is a large iron (Fe)-binding protein ( approximately 450 kDa) that is found in plant and animal cells and can sequester up to 4500 Fe atoms per Ft molecule. Our previous studies on intestinal Caco-2 cells have shown that dietary factors affect the uptake of Fe from Ft in a manner different from that of Fe from FeSO4, suggesting a different mechanism for cellular uptake. The objective of this study was to determine the mechanism for Ft-Fe uptake using Caco-2 cells. Binding of (59)Fe-labeled Ft at 4 degrees C showed saturable kinetics, and Scatchard analysis resulted in a K(d) of 1.6 muM, strongly indicating a receptor-mediated process. Competitive binding studies with excess unlabelled Ft significantly reduced binding, and uptake studies at 37 degrees C showed saturation after 4 h. Enhancing and blocking endocytosis using Mas-7 (a G-protein activator) and hypertonic medium (0.5 M sucrose), respectively, demonstrated that Ft-Fe uptake by Mas-7-treated cells was 140% of control cells, whereas sucrose treatment resulted in a statistically significant reduction in Ft-Fe uptake by 70% as compared to controls. Inhibition of macropinocytosis with 5-(N,N-dimethyl)-amiloride (Na+/H+ antiport blocker) resulted in a decrease (by approximately 20%) in Ft-Fe uptake at high concentrations of Ft, suggesting that enterocytes can use more than one Ft uptake mechanism in a concentration-dependent manner. These results suggest that Ft uptake by enterocytes is carried out via endocytosis when Ft levels are within a physiological range, whereas Ft at higher concentrations may be absorbed using the additional mechanism of macropinocytosis.
To elucidate the mechanisms underlying peripheral neuropathic pain in the context of HIV infection and antiretroviral therapy, we measured gene expression in dorsal root ganglia (DRG) of rats subjected to systemic treatment with the anti-retroviral agent, ddC (Zalcitabine) and concomitant delivery of HIV-gp120 to the rat sciatic nerve. L4 and L5 DRGs were collected at day 14 (time of peak behavioural change) and changes in gene expression were measured using Affymetrix whole genome rat arrays. Conventional analysis of this data set and Gene Set Enrichment Analysis (GSEA) was performed to discover biological processes altered in this model. Transcripts associated with G protein coupled receptor signalling and cell adhesion were enriched in the treated animals, while ribosomal proteins and proteasome pathways were associated with gene down-regulation. To identify genes that are directly relevant to neuropathic mechanical hypersensitivity, as opposed to epiphenomena associated with other aspects of the response to a sciatic nerve lesion, we compared the gp120+ddC-evoked gene expression with that observed in a model of traumatic neuropathic pain (L5 spinal nerve transection), where hypersensitivity to a static mechanical stimulus is also observed. We identified 39 genes/expressed sequence tags that are differentially expressed in the same direction in both models. Most of these have not previously been implicated in mechanical hypersensitivity and may represent novel targets for therapeutic intervention. As an external control, the RNA expression of three genes was examined by RT-PCR, while the protein levels of two were studied using western blot analysis.
Also flagged:Huntington diseaseHDmitochondriaglutamatemalatepyruvate
Journal Article2008-07-07✓ 5 SnippetsGellerich FN, Gizatullina Z, Nguyen HP, Trumbeckaite S, Vielhaber S, Seppet E, Zierz S, Landwehrmeyer B, Riess O, von Hörsten S, Striggow F.
In-Text Gene Mentions
Abstract)
…In contrast, htt(51Q) mitochondria showed a deficient state 3 respiration, a lower sensitivity to Ca(2+) activation, and a higher susceptibility to Ca(2+)-dependent inhibition.…
Abstract)
…Huntington disease (HD) is characterized by polyglutamine expansions of huntingtin (htt), but the underlying pathomechanisms have remained unclear.…
Abstract)
…We studied brain mitochondria of transgenic HD rats with 51 glutamine repeats (htt(51Q)), modeling the adult form of HD.…
Abstract)
…Interactions between htt(51Q) and distinct targets such as aralar and/or the PT pore may underlie mitochondrial dysregulation leading to energetic depression, cell death, and tissue atrophy in HD.…
Abstract)
…Furthermore htt(51Q) mitochondria exhibited a diminished membrane potential stability in response to Ca(2+), lower capacities and rates of Ca(2+) accumulation, and a decreased Ca(2+) threshold for PT in a substrate-independent but cyclosporin A-sensitive manner.…
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Huntington disease (HD) is characterized by polyglutamine expansions of huntingtin (htt), but the underlying pathomechanisms have remained unclear. We studied brain mitochondria of transgenic HD rats with 51 glutamine repeats (htt(51Q)), modeling the adult form of HD. Ca(free)(2+) up to 2 mum activated state 3 respiration of wild type mitochondria with glutamate/malate or pyruvate/malate as substrates. Ca(free)(2+) above 2 mum inhibited respiration via cyclosporin A-dependent permeability transition (PT). Ruthenium red, an inhibitor of the mitochondrial Ca(2+) uniporter, did not affect the Ca(2+)-dependent activation of respiration but reduced Ca(2+)-induced inhibition. Thus, Ca(2+) activation was mediated exclusively by extramitochondrial Ca(2+), whereas inhibition was promoted also by intramitochondrial Ca(2+). In contrast, htt(51Q) mitochondria showed a deficient state 3 respiration, a lower sensitivity to Ca(2+) activation, and a higher susceptibility to Ca(2+)-dependent inhibition. Furthermore htt(51Q) mitochondria exhibited a diminished membrane potential stability in response to Ca(2+), lower capacities and rates of Ca(2+) accumulation, and a decreased Ca(2+) threshold for PT in a substrate-independent but cyclosporin A-sensitive manner. Compared with wild type, Ca(2+)-induced inhibition of respiration of htt(51Q) mitochondria was less sensitive to ruthenium red, indicating the involvement of extramitochondrial Ca(2+). In conclusion, we demonstrate a novel mechanism of mitochondrial regulation by extramitochondrial Ca(2+). We suggest that specific regulatory Ca(2+) binding sites on the mitochondrial surface, e.g. the glutamate/aspartate carrier (aralar), mediate this regulation. Interactions between htt(51Q) and distinct targets such as aralar and/or the PT pore may underlie mitochondrial dysregulation leading to energetic depression, cell death, and tissue atrophy in HD.
Also flagged:Ironmyelodysplastic syndromesaplastic anemiabone marrow-failure syndromesdeferoxaminedeferasirox
Journal Article2008-07-05✓ 3 SnippetsLee JW.
In-Text Gene Mentions
Methods)
…with overt secondaryhemochromatosis, and is not…
Methods)
…the prevention ofhemochromatosis.…
I A O 0000615)
…treatment of secondaryhemochromatosisin Korea.…
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Emerging clinical data indicate that transfusion-dependent patients with bone marrow-failure syndromes (BMFS) are at risk of the consequences of iron overload, including progressive damage to hepatic, endocrine, and cardiac organs. Despite the availability of deferoxamine (DFO) in Korea since 1998, data from patients with myelodysplastic syndromes, aplastic anemia, and other BMFS show significant iron overload and damage to the heart and liver. The recent introduction of deferasirox, a once-daily, oral iron chelator, may improve the availability of iron chelation therapy to iron-overloaded patients, and improve compliance in patients who may otherwise find adherence to the DFO regimen difficult.
Also flagged:synthesiscarcinomanitric oxideoleanolic acidliver cancershepatocellular carcinoma
Journal Article2008-07-04No SnippetsChen L, Zhang Y, Kong X, Lan E, Huang Z, Peng S, Kaufman DL, Tian J.
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Novel furoxan-based nitric oxide (NO) releasing derivatives of oleanolic acid (OA) were synthesized for potential therapy of liver cancers. Six compounds produced high levels of NO in human hepatocellular carcinoma (HCC) cells and exhibited strong cytotoxicity selectively against HCC in vitro. Treatment with 8b or 16b significantly inhibited the growth of HCC tumors in vivo. These data provide a proof-in-principle that furoxan/OA hybrids may be used for therapeutic intervention of human liver cancers.
<h4>Background</h4>The identification of polymorphisms associated with a disease can help to elucidate its pathogenesis, and this knowledge can be used to improve prognosis for women with a particular disorder, such as polycystic ovary syndrome (PCOS). Since an altered response to ovarian stimulation is also a characteristic of the disease, further knowledge about its aetiology could help in defining the parameters that determine the response of an individual to ovarian stimulation.<h4>Methods</h4>PubMed and EMBASE databases were systematically searched for gene association studies published until the end of August 2007, using search criteria relevant to PCOS and ovarian response to stimulation. Data from additional papers identified through hand searches were also included; 139 publications were reviewed.<h4>Results</h4>Several genes involved in ovarian function and metabolism are associated with increased susceptibility to PCOS, but none is strong enough to correlate alone with susceptibility to the disease, or response to therapy. A single-nucleotide polymorphism in exon 10 of the FSH receptor (FSHR) gene, FSHR p.N680S, was consistently identified as having a significant association with ovarian response to FSH.<h4>Conclusions</h4>No consistent association between gene polymorphism and PCOS could be identified. The FSHR gene may play a significant role in the success of ovarian stimulation, and can be used as a marker to predict differences in FSHR function and ovarian response to FSH. Genotyping the FSHR p.N680S polymorphism may provide a means of identifying a population of poor responders before in vitro fertilization procedures are initiated.
Also flagged:axoncytoskeletal proteinsvesicleSec61alphaRan GTPasebrain development
Journal Article2008-07-04No SnippetsSepp KJ, Hong P, Lizarraga SB, Liu JS, Mejia LA, Walsh CA, Perrimon N.
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While genetic screens have identified many genes essential for neurite outgrowth, they have been limited in their ability to identify neural genes that also have earlier critical roles in the gastrula, or neural genes for which maternally contributed RNA compensates for gene mutations in the zygote. To address this, we developed methods to screen the Drosophila genome using RNA-interference (RNAi) on primary neural cells and present the results of the first full-genome RNAi screen in neurons. We used live-cell imaging and quantitative image analysis to characterize the morphological phenotypes of fluorescently labelled primary neurons and glia in response to RNAi-mediated gene knockdown. From the full genome screen, we focused our analysis on 104 evolutionarily conserved genes that when downregulated by RNAi, have morphological defects such as reduced axon extension, excessive branching, loss of fasciculation, and blebbing. To assist in the phenotypic analysis of the large data sets, we generated image analysis algorithms that could assess the statistical significance of the mutant phenotypes. The algorithms were essential for the analysis of the thousands of images generated by the screening process and will become a valuable tool for future genome-wide screens in primary neurons. Our analysis revealed unexpected, essential roles in neurite outgrowth for genes representing a wide range of functional categories including signalling molecules, enzymes, channels, receptors, and cytoskeletal proteins. We also found that genes known to be involved in protein and vesicle trafficking showed similar RNAi phenotypes. We confirmed phenotypes of the protein trafficking genes Sec61alpha and Ran GTPase using Drosophila embryo and mouse embryonic cerebral cortical neurons, respectively. Collectively, our results showed that RNAi phenotypes in primary neural culture can parallel in vivo phenotypes, and the screening technique can be used to identify many new genes that have important functions in the nervous system.
Also flagged:Monoamine oxidaseMonoamine oxidasesmitochondrial boundaminesmonoaminedegradation
Journal Article2008-07-04No SnippetsBortolato M, Chen K, Shih JC.
