The extensive use of the glycosaminoglycan (GAG) heparin in the design of emerging biomaterials has made the physical characterization of this heterogeneous biomacromolecule increasingly important. In this work, heparin solutions are characterized via dynamic light scattering to investigate heparin's self-association, since this behavior was recently hypothesized to play a role in the gelation of heparin-functionalized polymer hydrogels. Samples of either low molecular weight heparin or high molecular weight heparin were filtered using membranes with 100, 220, or 450 nm average pore sizes. The 100 and 220 nm filters produce a single population of monomers with a diameter range of 3-10nm in the intensity-weighted size distribution. However, the 450 nm filters reveal a second population of associated heparin. Increasing the solution concentration of high molecular weight heparin (HMWH) from 2.5 to 10 wt% causes the magnitude of the smaller population to decrease, while the diameter of the larger associated species approximately doubles. HMWH from different manufacturers displays varying degrees of association. Therefore, weaker associating HMWH can potentially be identified to control heparin self-interactions. Finally, fractionated, N-deacetylated low molecular weight heparin (LMWH) is compared to unmodified LMWH. The chemically modified heparin exhibits a heightened degree of association, suggesting an enhanced self-interaction. The increased negative charge of LMWH in the fractionated sample likely enhances polyelectrolyte interactions proposed to drive the association of these similarly charged polysaccharides. A more detailed understanding of heparin-heparin interactions will assist in the design of new scaffold materials with controlled release profiles, in the clinical use of heparin as an anticoagulant, and in investigations of interactions of other like-charged biomacromolecules.
Also flagged:coumarin glycosidephenethyl vanillatebindingdopamine receptorsfalcarindiolopioid receptors
Journal Article2007-12-31No SnippetsMa Z, Xu W, Liu-Chen LY, Lee DY.
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Bioactivity-guided fractionation of Notopterygium forbesii has resulted in the isolation of one new coumarin glycoside and one new phenethyl vanillate, together with seventeen known compounds. The structures of these compounds were characterized by spectroscopic methods. These compounds were evaluated for their binding affinities to the opioid and dopamine receptors, and falcarindiol showed weak binding affinities to opioid receptors and moderate affinity for D1 receptor (K(i)=192+/-6 nM).
Also flagged:Parkinson diseasesprion encephalopathiesParkinson diseaseAggregationHuntingtinchaperone
Journal Article2007-12-31✓ 1 SnippetMuchowski PJ, Ramsden R, Nguyen Q, Arnett EE, Greiling TM, Anderson SK, Clark JI.
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Many diverse human diseases are associated with protein aggregation in ordered fibrillar structures called amyloid. Amyloid formation may mediate aberrant protein interactions that culminate in neurodegeneration in Alzheimer, Huntington, and Parkinson diseases and in prion encephalopathies. Studies of protein aggregation in the brain are hampered by limitations in imaging techniques and often require invasive methods that can only be performed postmortem. Here we describe transgenic mice in which aggregation-prone proteins that cause Huntington and Parkinson disease are expressed in the ocular lens. Expression of a mutant huntingtin fragment or alpha-synuclein in the lens leads to protein aggregation and cataract formation, which can be monitored in real time by noninvasive, highly sensitive optical techniques. Expression of a mutant huntingtin fragment in mice lacking the major lens chaperone, alphaB-crystallin, markedly accelerated the onset and severity of aggregation, demonstrating that the endogenous chaperone activity of alphaB-crystallin suppresses aggregation in vivo. These novel mouse models will facilitate the characterization of protein aggregation in vivo and are being used in efficient and economical screens for chemical and genetic modifiers of disease-relevant protein aggregation.
Also flagged:RNA-binding protein TLSpolyglutaminepolyglutamine (polyQ) diseasesRNA-binding protein translocatedin liposarcomaHuntington disease
Journal Article2007-12-31No SnippetsDoi H, Okamura K, Bauer PO, Furukawa Y, Shimizu H, Kurosawa M, Machida Y, Miyazaki H, Mitsui K, Kuroiwa Y, Nukina N.
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Formation of intracellular aggregates is the hallmark of polyglutamine (polyQ) diseases. We analyzed the components of purified nuclear polyQ aggregates by mass spectrometry. As a result, we found that the RNA-binding protein translocated in liposarcoma (TLS) was one of the major components of nuclear polyQ aggregate-interacting proteins in a Huntington disease cell model and was also associated with neuronal intranuclear inclusions of R6/2 mice. In vitro study revealed that TLS could directly bind to truncated N-terminal huntingtin (tNhtt) aggregates but could not bind to monomer GST-tNhtt with 18, 42, or 62Q, indicating that the tNhtt protein acquired the ability to sequester TLS after forming aggregates. Thioflavin T assay and electron microscopic study further supported the idea that TLS bound to tNhtt-42Q aggregates at the early stage of tNhtt-42Q amyloid formation. Immunohistochemistry showed that TLS was associated with neuronal intranuclear inclusions of Huntington disease human brain. Because TLS has a variety of functional roles, the sequestration of TLS to polyQ aggregates may play a role in diverse pathological changes in the brains of patients with polyQ diseases.
Low density lipoprotein contains traces of biologically active platelet-activating factor (PAF)-like ether phosphatidylcholines (PCs). These oxidatively truncated alkylacylphosphatidylcholines (OxPAFs) are presumably formed through the oxidative truncation of 1-alkyl-2-polyunsaturated fatty acyl PCs. We now report that a diverse structural variety of OxPAFs are generated in small unilamellar vesicles (SUVs) upon myeloperoxidase (MPO)-promoted autoxidation of ether PCs that incorporate linoleoyl, arachidonyl, or docosahexaenoyl groups at the sn-2 position. Total syntheses are reported that confirm the identities of the new OxPAFs and will facilitate the evaluation of their biologically important chemistry and activities. Especially noteworthy is the formation of OxPAFs containing gamma-hydroxyalkenal functionality. Analogous oxidatively truncated diacylphosphatidylcholines are biologically important because they and their more oxidized derivatives are strong ligands for the scavenger receptor CD36. Furthermore, their covalent adduction with proteins can interfere with protein function or generate biologically active carboxyalkylpyrrole derivatives. We now find a profound influence of membrane composition on the stability of OxPAFs. In the presence of a polyunsaturated diacyl PC, the linoleic acid ester of 2-lysophosphatidylcholine, MPO induces the oxidation of aldehydes to carboxylic acids and the further oxidative truncation of gamma-hydroxyalkenals. Remarkably, these reactions do not occur readily with MPO in SUVs composed entirely of saturated diacyl-PCs. A mechanistic rationale is presented that can account for this dichotomy.
Also flagged:Gonadotrophin Releasing HormoneGnRHfollicle stimulating hormonetostimulationgonadotrophins
Journal Article2007-12-28No SnippetsSunkara SK, Coomarasamy A, Khalaf Y, Braude P.
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<h4>Background</h4>Poor response to ovarian stimulation with exogenous gonadotrophins occurs in 9-24% of women undergoing in vitro fertilisation (IVF) treatment, which represents an estimated 4000-10,000 women per year in the UK. Poor responders often have their treatment cycle cancelled because of expected poor outcome.One treatment strategy that may influence outcome is the choice of pituitary suppression regimen prior to the initiation of ovarian stimulation. The three commonly used pituitary suppression regimens in IVF treatment are:(1) the GnRH agonist long regimen,(2) the GnRH agonist short regimen and(3) the GnRH antagonist regimen.A systematic review of randomised controlled trials of these pituitary suppression regimens has shown the evidence to be either inconclusive or inconsistent. We therefore designed a three arm randomised trial to evaluate the effectiveness of these regimens in women who had poor ovarian response in a previous IVF treatment cycle.<h4>Methods/design</h4>Consenting, eligible women will be randomised to one of the three regimens using an internet-based trial management programme that ensures allocation concealment and employs block randomisation and minimisation for prognostic variables. The primary outcome is the number of oocytes retrieved. Other outcomes include total dose of follicle stimulating hormone (FSH) used for ovarian stimulation, mature oocytes retrieved, embryos available for transfer, implantation rate and clinical pregnancy rate.The sample size for this trial has been estimated as 102 participants with 34 participants in each of the three arms. Appropriate interim analysis will be conducted by a Data Monitoring and Ethics Committee (DMEC), and the final analysis will be by intention to treat.<h4>Trial registration</h4>ISRCTN27044628.
Also flagged:SynthesisFolate receptorscancerleukemiafolateFR
Journal Article2007-12-28No SnippetsXiang G, Wu J, Lu Y, Liu Z, Lee RJ.
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Folate receptors (FRs) have been identified as cellular surface markers for cancer and leukemia. Liposomes containing lipophilic derivatives of folate have been shown to effectively target FR-expressing cells. Here, we report the synthesis of a novel lipophilic folate derivative, folate-polyethylene glycol-cholesterol hemisuccinate (F-PEG-CHEMS), and its evaluation as a targeting ligand for liposomal doxorubicin (L-DOX) in FR-expressing cells. Liposomes containing F-PEG-CHEMS, with a mean diameter of 120+/-20 nm, were synthesized by polycarbonate membrane extrusion and were shown to have excellent colloidal stability. The liposomes were taken up selectively by KB cells, which overexpress FR-alpha. Compared to folate-PEG-cholesterol (F-PEG-Chol), which contains a carbamate linkage, F-PEG-CHEMS better retained its FR-targeting activity during prolonged storage. In addition, F-PEG-CHEMS containing liposomes loaded with DOX (F-L-DOX) showed greater cytotoxicity (IC(50)=10.0muM) than non-targeted control L-DOX (IC(50)=57.5 microM) in KB cells. In ICR mice, both targeted and non-targeted liposomes exhibited long circulation properties, although F-L-DOX (t(1/2)=12.34 h) showed more rapid plasma clearance than L-DOX (t(1/2)=17.10h). These results suggest that F-PEG-CHEMS is effective as a novel ligand for the synthesis of FR-targeted liposomes.
Also flagged:SLC40A1ironinsulin-resistancenon-alcoholic fatty liver diseaseferroportin disease
Journal Article2007-12-27✓ 1 SnippetPelucchi S, Mariani R, Salvioni A, Bonfadini S, Riva A, Bertola F, Trombini P, Piperno A.
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Abstract)
…tested negative forHFEmutations and other…
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The aim of this study was to search for SLC40A1 mutations in iron overloaded patients, which tested negative for HFE mutations and other iron-related genes. After a careful differential diagnosis, we selected 56 patients with unexplained iron overload whose phenotype could suggest the ferroportin disease. Iron overload was assessed by liver biopsy or by superconducting quantum interference device. SLC40A1 exons and intron-exon boundaries were amplified by polymerase chain reaction and sequenced. We also evaluated the presence of the insulin-resistance hepatic iron overload and of non-alcoholic fatty liver disease. Iron status was assessed in 44 families. We identified two novel mutations (D157N and V72F) at the heterozygous state in two probands. Phenotype heterogeneity was observed in both families, suggesting variable penetrance and expression. Including the two affected ones, 25 of the 44 families (57%) available for the iron study had one or more relatives with increased serum iron indices. Our findings not only suggest that the presence of major alterations of serum iron parameters in probands' relatives is a main criteria to improve the power of the genetic testing for ferroportin disease but also indicate that a number of patients exists in which the etiology of iron overload remains still undefined.
Also flagged:HMGB1transcription factorschromatinluciferasehepatocyte nuclear factor 1αbinding
Journal Article2007-12-26No SnippetsYu M, Wang J, Li W, Yuan YZ, Li CY, Qian XH, Xu WX, Zhan YQ, Yang XM.
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Hepatocyte nuclear factor (HNF)-1alpha is one of the liver-enriched transcription factors involved in many tissue-specific expressions of hepatic genes. The molecular mechanisms for determining HNF1alpha-mediated transactivation have not been explained fully. To identify unknown proteins that interact with HNF1alpha, we developed a co-IP-MS strategy to search HNF1alpha interactions, and high mobility group protein-B1 (HMGB1), a chromosomal protein, was identified as a novel HNF1alpha-interacting protein. In vitro glutathione S-transferase pull-down and in vivo co-immunoprecipitation studies confirmed an interaction between HMGB1 and HNF1alpha. The protein-protein interaction was mediated through the HMG box domains of HMGB1 and the homeodomain of HNF1alpha. Furthermore, electrophoretic mobility shift assay and chromatin-immunoprecipitation assay demonstrated that HMGB1 was recruited to endogenous HNF1alpha-responsive promoters and enhanced HNF1alpha binding to its cognate DNA sequences. Moreover, luciferase reporter analyses showed that HMGB1 potentiated the transcriptional activities of HNF1alpha in cultured cells, and downregulation of HMGB1 by RNA interference specifically affected the HNF1alpha-dependent gene expression in HepG2 cell. Taken together, these findings raise the intriguing possibility that HMGB1 is a new cofactor of HNF1alpha and participates in HNF1alpha-mediated transcription regulation through protein-protein interaction.
Also flagged:Huntingtin-interacting protein 14palmitoyl transferaseexocytosislocalizationneurotransmittersynaptic transmission
Journal Article2007-12-24✓ 5 SnippetsOhyama T, Verstreken P, Ly CV, Rosenmund T, Rajan A, Tien AC, Haueter C, Schulze KL, Bellen HJ.