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Monoamine oxidases (MAOs) A and B are mitochondrial bound isoenzymes which catalyze the oxidative deamination of dietary amines and monoamine neurotransmitters, such as serotonin, norepinephrine, dopamine, beta-phenylethylamine and other trace amines. The rapid degradation of these molecules ensures the proper functioning of synaptic neurotransmission and is critically important for the regulation of emotional behaviors and other brain functions. The byproducts of MAO-mediated reactions include several chemical species with neurotoxic potential, such as hydrogen peroxide, ammonia and aldehydes. As a consequence, it is widely speculated that prolonged excessive activity of these enzymes may be conducive to mitochondrial damages and neurodegenerative disturbances. In keeping with these premises, the development of MAO inhibitors has led to important breakthroughs in the therapy of several neuropsychiatric disorders, ranging from mood disorders to Parkinson's disease. Furthermore, the characterization of MAO knockout (KO) mice has revealed that the inactivation of this enzyme produces a number of functional and behavioral alterations, some of which may be harnessed for therapeutic aims. In this article, we discuss the intriguing hypothesis that the attenuation of the oxidative stress induced by the inactivation of either MAO isoform may contribute to both antidepressant and antiparkinsonian actions of MAO inhibitors. This possibility further highlights MAO inactivation as a rich source of novel avenues in the treatment of mental disorders.
Also flagged:CAScellular apoptosis susceptibility proteincancertumourmicrotubulespindle
Journal Article2008-07-03✓ 4 SnippetsLiao CF, Luo SF, Li LT, Lin CY, Chen YC, Jiang MC.
In-Text Gene Mentions
Title)
…CSE1L/CAS, the cellular apoptosis susceptibility protein, enhances invasion and metastasis but not proliferation of cancer cells…
Abstract)
…However, there is no any actual experimental study showing CAS (or CSE1 and CSE1L) can increase the proliferation of cancer cells.…
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…CSE1L/CAS, the cellular apoptosis…
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…(or CSE1 andCSE1L) can increase the…
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<h4>Background</h4>The cellular apoptosis susceptibility (CAS) protein is regarded as a proliferation-associated protein that associates with tumour proliferation as it associates with microtubule and functions in the mitotic spindle checkpoint. However, there is no any actual experimental study showing CAS (or CSE1 and CSE1L) can increase the proliferation of cancer cells. Previous pathological study has reported that CAS was strongly positive stained in all of the metastasis melanoma that be examined. Thus, CAS may regulate the invasion and metastasis of cancers. CAS is highly expressed in cancers; if CAS is associated with cancer proliferation, then increased CAS expression should be able to increase the proliferation of cancer cells. We studied whether increased CAS expression can increase cancer cell proliferation and whether CAS regulates the invasion of cancer cells.<h4>Methods</h4>We enhanced or reduced CAS expression by transfecting CAS or anti-CAS expression vectors into human MCF-7 breast cancer cells. The proliferations of cells were determined by trypan blue exclusion assay and flow cytometry analysis. Invasion of cancer cells were determined by matrigel-based invasion assay.<h4>Results</h4>Our studies showed that increased CAS expression was unable to enhance cancer cell proliferation. Immunofluorescence showed CAS was distributed in cytoplasm areas near cell membrane and cell protrusions. CAS was localized in cytoplasmic vesicle and immunogold electronmicroscopy showed CAS was located in vesicle membrane. CAS overexpression enhanced matrix metalloproteinase-2 (MMP-2) secretion and cancer cell invasion. Animal experiments showed CAS reduction inhibited the metastasis of B16-F10 melanoma cells by 56% in C57BL/6 mice.<h4>Conclusion</h4>Our results indicate that CAS increases the invasion but not the proliferation of cancer cells. Thus, CAS plus ECM-degradation proteinases may be used as the markers for predicting the advance of tumour metastasis.
<h4>Introduction</h4>Infrapatellar fat pad (IPFP) is a possible source of stem cells for the repair of articular cartilage defects. In this study, adherent proliferative cells were isolated from digests of IPFP tissue. The effects of the expansion of these cells in fibroblast growth factor-2 (FGF-2) were tested on their proliferation, characterisation, and chondrogenic potential.<h4>Methods</h4>IPFP tissue was obtained from six patients undergoing total knee replacement, and sections were stained with 3G5, alpha smooth muscle actin, and von Willebrand factor to identify different cell types in the vasculature. Cells were isolated from IPFP, and both mixed populations and clonal lines derived from them were characterised for cell surface epitopes, including 3G5. Cells were expanded with and without FGF-2 and were tested for chondrogenic differentiation in cell aggregate cultures.<h4>Results</h4>3G5-positive cells were present in perivascular regions in tissue sections of the IPFP, and proliferative adherent cells isolated from the IPFP were also 3G5-positive. However, 3G5 expression was on only a small proportion of cells in all populations and at all passages, including the clonally expanded cells. The cells showed cell surface epitope expression similar to adult stem cells. They stained strongly for CD13, CD29, CD44, CD90, and CD105 and were negative for CD34 and CD56 but were also negative for LNGFR (low-affinity nerve growth factor receptor) and STRO1. The IPFP-derived cells showed chondrogenic differentiation in cell aggregate cultures, and prior expansion with FGF-2 enhanced chondrogenesis. Expansion in FGF-2 resulted in greater downregulation of many cartilage-associated genes, but on subsequent chondrogenic differentiation, they showed stronger upregulation of these genes and this resulted in greater matrix production per cell.<h4>Conclusion</h4>These results show that these cells express mesenchymal stem cell markers, but further work is needed to determine the true origin of these cells. These results suggest that the expansion of these cells with FGF-2 has important consequences for facilitating their chondrogenic differentiation.
…secondary diabetes (e.g.,hemochromatosis, pancreatitis) were excluded…
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<h4>Background</h4>Recent genome-wide association (GWA) studies have identified several unsuspected genes associated with type 2 diabetes (T2D) with previously unknown functions. In this investigation, we have examined the role of 9 most significant SNPs reported in GWA studies: [peroxisome proliferator-activated receptor gamma 2 (PPARG2; rs 1801282); insulin-like growth factor two binding protein 2 (IGF2BP2; rs 4402960); cyclin-dependent kinase 5, a regulatory subunit-associated protein1-like 1 (CDK5; rs7754840); a zinc transporter and member of solute carrier family 30 (SLC30A8; rs13266634); a variant found near cyclin-dependent kinase inhibitor 2A (CDKN2A; rs10811661); hematopoietically expressed homeobox (HHEX; rs 1111875); transcription factor-7-like 2 (TCF7L2; rs 10885409); potassium inwardly rectifying channel subfamily J member 11(KCNJ11; rs 5219); and fat mass obesity-associated gene (FTO; rs 9939609)].<h4>Methods</h4>We genotyped these SNPs in a case-control sample of 918 individuals consisting of 532 T2D cases and 386 normal glucose tolerant (NGT) subjects of an Asian Sikh community from North India. We tested the association between T2D and each SNP using unconditional logistic regression before and after adjusting for age, gender, and other covariates. We also examined the impact of these variants on body mass index (BMI), waist to hip ratio (WHR), fasting insulin, and glucose and lipid levels using multiple linear regression analysis.<h4>Results</h4>Four of the nine SNPs revealed a significant association with T2D; PPARG2 (Pro12Ala) [odds ratio (OR) 0.12; 95% confidence interval (CI) (0.03-0.52); p = 0.005], IGF2BP2 [OR 1.37; 95% CI (1.04-1.82); p = 0.027], TCF7L2 [OR 1.64; 95% CI (1.20-2.24); p = 0.001] and FTO [OR 1.46; 95% CI (1.11-1.93); p = 0.007] after adjusting for age, sex and BMI. Multiple linear regression analysis revealed significant association of two of nine investigated loci with diabetes-related quantitative traits. The 'C' (risk) allele of CDK5 (rs 7754840) was significantly associated with decreased HDL-cholesterol levels in both NGT (p = 0.005) and combined (NGT and T2D) (0.005) groups. The less common 'C' (risk) allele of TCF7L2 (rs 10885409) was associated with increased LDL-cholesterol (p = 0.010) in NGT and total and LDL-cholesterol levels (p = 0.008; p = 0.003, respectively) in combined cohort.<h4>Conclusion</h4>To our knowledge, this is first study reporting the role of some recently emerged loci with T2D in a high risk population of Asian Indian origin. Further investigations are warranted to understand the pathway-based functional implications of these important loci in T2D pathophysiology in different ethnicities.
Also flagged:ironalcoholic liver diseaseperoxynitritealcohol(Tf) receptor-1dextran
Journal Article2008-07-03✓ 5 SnippetsXiong S, She H, Zhang AS, Wang J, Mkrtchyan H, Dynnyk A, Gordeuk VR, French SW, Enns CA, Tsukamoto H.
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…Chronic alcohol feeding in rats results in increased expression of transferrin (Tf) receptor-1 and hemochromatosis gene (HFE), enhanced iron uptake, an increase in nonheme iron content, and accentuated ILI response for NF-kappaB activation in KC.…
…and hemochromatosis gene (HFE), enhanced iron uptake,…
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One prime feature of alcoholic liver disease (ALD) is iron accumulation in hepatic macrophages/Kupffer cells (KC) associated with enhanced NF-kappaB activation. Our recent work demonstrates a peroxynitrite-mediated transient rise in intracellular labile iron (ILI) as novel signaling for endotoxin-induced IKK and NF-kappaB activation in rodent KC. The present study investigated the mechanism of KC iron accumulation and its effects on ILI response in experimental ALD. We also tested ILI response in human blood monocytes. Chronic alcohol feeding in rats results in increased expression of transferrin (Tf) receptor-1 and hemochromatosis gene (HFE), enhanced iron uptake, an increase in nonheme iron content, and accentuated ILI response for NF-kappaB activation in KC. Ex vivo treatment of these KC with an iron chelator abrogates the increment of iron content, ILI response, and NF-kappaB activation. The ILI response is evident in macrophages derived from human blood monocytes by PMA treatment but not in vehicle-treated monocytes, and this differentiation-associated phenomenon is essential for maximal TNF-alpha release. PMA-induced macrophages load iron dextran and enhance ILI response and TNF-alpha release. These effects are reproduced in KC selectively loaded in vivo with iron dextran in mice and more importantly aggravate experimental ALD. Our results suggest enhanced iron uptake as a mechanism of KC iron loading in ALD and demonstrate the ILI response as a function acquired by differentiated macrophages in humans and as a priming mechanism for ALD.
Also flagged:helicasessDNA binding proteincoumarinDNA helicasesDNA Binding ProteinSSB
Journal Article2008-07-03✓ 1 SnippetDillingham MS, Tibbles KL, Hunter JL, Bell JC, Kowalczykowski SC, Webb MR.
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The formation and maintenance of single-stranded DNA (ssDNA) are essential parts of many processes involving DNA. For example, strand separation of double-stranded DNA (dsDNA) is catalyzed by helicases, and this exposure of the bases on the DNA allows further processing, such as replication, recombination, or repair. Assays of helicase activity and probes for their mechanism are essential for understanding related biological processes. Here we describe the development and use of a fluorescent probe to measure ssDNA formation specifically and in real time, with high sensitivity and time resolution. The reagentless biosensor is based on the ssDNA binding protein (SSB) from Escherichia coli, labeled at a specific site with a coumarin fluorophore. Its use in the study of DNA manipulations involving ssDNA intermediates is demonstrated in assays for DNA unwinding, catalyzed by DNA helicases.
Also flagged:Localizationtransmembrane proteinp23ADpathogenesisγ-secretases
Journal Article2008-07-03✓ 1 SnippetVetrivel KS, Kodam A, Gong P, Chen Y, Parent AT, Kar S, Thinakaran G.
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Sequential processing of amyloid precursor protein by beta- and gamma-secretases generates Alzheimer's disease (AD)-associated beta-amyloid peptides. Recently it was reported that the transmembrane protein p23/TMP21 associates with gamma-secretase, and negatively regulates beta-amyloid production. Despite the link between p23 function and AD pathogenesis, the expression of p23 has not been examined in the brain. Here, we describe the detailed immunohistochemical characterization of p23 expression in rodent and human brain. We report that p23 is co-expressed with gamma-secretase subunits in select neuronal cell populations in rodent brain. Interestingly, the steady-state level of p23 in the brain is high during embryonic development and then declines after birth. Furthermore, the steady-state p23 levels are reduced in the brains of individuals with AD. We conclude that p23 is expressed in neurons throughout the brain and the decline in p23 expression during postnatal development may significantly contribute to enhanced beta-amyloid production in the adult brain.
Also flagged:NF-kappaBnetrin-1tumornetrin-1 receptorsdependencecolorectal cancer
Journal Article2008-07-03✓ 2 SnippetsParadisi A, Maisse C, Bernet A, Coissieux MM, Maccarrone M, Scoazec JY, Mehlen P.
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Abstract)
…The level of netrin-1, netrin-1 receptors, ie, DCC, UNC5H1, UNC5H2, UNC5H3, and the proinflammatory markers cyclooxygenase-2 and inhibitor of nuclear factor-kappaB (IkappaB) alpha were analyzed in a panel of 59 primary sporadic colorectal carcinomas.…
<h4>Background & aims</h4>Netrin-1 was recently proposed to play a crucial role during colorectal tumorigenesis by regulating apoptosis. Because netrin-1 receptors belong to the family of dependence receptors, a selective advantage for a tumor is either to lose netrin-1 receptors or to gain autocrine expression of netrin-1. We have investigated whether netrin-1 is up-regulated in colorectal cancer and have searched for a link between NF-kappaB activation and netrin-1 up-regulation.<h4>Methods</h4>The level of netrin-1, netrin-1 receptors, ie, DCC, UNC5H1, UNC5H2, UNC5H3, and the proinflammatory markers cyclooxygenase-2 and inhibitor of nuclear factor-kappaB (IkappaB) alpha were analyzed in a panel of 59 primary sporadic colorectal carcinomas. Netrin-1 expression was investigated in tumor cells and in mouse colonic crypts in response to NF-kappaB activation but also in a mouse model of inflammation-induced colorectal cancer. Binding of NF-kappaB to netrin-1 promoter and effect of NF-kappaB activation to the proapoptotic activity of UNC5H2 were also analyzed.<h4>Results</h4>We show that colorectal tumors with a gain of netrin-1 are tumors that display increased activation of the NF-kappaB pathway. Moreover, netrin-1 up-regulation, which is associated with tumor formation in mice, is observed in mouse colonic crypts in response to NF-kappaB activation but also in a mouse model of inflammation-induced colorectal cancer. We demonstrate that the netrin-1 gene is a direct transcriptional target of NF-kappaB. We show that NF-kappaB-induced netrin-1 expression inhibits proapoptotic activity of the netrin-1 receptors.<h4>Conclusions</h4>We propose that NF-kappaB activation that occurs in response to inflammation confers a selective advantage for tumor development through NF-kappaB-mediated netrin-1 up-regulation.
Also flagged:syntaxin 1ASTX1Aautismpervasive developmental disorderSerotonin transporterserotonin
Journal Article2008-07-02✓ 5 SnippetsNakamura K, Anitha A, Yamada K, Tsujii M, Iwayama Y, Hattori E, Toyota T, Suda S, Takei N, Iwata Y, Suzuki K, Matsuzaki H, Kawai M, Sekine Y, Tsuchiya KJ, Sugihara G, Ouchi Y, Sugiyama T, Yoshikawa T, Mori N.
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…Therefore, factors that regulate 5-HTT expression might be implicated in autism.…
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…Serotonin transporter (5-HTT), which modulates serotonin levels, is a major therapeutic target in autism.…
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…Serotonin transporter (5-HTT), which modulates serotonin…
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…factors that regulate5-HTTexpression might be…
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…One candidate5-HTT-regulatoryprotein is the…
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Autism is a pervasive developmental disorder diagnosed in early childhood. Abnormalities of serotonergic neurotransmission have been reported in autism. Serotonin transporter (5-HTT), which modulates serotonin levels, is a major therapeutic target in autism. Therefore, factors that regulate 5-HTT expression might be implicated in autism. One candidate 5-HTT-regulatory protein is the presynaptic protein, syntaxin 1A (STX1A). We examined the association of STX1A with autism in a trio association study using DNA samples from 249 AGRE trios with autistic probands. Only male probands were selected, since autism is more prevalent among males. The probands of 102 trios had IQ>70, and were considered as high functioning autism (HFA). In transmission disequilibrium test (TDT) analysis, rs2293485 (p=0.034) and rs4717806 (p=0.033) showed nominal associations with HFA; modest haplotype association was also observed. The SNPs that showed associations were related to early developmental abnormalities (ADI-R_D). We further compared STX1A mRNA expression in the lymphocytes of drug-naive HFA patients (n=12) and age- and sex-matched controls (n=13). STX1A expression in the HFA group was significantly higher (p=0.001) than that of controls. Thus, we suggest a possible role of STX1A in the pathogenesis of HFA. During early childhood, there is a period of high brain serotonin synthesis that is disrupted in autistic children; STX1A might influence the serotonergic system during this stage of neurodevelopment, as implied by the association with ADI-R_D.
Also flagged:ironmetabolismoxygenpeptideironsendocrine dysfunctions
Journal Article2008-07-02No SnippetsKohgo Y, Ikuta K, Ohtake T, Torimoto Y, Kato J.
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Iron is an essential metal for the body, while excess iron accumulation causes organ dysfunction through the production of reactive oxygen species. There is a sophisticated balance of body iron metabolism of storage and transport, which is regulated by several factors including the newly identified peptide hepcidin. As there is no passive excretory mechanism of iron, iron is easily accumulated when exogenous iron is loaded by hereditary factors, repeated transfusions, and other diseased conditions. The free irons, non-transferrin-bound iron, and labile plasma iron in the circulation, and the labile iron pool within the cells, are responsible for iron toxicity. The characteristic features of advanced iron overload are failure of vital organs such as liver and heart in addition to endocrine dysfunctions. For the estimation of body iron, there are direct and indirect methods available. Serum ferritin is the most convenient and widely available modality, even though its specificity is sometimes problematic. Recently, new physical detection methods using magnetic resonance imaging and superconducting quantum interference devices have become available to estimate iron concentration in liver and myocardium. The widely used application of iron chelators with high compliance will resolve the problems of organ dysfunction by excess iron and improve patient outcomes.
Also flagged:fluoxetineserotoninanxiety5-HT transporter5-Hydroxytryptamine5-HT1A receptor
Journal Article2008-07-02✓ 2 SnippetsNorcross M, Mathur P, Enoch AJ, Karlsson RM, Brigman JL, Cameron HA, Harvey-White J, Holmes A.
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<h4>Rationale</h4>5-Hydroxytryptamine (5-HT, serotonin) plays a major role in brain ontogeny. Disruption of 5-HT during early postnatal development produces lasting changes in rodent 'emotion-related' behaviors. Adverse effects of treatment with serotonin reuptake inhibitor (SRI) antidepressants have been reported in human adolescents. However, the long-term effects of chronic SRI treatment during adolescence in rodents remain unclear.<h4>Objectives</h4>The objectives of the study are to assess the effects of fluoxetine treatment throughout the adolescent period in measures of fear-, anxiety- and stress-related endpoints in drug-free adults and to examine these effects in two genetic strains of mice differing in baseline stress- and anxiety-related behaviors and sensitivity to SRIs.<h4>Materials and methods</h4>C57BL/6J and BALB/cJ mice received one of two fluoxetine doses for 4 weeks during adolescence (3-7 weeks old). A separate group of C57BL/6J and BALB/cJ mice received fluoxetine for 4 weeks during adulthood (8-12 weeks old). After a 3-week washout period, mice were tested for anxiety-like behaviors (novel open field, elevated plus-maze), fear conditioning and extinction, and stress-related responses to forced swim, as well as serotonin brain levels.<h4>Results</h4>Adolescent fluoxetine treatment did not increase adult measures of anxiety-, fear- or stress-related behaviors, or brain serotonin levels. The same duration of treatment in adulthood also had no effects on these measures when tested after a 3-week washout period.<h4>Conclusions</h4>In clear contrast with emotion-related abnormalities caused by preadolescent fluoxetine treatment or genetic inactivation of fluoxetine's pharmacological target, the 5-HT transporter, fluoxetine treatment throughout mouse adolescence did not produce detectable, lasting abnormalities in either "high" or "low anxiety" inbred mouse strains.
In the search of facile and efficient methods for cellular delivery of peptide nucleic acids (PNA), we have synthesized PNAs conjugated to oligophosphonates via phosphonate glutamine and bis-phosphonate lysine amino acid derivatives thereby introducing up to twelve phosphonate moieties into a PNA oligomer. This modification of the PNA does not interfere with the nucleic acid target binding affinity based on thermal stability of the PNA/RNA duplexes. When delivered to cultured HeLa pLuc705 cells by Lipofectamine, the PNAs showed dose-dependent nuclear antisense activity in the nanomolar range as inferred from induced luciferase activity as a consequence of pre-mRNA splicing correction by the antisense-PNA. Antisense activity depended on the number of phosphonate moieties and the most potent hexa-bis-phosphonate-PNA showed at least 20-fold higher activity than that of an optimized PNA/DNA hetero-duplex. These results indicate that conjugation of phosphonate moieties to the PNA can dramatically improve cellular delivery mediated by cationic lipids without affecting on the binding affinity and sequence discrimination ability, exhibiting EC(50) values down to one nanomolar. Thus the intracellular efficacy of PNA oligomers rival that of siRNA and the results therefore emphasize that provided sufficient in vivo bioavailability of PNA can be achieved these molecules may be developed into potent gene therapeutic drugs.
Also flagged:oxygennitric oxidepsychological distressgene expressionmetabolismphosphorylation
Journal Article2008-07-02No SnippetsDusek JA, Otu HH, Wohlhueter AL, Bhasin M, Zerbini LF, Joseph MG, Benson H, Libermann TA.