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Introduction)
…(n-Syb), and Huntingtin (Htt; el-Husseini Ael and…
Introduction)
…of Drosophila melanogasterhtt-interacting protein 14protein 14 (…
Introduction)
…shown to palmitoylateHttin vertebrates (…
Results)
…I, SNAP25, andHttin cell culture…
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…repeats in pathogenicHttprotein has been…
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Posttranslational modification through palmitoylation regulates protein localization and function. In this study, we identify a role for the Drosophila melanogaster palmitoyl transferase Huntingtin-interacting protein 14 (HIP14) in neurotransmitter release. hip14 mutants show exocytic defects at low frequency stimulation and a nearly complete loss of synaptic transmission at higher temperature. Interestingly, two exocytic components known to be palmitoylated, cysteine string protein (CSP) and SNAP25, are severely mislocalized at hip14 mutant synapses. Complementary DNA rescue and localization experiments indicate that HIP14 is required solely in the nervous system and is essential for presynaptic function. Biochemical studies indicate that HIP14 palmitoylates CSP and that CSP is not palmitoylated in hip14 mutants. Furthermore, the hip14 exocytic defects can be suppressed by targeting CSP to synaptic vesicles using a chimeric protein approach. Our data indicate that HIP14 controls neurotransmitter release by regulating the trafficking of CSP to synapses.
Also flagged:HDp53tumor suppressorcancerHuntington's diseasepolyglutamine
Journal Article2007-12-23No SnippetsRyan A, Scrable H.
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Loss of function mutations in the p53 tumor suppressor gene predispose mice and humans to cancer, resulting in abbreviated life spans. A dominant mutation in the murine HD gene, similar to mutations that cause Huntington's disease in humans, reverses some of the effects of p53 mutations on longevity. We attribute this to the enhanced apoptotic effect of the expanded polyglutamine region in the HD protein on proliferating cells lacking p53.
Also flagged:diffuse pulmonary arterial thrombosisnephrotic syndromehypoproteinemianephritic syndromeminimal change diseaseheparin
Journal Article2007-12-21✓ 1 SnippetMatsuda A, Tsuchiya K, Yabuki Y, Naito M, Koike M, Yumura W, Nitta K.
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Abstract)
…of antithrombin III (ATIII) - a cofactor…
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A 21-year-old man was admitted to our hospital because of leg edema. Because laboratory findings revealed massive proteinuria and hypoproteinemia, he was diagnosed as having nephritic syndrome caused by minimal change disease. He was given a continuous heparin infusion and intravenous steroid therapy, at a prednisolone dose of 1 mg/kg per day, and his condition gradually improved. Five months after discharge, the patient's proteinuria relapsed. He was readmitted to our hospital and we restarted anticoagulant treatment with intravenous heparin and 60 mg prednisolone. On the third hospital day, he complained of chest pain with sudden onset and dyspnea. He quickly developed shock and died. The findings of an autopsy confirmed the presence of diffuse fibrin thrombi in bilateral pulmonary arteries, and we diagnosed the cause of death as diffuse pulmonary artery thrombosis. A coagulation test for activated partial thromboplastin time (aPTT) had already shown that aPTT was prolonged before the initiation of treatment. There may have been a deficit of antithrombin III (ATIII) - a cofactor of heparin - because of the proteinuria; thus, the continuous heparin treatment might not have been effective for the prevention of thrombosis. Alternatives to heparin treatment that do not suppress AT III, such as nafamostat mesilate or argatroban, which do not require the presence of AT III for their anticoagulant action, should be considered in cases similar to the that in the patient reported here. In patients with nephrotic syndrome who exhibit altered coagulation test results, the choice of anticoagulation therapy for treatment of the hypercoagulabilty status associated with nephrotic syndrome should be carefully considered.
Also flagged:gene expressionHuntington's diseasetranscription factorshistone acetyltransferaseshistonechromatin
Journal Article2007-12-21✓ 1 SnippetAnderson AN, Roncaroli F, Hodges A, Deprez M, Turkheimer FE.
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Abstract)
…Recent studies suggested that Huntington's disease is due to aberrant interactions between mutant huntingtin protein, transcription factors and transcriptional co-activators resulting in widespread transcriptional dysregulation.…
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Recent studies suggested that Huntington's disease is due to aberrant interactions between mutant huntingtin protein, transcription factors and transcriptional co-activators resulting in widespread transcriptional dysregulation. Mutant huntingtin also interacts with histone acetyltransferases, consequently interfering with the acetylation and deacetylation states of histones. Because histone modifications and chromatin structure coordinate the expression of gene clusters, we have applied a novel mathematical approach, Chromowave, to analyse microarray datasets of brain tissue and whole blood to understand how genomic regions are altered by the effects of mutated huntingtin on chromatin structure. Results show that, in samples of caudate and whole blood from Huntington's disease patients, transcription is indeed deregulated in large genomic regions in coordinated fashion, that transcription in these regions is associated with disease progression and that altered chromosomal clusters in the two tissues are remarkably similar. These findings support the notion of a common genome-wide mechanism of disruption of RNA transcription in the brain and periphery of Huntington's disease patients.
Also flagged:fluorenedioxygenasepolycyclic aromatic hydrocarbonsheteroaromaticsphenanthrenefluorenone
Journal Article2007-12-21✓ 1 SnippetSchuler L, Ní Chadhain SM, Jouanneau Y, Meyer C, Zylstra GJ, Hols P, Agathos SN.
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…Pseudomonas resinovorans CA10…
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In this study, the genes involved in the initial attack on fluorene by Sphingomonas sp. strain LB126 were investigated. The alpha and beta subunits of a dioxygenase complex (FlnA1-FlnA2), showing 63 and 51% sequence identity, respectively, to the subunits of an angular dioxygenase from the gram-positive dibenzofuran degrader Terrabacter sp. strain DBF63, were identified. When overexpressed in Escherichia coli, FlnA1-FlnA2 was responsible for the angular oxidation of fluorene, 9-hydroxyfluorene, 9-fluorenone, dibenzofuran, and dibenzo-p-dioxin. Moreover, FlnA1-FlnA2 was able to oxidize polycyclic aromatic hydrocarbons and heteroaromatics, some of which were not oxidized by the dioxygenase from Terrabacter sp. strain DBF63. The quantification of resulting oxidation products showed that fluorene and phenanthrene were the preferred substrates of FlnA1-FlnA2.
…The patient was also heterozygous for the common HFE H63D polymorphism, but did not have coding region mutations in TFR2, HAMP, or HFE2.<h4>Conclusions</h4>We conclude that this patient represents a unique example of hemochromatosis due to a single base-pair mutation of SLC40A1 that results in aberrant splicing and truncation of ferroportin.…
Abstract)
…<h4>Background/aims</h4>To determine the molecular basis of a mild hemochromatosis phenotype in a man of Scottish-Irish descent.<h4>Methods</h4>We sequenced genomic DNA to detect mutations of HFE, SLC40A1, TFR2, HAMP, and HFE2.…
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…of a mildhemochromatosisphenotype in a…
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…detect mutations ofHFE, SLC40A1, TFR2, HAMP,…
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…for the commonHFEH63D polymorphism, but…
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<h4>Background/aims</h4>To determine the molecular basis of a mild hemochromatosis phenotype in a man of Scottish-Irish descent.<h4>Methods</h4>We sequenced genomic DNA to detect mutations of HFE, SLC40A1, TFR2, HAMP, and HFE2. RNA isolated from blood mononuclear cells was used to make cDNA. RT-PCR was performed to amplify ferroportin from cDNA, and amplified products were visualized by electrophoresis and sequenced.<h4>Results</h4>The proband was heterozygous for the novel mutation c.1402G-->A (predicted G468S) in exon 7 of the ferroportin gene (SLC40A1). Located in the last nucleotide before the splice junction, this mutation results in aberrant splicing to a cryptic upstream splice site located at nt 990 within the same exon. This causes truncation of ferroportin after glycine 330 and the addition of 4 irrelevant amino acids before terminating. The truncated ferroportin protein, missing its C-terminal 241 amino acids, would lack all structural motifs beyond transmembrane region 7. The patient was also heterozygous for the common HFE H63D polymorphism, but did not have coding region mutations in TFR2, HAMP, or HFE2.<h4>Conclusions</h4>We conclude that this patient represents a unique example of hemochromatosis due to a single base-pair mutation of SLC40A1 that results in aberrant splicing and truncation of ferroportin.
Also flagged:hereditary hemochromatosisironhyperferritinemiachromosome
Journal Article2007-12-21✓ 5 SnippetsCurcio M, Fornaciari S, Mariotti ML, Chelazzi S, Scatena F, Presciuttini S.
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Abstract)
…We screened by direct sequencing the coding sequence and intron-exon boundaries of HFE in 265 patients with hyperferritinemia and 185 subjects from the general population.…
Abstract)
…haplotypes. Among other sequence variants of HFE , IVS2+4t/c polymorphism has…
Abstract)
…HFE gene, one (C282Y) being a major gene for hereditary hemochromatosis…
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…polymorphisms of theHFEgene reveals rare…
Abstract)
…mutations of theHFEgene, one (C282Y)…
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<h4>Objective</h4>Two missense mutations of the HFE gene, one (C282Y) being a major gene for hereditary hemochromatosis and the other (H63D) playing a minor role in this disease, are carried by different haplotypes. Among other sequence variants of HFE, IVS2+4t/c polymorphism has been reported as a possible splicing mutation or risk modifier. Our aims were to identify sequence variants possibly associated with iron overload in our population, to study the intragenic haplotypes of the HFE gene, and to evaluate the role of IVS2+4t/c in hyperferritinemia.<h4>Methods</h4>We screened by direct sequencing the coding sequence and intron-exon boundaries of HFE in 265 patients with hyperferritinemia and 185 subjects from the general population.<h4>Results</h4>Linkage disequilibrium between the three pairs of polymorphic sites was complete between H63D and C282Y, whereas all four gametic types were present for both the H63D-IVS2+4t/c and the IVS2+4t/c-C282Y site pairs. The data supported a model in which the IVS2+4t/c polymorphism was ancestral, the D(63) mutation occurred on the t chromosome, and the Y(282) mutation occurred on the c chromosome; after the population spread of both mutations, intragenic recombination occurred on both sides of the t/c polymorphism, generating the rare haplotypes D(63)-c(IVS2+4)-C(282) and H(63)-t(IVS2+4)-Y(282).<h4>Conclusions</h4>The IVS2+4c/t is a neutral polymorphism with regard to risk of iron overload. The presence of recombinant haplotypes on both its sides suggests a considerable evolutionary age of the two main risk alleles.
…This review discusses the normal structure and function of CALM and AF10, describes the spectrum of clinical findings seen in patients with CALM-AF10 fusions, summarizes recently published CALM-AF10 mouse models and highlights the role of HOXA cluster gene activation in CALM-AF10 leukemia.…
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Chromosomal translocations are important genetic perturbations frequently associated with hematologic malignancies; characterization of these events has been a rich source of insights into the mechanisms that lead to malignant transformation. The t(10;11)(p13;q14-21) results in a recently identified rare but recurring chromosomal translocation seen in patients with ALL as well as AML, and results in the production of a CALM-AF10 fusion gene. Although the details by which the CALM-AF10 fusion protein exerts its leukemogenic effect remain unclear, emerging data suggests that the CALM-AF10 fusion impairs differentiation of hematopoietic cells, at least in part via an upregulation of HOXA cluster genes. This review discusses the normal structure and function of CALM and AF10, describes the spectrum of clinical findings seen in patients with CALM-AF10 fusions, summarizes recently published CALM-AF10 mouse models and highlights the role of HOXA cluster gene activation in CALM-AF10 leukemia.
Also flagged:leiomyomasleiomyomaleiomyosarcomapathogenesisgene expressionsteroids
Journal Article2007-12-20No SnippetsPan Q, Luo X, Chegini N.
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Given the emerging roles of microRNAs (miRNAs) as key regulator of mRNA stability we assessed their expression profile in paired myometrium and leiomyoma, their isolated smooth muscle cells (MSMC and LSMC), a spontaneously transformed leiomyoma smooth muscle cells (T-LSMC) and SK-LMS-1, a leiomyosarcoma cell line using microarray and real time PCR. Based on global normalization of expression values of 385 miRNAs and statistical analysis (anova), 91 miRNAs were expressed above the threshold levels in myometrium, with a progressive decline in numbers in leiomyomas, MSMC, LSMC, T-LSMC and SK-LMS-1 (P<0.05). We selected and validated the expression of miR-20a, miR-21, miR-26a, miR-18a, miR-206, miR-181a and miR-142-5p and found their differential expression in tissue and cell-specific manners (P<0.05). Treatments of MSMC and LSMC with 17beta estradiol and medroxyprogesterone acetate (10(-8)M), or ICI-182780 and RU-486 (10(-6)M) resulted in differential regulation of these miRNAs (P<0.05). In conclusion, the expression of a number of miRNAs in myometrium and leiomyoma with their progressive aberrant from normal MSMC into LSMC, transformed and cancerous stage, suggests that miRNAs and their regulation by ovarian steroids play a key role in pathogenesis of leiomyoma through gene expression stability.
Also flagged:RNA-binding proteinsribonucleoproteindouble-stranded RNA-binding proteinslocalizationStau2metabolism
Journal Article2007-12-19✓ 5 SnippetsFuric L, Maher-Laporte M, DesGroseillers L.
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Abstract)
…Consistent with a model of post-transcriptional gene regulation, our results show that Stau1- and Stau2-mRNPs associate with distinct but overlapping sets of cellular mRNAs.…
Abstract)
…are found inStau1- and in Stau2-containing…
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…A comparison ofStau1- and Stau2-containing mRNAs…
Abstract)
…results show thatStau1- and Stau2-mRNPs associate…
Abstract)
…HEK293T cells withStau155 -HA, Stau2…
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Messenger RNAs are associated with multiple RNA-binding proteins to form ribonucleoprotein (mRNP) complexes. These proteins are important regulators of the fate of their target mRNAs. In human cells, Staufen1 and Staufen2 proteins, coded by two different genes, are double-stranded RNA-binding proteins involved in several cellular functions including mRNA localization, translation, and decay. Although 51% identical, these proteins are nevertheless found in different RNA particles. In addition, differential splicing events generate Staufen2 isoforms that only differ at their N-terminal extremities. In this paper, we used a genome-wide approach to identify and compare the mRNA targets of mammalian Staufen proteins. The mRNA content of Staufen mRNPs was identified by probing DNA microarrays with probes derived from mRNAs isolated from immunopurified Staufen-containing complexes following transfection of HEK293T cells with Stau1(55)-HA, Stau2(59)-HA, or Stau2(62)-HA expressors. Our results indicate that 7% and 11% of the cellular RNAs expressed in HEK293T cells are found in Stau1- and in Stau2-containing mRNPs, respectively. A comparison of Stau1- and Stau2-containing mRNAs identifies a relatively low percentage of common mRNAs; the percentage of common mRNAs highly increases when mRNAs in Stau2(59)-HA- and Stau2(62)-containing mRNPs are compared. There is a predominance of mRNAs involved in cell metabolism, transport, transcription, regulation of cell processes, and catalytic activity. All these subsets of mRNAs are mostly distinct from those associated with FMRP or IMP, although some mRNAs overlap. Consistent with a model of post-transcriptional gene regulation, our results show that Stau1- and Stau2-mRNPs associate with distinct but overlapping sets of cellular mRNAs.
…Mutations in TfR2 result in iron overload with similar features to HFE-associated hereditary hemochromatosis.…
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…HFE-associated hereditary hemochromatosis…
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…TfR2 result in iron overload with similar features to HFE-associated hereditary hemochromatosis…
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…similar features toHFE-associated hereditary hemochr…
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Transferrin receptor 2 (TfR2), a homologue of transferrin receptor 1 (TfR1), is a key molecule involved in the regulation of iron homeostasis. Mutations in TfR2 result in iron overload with similar features to HFE-associated hereditary hemochromatosis. The precise role of TfR2 in iron metabolism and the functional consequences of disease-causing mutations have not been fully determined. We have expressed wild-type and various mutant forms of TfR2 that are associated with human disease in a mouse liver cell line. Intracellular and surface analysis shows that all the TfR2 mutations analyzed cause the intracellular retention of the protein in the endoplasmic reticulum, whereas the wild-type protein is expressed in endocytic structures and at the cell surface. Our results indicate that the majority of mutations that cause type 3 hereditary hemochromatosis are a consequence of the defective localization of the protein.
Human adaptor protein, phosphotyrosine interaction, PH domain and leucine zipper containing 1 (APPL1) and adaptor protein, phosphotyrosine interaction, PH domain and leucine zipper containing 2 (APPL2) are homologous effectors of the small guanosine triphosphatase RAB5 that interact with a diverse set of receptors and signaling proteins and are proposed to function in endosome-mediated signaling. Herein, we investigated the membrane-targeting properties of the APPL1 and APPL2 Bin/Amphiphysin/Rvs (BAR), pleckstrin homology (PH) and phosphotyrosine binding (PTB) domains. Coimmunoprecipitation and yeast two-hybrid studies demonstrated that full-length APPL proteins formed homooligomers and heterooligomers and that the APPL minimal BAR domains were necessary and sufficient for mediating APPL-APPL interactions. When fused to a fluorescent protein and overexpressed, all three domains (minimal BAR, PH and PTB) were targeted to cell membranes. Furthermore, full-length APPL proteins bound to phosphoinositides, and the APPL isolated PH or PTB domains were sufficient for in vitro phosphoinositide binding. Live cell imaging showed that full-length APPL-yellow fluorescent protein (YFP) fusion proteins associated with cytosolic membrane structures that underwent movement, fusion and fission events. Overexpression of full-length APPL-YFP fusion proteins was sufficient to recruit endogenous RAB5 to enlarged APPL-associated membrane structures, although APPL1 was not necessary for RAB5 membrane targeting. Taken together, our findings suggest a role for APPL proteins as dynamic scaffolds that modulate RAB5-associated signaling endosomal membranes by their ability to undergo domain-mediated oligomerization, membrane targeting and phosphoinositide binding.
Also flagged:epithelial neoplasiashepatocellular carcinomasmalignant epithelial tumorsepithelialtumoracute leukemias
Journal Article2007-12-18No SnippetsBaudis M.
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<h4>Background</h4>Chromosomal abnormalities have been associated with most human malignancies, with gains and losses on some genomic regions associated with particular entities.<h4>Methods</h4>Of the 15429 cases collected for the Progenetix molecular-cytogenetic database, 5918 malignant epithelial neoplasias analyzed by chromosomal Comparative Genomic Hybridization (CGH) were selected for further evaluation. For the 22 clinico-pathological entities with more than 50 cases, summary profiles for genomic imbalances were generated from case specific data and analyzed.<h4>Results</h4>With large variation in overall genomic instability, recurring genomic gains and losses were prominent. Most entities showed frequent gains involving 8q2, while gains on 20q, 1q, 3q, 5p, 7q and 17q were frequent in different entities. Loss "hot spots" included 3p, 4q, 13q, 17p and 18q among others. Related average imbalance patterns were found for clinically distinct entities, e.g. hepatocellular carcinomas (ca.) and ductal breast ca., as well as for histologically related entities (squamous cell ca. of different sites).<h4>Conclusion</h4>Although considerable case-by-case variation of genomic profiles can be found by CGH in epithelial malignancies, a limited set of variously combined chromosomal imbalances may be typical for carcinogenesis. Focus on the respective regions should aid in target gene detection and pathway deduction.
Also flagged:cytokinegene expressionneurotrophinsaxontrkCBDNF
Journal Article2007-12-18✓ 5 SnippetsLisak RP, Benjamins JA, Bealmear B, Nedelkoska L, Yao B, Land S, Studzinski D.
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…DCC is a RAF kinase inhibitory protein (RKIF), previously called phosphtidylethanolamine binding protein, which seems to have tumor suppressor activity [221] and is deleted in several types of tumors, including some colorectal cancers in humans [222].…
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…As examples, BIG-2 could be considered a neuronal protein but is also an adhesion molecule; deleted in colon cancer (DCC) is a cancer-related protein but also a neuronal protein.…
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…in colon cancer (DCC) is a cancer-related…
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…in colorectal cancer (DCC), both of which…
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…if BRCA1 andDCCare expressed in…
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<h4>Background</h4>In multiple sclerosis, inflammatory cells are found in both active and chronic lesions, and it is increasingly clear that cytokines are involved directly and indirectly in both formation and inhibition of lesions. We propose that cytokine mixtures typical of Th1 or Th2 lymphocytes, or monocyte/macrophages each induce unique molecular changes in glial cells.<h4>Methods</h4>To examine changes in gene expression that might occur in glial cells exposed to the secreted products of immune cells, we have used gene array analysis to assess the early effects of different cytokine mixtures on mixed CNS glia in culture. We compared the effects of cytokines typical of Th1 and Th2 lymphocytes and monocyte/macrophages (M/M) on CNS glia after 6 hours of treatment.<h4>Results</h4>In this paper we focus on changes with potential relevance for neuroprotection and axon/glial interactions. Each mixture of cytokines induced a unique pattern of changes in genes for neurotrophins, growth and maturation factors and related receptors; most notably an alternatively spliced form of trkC was markedly downregulated by Th1 and M/M cytokines, while Th2 cytokines upregulated BDNF. Genes for molecules of potential importance in axon/glial interactions, including cell adhesion molecules, connexins, and some molecules traditionally associated with neurons showed significant changes, while no genes for myelin-associated genes were regulated at this early time point. Unexpectedly, changes occurred in several genes for proteins initially associated with retina, cancer or bone development, and not previously reported in glial cells.<h4>Conclusion</h4>Each of the three cytokine mixtures induced specific changes in gene expression that could be altered by pharmacologic strategies to promote protection of the central nervous system.
Also flagged:Nck adaptor proteinsorganizationaxon guidance receptorsNck1Nck2SH2
Journal Article2007-12-18✓ 1 SnippetFawcett JP, Georgiou J, Ruston J, Bladt F, Sherman A, Warner N, Saab BJ, Scott R, Roder JC, Pawson T.
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The intracellular signaling targets used by mammalian axon guidance receptors to organize the nervous system in vivo are unclear. The Nck1 and Nck2 SH2/SH3 adaptors (collectively Nck) can couple phosphotyrosine (pTyr) signals to reorganization of the actin cytoskeleton and are therefore candidates for linking guidance cues to the regulatory machinery of the cytoskeleton. We find that selective inactivation of Nck in the murine nervous system causes a hopping gait and a defect in the spinal central pattern generator, which is characterized by synchronous firing of bilateral ventral motor neurons. Nck-deficient mice also show abnormal projections of corticospinal tract axons and defective development of the posterior tract of the anterior commissure. These phenotypes are consistent with a role for Nck in signaling initiated by different classes of guidance receptors, including the EphA4 receptor tyrosine kinase. Our data indicate that Nck adaptors couple pTyr guidance signals to cytoskeletal events required for the ipsilateral projections of spinal cord neurons and thus for normal limb movement.
Also flagged:gene expressiongene expressionsTUBG1HNRPABPSMD2AHSA1
Journal Article2007-12-18No SnippetsYang Y, Tashman AP, Lee JY, Yoon S, Mao W, Ahn K, Kim W, Mendell NR, Gordon D, Finch SJ.
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About 28% of genes appear to have an expression pattern that follows a mixture distribution. We use first- and second-order partial correlation coefficients to identify trios and quartets of non-sex-linked genes that are highly associated and that are also mixtures. We identified 18 trio and 35 quartet mixtures and evaluated their mixture distribution concordance. Concordance was defined as the proportion of observations that simultaneously fall in the component with the higher mean or simultaneously in the component with the lower mean based on their Bayesian posterior probabilities. These trios and quartets have a concordance rate greater than 80%. There are 33 genes involved in these trios and quartets. A factor analysis with varimax rotation identifies three gene groups based on their factor loadings. One group of 18 genes has a concordance rate of 56.7%, another group of 8 genes has a concordance rate of 60.8%, and a third group of 7 genes has a concordance rate of 69.6%. Each of these rates is highly significant, suggesting that there may be strong biological underpinnings for the mixture mechanisms of these genes. Bayesian factor screening confirms this hypothesis by identifying six single-nucleotide polymorphisms that are significantly associated with the expression phenotypes of the five most concordant genes in the first group.
Packing of bone defect with particulate allografts is a commonly performed clinical procedure. However, the ideal size of bone particles used to fill bone defects is ill-defined. For this reason the study of biology of bone allografts with different particle sizes has been performed. Standard size bone defects in the femur and the tibia of experimental animals were filled with freeze-dried cortical bone allografts with particle sizes of 1-2mm, 800-500mum, 500-300mum, 300-90mum, 250-125mum, 125-106mum, 106 to 75mum and 75-25mum. Unfilled defects and those filled with autologous bone served as controls. Cortical bone was chosen because it produced better clinical results than did cancellous bone. Likewise freeze-dried particulate bone effected more rapid healing than did frozen bone. Numerical scores were assigned to each defect based on the gross, radiographic and histomorphometric studies. Particles in the range of 300 to 90 microns produced rapid healing by direct ossification. Particles below 100microm had a significantly reduced osteogenic potential. Particles in the range of 75-25mum failed to heal the defects all together. Healing of defects packed with particles larger than 300mum was slower than with 300 - 90 mum grafts. Rapid healing of bone defects packed with particulate bone allografts in the range of 300 to 90mum indicates such allografts can be used effectively in the filling of bone defects. This is of clinical relevance.
Journal Article2007-12-17✓ 5 SnippetsIzzo A, Regnard C, Morales V, Kremmer E, Becker PB.
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…dosage compensation complex (DCC), which is an…
Introduction)
…dosage compensation complex (DCC; also known as…
Introduction)
…TheDCCpresumably first assembles…
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…proteins of theDCCare known to…
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…in targeting theDCCto the X…
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Loss of function of the RNA helicase maleless (MLE) in Drosophila melanogaster leads to male-specific lethality due to a failure of X chromosome dosage compensation. MLE is presumably involved in incorporating the non-coding roX RNA into the dosage compensation complex (DCC), which is an essential but poorly understood requirement for faithful targeting of the complex to the X chromosome. Sequence comparison predicts several RNA-binding domains in MLE but their properties have not been experimentally verified. We evaluated the RNA-binding characteristics of these conserved motifs and their contributions to RNA-stimulated ATPase activity, to helicase activity, as well as to the targeting of MLE to the nucleus and to the X chromosome territory. We find that RB2 is the dominant, conditional RNA-binding module, which is indispensable for ATPase and helicase activity whereas the N-terminal RB1 motif does not bind RNA, but is involved in targeting MLE to the X chromosome. The C-terminal domain containing a glycine-rich heptad repeat adds potential dimerization and RNA-binding surfaces which are not required for helicase activity.
Also flagged:epithelial-mesenchymal transitionSPRR2Aspindleresponse to stressSmall Proline Rich Proteinssmall proline rich protein (SPRR) 2A
Journal Article2007-12-17No SnippetsDemetris AJ, Specht S, Nozaki I, Lunz JG, Stolz DB, Murase N, Wu T.