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<h4>Background</h4>Mind-body practices that elicit the relaxation response (RR) have been used worldwide for millennia to prevent and treat disease. The RR is characterized by decreased oxygen consumption, increased exhaled nitric oxide, and reduced psychological distress. It is believed to be the counterpart of the stress response that exhibits a distinct pattern of physiology and transcriptional profile. We hypothesized that RR elicitation results in characteristic gene expression changes that can be used to measure physiological responses elicited by the RR in an unbiased fashion.<h4>Methods/principal findings</h4>We assessed whole blood transcriptional profiles in 19 healthy, long-term practitioners of daily RR practice (group M), 19 healthy controls (group N(1)), and 20 N(1) individuals who completed 8 weeks of RR training (group N(2)). 2209 genes were differentially expressed in group M relative to group N(1) (p<0.05) and 1561 genes in group N(2) compared to group N(1) (p<0.05). Importantly, 433 (p<10(-10)) of 2209 and 1561 differentially expressed genes were shared among long-term (M) and short-term practitioners (N(2)). Gene ontology and gene set enrichment analyses revealed significant alterations in cellular metabolism, oxidative phosphorylation, generation of reactive oxygen species and response to oxidative stress in long-term and short-term practitioners of daily RR practice that may counteract cellular damage related to chronic psychological stress. A significant number of genes and pathways were confirmed in an independent validation set containing 5 N(1) controls, 5 N(2) short-term and 6 M long-term practitioners.<h4>Conclusions/significance</h4>This study provides the first compelling evidence that the RR elicits specific gene expression changes in short-term and long-term practitioners. Our results suggest consistent and constitutive changes in gene expression resulting from RR may relate to long term physiological effects. Our study may stimulate new investigations into applying transcriptional profiling for accurately measuring RR and stress related responses in multiple disease settings.
Also flagged:5-HT1B receptorsleep3,4-methylenedioxymethamphetamine5-hydroxytryptamine-1B5-HT(1B)) receptor5-HT(1B) receptor
Journal Article2008-07-02✓ 1 SnippetGyongyosi N, Balogh B, Kirilly E, Kitka T, Kantor S, Bagdy G.
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…5-HT transporter (5-HTT) immunohistochemistry was mea…
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The possible long-term effects of the recreational drug "ecstasy" (3,4-methylenedioxymethamphetamine, MDMA) on the function of 5-hydroxytryptamine-1B (5-HT(1B)) receptor in sleep and motor control were investigated using a selective 5-HT(1B) receptor agonist, 5-propoxy-3-(1,2,3,6-tetrahydro-4-pyrinzidyl)-1H-pyrrolo([3,2-b])pyridine hydrochloride (CP-94,253; 5 mg/kg). CP-94,253 or vehicle was administered to freely moving rats pre-treated with MDMA (15 mg/kg) or vehicle 6 months earlier, and polygraphic recording for 24 h and motor activity measurements were performed. Active wake (AW), passive wake (PW), light slow wave sleep (SWS-1), deep slow wave sleep (SWS-2), paradoxical sleep (PS), and diurnal rhythm were analyzed for the whole period. In additional, the EEG power spectrum was calculated for the second hour after the acute treatment for AW, PW, SWS-1, and SWS-2. 5-HT transporter (5-HTT) immunohistochemistry was measured in brain areas related to sleep and motor control 6 months after MDMA treatment. CP-94,253 increased AW and PW, decreased SWS-2 and PS, and altered parameters of diurnal rhythm in control animals. CP-94,253 decreased the EEG power spectra at higher frequencies. The effects of CP-94,253 on AW and diurnal rhythm were reduced or eliminated in MDMA-treated animals. MDMA treatment decreased 5-HTT fibre density in posterior hypothalamus, tuberomammillary nucleus, caudate putamen and ventrolateral striatum. These data suggest that long-term changes in 5-HT(1B) receptor function occur after serotonergic damage caused by a single dose of MDMA.
Also flagged:fibrinogenclottingHaemostasisintravascular coagulationstrokecancer
Journal Article2008-07-01✓ 1 SnippetXu Z, Chen N, Kamocka MM, Rosen ED, Alber M.
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A two-dimensional multiscale model is introduced for studying formation of a thrombus (clot) in a blood vessel. It involves components for modelling viscous, incompressible blood plasma; non-activated and activated platelets; blood cells; activating chemicals; fibrinogen; and vessel walls and their interactions. The macroscale dynamics of the blood flow is described by the continuum Navier-Stokes equations. The microscale interactions between the activated platelets, the platelets and fibrinogen and the platelets and vessel wall are described through an extended stochastic discrete cellular Potts model. The model is tested for robustness with respect to fluctuations of basic parameters. Simulation results demonstrate the development of an inhomogeneous internal structure of the thrombus, which is confirmed by the preliminary experimental data. We also make predictions about different stages in thrombus development, which can be tested experimentally and suggest specific experiments. Lastly, we demonstrate that the dependence of the thrombus size on the blood flow rate in simulations is close to the one observed experimentally.
Also flagged:Peroxiredoxin 6bindinglipidphospholipidhydroperoxidespropidium iodide
Journal Article2008-07-01✓ 5 SnippetsWang Y, Feinstein SI, Fisher AB.
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…We evaluated the antioxidant role of peroxiredoxin 6 (Prdx6) in primary lung alveolar epithelial type II cells (AEC II) that were isolated from wild type (WT), Prdx6-/-, or Prdx6 transgenic (Tg) overexpressing mice and exposed to H(2)O(2) at 50-500 microM for 1-24 h.…
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…of peroxiredoxin 6 (Prdx6) in primary lung…
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…Prdx6null AEC II…
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…was least inPrdx6Tg cells.…
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…Thus,Prdx6functions as an…
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We evaluated the antioxidant role of peroxiredoxin 6 (Prdx6) in primary lung alveolar epithelial type II cells (AEC II) that were isolated from wild type (WT), Prdx6-/-, or Prdx6 transgenic (Tg) overexpressing mice and exposed to H(2)O(2) at 50-500 microM for 1-24 h. Expression of Prdx6 in Tg AEC II was sevenfold greater than WT. Prdx6 null AEC II exposed to H(2)O(2) showed concentration-dependent cytotoxicity indicated by decreased "live/dead" cell ratio, increased propidium iodide (PI) staining, increased annexin V binding, increased DNA fragmentation by TUNEL assay, and increased lipid peroxidation by diphenylpyrenylphosphine (DPPP) fluorescence. Compared to Prdx6 null cells, oxidant-mediated damage was significantly less in WT AEC II and was least in Prdx6 Tg cells. Thus, Prdx6 functions as an antioxidant enzyme in mouse AEC II. Prdx6 has been shown previously to reduce phospholipid hydroperoxides and we postulate that this activity is a major mechanism for the effectiveness of Prdx6 as an antioxidant enzyme.
Also flagged:MAOmonoamine oxidase5-HT transportereating disordersBulimia
Journal Article2008-07-01✓ 1 SnippetAkkermann K, Paaver M, Nordquist N, Oreland L, Harro J.
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…Association of5-HTTgene polymorphism, platelet…
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<h4>Objective</h4>Several lines of evidence suggest that alterations in serotonergic activity contribute to the pathophysiology of abnormal eating behaviors. Since platelet monoamine oxidase (MAO) activity and the 5-HT transporter gene promoter polymorphism (5-HTTLPR) have been associated with eating disorders, the knowledge from a population-based sample may provide useful information which changes in 5-HT function observed in eating disorders represent trait vs. state effects.<h4>Method</h4>The sample was based on both cohorts of the Estonian Children Personality, Behavior and Health Study (ECPBHS). The current study was conducted during the second follow-up where altogether 82% from the original sample was recruited. EDI-2 subscales--Drive for Thinness and Bulimia--were used to determine eating attitudes and behaviors. Platelet MAO activity was measured and the participants were genotyped for the 5-HTTLPR.<h4>Results</h4>Allelic variation of 5-HTTLPR or platelet MAO activity were not independently associated with drive for thinness or binge eating, but girls homozygous for the 5-HTTLPR long allele and with high platelet MAO activity, both considered indicators of a higher capacity 5-HT system, exhibited higher scores of drive for thinness.<h4>Conclusion</h4>The results suggest that drive for thinness is the highest in girls with the presence of two markers of higher serotonergic capacity.
Also flagged:signal transductionimmune responsesphosphorylationCYLDimmune responseE3 ligases
Journal Article2008-07-01No SnippetsSun SC.
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Ubiquitylation is a fundamental mechanism of signal transduction that regulates immune responses and many other biological processes. Similar to phosphorylation, ubiquitylation is a reversible process that is counter-regulated by ubiquitylating enzymes and deubiquitylating enzymes (DUBs). Despite the identification of a large number of DUBs, our knowledge of the function and activities of this family of enzymes is just starting to accumulate. As described in this Review, recent studies of several DUBs, in particular CYLD and A20, show that deubiquitylation has an important role in the regulation of both innate and adaptive immune responses.
…Identification and allele-specific silencing of the mutant huntingtin allele in Huntington's disease patient-derived fibroblasts.…
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…Huntington's disease (HD) is a dominantly inherited neurodegenerative disorder caused by the expression of mutant huntingtin protein (Htt).…
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…mutant huntingtin protein (Htt).…
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…Suppression ofHttexpression, using RNA…
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…of endogenous mutantHttprotein, using this…
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Huntington's disease (HD) is a dominantly inherited neurodegenerative disorder caused by the expression of mutant huntingtin protein (Htt). Suppression of Htt expression, using RNA interference, might be an effective therapy. However, if reduction of wild-type protein is not well tolerated in the brain, it may be necessary to suppress just the product of the mutant allele. We present a small interfering RNA (siRNA) that selectively reduces the endogenous mRNA for a heterozygous HD donor's pathogenic allele by approximately 80% by specifically targeting a single-nucleotide polymorphism (SNP) located several thousand bases downstream from the disease-causing mutation. In addition, we show selective suppression of endogenous mutant Htt protein, using this siRNA. We further present a method, using just a heterozygous patient's own mRNA, to determine which SNP variants correspond to the mutant allele. The method may be useful in any disorder in which a targeted SNP is far downstream from the pathogenic mutation. These results indicate that allele-specific treatment for Huntington's disease may be clinically feasible and practical.
Also flagged:Viral infectionironmetabolismsynthesisbindingtransferrin receptor 1
Journal Article2008-07-01✓ 1 SnippetDrakesmith H, Prentice A.
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…homeostasis, such asHFEand hepcidin.…
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Fundamental cellular operations, including DNA synthesis and the generation of ATP, require iron. Viruses hijack cells in order to replicate, and efficient replication needs an iron-replete host. Some viruses selectively infect iron-acquiring cells by binding to transferrin receptor 1 during cell entry. Other viruses alter the expression of proteins involved in iron homeostasis, such as HFE and hepcidin. In HIV-1 and hepatitis C virus infections, iron overload is associated with poor prognosis and could be partly caused by the viruses themselves. Understanding how iron metabolism and viral infection interact might suggest new methods to control disease.
Also flagged:STAT-1MHCneonatal Fc receptorFcRnMHC class IIgG
Journal Article2008-07-01✓ 1 SnippetLiu X, Ye L, Bai Y, Mojidi H, Simister NE, Zhu X.
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…chromatin modifiers…
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Expression of many MHC genes is enhanced at the transcriptional or posttranscriptional level following exposure to the cytokine IFN-gamma. However, in this study we found that IFN-gamma down-regulated the constitutive expression of the neonatal Fc receptor (FcRn), an MHC class I-related molecule that functions to transport maternal IgG and protect IgG and albumin from degradation. Epithelial cell, macrophage-like THP-1 cell, and freshly isolated human PBMC exposure to IFN-gamma resulted in a significant decrease of FcRn expression as assessed by real-time RT-PCR and Western blotting. The down-regulation of FcRn was not caused by apoptosis or the instability of FcRn mRNA. Chromatin immunoprecipitation and gel mobility shift assays showed that STAT-1 bound to an IFN-gamma activation site in the human FcRn promoter region. Luciferase expression from an FcRn promoter-luciferase reporter gene construct was not altered in JAK1- and STAT-1-deficient cells following exposure to IFN-gamma, whereas expression of JAK1 or STAT-1 protein restored the IFN-gamma inhibitory effect on luciferase activity. The repressive effect of IFN-gamma on the FcRn promoter was selectively reversed or blocked by mutations of the core nucleotides in the IFN-gamma activation site sequence and by overexpression of the STAT-1 inhibitor PIAS1 or the dominant negative phospho-STAT-1 mutations at Tyr-701 and/or Ser-727 residues. Furthermore, STAT-1 might down-regulate FcRn transcription through sequestering the transcriptional coactivator CREB binding protein/p300. Functionally, IFN-gamma stimulation dampened bidirectional transport of IgG across a polarized Calu-3 lung epithelial monolayer. Taken together, our results indicate that the JAK/STAT-1 signaling pathway was necessary and sufficient to mediate the down-regulation of FcRn gene expression by IFN-gamma.
Also flagged:gene expressionTP53CDKN1AFDXRSESN1BBC3
Journal Article2008-07-01No SnippetsPaul S, Amundson SA.
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<h4>Purpose</h4>In a large-scale radiologic emergency, estimates of exposure doses and radiation injury would be required for individuals without physical dosimeters. Current methods are inadequate for the task, so we are developing gene expression profiles for radiation biodosimetry. This approach could provide both an estimate of physical radiation dose and an indication of the extent of individual injury or future risk.<h4>Methods and materials</h4>We used whole genome microarray expression profiling as a discovery platform to identify genes with the potential to predict radiation dose across an exposure range relevant for medical decision making in a radiologic emergency. Human peripheral blood from 10 healthy donors was irradiated ex vivo, and global gene expression was measured both 6 and 24 h after exposure.<h4>Results</h4>A 74-gene signature was identified that distinguishes between four radiation doses (0.5, 2, 5, and 8 Gy) and controls. More than one third of these genes are regulated by TP53. A nearest centroid classifier using these same 74 genes correctly predicted 98% of samples taken either 6 h or 24 h after treatment as unexposed, exposed to 0.5, 2, or > or =5 Gy. Expression patterns of five genes (CDKN1A, FDXR, SESN1, BBC3, and PHPT1) from this signature were also confirmed by real-time polymerase chain reaction.<h4>Conclusion</h4>The ability of a single gene set to predict radiation dose throughout a window of time without need for individual pre-exposure controls represents an important advance in the development of gene expression for biodosimetry.
Hepatopulmonary syndrome is an uncommon complication of nonacute liver failure, and in rare cases, hypoxia may be the presenting sign of liver dysfunction. The condition, once thought to be a contraindication, is improved in most cases by transplantation. There is a significant risk of postoperative, hypoxia-related morbidity and mortality in patients with hepatopulmonary syndrome. We present a case of life-threatening hypoxia following liver transplantation for liver failure and associated hepatopulmonary syndrome, with successful management using extracorporeal membrane oxygenation.
Also flagged:ironglutathioneoral canceroral cavity cancerpremalignancyzinc
Journal Article2008-07-01✓ 1 SnippetRichie JP, Kleinman W, Marina P, Abraham P, Wynder EL, Muscat JE.
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…hemochromatosis…
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The risk of oral cavity cancer was determined in relation to serological levels of iron; vitamins A, B2, C, E; zinc; thiamin; and glutathione (GSH). The study included 65 hospitalized patients with oral cancer and 85 matched controls. In comparing the highest to the lowest tertiles, the risk was odds ratio (OR) = 0.3 [95% confidence interval (CI) = 0.1-0.6] for iron; 3.2 (95% CI = 1.3-8.1) for total iron binding capacity (TIBC), which measures the concentration of the iron delivery protein transferrin; and 0.4 (95% CI = 0.2-0.9) for transferrin saturation (iron/TIBC x 100). These associations were stronger in never smokers than in ever smokers. The risk associated with the iron storage protein ferritin was significantly elevated, but this association could reflect disease-related inflammation or comorbidity. The OR for GSH was 0.4 (95% CI = 0.1-0.9), and the OR for GSH reductase activity coefficient (indicative of riboflavin deficiency) was 1.6 (95% CI = 1.3-3.7). These findings suggest that mild iron deficiency and low GSH levels, which are associated with increased oxidative stress, increase the risk of oral cavity cancer.
Also flagged:huntingtin-associated protein 1bindingHAP1Huntingtin Associated Protein 1GFPlocalization
Journal Article2008-07-01✓ 1 SnippetMercer KB, Szlam SM, Manning E, Gernert KM, Walthall WW, Benian GM, Gutekunst CA.
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…htt…
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Huntingtin-associated protein 1 (HAP1) is a binding partner for huntingtin, the protein responsible for Huntington's disease. In mammals, HAP1 is mostly found in brain where it is expressed in neurons. Although several functions have been proposed for HAP1, its role has not yet been clearly established. In this paper, we report on the identification of a HAP1 Caenorhabditis elegans homolog called T27A3.1. T27A3.1 shows conservation with rat and human HAP1, as well as with Milton, a Drosophila HAP1 homolog. To determine the cellular expression of T27A3.1 (multiple isoforms; a-e), we generated several transgenic worm lines expressing a fluorescent reporter protein [green fluorescent protein (GFP) and DsRed2] under the control of the promoter for T27A3.1. We have found that T27A3.1 is expressed in many cell types including a subset of chemosensory neurons in the head and tail. These include the amphid chemosensory neurons ASKL and R, ASIL and R, ADFL and ASEL, the phasmid neurons PHBL and R, and the CAN neurons that are required for worm survival.
Also flagged:Antimicrobial Peptidespeptidessynthesisoxanorbornenehost-defenseantibodies
Journal Article2008-07-01No SnippetsLienkamp K, Madkour AE, Musante A, Nelson CF, Nüsslein K, Tew GN.
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Synthetic Mimics of Antimicrobial Peptides (SMAMPs) imitate natural host-defense peptides, a vital component of the body's immune system. This work presents a molecular construction kit that allows the easy and versatile synthesis of a broad variety of facially amphiphilic oxanorbornene-derived monomers. Their ring-opening metathesis polymerization (ROMP) and deprotection provide several series of SMAMPs. Using amphiphilicity, monomer feed ratio, and molecular weight as parameters, polymers with 533 times higher selectivitiy (selecitviy = hemolytic concentration/minimum inhibitory concentration) for bacteria over mammalian cells were discovered. Some of these polymers were 50 times more selective for Gram-positive over Gram-negative bacteria while other polymers surprisingly showed the opposite preference. This kind of "double selectivity" (bacteria over mammalian and one bacterial type over another) is unprecedented in other polymer systems and is attributed to the monomer's facial amphiphilicity.
Journal Article2008-07-01No SnippetsGough MJ, Ruby CE, Redmond WL, Dhungel B, Brown A, Weinberg AD.
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Acquisition of full T-cell effector function and memory differentiation requires appropriate costimulatory signals, including ligation of the costimulatory molecule OX40 (TNFRSF4, CD134). Tumors often grow despite the presence of tumor-specific T cells and establish an environment with weak costimulation and immune suppression. Administration of OX40 agonists has been shown to significantly increase the survival of tumor-bearing mice and was dependent on the presence of both CD4 and CD8 T cells during tumor-specific priming. To understand how OX40 agonists work in mice with established tumors, we developed a model to study changes in immune cell populations within the tumor environment. We show here that systemic administration of OX40 agonist antibodies increased the proportion of CD8 T cells at the tumor site in three different tumor models. The function of the CD8 T cells at the tumor site was also increased by administration of OX40 agonist antibody, and we observed an increase in the proportion of antigen-specific CD8 T cells within the tumor. Despite decreases in the proportion of T regulatory cells at the tumor site, T regulatory cell function in the spleen was unaffected by OX40 agonist antibody therapy. Interestingly, administration of OX40 agonist antibody caused significant changes in the tumor stroma, including decreased macrophages, myeloid-derived suppressor cells, and decreased expression of transforming growth factor-beta. Thus, therapies targeting OX40 dramatically changed the tumor environment by enhancing the infiltration and function of CD8 T cells combined with diminished suppressive influences within the tumor.
Also flagged:methylationhead and neck squamous cell carcinomastumourCDKN2ACCNA1hypermethylation
Journal Article2008-07-01✓ 5 SnippetsTan HK, Saulnier P, Auperin A, Lacroix L, Casiraghi O, Janot F, Fouret P, Temam S.
In-Text Gene Mentions
Methods)
…As methylation of CDKN2A, CCNA1 and DCC exist only in very low levels in normal cells (Carvalho et al, 2006; Shaw et al, 2006), we calculated a separate index, which we termed as the weighted tumour methylation index (WTMI) to better reflect methylation levels in the tumour cells:…
Discussion)
…Performing QMSP with a panel of three genes (CDKN2A, CCNA1 and DCC), we found 64% of HNSCC tumours were hypermethylation informative.…
Discussion)
…The possible presence of LOH in CDKN2A (Koscielny et al, 2007) and DCC (Papadimitrakopoulou et al, 1998) may increase the likelihood of tumours being non-informative for these two markers.…
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…We utilised QMSP to interrogate the methylation profiles of CDKN2A, CCNA1 and DCC in the resection margins in a cohort of patients who underwent curative resections of HNSCCs.…
Results)
…Quantitative MSP of the three selected genes CDKN2A, CCNA1 and DCC was performed on 42 tumours.…
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This study sought to determine whether the presence of hypermethylated genes in the surgical margins can predict local recurrences in head and neck squamous cell carcinomas (HNSCCs). We prospectively collected tumour and surgical margin specimens from patients with HNSCCs who had undergone surgical resections. Quantitative methylation-specific PCR (QMSP) of CDKN2A, CCNA1 and DCC were performed in these specimens and correlated with clinical data. Of the 42 patients eligible for the study, 27 were hypermethylation informative for the above three genes. This latter group was associated with longer disease-free survivals (P=0.007) and longer time to disease-specific deaths (P=0.004). Multivariate analyses confirmed hypermethylation non-informative tumours as an independent prognosticating factor for disease-specific deaths (risk ratio 3.8, P=0.026). Quantitative MSP of the margins of 24 hypermethylation informative tumours revealed that 11 patients had molecularly positive margins, of which, five developed disease-specific events (DSEs, three local recurrences and two metastases), compared to none in patients with molecularly negative margins, after a median follow-up of 48 months. Log-rank analyses showed that molecularly positive margins were associated with shorter time to local recurrences and disease-specific deaths (P=0.03 and 0.01, respectively). This study demonstrated that QMSP of hypermethylated promoters in surgical margins predicted all the local recurrences in our series of HNSCC patients. We have also identified hypermethylation non-informative tumours as an independent predictor for the development of DSEs.
Also flagged:arthritisRheumatoid arthritisRAautoimmune diseasepathogenesisautoimmune arthritis
Journal Article2008-07-01No SnippetsXiong Q, Jiao Y, Hasty KA, Stuart JM, Postlethwaite A, Kang AH, Gu W.