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<h4>Background/aims</h4>Deficient biliary epithelial cell (BEC) expression of small proline-rich protein (SPRR) 2A in IL-6(-/-) mice is associated with defective biliary barrier function after bile duct ligation. And numerous gene array expression studies show SPRR2A to commonly be among the most highly up-regulated genes in many non-squamous, stressed and remodeling barrier epithelia. Since the function of SPRR in these circumstances is unknown, we tested the exploratory hypothesis that BEC SPRR2A expression contributes to BEC barrier function and wound repair.<h4>Methods</h4>The effect of SPRR2A expression was studied in primary mouse BEC cultures; in a BEC cell line after forced overexpression of SPRR2A; and in human livers removed at the time of liver transplantation.<h4>Results</h4>Forced SPRR2A overexpression showed that it functions as a SH3 domain ligand that increases resistance to oxidative injury and promotes wound restitution by enhancing migration and acquisition of mesenchymal characteristics. Low confluency non-neoplastic mouse BEC cultures show a phenotype similar to the stable transfectants, as did spindle-shaped BEC participating in atypical ductular reactions in primary biliary cirrhosis.<h4>Conclusions</h4>These observations suggest that SPRR2A-related BEC barrier modifications represent a novel, but widely utilized and evolutionarily conserved, response to stress that is worthy of further study.
Also flagged:Synthesiscarbonyloxygenamino acidadenosinecytidines
Journal Article2007-12-15No SnippetsZhong M, Strobel SA.
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Isotopomers of the ribosomal P-site substrate, the trinucleotide peptide conjugate CCA-pcb (Zhong, M.; Strobel, S. A. Org. Lett. 2006, 8, 55-58), have been designed and synthesized in 26-35 steps. These include individual isotopic substitution at the alpha-hydrogen, carbonyl carbon, and carbonyl oxygen of the amino acid, the O2' and O3' of the adenosine, and a remote label in the N3 and N4 of both cytidines. These isotopomers were synthesized by coupling cytidylyl-(3',5')-cytidine phosphoramidite isotopomers as the common synthetic intermediates, with isotopically substituted A-Phe-cap-biotin (A-pcb). The isotopic enrichment is higher than 99% for 1-13C (Phe), 2-2H (Phe), and 3,4-15N2 (cytidine), 93% for 2'/3'-18 O (adenosine), and 64% for 1-18 O (Phe). A new synthesis of highly enriched [1-18 O2]phenylalanine has been developed. The synthesis of [3'-18 O]adenosine was improved by Lewis acid aided regioselective ring opening of the epoxide and by an economical SN2-SN2 method with high isotopic enrichment (93%). Such substrates are valuable for studies of the ribosomal peptidyl transferase reaction by complete kinetic isotope effect analysis and of other biological processes catalyzed by nucleic acid related enzymes, including polymerases, reverse transcriptases, ligases, nucleases, and ribozymes.
Also flagged:Sex steroid receptorsosteosarcomaestrogen receptorsERprogesterone receptorsPR
Journal Article2007-12-15No SnippetsDohi O, Hatori M, Suzuki T, Ono K, Hosaka M, Akahira J, Miki Y, Nagasaki S, Itoi E, Sasano H.
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Sex steroid receptors including estrogen receptors (ER), progesterone receptors (PR), and androgen receptors (AR) have been sporadically reported in human osteosarcoma or its cell lines. Therefore, sex steroids have been considered to play some roles in human osteosarcoma, but no systematic and detailed studies regarding the correlation between the status of these receptors in sarcoma cells and clinicopathological parameters have been reported. We examined the existence of ER, PR and AR in 28 cases of osteosarcoma using immunohistochemistry. We then characterized the potential influence of sex steroids on cell proliferation of osteosarcoma cells using MG-63 human osteosarcoma cell line, which expressed all of these receptors. ER-beta and PR were detected in the great majority of the cases (23 and 24 cases, respectively) but ER-alpha and aromatase were not detected in all the cases, and AR was detected only in eight cases. There was a significant positive correlation between ER-beta and Ki-67 (MIB1) labeling indexes. The absence of aromatase in tumors also suggests the relative importance of concentrations of circulating sex steroids. Proliferation of MG-63 cells was significantly stimulated by estradiol, progesterone, and 5 alpha-dihydrotestosterone (DHT), and was significantly suppressed by the addition of fulvestrant (ICI), mifepristone (RU), and hydroxiflutamide, blockers for ER, PR and AR, respectively. Sex steroids, particularly estrogen and progesterone, are considered to play important roles in the regulation of cell proliferation in human osteosarcoma. In addition, these data suggest the potential for a novel endocrine therapy in osteosarcoma using clinically available inhibitors of progesterone and estrogen actions.
TDP-43, recently identified as a signature protein of the pathogenic inclusions in the brains cells of frontotemporal lobar degeneration patients, is a 43 kDa RNA-binding protein. It has been known mainly as a nuclear factor capable of repressing transcription and promoting exon exclusion. TDP-43 also forms distinct nuclear substructures linking different types of nuclear bodies. In this study, we provide the first evidence supporting TDP-43 as a neuronal activity-responsive factor in the dendrites of hippocampal neurons. In particular, TDP-43 resides in the somatodendrites mainly in the form of RNA granules colocalized with the post-synaptic protein PSD-95. These granules also contain RNAs including at least the beta-actin mRNA and CaMKIIalpha mRNA. Furthermore, TDP-43 is localized in the dendritic processing (P) body and it behaves as a translational repressor in an in vitro assay. Related to this, repetitive stimuli by KCl greatly enhance the colocalization of TDP-43 granules with FMRP and Staufen 1, two RNA-binding proteins known to regulate mRNA transport and local translation in neurons. These data together suggest that TDP-43 is a neuronal activity-responsive factor functioning in the regulation of neuronal plasticity, the impairment of which would lead to the development of certain forms of neurodegenerative diseases including frontotemporal lobar degeneration.
Also flagged:ATAC histone acetylaseATAChistone acetylaseAda2achromosomeIswi
Journal Article2007-12-14✓ 1 SnippetCarré C, Ciurciu A, Komonyi O, Jacquier C, Fagegaltier D, Pidoux J, Tricoire H, Tora L, Boros IM, Antoniewski C.
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Drosophila Gcn5 is the catalytic subunit of the SAGA and ATAC histone acetylase complexes. Here, we show that mutations in Gcn5 and the ATAC component Ada2a induce a decondensation of the male X chromosome, similar to that induced by mutations in the Iswi and Nurf301 subunits of the NURF nucleosome remodelling complex. Genetic studies as well as transcript profiling analysis indicate that ATAC and NURF regulate overlapping sets of target genes during development. In addition, we find that Ada2a chromosome binding and histone H4-Lys12 acetylation are compromised in Iswi and Nurf301 mutants. Our results strongly suggest that NURF is required for ATAC to access the chromatin and to regulate global chromosome organization.
Also flagged:5-HT transporter5-HT2A receptorbehavioural5-HT receptor5-HT(2A) receptor5-HT(2) receptor
Journal Article2007-12-14✓ 5 SnippetsJennings KA, Sheward WJ, Harmar AJ, Sharp T.
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Abstract)
…the 5-HT transporter (5-HTT) gene in the…
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…used a novel5-HTToverexpressing transgenic mous…
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…that variability in5-HTTexpression may alter…
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…demonstrate that elevated5-HTTexpression is accompanied…
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…in levels of5-HTTexpression may therefore…
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Variability in expression of the 5-HT transporter (5-HTT) gene in the human population has been associated with a range of behavioural phenotypes. The underlying mechanisms are unclear but may involve changes in 5-HT receptor levels and/or signalling. The present study used a novel 5-HTT overexpressing transgenic mouse to test the hypothesis that variability in 5-HTT expression may alter 5-HT(2A) receptor function. In wildtype mice, the 5-HT(2) receptor agonist DOI increased regional brain mRNA expression of two immediate early genes (c-fos and Arc), and induced head twitches, and both effects were abolished by pre-treatment with the 5-HT(2A) receptor antagonist MDL 100907. In 5-HTT overexpressing mice, DOI induced a greater increase in both c-fos and Arc mRNA expression in cortical brain regions, and more head twitches, compared to wildtype mice. Autoradiographic and in situ hybridisation experiments showed that 5-HT(2A) receptor binding sites and 5-HT(2A) receptor mRNA did not differ between transgenic and wildtype mice. Finally, the transgenic mice had lower regional brain 5-HT levels compared to wildtype mice. This depletion of 5-HT may underpin the increase in 5-HT(2A) receptor function because in wildtype mice 5-HT depletion using the 5-HT synthesis inhibitor, p-chlorophenylalanine, enhanced the head twitch response to DOI. These data demonstrate that elevated 5-HTT expression is accompanied by increased 5-HT(2A) receptor function, an effect possibly mediated by decreased availability of synaptic 5-HT. Variation in levels of 5-HTT expression may therefore be a source of variability in 5-HT(2A) receptor function, which may be an important modifier of 5-HTT-linked phenotypes.
Clinical manifestations of cystic fibrosis (CF) are variable. Genetic and environmental factors that determine whether an individual will develop associated complications are still under investigation. The present study reports the genetic analysis of a family with different clinical forms of CF and addresses the difficulty of CF diagnosis in an individual with mutant alleles G542X and R117H because of the variable phenotype associated with R117H mutation. Both children in this family were heterozygous for G542X/R117H with the same thymine sequence (7T/9T) in intron 8 of CF transmembrane conductance regulator. The girl was diagnosed with CF, whereas the boy was diagnosed with azoospermia as the sole clinical manifestation. The possible implication of the hemochromatosis gene as a CF modifier locus was analyzed because the 2 children had the same genotype. No genetic differences were detected between brother and sister that explained the different clinical manifestations of CF.
The kynurenine pathway of tryptophan degradation is hypothesized to play an important role in Huntington disease, a neurodegenerative disorder caused by a polyglutamine expansion in the protein huntingtin. Neurotoxic metabolites of the kynurenine pathway, generated in microglia and macrophages, are present at increased levels in the brains of patients and mouse models during early stages of disease, but the mechanism by which kynurenine pathway up-regulation occurs in Huntington disease is unknown. Here we report that expression of a mutant huntingtin fragment was sufficient to induce transcription of the kynurenine pathway in yeast and that this induction was abrogated by impairing the activity of the histone deacetylase Rpd3. Moreover, numerous genetic suppressors of mutant huntingtin toxicity that are functionally unrelated converged unexpectedly on the kynurenine pathway, supporting a critical role for the kynurenine pathway in mediating mutant huntingtin toxicity in yeast. Histone deacetylase-dependent regulation of the kynurenine pathway was also observed in a mouse model of Huntington disease, in which treatment with a neuroprotective histone deacetylase inhibitor blocked activation of the kynurenine pathway in microglia expressing a mutant huntingtin fragment in vitro and in vivo. These findings suggest that a mutant huntingtin fragment can perturb transcriptional programs in microglia, and thus implicate these cells as potential modulators of neurodegeneration in Huntington disease that are worthy of further investigation.
In situ estrogen synthesis is implicated in tumor cell proliferation through autocrine or paracrine mechanisms especially in postmenopausal women. Several recent studies demonstrated activity of aromatase, an enzyme that plays a critical role in estrogen synthesis in breast tumors. Proline-, glutamic acid-, and leucine-rich protein-1 (PELP1/MNAR) is an estrogen receptor (ER) coregulator, and its expression is deregulated in breast tumors. In this study, we examined whether PELP1 promotes tumor growth by promoting local estrogen synthesis using breast cancer cells (MCF7) that stably overexpress PELP1. Immunohistochemistry revealed increased aromatase expression in MCF7-PELP1-induced xenograft tumors. Real-time PCR analysis showed enhanced activation of the aromatase promoter in MCF7-PELP1 clones compared with MCF7 cells. Using a tritiated-water release assay, we demonstrated that MCF7-PELP1 clones exhibit increased aromatase activity compared with control MCF-7 cells. PELP1 deregulation uniquely up-regulated aromatase expression via activation of aromatase promoter I.3/II, and growth factor signaling enhanced PELP1 activation of aromatase. PELP1-mediated induction of aromatase requires functional Src and phosphatidylinositol-3-kinase pathways. Mechanistic studies revealed that PELP1 interactions with ER-related receptor-alpha and proline-rich nuclear receptor coregulatory protein 2 lead to activation of aromatase. Immunohistochemistry analysis of breast tumor array showed increased expression of aromatase in ductal carcinoma in situ and node-positive tumors compared with no or weak expression in normal breast tissue. Fifty-four percent (n = 79) of PELP1-overexpressing tumors also overexpressed aromatase compared with 36% (n = 47) in PELP1 low-expressing tumors. Our results suggest that PELP1 regulation of aromatase represents a novel mechanism for in situ estrogen synthesis leading to tumor proliferation by autocrine loop and open a new avenue for ablating local aromatase activity in breast tumors.
Journal Article2007-12-13✓ 2 SnippetsBartlett NL, Younes A, Carabasi MH, Forero A, Rosenblatt JD, Leonard JP, Bernstein SH, Bociek RG, Lorenz JM, Hart BW, Barton J.
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…>1000: grand forhemochromatosisscreening?…
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…μg/L to detectHFE hemochromatosishemochromatosis and increased…
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Phase 1 testing of SGN-30, a chimeric monoclonal antibody for the treatment of CD30(+) malignancies, was conducted in a multicenter study. To explore the safety profile and establish the maximum tolerated dose (MTD), 24 patients with refractory or relapsed Hodgkin lymphoma or CD30(+) non-Hodgkin lymphoma received 6 weekly doses of intravenous SGN-30 at 4 dose levels (2, 4, 8, or 12 mg/kg). Serum concentrations of SGN-30 rose rapidly and were dose dependent. Adverse events were mild, with nausea, fatigue, and fever attributed to study treatment. One episode of hypersensitivity rash was reported. The MTD was not reached. Serious adverse events included herpes zoster (n = 2), influenza, and pneumonia. One patient with cutaneous anaplastic large cell lymphoma (8 mg/kg) achieved a complete response. Six patients, of whom 4 had Hodgkin lymphoma, achieved stable disease with durations ranging from 6 to 16 months. The pharmacokinetic profile of SGN-30 showed a biphasic disposition, and estimated half-lives ranging between 1 to 3 weeks. The 6 weekly infusions of SGN-30 resulted in approximately 2- to 3-fold accumulation in serum exposures consistently across the dose range. These results demonstrate that weekly administration of SGN-30 is safe and has modest clinical activity in patients with CD30(+) tumors. This trial is registered at http://www.ClinicalTrials.gov as no. NCT00051597.
Discovery of genetic variants of the HFE gene has made it possible to screen for hereditary hemochromatosis. However, genetic screening raises ethical, legal, social, and psychological questions, which need to be addressed. To assess the psychological impact on individuals undergoing genetic screening for hereditary hemochromatosis and to determine the effects of providing different levels of information to the participants. Male residents, aged 30-50 years (n = 10,993) were invited to a genetic screening for hereditary hemochromatosis. Carriers of the gene variants H63D, S65C, and C282Y were offered additional biochemical screening using serum ferritin and transferrin saturation. Psychological factors were evaluated through questionnaires before and after genetic and biochemical screening. According to genotype, participants were divided into three groups with different risks profiles for having/developing clinical hemochromatosis (at-risk, uncertain risk, no risk). Before completion of the questionnaires, 929 participants received only genetic information and 366 received both genetic and biochemical information. At-risk participants receiving only genetic information generally displayed negative reactions to the test result, whereas participants receiving both genetic and biochemical information were more satisfied and had fewer negative psychological reactions to the test result. Genetic screening is more readily accepted by subjects when genetic information is supported by biochemical measurements, especially in participants with a risk of clinical disease.
Also flagged:craniosynostosisfibroblast growth factortransforming growth factor betaephringene expressionglypican 3
Journal Article2007-12-12No SnippetsCoussens AK, Wilkinson CR, Hughes IP, Morris CP, van Daal A, Anderson PJ, Powell BC.
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<h4>Background</h4>Craniosynostosis, the premature fusion of calvarial sutures, is a common craniofacial abnormality. Causative mutations in more than 10 genes have been identified, involving fibroblast growth factor, transforming growth factor beta, and Eph/ephrin signalling pathways. Mutations affect each human calvarial suture (coronal, sagittal, metopic, and lambdoid) differently, suggesting different gene expression patterns exist in each human suture. To better understand the molecular control of human suture morphogenesis we used microarray analysis to identify genes differentially expressed during suture fusion in children with craniosynostosis. Expression differences were also analysed between each unfused suture type, between sutures from syndromic and non-syndromic craniosynostosis patients, and between unfused sutures from individuals with and without craniosynostosis.<h4>Results</h4>We identified genes with increased expression in unfused sutures compared to fusing/fused sutures that may be pivotal to the maintenance of suture patency or in controlling early osteoblast differentiation (i.e. RBP4, GPC3, C1QTNF3, IL11RA, PTN, POSTN). In addition, we have identified genes with increased expression in fusing/fused suture tissue that we suggest could have a role in premature suture fusion (i.e. WIF1, ANXA3, CYFIP2). Proteins of two of these genes, glypican 3 and retinol binding protein 4, were investigated by immunohistochemistry and localised to the suture mesenchyme and osteogenic fronts of developing human calvaria, respectively, suggesting novel roles for these proteins in the maintenance of suture patency or in controlling early osteoblast differentiation. We show that there is limited difference in whole genome expression between sutures isolated from patients with syndromic and non-syndromic craniosynostosis and confirmed this by quantitative RT-PCR. Furthermore, distinct expression profiles for each unfused suture type were noted, with the metopic suture being most disparate. Finally, although calvarial bones are generally thought to grow without a cartilage precursor, we show histologically and by identification of cartilage-specific gene expression that cartilage may be involved in the morphogenesis of lambdoid and posterior sagittal sutures.<h4>Conclusion</h4>This study has provided further insight into the complex signalling network which controls human calvarial suture morphogenesis and craniosynostosis. Identified genes are candidates for targeted therapeutic development and to screen for craniosynostosis-causing mutations.
Also flagged:neurodegenerative disorderpolyglutaminebrain-derived neurotrophic factorBDNFgene expressionHD
Journal Article2007-12-12✓ 3 SnippetsGharami K, Xie Y, An JJ, Tonegawa S, Xu B.
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Abstract)
…We employed a Bdnf transgene driven by the promoter for the alpha subunit of Ca(2+)/calmodulin-dependent kinase II to over-express BDNF in the forebrain of R6/1 mice which express a fragment of mutant htt with a 116-glutamine tract.…
Abstract)
…Huntington's disease (HD), a dominantly inherited neurodegenerative disorder characterized by relatively selective degeneration of striatal neurons, is caused by an expanded polyglutamine tract of the huntingtin (htt) protein.…
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Huntington's disease (HD), a dominantly inherited neurodegenerative disorder characterized by relatively selective degeneration of striatal neurons, is caused by an expanded polyglutamine tract of the huntingtin (htt) protein. The htt mutation reduces levels of brain-derived neurotrophic factor (BDNF) in the striatum, likely by inhibiting cortical BDNF gene expression and anterograde transport of BDNF from cortex to striatum. However, roles of the BDNF reduction in HD pathogenesis have not been established conclusively. We reasoned that increasing striatal BDNF through over-expression would slow progression of the disease if BDNF reduction plays a pivotal role in HD pathogenesis. We employed a Bdnf transgene driven by the promoter for the alpha subunit of Ca(2+)/calmodulin-dependent kinase II to over-express BDNF in the forebrain of R6/1 mice which express a fragment of mutant htt with a 116-glutamine tract. The Bdnf transgene increased BDNF levels and TrkB signaling activity in the striatum, ameliorated motor dysfunction, and reversed brain weight loss in R6/1 mice. Furthermore, it normalized DARPP-32 expression of the 32 kDa dopamine and cAMP-regulated phosphoprotein, increased the number of enkephalin-containing boutons, and reduced formation of neuronal intranuclear inclusions in the striatum of R6/1 mice. These results demonstrate crucial roles of reduced striatal BDNF in HD pathogenesis and suggest potential therapeutic values of BDNF to HD.
Also flagged:cysteic acidgliomatumormetabolismtumorsglutamic acid
Journal Article2007-12-11No SnippetsJia B, Liu Z, Shi J, Yu Z, Yang Z, Zhao H, He Z, Liu S, Wang F.
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In this report, we present in vitro and in vivo evaluation of three 111 In-labeled DTPA conjugates of a cyclic RGDfK dimer: DTPA-Bn-SU016 (SU016 = E[c(RGDfK)] 2; DTPA-Bn = 2-( p-isothioureidobenzyl)diethylenetriaminepentaacetic acid), DTPA-Bn-E-SU016 ( E = glutamic acid) and DTPA-Bn-Cys-SU016 (Cys = cysteic acid). The integrin alpha vbeta 3 binding affinities of SU016, DTPA-Bn-SU016, DTPA-Bn-E-SU016, and DTPA-Bn-Cys-SU016 were determined to be 5.0 +/- 0.7 nM, 7.9 +/- 0.6 nM, 5.8 +/- 0.6 nM, and 6.9 +/- 0.9 nM, respectively, against 125 I-c(RGDyK) in binding to integrin alpha vbeta3, suggesting that E or Cys residue has little effect on the integrin alpha vbeta3 affinity of E[c(RGDfK)] 2. It was also found that the 111 In-labeling efficiency of DTPA-Bn-SU016 and DTPA-Bn-E-SU016 is 3-5 times better than that of DOTA analogues due to fast chelation kinetics and high-yield 111 In-labeling under mild conditions (e.g., room temperature). Biodistribution studies were performed using BALB/c nude mice bearing U87MG human glioma xenografts. 111 In-DTPA-Bn-SU016, 111 In-DTPA-Bn-E-SU016, and 111 In-DTPA-Bn-Cys-SU016 all displayed rapid blood clearance. Their tumor uptake was comparable between 0.5 and 4 h postinjection (p.i.) within experimental error. 111 In-DTPA-Bn-E-SU016 had a significantly lower ( p < 0.01) kidney uptake than 111 In-DTPA-Bn-SU016 and 111 In-DTPA-Bn-Cys-SU016. The liver uptake of 111 In-DTPA-Bn-SU016 was 1.69 +/- 0.18% ID/g at 24 h p.i., while the liver uptake values of 111 In-DTPA-Bn-E-SU016 and 111 In-DTPA-Bn-Cys-SU016 were 0.55 +/- 0.11% ID/g and 0.79 +/- 0.15% ID/g at 24 h p.i., respectively. Among the three 111 In radiotracers evaluated in this study, 111 In-DTPA-Bn-E-SU016 has the lowest liver and kidney uptake and the best tumor/liver and tumor/kidney ratios. Results from metabolism studies indicated that there is little metabolism (<10%) for three 111 In radiotracers at 1 h p.i. Imaging data showed that tumors can be clearly visualized at 4 h p.i. with good contrast in the tumor-bearing mice administered with 111 In-DTPA-Bn-E-SU016. It is concluded that using a glutamic acid linker can significantly improve excretion kinetics of the 111 In-labeled E[c(RGDfK)] 2 from liver and kidneys.
Also flagged:Netrinsignal transductionguanine nucleotide exchange factoraxon guidancesmall GTPaseRac1
Journal Article2007-12-09✓ 4 SnippetsLi X, Gao X, Liu G, Xiong W, Wu J, Rao Y.
In-Text Gene Mentions
Abstract)
…Netrin promoted the formation of a protein-protein interaction complex that included DOCK180 and the netrin receptor deleted in colorectal carcinoma (DCC).…
Abstract)
…in colorectal carcinoma (DCC).…
Abstract)
…recruits DOCK180 throughDCC, which then activates…
Text
…DCC…
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Netrins are prototypical axon guidance cues whose attractive signaling requires the small GTPase Rac1. It remains unclear how Rac1 is regulated in the netrin pathway. DOCK180 is a member of a new family of guanine nucleotide exchange factors for Rho GTPases. Here we provide evidence implicating DOCK180 in netrin signal transduction. Netrin promoted the formation of a protein-protein interaction complex that included DOCK180 and the netrin receptor deleted in colorectal carcinoma (DCC). Inhibition of DOCK180 reduced activation of Rac1 by netrin. Both axon outgrowth and axon attraction induced by netrin were inhibited after DOCK180 knockdown in vertebrate neurons. The in vivo functional role of DOCK180 was demonstrated by its requirement for projection of commissural axons in the neural tube. These findings indicate that netrin stimulation recruits DOCK180 through DCC, which then activates small GTPases, suggesting an essential role for DOCK180 in mediating attractive responses by neurons to netrin-1.
Also flagged:physiologyironiron deficiency anemiaatherosclerotic cardiovascular diseasesiron deficiencymitochondrial
Journal Article2007-12-08No SnippetsFranchini M, Targher G, Montagnana M, Lippi G.
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Although essential for cell physiology, an increase or depletion of body iron has harmful effects on health. Apart from iron deficiency anemia and iron overload-related organ tissue damage, there are increasing evidences that body iron status is implicated in atherosclerotic cardiovascular diseases. The hypothesis formulated in 1981 that iron depletion may protect against cardiovascular events is intriguing and has generated a significant debate in the last two decades. Indeed, to study this phenomenon, several investigators have tried to design appropriate experimental and clinical studies and to identify useful biochemical and genetic markers of iron status. The results of the literature on the effect of iron deficiency and overload on vascular health are critically reviewed in this study from a pathogenic and clinical point of view.
Also flagged:iodoacetamideCysteineperoxiredoxinsproteasesphenylthioredoxin
Journal Article2007-12-08No SnippetsNelson KJ, Day AE, Zeng BB, King SB, Poole LB.
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Cysteine reactivity in enzymes is imparted to a large extent by the stabilization of the deprotonated form of the reduced cysteine (i.e., the thiolate) within the active site. Although this is likely to be an important chemical attribute of many thiol-based enzymes, including cysteine-dependent peroxidases (peroxiredoxins) and proteases, only relatively few pK(a) values have been determined experimentally. Presented here is a new technique for determining the pK(a) value of cysteine residues through quantitative mass spectrometry following chemical modification with an iodoacetamide-based reagent over a range of pH buffers. This isotope-coded reagent, N-phenyl iodoacetamide (iodoacetanilide), is readily prepared in deuterated (d(5)) and protiated (d(0)) versions and is more reactive toward free cysteine than is iodoacetamide. Using this approach, the pK(a) values for the two cysteine residues in Escherichia coli thioredoxin were determined to be 6.5 and greater than 10.0, in good agreement with previous reports using chemical modification approaches. This technique allows the pK(a) of specific cysteine residues to be determined in a clear, fast, and simple manner and, because cysteine residues on separate tryptic peptides are measured separately, is not complicated by the presence of multiple cysteines within the protein of interest.
…We show that Pak1 overexpression enhanced htt toxicity in cell models and neurons in parallel with its ability to promote aggregation, while Pak1 knockdown suppressed both aggregation and toxicity.…
Abstract)
…Huntington's disease (HD) is caused by a polyglutamine (polyQ) expansion in the huntingtin (htt) protein.…
Abstract)
…Pak1 colocalized with mutant htt (muhtt) aggregates in cell models and in human HD brains.…
Abstract)
…in the huntingtin (htt) protein.…
Abstract)
…(Pak1) binds tohttin vivo and…
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Huntington's disease (HD) is caused by a polyglutamine (polyQ) expansion in the huntingtin (htt) protein. While aggregation is a pathological hallmark of HD and related polyQ expansion diseases, the role of aggregates has been disputed. Here we report that p21-activated kinase 1 (Pak1) binds to htt in vivo and in vitro. Pak1 colocalized with mutant htt (muhtt) aggregates in cell models and in human HD brains. Pak1 overexpression enhanced the aggregation of muhtt. Furthermore, we observed SDS-soluble wild-type htt (wthtt)-wthtt, wthtt-muhtt and muhtt-muhtt interactions, which were enhanced by the presence of Pak1. We show that Pak1 overexpression enhanced htt toxicity in cell models and neurons in parallel with its ability to promote aggregation, while Pak1 knockdown suppressed both aggregation and toxicity. Overexpression of either kinase-dead or wild-type Pak enhanced both aggregation and toxicity. Our data reveal a novel mechanism regulating muhtt oligomerization and toxicity and suggest that pathology may be at least partly dependent on soluble muhtt-muhtt interactions.