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Rheumatoid arthritis (RA) is an autoimmune disease, the pathogenesis of which is affected by multiple genetic and environmental factors. To understand the genetic and molecular basis of RA, a large number of quantitative trait loci (QTL) that regulate experimental autoimmune arthritis have been identified using various rat models for RA. However, identifying the particular responsible genes within these QTL remains a major challenge. Using currently available genome data and gene annotation information, we systematically examined RA-associated genes and polymorphisms within and outside QTL over the whole rat genome. By the whole genome analysis of genes and polymorphisms, we found that there are significantly more RA-associated genes in QTL regions as contrasted with non-QTL regions. Further experimental studies are necessary to determine whether these known RA-associated genes or polymorphisms are genetic components causing the QTL effect.
<h4>Background</h4>Although an autoimmune mechanism has been postulated for myocarditis and acute-onset inflammatory dilated cardiomyopathy (DCM), immunomodulatory treatment strategies are still under investigation.<h4>Methods and results</h4>The clinical data of six patients with acute inflammatory DCM referred for evaluation for possible heart transplantation were reviewed. All patients were admitted with acute congestive heart failure and severely impaired left ventricular (LV) function and were treated with high-dose (2 g/kg) intravenous immunoglobulin (IVIG). The diagnosis of acute inflammatory DCM was based on recent onset of congestive heart failure (New York Heart Association functional class III or IV) with severely depressed LV ejection fraction ([LVEF] 30% or lower) occurring shortly after viral-like illness. All patients had inflammation on endomyocardial biopsy or elevated cardiac enzymes, as well as a normal coronary angiogram. All patients were in New York Heart Association class I or II at the time of hospital discharge. The mean LVEF improved from 21.7+/-7.5% at baseline to 50.3+/-8.6% at discharge (P=0.005). Four patients had complete recovery (LVEF 50% or higher) and two patients had partial LV recovery. Patients were followed for a median 13.2 months (range two to 24 months) and had a mean LVEF of 53+/-6% (P not significant versus LVEF at discharge).<h4>Conclusions</h4>Therapy with intravenous high-dose IVIG may be a potentially useful treatment in selected patients if given early in the course of acute fulminant inflammatory DCM. A randomized, prospective trial is warranted to prove the real benefit of IVIG in this patient population.
Also flagged:retrograde amnesiaserotonin transporteranxietydepressionserotoninbinding
Journal Article2008-07-01✓ 5 SnippetsStrange BA, Kroes MC, Roiser JP, Tan GC, Dolan RJ.
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Abstract)
…Here, we demonstrate that whereas emotional memory for aversive events per se is not influenced by 5-HTT polymorphism, an emotion-induced retrograde amnesia is expressed solely in the presence of the short allele.…
Title)
…Emotion-induced retrograde amnesia is determined by a 5-HTT genetic polymorphism.…
Abstract)
…A polymorphism in the human serotonin transporter (5-HTT) gene is implicated in susceptibility to anxiety and depression and in enhanced emotion-induced activation in the amygdala.…
Title)
…determined by a5-HTTgenetic polymorphism.…
Abstract)
…human serotonin transporter (5-HTT) gene is implicated…
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A polymorphism in the human serotonin transporter (5-HTT) gene is implicated in susceptibility to anxiety and depression and in enhanced emotion-induced activation in the amygdala. A role for 5-HTT polymorphism in the emotional modulation of human episodic memory has yet to be demonstrated. Here, we demonstrate that whereas emotional memory for aversive events per se is not influenced by 5-HTT polymorphism, an emotion-induced retrograde amnesia is expressed solely in the presence of the short allele. The findings indicate a critical role for the serotonin system in emotion-mediated memory disruption.
Also flagged:peroxidasephenylhydrazineHRPhydroquinoneactivity
Journal Article2008-07-01No SnippetsYang ZS, Wu WL, Chen X, Liu YC.
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An amperometric horseradish peroxidase (HRP) inhibition biosensor has been substantially constructed by the help of N,N-dicyclohexylcarbodiimide (DCC), N-hydroxysuccinimide (NHS). The preparation steps and the biosensor response to phenylhydrazine were monitored by electrochemical impedance spectroscopy (EIS), cyclic voltammetry, and chronoamperometry. The proposed biosensor could be applied to determine phenylhydrazine in a 0.10 M phosphate buffer solution containing 1.2 mM hydroquinone and 0.50 mM H(2)O(2) by phenylhydrazine, inhibiting the catalytic activity of the HRP enzyme in the reduction of H(2)O(2). The system was optimized to realize a reliable determination of phenylhydrazine in the range of 2.5 x 10(-7) to 1.1 x 10(-6) M with a detection limit of 8.2 x 10(-8) M and a correlation coefficient of 0.999. The modified electrode displayed good reproducibility, sensitivity and stability for the determination of phenylhydrazine.
Also flagged:HIV-1 infectioncell activationimmunoglobulinAIDShypergammaglobulinemiaNF-κB
Journal Article2008-07-01✓ 1 SnippetSwingler S, Zhou J, Swingler C, Dauphin A, Greenough T, Jolicoeur P, Stevenson M.
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…HFE…
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B lymphocyte hyperactivation and elevated immunoglobulin levels (hypergammaglobulinemia) are pathogenic manifestations of HIV-1 infection. Here we provide evidence that these hallmarks are caused by a soluble factor whose production by infected macrophages is induced by the HIV-1 Nef protein. In vitro, HIV-1-infected macrophages or macrophages expressing Nef promoted B cell activation and differentiation to immunoglobulin-secreting cells. Nef-mediated activation of NF-kappaB in macrophages induced secretion of the acute-phase protein ferritin, and ferritin was necessary and sufficient for the observed Nef-dependent B cell changes. The extent of hypergammaglobulinemia in HIV-1-infected individuals correlated directly with plasma ferritin levels and with viral load. Furthermore, the induction of ferritin production and hypergammaglobulinemia was recapitulated when Nef was specifically expressed in macrophages and T cells of transgenic mice. Collectively, these results indicate that the HIV-1 Nef protein carries a pathogenic determinant that governs B cell defects in HIV-1 infection.
Also flagged:Trim11neurogenic transcription factortranscription factorPax6embryogenesisTRIM
Journal Article2008-07-01✓ 1 SnippetTuoc TC, Stoykova A.
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…Htt…
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The transcription factor Pax6 is an important developmental regulator. Spatiotemporal control of Pax6 expression during embryogenesis is crucial for regulating distinct aspects of cortical development. Here, we report that Trim11, a member of the TRIM/RBCC protein family of E3 ubiquitin ligases, interacts with Pax6 and mediates Pax6 degradation via the ubiquitin-proteasome system. Trim11 overexpression decreases endogenous Pax6 protein levels and represses Pax6 functions, including Pax6-dependent transactivation and neurogenesis. Abrogation of endogenous Trim11 expression in the developing cortex increases the level of insoluble forms of Pax6 and enhances apoptosis. We provide evidence that the B30.2 domain of Trim11 is essential for the clearance of insoluble cell proteins. Furthermore, we show that the expression of Trim11 is directly regulated by Pax6 in developing cortex in vivo. Our findings indicate that an autoregulatory feedback loop between Trim11 and Pax6 maintains a balance between the levels of Pax6 and Trim11 proteins in cortical progenitors, having an essential role for the Pax6-dependent neurogenesis.
<h4>Background</h4>Androgens are critical for specifying prostate development, with the fetal prostate sensitive to altered hormone levels and endocrine-disrupting chemicals (EDCs) that exhibit estrogenic or antiandrogenic properties. Prostatic inflammation (prostatitis) affects 9% of men of all ages, and > 90% of cases are of unknown etiology.<h4>Objectives</h4>In this study we aimed to evaluate effects of in utero exposure to the antiandrogenic EDC vinclozolin, during the period of male reproductive tract development, on neonatal, prepubertal, and postpubertal prostate gland function of male offspring.<h4>Methods</h4>Fetal rats were exposed to vinclozolin (100 mg/kg body weight) or vehicle control (2.5 mL/kg body weight) in utero from gestational day 14 (GD14) to GD19 via oral administration to pregnant dams. Tissue analysis was carried out when male offspring were 0, 4, or 8 weeks of age.<h4>Results</h4>In utero exposure to vinclozolin was insufficient to perturb prostatic development and branching, although expression of androgen receptor and mesenchymal fibroblast growth factor-10 was down-regulated. Prostate histology remained normal until puberty, but 100% of animals displayed prostatitis postpubertally (56 days of age). Prostatic inflammation was associated with phosphorylation and nuclear translocation of nuclear factor-kappa B (NFkappaB) and postpubertal activation of proinflammatory NFkappaB-dependent genes, including the chemokine interleukin-8 and the cytokine transforming growth factor-beta1. Significantly, inflammation arising from vinclozolin exposure was not associated with the emergence of premalignant lesions, such as prostatic intra-epithelial neoplasia or proliferative inflammatory atrophy, and hence mimics nonbacterial early-onset prostatitis that commonly occurs in young men.<h4>Conclusions</h4>These data are the first to unequivocally implicate EDCs as a causative factor and fill an important knowledge gap on the etiology of prostatitis.
Also flagged:chromosomemetaphasechromosomessister-chromatidanaphasetopoisomerase II
Journal Article2008-07-01✓ 2 SnippetsD'Ambrosio C, Kelly G, Shirahige K, Uhlmann F.
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Title)
…Condensin-dependent rDNA decatenation i…
Abstract)
…Condensinand topo II…
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The chromosomal condensin complex gives metaphase chromosomes structural stability. In addition, condensin is required for sister-chromatid resolution during their segregation in anaphase [1-7]. How condensin promotes chromosome resolution is poorly understood. Chromosome segregation during anaphase also fails after inactivation of topoisomerase II (topo II), the enzyme that removes catenation between sister chromatids left behind after completion of DNA replication [8, 9]. This has led to the proposal that condensin promotes DNA decatenation [3, 10, 11], but direct evidence for this is missing and alternative roles for condensin in chromosome resolution have been suggested [12-14]. Using the budding-yeast rDNA as a model, we now show that anaphase bridges in a condensin mutant are resolved by ectopic expression of a foreign (Chlorella virus) but not endogenous topo II. This suggests that catenation prevents sister-rDNA segregation but that yeast topo II is ineffective in decatenating the locus without condensin. Condensin and topo II colocalize along both rDNA and euchromatin, consistent with coordination of their activities. We investigate the physiological consequences of condensin-dependent rDNA decatenation and find that late decatenation determines the late segregation timing of this locus during anaphase. Regulation of decatenation therefore provides a means to fine tune the segregation timing of chromosomes in mitosis.
Also flagged:viral hepatitisalcoholnonalcoholic fatty liver diseaseautoimmune liver diseaseshereditary diseaseshepatobiliary malignancies
Journal Article2008-07-01✓ 1 SnippetShimizu Y.
In-Text Gene Mentions
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…hemochromatosis…
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Potential causes of abnormal liver function tests include viral hepatitis, alcohol intake, nonalcoholic fatty liver disease, autoimmune liver diseases, hereditary diseases, hepatobiliary malignancies or infection, gallstones and drug-induced liver injury. Moreover, the liver may be involved in systemic diseases that mainly affect other organs. Therefore, in patients without etiology of liver injury by screening serology and diagnostic imaging, but who have systemic diseases, the abnormal liver function test results might be caused by the systemic disease. In most of these patients, the systemic disease should be treated primarily. However, some patients with systemic disease and severe liver injury or fulminant hepatic failure require intensive treatments of the liver.
Also flagged:Chronic hepatitis C infectionChronic) infectionmixed cryoglobulinemiaB-cell lymphoproliferative disordersHCV infection
Journal Article2008-07-01✓ 1 SnippetBethlen S, Chandrikakumari K, de Leval L, Giot JB, Mukeba D, Leonard P, Frippiat F, Meuris C, Delwaide J, Moutschen M.