Also flagged:Gene expressioncerebral malariapathogenesisgene-expressioninfectioninflammatory response
Journal Article2007-12-06No SnippetsDelahaye NF, Coltel N, Puthier D, Barbier M, Benech P, Joly F, Iraqi FA, Grau GE, Nguyen C, Rihet P.
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<h4>Background</h4>Microarray analyses allow the identification and assessment of molecular signatures in whole tissues undergoing pathological processes. To better understand cerebral malaria pathogenesis, we investigated intra-cerebral gene-expression profiles in well-defined genetically cerebral malaria-resistant (CM-R) and CM-susceptible (CM-S) mice, upon infection by Plasmodium berghei ANKA (PbA). We investigated mouse transcriptional responses at early and late stages of infection by use of cDNA microarrays.<h4>Results</h4>Through a rigorous statistical approach with multiple testing corrections, we showed that PbA significantly altered brain gene expression in CM-R (BALB/c), and in CM-S (CBA/J and C57BL/6) mice, and that 327 genes discriminated between early and late infection stages, between mouse strains, and between CM-R and CM-S mice. We further identified 104, 56, 84 genes with significant differential expression between CM-R and CM-S mice on days 2, 5, and 7 respectively. The analysis of their functional annotation indicates that genes involved in metabolic energy pathways, the inflammatory response, and the neuroprotection/neurotoxicity balance play a major role in cerebral malaria pathogenesis. In addition, our data suggest that cerebral malaria and Alzheimer's disease may share some common mechanisms of pathogenesis, as illustrated by the accumulation of beta-amyloid proteins in brains of CM-S mice, but not of CM-R mice.<h4>Conclusion</h4>Our microarray analysis highlighted marked changes in several molecular pathways in CM-S compared to CM-R mice, particularly at early stages of infection. This study revealed some promising areas for exploration that may both provide new insight into the knowledge of CM pathogenesis and the development of novel therapeutic strategies.
Also flagged:colon cancersadenomatous polypstumorpolyposispolypsMC
Journal Article2007-12-06No SnippetsGounaris E, Erdman SE, Restaino C, Gurish MF, Friend DS, Gounari F, Lee DM, Zhang G, Glickman JN, Shin K, Rao VP, Poutahidis T, Weissleder R, McNagny KM, Khazaie K.
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It is generally agreed that most colon cancers develop from adenomatous polyps, and it is this fact on which screening strategies are based. Although there is overwhelming evidence to link intrinsic genetic lesions with the formation of these preneoplastic lesions, recent data suggest that the tumor stromal environment also plays an essential role in this disease. In particular, it has been suggested that CD34(+) immature myeloid precursor cells are required for tumor development and invasion. Here we have used mice conditional for the stabilization of beta-catenin or defective for the adenomatous polyposis coli (APC) gene to reinvestigated the identity and importance of tumor-infiltrating hematopoietic cells in polyposis. We show that, from the onset, polyps are infiltrated with proinflammatory mast cells (MC) and their precursors. Depletion of MC either pharmacologically or through the generation of chimeric mice with genetic lesions in MC development leads to a profound remission of existing polyps. Our data suggest that MC are an essential hematopoietic component for preneoplastic polyp development and are a novel target for therapeutic intervention.
Also flagged:Unipolarmajor depressive disorderdepressionnorepinephrine transporterNETSLC6A2
Journal Article2007-12-06✓ 1 SnippetHahn MK, Blackford JU, Haman K, Mazei-Robison M, English BA, Prasad HC, Steele A, Hazelwood L, Fentress HM, Myers R, Blakely RD, Sanders-Bush E, Shelton R.
In-Text Gene Mentions
Text
…5-HTT…
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Unipolar major depressive disorder (MDD) is a prevalent, disabling condition with multiple genetic and environmental factors impacting disease risk. The diagnosis of MDD relies on a cumulative measure derived from multiple trait dimensions and alone is limited in elucidating MDD genetic determinants. We and others have proposed that MDD may be better dissected using paradigms that assess how specific genes associate with component features of MDD. This within-disease design requires both a well-phenotyped cohort and a robust statistical approach that retains power with multiple tests of genetic association. In the present study, common polymorphic variants of genes related to central monoaminergic and cholinergic pathways that previous studies align with functional change in vitro or depression associations in vivo were genotyped in 110 individuals with unipolar MDD. Subphenotypic characteristics were examined using responses to individual items assessed with the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders (DSM IV), the 17-item Hamilton Rating Scale for Depression (HAM-D) and the NEO Five Factor Inventory. Multivariate Permutation Testing (MPT) was used to infer genotype-phenotype relationships underlying dimensional findings within clinical categories. MPT analyses show significant associations of the norepinephrine transporter (NET, SLC6A2) -182 T/C (rs2242446) with recurrent depression [odds ratio, OR = 4.15 (1.91-9.02)], NET -3081 A/T (rs28386840) with increase in appetite [OR = 3.58 (1.53-8.39)] and the presynaptic choline transporter (CHT, SLC5A7) Ile89Val (rs1013940) with HAM-D-17 total score {i.e. overall depression severity [OR = 2.74 (1.05-7.18)]}. These relationships illustrate an approach to the elucidation of gene influences on trait components of MDD and with replication, may help identify MDD subpopulations that can benefit from more targeted pharmacotherapy.
Also flagged:serotonin transporterglucocorticoiddexamethasonecortisoltranscriptional regulators5
Journal Article2007-12-06✓ 2 SnippetsKinnally EL, Lyons LA, Abel K, Mendoza S, Capitanio JP.
In-Text Gene Mentions
Abstract)
…pheral serotonin transporter (5-HTT) regulation in response…
Abstract)
…strong influence on5-HTTregulation during a…
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The moderating effect of early experience on gene-behavior associations has been well characterized. The molecular events that allow for such moderation are not well understood, however. We assessed the impact of early experience and serotonin transporter linked promoter polymorphism (rh5-HTTLPR) genotype on peripheral serotonin transporter (5-HTT) regulation in response to a maternal/social separation and relocation stressor in infant rhesus macaques. We further tested the hypothesis that modulation of 5-HTT regulation by rearing and/or genotype is mediated by glucocorticoid (GC) availability. Fifty-three infant (3-4 months of age) rhesus macaques that were either nursery reared (NR) or mother reared (MR) were genotyped for rh5-HTTLPR. Infants were blood sampled within 2.5 h of maternal or social separation/relocation and again 5 h later. Infants were then administered dexamethasone, a synthetic GC and blood sampled 16.5 h later. 5-HTT RNA was quantified from peripheral blood mononuclear cells. Plasma cortisol was measured at all time points. The MR individuals upregulated 5-HTT significantly during maternal/social separation, while NR individuals did not. Concomitant increases in cortisol were not observed, but dexamethasone treatment stimulated 5-HTT expression regardless of genotype/rearing group, and 5-HTT expression in the post-stressor sample was correlated with plasma cortisol levels at all time points. Our data indicate that early experience exerted a strong influence on 5-HTT regulation during a stressor in infant rhesus macaques independent of rh5-HTTLPR genotype. We also showed that GCs may stimulate 5-HTT expression but that there likely exist faster-acting transcriptional regulators of 5-HTT that are in place as a function of experience.
Also flagged:endoplasmic reticulumhereditary haemochromatosisHHironMHC-Iantigen presentation
Journal Article2007-12-05✓ 5 Snippetsde Almeida SF, de Sousa M.
In-Text Gene Mentions
Abstract)
…HFE has been amongst the preferred targets of interest, since the discovery that its C282Y mutation was associated with HH.…
S I O 001029)
…A more detailed characterization of this link and, particularly, of the HFE C282Y-associated UPR contribution for the establishment and progression of viral infections emerges as an attractive challenge.…
S I O 001029)
…Similarly, Nef (an HIV-1 protein important for the progression to AIDS) reroutes HFE to a perinuclear compartment causing a 90% reduction of cell surface expression [24].…
Discussion)
…Haemochromatosis can also result from mutations in genes other than HFE, like transferrin receptor 2, ferroportin or hemojuvelin [10].…
Abstract)
…HFEhas been amongst…
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To cope with the accumulation of unfolded or misfolded proteins the endoplasmic reticulum (ER) has evolved specific signalling pathways collectively called the unfolded protein response (UPR). Elucidation of the mechanisms governing ER stress signalling has linked this response to the regulation of diverse physiologic processes as well as to the progression of a number of diseases. Interest in hereditary haemochromatosis (HH) has focused on the study of proteins implicated in iron homeostasis and on the identification of new alleles related with the disease. HFE has been amongst the preferred targets of interest, since the discovery that its C282Y mutation was associated with HH. However, the discrepancies between the disease penetrance and the frequency of this mutation have raised the possibility that its contribution to disease progression might go beyond the mere involvement in regulation of cellular iron uptake. Recent findings revealed that activation of the UPR is a feature of HH and that this stress response may be involved in the genesis of immunological anomalies associated with the disease. This review addresses the connection of the UPR with HH, including its role in MHC-I antigen presentation pathway and possible implications for new clinical approaches to HH.
Also flagged:Cancerpiwil2tumourmalignant tumoursmalignant tumourgenetic diseases
Journal Article2007-12-05✓ 1 SnippetGao JX.
In-Text Gene Mentions
S I O 001029)
…The mutation of DCC or DPC4/SMAD4 located at the 18q chromosome further drives the pre-malignant lesion to late adenoma.…
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How a cancer is initiated and established remains elusive despite all the advances in decades of cancer research. Recently the cancer stem cell (CSC) hypothesis has been revived, challenging the long-standing model of "clonal evolution" for cancer development and implicating the dawning of a potential cure for cancer [1]. The recent identification of precancerous stem cells (pCSCs) in cancer, an early stage of CSC development, however, implicates that the "clonal evolution" is not contradictory to the CSC hypothesis, but is rather an aspect of the process of CSC development [2]. The discovery of pCSC has revealed and will continue to reveal the volatile properties of CSC with respects to their phenotype, differentiation and tumorigenic capacity during initiation and progression. Both pCSC and CSC might also serve as precursors of tumor stromal components such as tumor vasculogenic stem/progenitor cells (TVPCs). Thus, the CSC hypothesis covers the developing process of tumor-initiating cells (TIC) --> pCSC --> CSC --> cancer, a cellular process that should parallel the histological process of hyperplasia/metaplasia (TIC) --> precancerous lesions (pCSC) --> malignant lesions (CSC --> cancer). The embryonic stem (ES) cell and germline stem (GS) cell genes are subverted in pCSCs. Especially the GS cell protein piwil2 may play an important role during the development of TIC --> pCSC --> CSC, and this protein may be used as a common biomarker for early detection, prevention, and treatment of cancer. As cancer stem cell research is yet in its infancy, definitive conclusions regarding the role of pCSC can not be made at this time. However this review will discuss what we have learned from pCSC and how this has led to innovative ideas that may eventually have major impacts on the understanding and treatment of cancer.
Also flagged:VP4polyacrylamideoligonucleotidebiotindigoxigeninreverse transcription
Journal Article2007-12-05No SnippetsSantos N, Honma S, Timenetsky Mdo C, Linhares AC, Ushijima H, Armah GE, Gentsch JR, Hoshino Y.
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A microtiter plate hybridization-based PCR-enzyme-linked immunosorbent assay (PCR-ELISA) has been used for the detection and identification of a variety of microorganisms. Here, we report the development of a PCR-ELISA for the identification of clinically relevant human rotavirus VP7 (G1 to G6, G8 to G10, and G12) and VP4 (P[4], P[6], P[8], P[9], and P[14]) genotypes. The G and P types of reference human and animal rotavirus strains for which specific probes were available were correctly identified by the PCR-ELISA. In addition, reference strains bearing G or P genotypes for which specific probes were unavailable, such as G11, G14, P[3], P[10], and P[11], did not display any cross-reactivity to the probes. The usefulness of the assay was further evaluated by analyzing a total of 396 rotavirus-positive stool samples collected in four countries: Brazil, Ghana, Japan, and the United States. The results of this study showed that the PCR-ELISA was sensitive and easy to perform without the use of any expensive and sophisticated equipment, the reagents used are easy to obtain commercially and advantageous over multiplex PCR since more than one type-specific probe is used and the selection of probes is more flexible.
Also flagged:, and mouth diseaseneurological disordersinfectionPV1EV71 infectionnucleotide
Journal Article2007-12-05No SnippetsArita M, Ami Y, Wakita T, Shimizu H.
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Enterovirus 71 (EV71) is a causative agent of hand, foot, and mouth disease and is also associated with serious neurological disorders. An attenuated EV71 strain [EV71(S1-3')] has been established in the cynomolgus monkey infection model; this strain contains the attenuation determinants derived from the type 1 poliovirus vaccine strain, Sabin 1 [PV1(Sabin)], in the 5' nontranslated region (NTR), 3D polymerase, and 3' NTR. In this study, we analyzed the effect of the attenuation determinants of PV1(Sabin) on EV71 infection in a NOD/SCID mouse infection model. We isolated a mouse-adapted EV71 strain [EV71(NOD/SCID)] that causes paralysis of the hind limbs in 3- to 4-week-old NOD/SCID mice by adaptation of the virulent EV71(Nagoya) strain in the brains of NOD/SCID mice. A single mutation at nucleotide 2876 that caused an amino acid change in capsid protein VP1 (change of the glycine at position 145 to glutamic acid) was essential for the mouse-adapted phenotype in NOD/SCID mice. Next, we introduced attenuation determinants derived from PV1(Sabin) along with the mouse adaptation mutation into the EV71(Nagoya) genome. In 4-week-old mice, the determinants in the 3D polymerase and 3' NTR, which are the major temperature-sensitive determinants, had a strong effect on attenuation. In contrast, the effect of individual determinants was weak in 3-week-old NOD/SCID mice, and all the determinants were required for substantial attenuation. These results suggest that a cooperative effect of the attenuation determinants of PV1(Sabin) is essential for attenuated neurovirulence of EV71.
Also flagged:peptidesbindingpeptideantibodiesNAC32Alpha Synuclein
Journal Article2007-12-05✓ 1 SnippetLynch SM, Zhou C, Messer A.
In-Text Gene Mentions
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…htt…
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Prevention of abnormal misfolding and aggregation of alpha synuclein (syn) protein in vulnerable neurons should be viable therapeutic strategies for reducing pathogenesis in Parkinson's disease. The nonamyloid component (NAC) region of alpha-syn shows strong tendencies to form beta-sheet structures, and deletion of this region has been shown to reduce aggregation and toxicity in vitro and in vivo. The binding of a molecular species to this region may mimic the effects of such deletions. Single-chain variable fragment (scFv) antibodies retain the binding specificity of antibodies and, when genetically manipulated to create high-diversity libraries, allow in vitro selection against peptides. Accordingly, we used a yeast surface display library of an entire naive repertoire of human scFv antibodies to select for binding to a NAC peptide. Candidate scFv antibodies (after transfer to mammalian expression vectors) were screened for viability in a neuronal cell line by transient cotransfection with A53T mutant alpha-syn. This provided a ranking of the protective efficacies of the initial panel of intracellular antibodies (intrabodies). High steady-state expression levels and apparent conformational epitope binding appeared more important than in vitro affinity in these assays. None of the scFv antibodies selected matched the sequences of previously reported anti-alpha-syn scFv antibodies. A stable cell line expressing the most effective intrabody, NAC32, showed highly significant reductions in abnormal aggregation in two separate models. Recently, intrabodies have shown promising antiaggregation and neuroprotective effects against misfolded mutant huntingtin protein. The NAC32 study extends such work significantly by utilizing information about the pathogenic capacity of a specific alpha-syn region to offer a new generation of in vitro-derived antibody fragments, both for further engineering as direct therapeutics and as a tool for rational drug design for Parkinson's disease.
Aldose-1-epimerase (mutarotase) catalyzes the interconversion of alpha and beta hexoses, which is essential for normal carbohydrate metabolism and the production of complex oligosaccharides. Galactose mutarotase (GALM) has been well characterized at the protein level, but information is lacking on the regulation of GALM gene expression. We report herein that all-trans-retinoic acid (RA), an active metabolite of vitamin A that is known to induce myeloid lineage cell differentiation into macrophage-like cells, induces a rapid and robust regulation of GALM mRNA expression in human myeloid cells. all-trans-RA at a physiological concentration (20 nM), or Am580, a ligand selective for the nuclear retinoid receptor RARalpha, increased GALM mRNA in THP-1 cells, with significantly increased expression in 2 h, increasing further to an approximately 8-fold elevation after 6-40 h (P < 0.005). In contrast, tumor necrosis factor-alpha did not increase GALM mRNA expression, although it is capable of inducing cell differentiation. RA also increased GALM mRNA in U937 and HL-60 cells. The increase in GALM mRNA by RA was blocked by pretreating THP-1 cells with actinomycin D but not by cycloheximide. GALM protein and mutarotase activity were also increased time dependently in RA-treated THP-1 cells. In addition to GALM, several other genes in the biosynthetic pathway of galactosyl-containing complex oligosaccharides were more highly expressed in RA-treated THP-1 cells, including B4GALT5, ST3GAL3, ST6GALNAC5, and GALNAC4S-6ST. Thus, the results of this study identify RA as a significant regulator of GALM and other galactose-related genes in myeloid-monocytic cells, which could affect energy utilization and synthesis of cell-surface glycoproteins or glycolipids involved in cell motility, adhesion, and/or functional properties.
Also flagged:phosphatidylserinemembranescortisolcreatine kinaseACTHstroke
Journal Article2007-12-04✓ 1 SnippetJäger R, Purpura M, Geiss KR, Weiß M, Baumeister J, Amatulli F, Schröder L, Herwegen H.
In-Text Gene Mentions
Methods)
…a tumor orhemochromatosisand one subject…
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<h4>Background</h4>A randomized, double-blind, placebo-controlled study was performed to evaluate the effect of oral phosphatidylserine (PS) supplementation on golf performance in healthy young golfers with handicaps of 15-40.<h4>Methods</h4>Perceived stress, heart rate and the quality of the ball flight was evaluated before (pre-test) and after (post-test) 42 days of 200 mg per day PS (n = 10) or placebo (n = 10) intake in the form of a nutritional bar. Subjects teed-off 20 times aiming at a green 135 meters from the tee area.<h4>Results</h4>PS supplementation significantly increased (p < 0.05) the number of good ball flights (mean: pre-test 8.3 +/- 3.5, post-test 10.1 +/- 3.0), whereas placebo intake (mean: pre-test 7.8 +/- 2.4, post-test 7.9 +/- 3.6) had no effect. PS supplementation showed a trend towards improving perceived stress levels during teeing-off (mean: pre-test 5.8 +/- 2.0, post-test 4.0 +/- 2.0, p = 0.07), whereas stress levels remained unchanged in the placebo group (mean: pre-test: 5.1 +/- 2.0, post-test: 5.1 +/- 3.1). Supplementation did not influence mean heart rate in either group.<h4>Conclusion</h4>It is concluded that six weeks of PS supplementation shows a statistically not significant tendency (p = 0.07) to improve perceived stress levels in golfers and significantly improves (p < 0.05) the number of good ball flights during tee-off which might result in improved golf scores.
Also flagged:American trypanosomiasisgene expressionPumilio/FBF1cytoplasmhelicaselocalization
Journal Article2007-12-04✓ 1 SnippetDallagiovanna B, Correa A, Probst CM, Holetz F, Smircich P, de Aguiar AM, Mansur F, da Silva CV, Mortara RA, Garat B, Buck GA, Goldenberg S, Krieger MA.
In-Text Gene Mentions
Title)
…with TcPUF6, aPumilio-like ProteinProtein from Trypanosoma…
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Trypanosoma cruzi is the protozoan parasite that causes Chagas disease or American trypanosomiasis. Kinetoplastid parasites could be considered as model organisms for studying factors involved in posttranscriptional regulation because they control gene expression almost exclusively at this level. The PUF (Pumilio/FBF1) protein family regulates mRNA stability and translation in eukaryotes, and several members have been identified in trypanosomatids. We used a ribonomic approach to identify the putative target mRNAs associated with TcPUF6, a member of the T. cruzi PUF family. TcPUF6 is expressed in discrete sites in the cytoplasm at various stages of the parasite life cycle and is not associated with the translation machinery. The overexpression of a tandem affinity purification-tagged TcPUF6 protein allowed the identification of associated mRNAs by affinity purification assays and microarray hybridization yielding nine putative target mRNAs. Whole expression analysis of transfected parasites showed that the mRNAs associated with TcPUF6 were down-regulated in populations overexpressing TcPUF6. The association of TcPUF6 with the TcDhh1 helicase in vivo and the cellular co-localization of these proteins in epimastigote forms suggest that TcPUF6 promotes degradation of its associated mRNAs through interaction with RNA degradation complexes. Analysis of the mRNA levels of the putative TcPUF6-regulated genes during the parasite life cycle showed that their transcripts were up-regulated in metacyclic trypomastigotes. In these infective forms no co-localization between TcPUF6 and TcDhh1 was observed. Our results suggest that TcPUF6 regulates the half-lives of its associated transcripts via differential association with mRNA degradation complexes throughout its life cycle.
Also flagged:PAH1PAH2chromatintranscription factorshistone deacetylaseSin3 corepressor
Journal Article2007-12-04✓ 1 SnippetSahu SC, Swanson KA, Kang RS, Huang K, Brubaker K, Ratcliff K, Radhakrishnan I.
In-Text Gene Mentions
Text
…Sin3 associated polypeptide…
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The recruitment of chromatin-modifying coregulator complexes by transcription factors to specific sites of the genome constitutes an important step in many eukaryotic transcriptional regulatory pathways. The histone deacetylase-associated Sin3 corepressor complex is recruited by a large and diverse array of transcription factors through direct interactions with the N-terminal PAH domains of Sin3. Here, we describe the solution structures of the mSin3A PAH1 domain in the apo form and when bound to SAP25, a component of the corepressor complex. Unlike the apo-mSin3A PAH2 domain, the apo-PAH1 domain is conformationally pure and is largely, but not completely, folded. Portions of the interacting segments of both mSin3A PAH1 and SAP25 undergo folding upon complex formation. SAP25 binds through an amphipathic helix to a predominantly hydrophobic cleft on the surface of PAH1. Remarkably, the orientation of the helix is reversed compared to that adopted by NRSF, a transcription factor unrelated to SAP25, upon binding to the mSin3B PAH1 domain. The reversal in helical orientations is correlated with a reversal in the underlying PAH1-interaction motifs, echoing a theme previously described for the mSin3A PAH2 domain. The definition of these so-called type I and type II PAH1-interaction motifs has allowed us to predict the precise location of these motifs within previously experimentally characterized PAH1 binders. Finally, we explore the specificity determinants of protein-protein interactions involving the PAH1 and PAH2 domains. These studies reveal that even conservative replacements of PAH2 residues with equivalent PAH1 residues are sufficient to alter the affinity and specificity of these protein-protein interactions dramatically.
Also flagged:carbohydratealcoholliver diseasetype 2 diabetes mellituscystic fibrosisC-reactive protein
Journal Article2007-12-04✓ 1 SnippetBergström JP, Helander A.
In-Text Gene Mentions
Abstract)
…including 3 withhemochromatosis, 1 with hepatitis…
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<h4>Background</h4>Carbohydrate-deficient transferrin (CDT) is an alcohol biomarker used for detection and follow-up of excessive alcohol consumption. This HPLC study evaluated some clinical conditions and medications previously suggested to interfere with and cause non-alcohol related elevations of CDT.<h4>Methods</h4>Serum samples were collected from patients with end-stage liver disease (n=50), type 2 diabetes mellitus (n=46), cystic fibrosis (n=24), an elevated C-reactive protein level (CRP>100 mg/L; n=15), and from patients taking enzyme inducing or non-enzyme inducing antiepileptic drugs (n=43). Subjects with known or suspected alcohol-related problems were excluded. A sensitive and specific HPLC candidate CDT reference method was used to determine the relative amount of disialotransferrin to total transferrin.<h4>Results</h4>Of the 178 samples, 9 (5%) had a %disialotransferrin level > or =1.8% (>97.5th percentile) and were considered CDT positive. The highest frequency of elevated results was found in patients with end-stage liver disease (12%, n=6), including 3 with hemochromatosis, 1 with hepatitis C, 1 with autoimmune hepatitis and 1 with unspecified liver disease and cirrhosis. The other elevated %disialotransferrin results were from 2 patients taking enzyme-inducing antiepileptic drugs and 1 with type 2 diabetes. Five of 8 examined %disialotransferrin positive samples were also positive for ethyl glucuronide (EtG).<h4>Conclusion</h4>This HPLC study found an overall low frequency of elevated %disialotransferrin levels in the clinical conditions and medications examined. Previous reports of frequent false-positive CDT results thus seem to be connected with the analytical methodology used rather than representing true clinical or pharmacological interferences.
Also flagged:extracellularserotoninbrain-derived neurotrophic factoranxietydepressionBDNF
Journal Article2007-12-04✓ 5 SnippetsMällo T, Kõiv K, Koppel I, Raudkivi K, Uustare A, Rinken A, Timmusk T, Harro J.
In-Text Gene Mentions
Abstract)
…However, LE animals had significantly higher levels of 5-HT transporter (5-HTT) binding in PFC and a larger increase in extracellular 5-HT levels after administration of citalopram (1 μM) into this area by retrograde dialysis.…
Discussion)
…However, the Wistar-Kyoto rats, considered as more anxious, have been reported to have lower levels of 5-HTT binding sites in the hippocampus when compared with the less anxious spontaneously hypertensive rats (Pollier et al., 2000), and animals that are bred for high anxiety-related behaviour in the elevated plus-maze show an increased number of 5-HTT binding sites in the hippocampus (Keck et al., 2005).…
Abstract)
…of 5-HT transporter (5-HTT) binding in PFC…
Introduction)
…Also, 5-HT transporter (5-HTT) levels were measured…
Methods)
…the determination of5-HTTlevels by specific…
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Serotonin (5-HT) system has a significant role in anxiety- and depression-related states and may be influenced by brain-derived neurotrophic factor (BDNF). This study examined extracellular 5-HT levels and expression of BDNF in rats with persistently low or high levels of exploratory activity (LE and HE, respectively). Baseline extracellular levels of 5-HT as assessed by in vivo microdialysis in conscious animals were similar in both groups in medial prefrontal cortex (PFC) and dentate gyrus (DG). No differences were found in parachloroamphetamine-induced 5-HT release in either region. However, LE animals had significantly higher levels of 5-HT transporter (5-HTT) binding in PFC and a larger increase in extracellular 5-HT levels after administration of citalopram (1 microM) into this area by retrograde dialysis. No difference in 5-HTT levels was found in hippocampus, while perfusion with citalopram was accompanied by a greater increase in extracellular 5-HT in the HE group in this brain region. LE-rats had higher levels of BDNF mRNA in the PFC but not hippocampus. In contrast, levels of nerve growth factor mRNA were similar in these brain regions of LE- and HE-rats. The differential regulation of 5-HT-ergic system in LE- and HE-rats in PFC and hippocampus may form the basis for their distinct anxiety-related behaviours.