In-Text Gene Mentions
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…hemochromatosis…
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Chronic hepatitis C virus (HCV) infection is associated with multifarious extra-hepatic manifestations; the most described and discussed being mixed cryoglobulinemia which is strongly related to B-cell lymphoproliferative disorders (LPDs). We present a case of chronic HCV infection and mixed cryoglobulinemia, with minimal liver involvement. The case is a 53-year-old patient who was diagnosed as having bone marrow hypoplasia at the age of three. She received several blood transfusions to normalize her haemoglobin. At the age of 31, she was diagnosed with rheumatoid arthritis on account of her diffuse joint pain and inflammation, elevated rheumatoid factor (RF) and Raynaud's phenomenon. Twenty years later, monoclonal gammopathy of IgG Lambda (one year later, changed to IgM Kappa) was detected during a routine examination. A bone marrow biopsy showed hypoplasia, Kappa positive B-lymphocytes and low-grade malignant lymphoma cells. PCR of the bone marrow aspirate was not contributory. No treatment was initiated owing to her poor bone marrow function and she is under regular follow-up.
Also flagged:ribonucleoproteinlocalizationsynapsestranslationallydendritesribonucleoprotein particles
Journal Article2008-07-01✓ 1 SnippetZeitelhofer M, Karra D, Macchi P, Tolino M, Thomas S, Schwarz M, Kiebler M, Dahm R.
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…Stau1…
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The dendritic localization of mRNAs and their subsequent translation at stimulated synapses contributes to the experience-dependent remodeling of synapses and thereby to the establishment of long-term memory. Localized mRNAs are transported in a translationally silent manner to distal dendrites in specific ribonucleoprotein particles (RNPs), termed transport RNPs. A recent study suggested that processing bodies (P-bodies), which have recently been identified as sites of RNA degradation and translational control in eukaryotic cells, may participate in the translational control of dendritically localized mRNAs in Drosophila neurons. This study raised the interesting question of whether dendritic transport RNPs are distinct from P-bodies or whether those structures share significant overlap in their molecular composition in mammalian neurons. Here, we show that P-body and transport RNP markers do not colocalize and are not transported together in the same particles in dendrites of mammalian neurons. Detailed time-lapse videomicroscopy analyses reveal, however, that both P-bodies and transport RNPs can interact in a dynamic manner via docking. Docking is a frequent event involving as much as 50% of all dendritic P-bodies. Chemically induced neuronal activity results in a 60% decrease in the number of P-bodies in dendrites, suggesting that P-bodies disassemble after synaptic stimulation. Our data lend support to the exciting hypothesis that dendritically localized mRNAs might be stored in P-bodies and be released and possibly translated when synapses become activated.
Also flagged:OmiHtrA2Huntington's diseaseneurodegenerative diseasesmitochondrialof
Journal Article2008-07-01✓ 4 SnippetsInagaki R, Tagawa K, Qi ML, Enokido Y, Ito H, Tamura T, Shimizu S, Oyanagi K, Arai N, Kanazawa I, Wanker EE, Okazawa H.
In-Text Gene Mentions
Abstract)
…of mutant huntingtin (htt) in striatal neurons…
Abstract)
…neurons expressing mutanthttalso confirmed the…
Abstract)
…with a mutanthtt-transgenic mouse line and…
Abstract)
…vector reverted mutanthtt-induced cell death in…
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Selective vulnerability of neurons is a critical feature of neurodegenerative diseases, but the underlying molecular mechanisms remain largely unknown. We here report that Omi/HtrA2, a mitochondrial protein regulating survival and apoptosis of cells, decreases selectively in striatal neurons that are most vulnerable to the Huntington's disease (HD) pathology. In microarray analysis, Omi/HtrA2 was decreased under the expression of mutant huntingtin (htt) in striatal neurons but not in cortical or cerebellar neurons. Mutant ataxin-1 (Atx-1) did not affect Omi/HtrA2 in any type of neuron. Western blot analysis of primary neurons expressing mutant htt also confirmed the selective reduction of the Omi/HtrA2 protein. Immunohistochemistry with a mutant htt-transgenic mouse line and human HD brains confirmed reduction of Omi/HtrA2 in striatal neurons. Overexpression of Omi/HtrA2 by adenovirus vector reverted mutant htt-induced cell death in primary neurons. These results collectively suggest that the homeostatic but not proapoptotic function of Omi/HtrA2 is linked to selective vulnerability of striatal neurons in HD pathology.
The diversity of cell types found within the vertebrate CNS arises in part from action of complex transcriptional programs. In the retina, the programs driving diversification of various cell types have not been completely elucidated. To investigate gene regulatory networks that underlie formation and function of one retinal circuit component, the bipolar cell, transcriptional regulation of three bipolar cell-enriched genes was analyzed. Using in vivo retinal DNA transfection and reporter gene constructs, a 200 bp Grm6 enhancer sequence, a 445 bp Cabp5 promoter sequence, and a 164 bp Chx10 enhancer sequence, were defined, each driving reporter expression specifically in distinct but overlapping bipolar cell subtypes. Bioinformatic analysis of sequences revealed the presence of potential paired-type and POU homeodomain-containing transcription factor binding sites, which were shown to be critical for reporter expression through deletion studies. The paired-type homeodomain transcription factors (TFs) Crx and Otx2 and the POU homeodomain factor Brn2 are expressed in bipolar cells and interacted with the predicted binding sequences as assessed by electrophoretic mobility shift assay. Grm6, Cabp5, and Chx10 reporter activity was reduced in Otx2 loss-of-function retinas. Endogenous gene expression of bipolar cell molecular markers was also dependent on paired-type homeodomain-containing TFs, as assessed by RNA in situ hybridization and reverse transcription-PCR in mutant retinas. Cabp5 and Chx10 reporter expression was reduced in dominant-negative Brn2-transfected retinas. The paired-type and POU homeodomain-containing TFs Otx2 and Brn2 together appear to play a common role in regulating gene expression in retinal bipolar cells.
Also flagged:olfactomedin 1axonOlfm1glycoproteinolfactomedineye development
Journal Article2008-07-01✓ 2 SnippetsNakaya N, Lee HS, Takada Y, Tzchori I, Tomarev SI.
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…OLFM4…
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…olfactomedin-2…
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Olfactomedin 1 (Olfm1) is a secreted glycoprotein belonging to a family of olfactomedin domain-containing proteins. It is involved in the regulation of neural crest production in chicken and promotes neuronal differentiation in Xenopus. Here, we investigate the functions of Olfm1 in zebrafish eye development. Overexpression of full-length Olfm1, and especially its BMY form lacking the olfactomedin domain, increased the thickness of the optic nerve and produced a more extended projection field in the optic tectum compared with control embryos. In contrast, injection of olfm1-morpholino oligonucleotide (Olfm1-MO) reduced the eye size, inhibited optic nerve extension, and increased the number of apoptotic cells in the retinal ganglion cell and inner nuclear layers. Overexpression of full-length Olfm1 increased the lateral separation of the expression domains of eye-field markers, rx3 and six3. The Olfm1-MO had the opposite effect. These data suggest that zebrafish Olfm1 may play roles in the early eye determination, differentiation, optic nerve extension, and branching of the retinal ganglion cell axon terminals, with the N-terminal region of Olfm1 being critical for these effects. Injection of RNA encoding WIF-1, a secreted inhibitor of Wnt signaling, caused changes in the expression pattern of rx3 similar to those observed after Olfm1-MO injection. Simultaneous overexpression of WIF-1 and Olfm1 abolished the WIF-1 effect. Physical interaction of WIF-1 and Olfm1 was demonstrated by coimmunoprecipitation experiments. We concluded that Olfm1 serves as a modulator of Wnt signaling.
…Genetic abnormalities affecting over 50% of cases include: in G-ADC, inactivation of suppressor genes of p53, APC and DCC tumor in its intestinal variant, hypoexpression of of caderine E in the diffuse variant and hyperexpression of cyclooxygenase-2 and cyclyn D in the intestinal form; in in CR-ADC, inactivation of of genes p53, APC and DCC together with mutational activation of k-ras oncogen, and in P-ADC, the inactivation of suppressor genes p53, p16 and DPC4 along with mutational activation of k-ras oncogen.…
Abstract)
…p53, APC andDCCtumor in its…
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…p53, APC andDCCtogether with mutational…
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Over 90% of digestive tract malignancies are adenocarcinomas (ADC) and almost 95% of them have gastric (G), colorectal (CR) or pancreatic (P) localizations. The objectives of this work are to review the genetic abnormalities of ADC in these locations and their potential coincidences, along with the histogenetic correlation of their emergence. Genetic abnormalities affecting over 50% of cases include: in G-ADC, inactivation of suppressor genes of p53, APC and DCC tumor in its intestinal variant, hypoexpression of of caderine E in the diffuse variant and hyperexpression of cyclooxygenase-2 and cyclyn D in the intestinal form; in in CR-ADC, inactivation of of genes p53, APC and DCC together with mutational activation of k-ras oncogen, and in P-ADC, the inactivation of suppressor genes p53, p16 and DPC4 along with mutational activation of k-ras oncogen. P-ADC is the one showing a more characteristic and exclusive genetic mark, followed by CR-ADC. Finally, the histogenetic correlation in the tumorigenic sequence is more evident in CR-ADC, followed by P-ADC. The complex biologic reality of G-ADC makes it more difficult to draw its genetic profile and its histogenetic correlation. In order to understand better the arguments of this work, the authors comment on the genetic-molecular basis governing the life and death of normal somatic cells and the biologic profile of the groups of genes mainly involved in tumorigenesis.
Also flagged:Folic acidcolorectal adenomascolorectal cancerpolypadenomaspolyps
Journal Article2008-07-01✓ 1 SnippetJaszewski R, Misra S, Tobi M, Ullah N, Naumoff JA, Kucuk O, Levi E, Axelrod BN, Patel BB, Majumdar AP.
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<h4>Aim</h4>To determine whether folic acid supplementation will reduce the recurrence of colorectal adenomas, the precursors of colorectal cancer, we performed a double-blind placebo-controlled trial in patients with adenomatous polyps.<h4>Methods</h4>In the current double-blind, placebo-controlled trial at this VA Medical Center, patients with colorectal adenomas were randomly assigned to receive either a daily 5 mg dose of folic acid or a matched identical placebo for 3 years. All polyps were removed at baseline colonoscopy and each patient had a follow up colonoscopy at 3 years. The primary endpoint was a reduction in the number of recurrent adenomas at 3 years.<h4>Results</h4>Of 137 subjects, who were eligible after confirmation of polyp histology and run-in period to conform compliance, 94 completed the study; 49 in folic acid group and 45 in placebo group. Recurrence of adenomas at 3-year was compared between the two groups. The mean number of recurrent polyps at 3-year was 0.36 (SD, 0.69) for folic acid treated patients compared to 0.82 (SD, 1.17) for placebo treated subjects, resulting in a 3-fold increase in polyp recurrence in the placebo group. Patients below 70 years of age and those with left-sided colonic adenomas or advanced adenomas responded better to folic acid supplementation.<h4>Conclusion</h4>High dose folic acid supplementation is associated with a significant reduction in the recurrence of colonic adenomas suggesting that folic acid may be an effective chemopreventive agent for colorectal neoplasia.
Journal Article2008-07-01No SnippetsHorak CE, Lee JH, Marshall JC, Shreeve SM, Steeg PS.
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Metastasis suppressor genes (MSGs) are defined by their ability to inhibit overt metastasis in a secondary organ without affecting tumor growth at the primary site. Over 20 MSGs have been confirmed in vivo. This class of genes is only unified by their capacity to suppress metastasis, as they encode for proteins with a wide range of biochemical activities that are components of a variety of signaling pathways. In addition, metastasis suppressors impinge upon different stages of the metastatic cascade to manifest their suppressive effects. The MSGs KISS1, KAI1, MKK4/7 and Nm23-H1 promote tumor dormancy at the metastatic site, since tumor cells with induced expression of these MSGs disseminate, but do not form overt metastases in the secondary organ throughout the duration of a metastasis assay. Evidence suggests that KISS1 triggers dormancy in solitary, metastatic tumor cells by causing growth arrest of solitary cells at the secondary site. KAI1 induces growth arrest prior to extravasation by binding a vascular endothelial cell surface marker. MKK4, MKK7 and Nm23-H1 appear to promote dormancy of micrometastatic colonies, after disseminated tumor cells have undergone several rounds of proliferation. Other MSGs may also function in tumor dormancy, but so far their role has not been fully elucidated. Therapeutic approaches that either mimic the effects of MSGs or re-establish MSG expression in metastatic lesions may hold promise for the establishment or maintenance of dormancy.
Also flagged:methylselenocysteinecircadian rhythmgene expressionPer2mammary tumorstumors
Journal Article2008-07-01No SnippetsZhang X, Zarbl H.
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It is known that organic forms of selenium inhibit chemically induced rat mammary carcinogenesis, although the molecular basis remains to be elucidated. To identify signaling pathways involved in carcinogenesis that are also modulated by methylselenocysteine, we compared the global gene expression profiles in mammary tissues from pubescent female rats maintained on a selenium-supplemented (3 ppm) diet with those on a standardized diet after N-nitroso-N-methylurea. Whereas the selenium-enriched diet altered the steady-state levels of genes involved in various cellular functions, the most dramatic effect was the coordinated changes in the expression of multiple genes that regulate circadian rhythm. Normal mammary tissue of rats fed a standardized diet showed little circadian oscillation relative to liver tissue. By contrast, mammary tissue of rats maintained on the selenium-enriched diet showed a progressive, time-dependent increase in the expression of circadian gene Per2 and circadian-regulated transcription factor DBP. Our results further showed that the expression of Per2 and DBP mRNAs was significantly decreased in mammary tumors arising in rats on the selenium-enriched diet, but not in tumors of rats on the control diet, suggesting that selenium-induced elevation in the expression of circadian genes was incompatible with mammary carcinogenesis. Given the previously reported role of Per2 as a tumor suppressor, these observations suggest that Per2 is an important target of methylselenocysteine during chemoprevention in N-nitroso-N-methylurea-induced rat mammary carcinogenesis, and for the first time provide a link between chemoprevention and circadian rhythm.
Also flagged:PrPprionneuroblastomaprionsneurodegenerative diseasesprion protein PrP c
Journal Article2008-07-01✓ 1 SnippetKrammer C, Kremmer E, Schätzl HM, Vorberg I.
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Prions are self-propagating infectious protein aggregates of mammals and fungi. The exact mechanism of prion formation is poorly understood. In a recent study, a comparative analysis of the aggregation propensities of chimeric proteins derived from the yeast Sup35p and mouse PrP prion proteins was performed in neuroblastoma cells. The cytosolic expression of the Sup35p domains NM, PrP and fusion proteins thereof revealed that the carboxyterminal domain of PrP (PrP90-230) mediated aggregate formation, while Sup35p N and M domains modulated aggregate size and frequency when fused to the globular domain of PrP. Here we further present co-aggregation studies of chimeric proteins with cytosolic PrP or a huntingtin fragment with an extended polyglutamine tract. Our studies demonstrate that cross-seeding by heterologous proteins requires sequence similarity with the aggregated protein domain. Taken together, these results demonstrate that nucleation and seeding of prion protein aggregates is strongly influenced by dynamic interactions between the aggregate core forming domain and its flanking regions.
Also flagged:colorectal cancerenzymestransportersthymidylate synthaseIL-8CXCR-2
Journal Article2008-07-01No SnippetsPohl A, Lenz HJ.
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To improve the treatment of patients with colorectal cancer, efforts must be directed toward the identification of patients likely to respond to a specific therapy, those who will experience severe toxicities, and those who will benefit from chemotherapy in the adjuvant setting. In recent years, studies on a global scale have attempted to define subsets of biochemical markers that may predict response to treatment (evaluated through clinical response, toxicity, and time to disease progression), and prognostic markers, which are equally important in determining how aggressive the disease is (generally evaluated in terms of overall survival), and the likelihood of disease recurrence after surgery. The science of pharmacogenomics is emerging as a useful molecular tool to investigate the disparity in drug efficacy by analyzing variations such as genetic polymorphisms in drug targets, metabolizing enzymes, transporters, and influential receptors. Consequently, the identification of accurate and validated predictive and prognostic markers combined with an increasing arsenal of therapeutic agents will improve the clinician's ability to tailor effective therapy to the molecular profile of the patient while minimizing life-threatening toxicities. This paper describes markers under study in the setting of colorectal cancer, including loss of heterozygosity of 18q and microsatellite instability, polymorphisms in thymidylate synthase, IL-8, CXCR-2, vascular endothelial growth factor, epidermal growth factor and their receptors, and K-ras mutations.
…pancreatic disorders orhemochromatosiswere not included…
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<h4>Background/aim</h4>Type 2 diabetes mellitus (DM-2) is more common in patients with chronic liver disease (CLD) in general and chronic hepatitis C virus (HCV) infection in particular. We aimed to determine the prevalence and factors affecting the occurrence of DM-2 in Saudi patients with CLD.<h4>Materials and methods</h4>Retrospective study at the King Fahd Central Hospital (KFCH), Gizan, Saudi Arabia. A total of 277 patients with either cirrhosis (CH) or hepatocellular carcinoma (HCC) were analyzed for patient demographics, severity of liver disease, HBsAg, and anti-HCV, associated diseases including DM-2, and presence of HCC. The prevalence of DM-2 was also estimated in 400 age- and sex-matched Saudi patients admitted for various nonliver diseases (control group). Chi-square test, univariate analysis, and multivariate regression.<h4>Results</h4>Prevalence of DM-2 in patients with CH was higher than in controls (19.2 vs. 9.2%; P = 0.001). Although those with HCC had a higher prevalence, the difference was not significant (10.9 vs. 9.2%; P = 0.5). Seventy-six percent of patients with HCC had associated CH. On multivariate analysis, age and hypertension were more common in diabetics. Although patients with HCV-related disease had a higher prevalence of DM-2 compared to HBV-related disease, the difference was not significant (26.3 vs. 15.7%; P > 0.05).<h4>Conclusions</h4>DM-2 occurred more frequently in CLD patients, particularly in cirrhotics. Age and hypertension predicted the occurrence of DM-2. Small sample size of patients with HCV-related CH probably precluded higher prevalence of DM-2 in them.
Also flagged:peptidespathogenesisurological disordersglomerular filtrationsecretionprostate cancer
Journal Article2008-07-01No SnippetsCoon JJ, Zürbig P, Dakna M, Dominiczak AF, Decramer S, Fliser D, Frommberger M, Golovko I, Good DM, Herget-Rosenthal S, Jankowski J, Julian BA, Kellmann M, Kolch W, Massy Z, Novak J, Rossing K, Schanstra JP, Schiffer E, Theodorescu D, Vanholder R, Weissinger EM, Mischak H, Schmitt-Kopplin P.
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Owing to its availability, ease of collection, and correlation with pathophysiology of diseases, urine is an attractive source for clinical proteomics. However, many proteomic studies have had only limited clinical impact, due to factors such as modest numbers of subjects, absence of disease controls, small numbers of defined biomarkers, and diversity of analytical platforms. Therefore, it is difficult to merge biomarkers from different studies into a broadly applicable human urinary proteome database. Ideally, the methodology for defining the biomarkers should combine a reasonable analysis time with high resolution, thereby enabling the profiling of adequate samples and recognition of sufficient features to yield robust diagnostic panels. Capillary electrophoresis coupled to mass spectrometry (CE-MS), which was used to analyze urine samples from healthy subjects and patients with various diseases, is a suitable approach for this task. The database of these datasets compiled from the urinary peptides enabled the diagnosis, classification, and monitoring of a wide range of diseases. CE-MS exhibits excellent performance for biomarker discovery and allows subsequent biomarker sequencing independent of the separation platform. This approach may elucidate the pathogenesis of many diseases, and better define especially renal and urological disorders at the molecular level.
Also flagged:epidermal growth factor receptoresophageal squamous cell carcinomaEGFRlung adenocarcinomacancerHER2
Journal Article2008-07-01✓ 1 SnippetMir MM, Dar NA, Salam I, Shah ZA.
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Activating mutations in Epidermal Growth Factor Receptor (EGFR) are common in lung adenocarcinoma of never smokers but are rare in other types of cancer. Here we have analysed mutations in exons 19 to 21 of EGFR and in exons 19 and 20 of the EGFR homolog HER2 in 54 cases of Esophageal Squamous Cell Carcinomas (ESCC) from patients recruited in Kashmir, India, a region of high incidence for this cancer. We report the detection of 3 mutations (6%) in the ATP-binding regulatory loops of the tyrosine kinase domain of EGFR (deletion 746-750, P753L, G719D). No mutation was found in HER2. This is the first report of activating EGFR mutations in ESCC, of the same type as those detected in lung adenocarcinoma of never-smokers. This suggests that a small proportion of ESCC patients in this high incidence area may benefit from treatment with EGFR tyrosine kinase inhibitors.
Also flagged:phosphatessynthesistartaric acidCalciumnitratediammonium
Journal Article2008-07-01No SnippetsSasikumar S, Vijayaraghavan R, Vijayaraghavan R.
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Synthetic calcium hydroxyapatite (HAP, Ca<sub>10</sub> (PO<sub>4</sub>)<sub>6</sub> (OH)<sub>2</sub>) is a well-known bioceramic material used in orthopedic and dental applications because of its excellent biocompatibility and bone-bonding ability due to its structural and compositional similarity to human bone. Here we report, for the first time, the synthesis of HAP by combustion employing tartaric acid as a fuel. Calcium nitrate is used as the source of calcium and diammonium hydrogen phosphate serves as the source of phosphate ions. Reaction processing parameters such as the pH, fuel-oxidant ratio and autoignition temperature are controlled and monitored. The products were characterized by powder x-ray diffraction, which revealed the formation of a hexagonal hydroxyapatite phase. Fourier transform infrared spectroscopy (FT-IR) spectra showed that the substitution of a carbonate ion occurs at the phosphate site. The morphology of the particles was imaged by scanning electron microscopy, which also revealed that the particles are of submicron size. Thermal analysis showed that the phase formation takes place at the time of combustion. Surface area and porosity analysis showed that the surface area is high and that the pores are of nanometer size. The mean grain size of the HAP powder, determined by the Debye-Scherrer formula, is in the range 20-30 nm. Chemical analyses to determine the Ca : P atomic ratio in synthesized ceramics were performed, and it was found to be 1 : 1.66.