Also flagged:Cyclin-Dependent Kinase 5 Regulatory subunit 1neuronal migrationCDK5R1neurodegenerative disordersmentalluciferase
Journal Article2007-12-03No SnippetsMoncini S, Bevilacqua A, Venturin M, Fallini C, Ratti A, Nicolin A, Riva P.
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<h4>Background</h4>CDK5R1 plays a central role in neuronal migration and differentiation during central nervous system development. CDK5R1 has been implicated in neurodegenerative disorders and proposed as a candidate gene for mental retardation. The remarkable size of CDK5R1 3'-untranslated region (3'-UTR) suggests a role in post-transcriptional regulation of CDK5R1 expression.<h4>Results</h4>The bioinformatic study shows a high conservation degree in mammals and predicts several AU-Rich Elements (AREs). The insertion of CDK5R1 3'-UTR into luciferase 3'-UTR causes a decreased luciferase activity in four transfected cell lines. We identified 3'-UTR subregions which tend to reduce the reporter gene expression, sometimes in a cell line-dependent manner. In most cases the quantitative analysis of luciferase mRNA suggests that CDK5R1 3'-UTR affects mRNA stability. A region, leading to a very strong mRNA destabilization, showed a significantly low half-life, indicating an accelerated mRNA degradation. The 3' end of the transcript, containing a class I ARE, specifically displays a stabilizing effect in neuroblastoma cell lines. We also observed the interaction of the stabilizing neuronal RNA-binding proteins ELAV with the CDK5R1 transcript in SH-SY5Y cells and identified three 3'-UTR sub-regions showing affinity for ELAV proteins.<h4>Conclusion</h4>Our findings evince the presence of both destabilizing and stabilizing regulatory elements in CDK5R1 3'-UTR and support the hypothesis that CDK5R1 gene expression is post-transcriptionally controlled in neurons by ELAV-mediated mechanisms. This is the first evidence of the involvement of 3'-UTR in the modulation of CDK5R1 expression. The fine tuning of CDK5R1 expression by 3'-UTR may have a role in central nervous system development and functioning, with potential implications in neurodegenerative and cognitive disorders.
Also flagged:HepcidinsynthesisHaemochromatosisironanaemiachronic disease
Journal Article2007-12-03✓ 5 SnippetsArnold J, Sangwaiya A, Bhatkal B, Arnold A.
In-Text Gene Mentions
Abstract)
…Hereditary Haemochromatosis is caused by disruption of iron homeostasis due to mutations in the HFE gene (C282Y or H63D).…
Title)
…Defective release of Hepcidin not defective synthesis is the primary pathogenic mechanism in HFE-Haemochromatosis.…
Abstract)
…Current thinking is that defective Hepcidin synthesis or defective iron-sensing mechanisms leading to Hepcidin deficiency is the cause of iron overload in HFE-Haemochromatosis.…
Abstract)
…Basal levels of Hepcidin appear to be normal in HFE-Haemochromatosis patients.…
Abstract)
…This contradicts current theories of defective Hepcidin synthesis as the cause of Hereditary HFE-Haemochromatosis.…
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Recent findings indicate a principal role for Hepcidin in iron homeostasis. Hepcidin is also thought to play a vital role in the pathogenic mechanism of anaemia in patients with inflammation or chronic disease. Under normal conditions influx and efflux of iron from duodenal enterocytes is regulated by Ferroportin. Ferroportin is a Hepcidin binding protein expressed in duodenal enterocytes. Hepcidin is a peptide synthesised in the liver and is the main regulator of iron homeostasis. It is a defensin like protein and exhibits anti-microbial and anti-fungal activity. The Hepcidin gene is principally expressed in hepatocytes but to a lesser extent in neutrophils and macrophages. Hereditary Haemochromatosis is caused by disruption of iron homeostasis due to mutations in the HFE gene (C282Y or H63D). Unrestricted uptake of iron by duodenal enterocytes causes iron overload which is the hallmark of the disease. Current thinking is that defective Hepcidin synthesis or defective iron-sensing mechanisms leading to Hepcidin deficiency is the cause of iron overload in HFE-Haemochromatosis. Thus HFE-Haemochromatosis has been described as an endocrine disease. Basal levels of Hepcidin appear to be normal in HFE-Haemochromatosis patients. This contradicts current theories of defective Hepcidin synthesis as the cause of Hereditary HFE-Haemochromatosis. We propose that the defect in HFE-Haemochromatosis is the loss of Hepcidin surge in response to intake of dietary iron and is not as a result of reduced synthesis.
Also flagged:tacrolimusazolesfungal infectionsvoriconazolemethoxynitro
Journal Article2007-12-03No SnippetsSun S, Li Y, Guo Q, Shi C, Yu J, Ma L.
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Combination therapy could be of use for the treatment of fungal infections, especially those caused by drug-resistant fungi. However, the methods and approaches used for data generation and result interpretation need further optimizing. The fractional inhibitory concentration index (FICI) is the most commonly used method, but it has several drawbacks in characterizing antifungal drug interaction. Alternatively, some new methods can be used such as the DeltaE model (difference between the predicted and measured fungal growth percentages) and the response surface approach, which uses the concentration-effect relationship over the whole concentration range instead of just the MIC. In the present study, in vitro interactions between tacrolimus (FK506) and three azoles-fluconazole (FLC), itraconazole (ITR), and voriconazole (VRC)-against Candida albicans were evaluated by the checkerboard microdilution method and time-killing test. The intensity of the interactions was determined by visual reading and the spectrophotometric method in a checkerboard assay, and the nature of the interactions was assessed by nonparametric models of FICI and DeltaE. Colony counting and colorimetric viable detection methods (2,3-bis {2-methoxy-4-nitro-5-[(sulfenylamino) carbonyl]-2H-tetrazolium hydroxide} [XTT] reduction test) were used for evaluating the combination antifungal effects over time. Synergistic and indifferent effects were found for the combination of FK506 and azoles against azole-sensitive strains, while strong synergy was found against azole-resistant strains analyzed by FICI. The DeltaE model gave more consistent results with FICI. The positive interactions were also confirmed by the time-killing test. Our findings suggest a potential role for combination therapy with calcineurin pathway inhibitors and azoles to augment activity against resistant C. albicans.
<h4>Purpose</h4>Elucidation of the CSF proteome may yield insights into the pathogenesis of CNS disease. We tested the hypothesis that individual CSF proteins distinguish CNS lymphoma from benign focal brain lesions.<h4>Methods</h4>We used a liquid chromatography/mass spectrometry-based method to differentially quantify and identify several hundred CSF proteins in CNS lymphoma and control patients. We used enzyme-linked immunosorbent assay (ELISA) to confirm one of these markers in an additional validation set of 101 cases.<h4>Results</h4>Approximately 80 CSF proteins were identified and found to be present at significantly different concentrations, both higher and lower, in training and test studies, which were highly concordant. To further validate these observations, we defined in detail the expression of one of these candidate biomarkers, antithrombin III (ATIII). ATIII RNA transcripts were identified within CNS lymphomas, and ATIII protein was localized selectively to tumor neovasculature. Determination of ATIII concentration by ELISA was significantly more accurate (> 75% sensitivity; > 98% specificity) than cytology in the identification of cancer. Measurement of CSF ATIII levels was found to potentially enhance the ability to diagnose and predict outcome.<h4>Conclusion</h4>Our findings demonstrate for the first time that proteomic analysis of CSF yields individual biomarkers with greater sensitivity in the identification of cancer than does CSF cytology. We propose that the discovery of CSF protein biomarkers will facilitate early and noninvasive diagnosis in patients with lesions not amenable to brain biopsy, as well as provide improved surrogates of prognosis and treatment response in CNS lymphoma and brain metastasis.
Also flagged:TNFSystemic lupus erythematosusSLEautoimmune diseaseIRF5tumor necrosis factor
Journal Article2007-12-02✓ 5 SnippetsCunninghame Graham DS, Graham RR, Manku H, Wong AK, Whittaker JC, Gaffney PM, Moser KL, Rioux JD, Altshuler D, Behrens TW, Vyse TJ.
In-Text Gene Mentions
Abstract)
…Two tumor necrosis factor (TNF) superfamily members located within intervals showing genetic linkage with SLE are TNFSF4 (also known as OX40L; 1q25), which is expressed on activated antigen-presenting cells (APCs) and vascular endothelial cells, and also its unique receptor, TNFRSF4 (also known as OX40; 1p36), which is primarily expressed on activated CD4+ T cells.…
Title)
…Polymorphism at the TNF superfamily gene TNFSF4 confers susceptibility to systemic lupus erythematosus.…
Abstract)
…We hypothesize that increased expression of TNFSF4 predisposes to SLE either by quantitatively augmenting T cell-APC interaction or by influencing the functional consequences of T cell activation via TNFRSF4.…
Abstract)
…Using both a family-based and a case-control study design, we show that the upstream region of TNFSF4 contains a single risk haplotype for SLE, which is correlated with increased expression of both cell-surface TNFSF4 and the TNFSF4 transcript.…
Systemic lupus erythematosus (SLE) is a multisystem complex autoimmune disease of uncertain etiology (OMIM 152700). Over recent years a genetic component to SLE susceptibility has been established. Recent successes with association studies in SLE have identified genes including IRF5 (refs. 4,5) and FCGR3B. Two tumor necrosis factor (TNF) superfamily members located within intervals showing genetic linkage with SLE are TNFSF4 (also known as OX40L; 1q25), which is expressed on activated antigen-presenting cells (APCs) and vascular endothelial cells, and also its unique receptor, TNFRSF4 (also known as OX40; 1p36), which is primarily expressed on activated CD4+ T cells. TNFSF4 produces a potent co-stimulatory signal for activated CD4+ T cells after engagement of TNFRSF4 (ref. 11). Using both a family-based and a case-control study design, we show that the upstream region of TNFSF4 contains a single risk haplotype for SLE, which is correlated with increased expression of both cell-surface TNFSF4 and the TNFSF4 transcript. We hypothesize that increased expression of TNFSF4 predisposes to SLE either by quantitatively augmenting T cell-APC interaction or by influencing the functional consequences of T cell activation via TNFRSF4.
Also flagged:myelodysplastic syndromesrefractory anemiaRARSiron-overloadRARAEB
Journal Article2007-12-01✓ 5 SnippetsNearman ZP, Szpurka H, Serio B, Warshawksy I, Theil K, Lichtin A, Sekeres MA, Maciejewski JP.
In-Text Gene Mentions
Abstract)
…Increased prevalence of HFE gene mutations is not a generalized feature of MDS, but some subgroups of MDS, especially those characterized by excessive accumulation of ringed sideroblasts, exhibit C282Y mutations at a higher frequency than in other forms of MDS and healthy controls.…
Abstract)
…HFE variation in other MDS…
Abstract)
…HFE alleles in patients with other forms of MDS…
Abstract)
…HFE gene mutations is not a generalized feature of MDS…
Title)
…Hemochromatosis-associated gene mutations in…
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We observed increased ferritin levels in newly diagnosed MDS-RARS patients without transfusional iron-overload. Hence, we hypothesized RARS patients may harbor hemochromatosis-related mutations, which could contribute to the pathophysiology of this myelodysplastic syndromes (MDS) subset. We studied a cohort of 140 MDS patients: 42 with RARS, 10 with increased ringed sideroblasts, and 96 with other forms of MDS (43 RA, 27 RAEB, 17 RAEB-T, 8 MDS/MPD, 1 CMML). Patients were genotyped using restriction fragment length polymorphism, designed to detect C282Y and H63D mutations of the HFE gene. We found significantly higher frequency of heterozygosity for C282Y mutation in RARS patients compared with a large control population of matched race individuals (21 vs. 9.8% in controls, P = 0.03); H63D genotype was not significantly increased. Frequency of HFE variation in other MDS subtypes failed to differ significantly from controls. Within this group, we included patients with a rare form of MDS, provisionally subclassified by WHO as RARS with thrombocytosis (RARSt). 10/14 RARSt patients were carriers of either C282Y or H63D allele significantly increased compared with the combined prevalence in a healthy population (71 vs. 33%, P < 0.01). We found expected distribution of mutant HFE alleles in patients with other forms of MDS (9.1 vs. 9.8%, P = 0.82). Increased prevalence of HFE gene mutations is not a generalized feature of MDS, but some subgroups of MDS, especially those characterized by excessive accumulation of ringed sideroblasts, exhibit C282Y mutations at a higher frequency than in other forms of MDS and healthy controls.
Also flagged:DVTpulmonary embolismdeep vein thrombosisPEcoagulationfactor V Leiden
Journal Article2007-12-01✓ 1 SnippetKim YH, Kim JS.
In-Text Gene Mentions
Abstract)
…V Leiden mutation,antithrombin-IIIlevel, and prothrombin…
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We evaluated 136 hips (104 patients) to determine the prevalence of and contributing factors in deep vein thrombosis (DVT) and pulmonary embolism (PE) in those who were not given thromboprophylaxis when undergoing primary cementless total hip arthroplasty (THA). We performed coagulation assays, a full blood count, blood typing, and serum chemical profile tests for all patients on three separate occasions. Molecular genetic testing was performed preoperatively to detect the genetic traits involving DVT. DVT was diagnosed by roentgenographic venography, and PE was diagnosed by perfusion lung scanning. Our patients had a low prevalence of DVT and no patient had PE. Patients with bilateral THA had similar rates (p = 0.158; CI, -0.134-0.125) of venographic DVT as patients with unilateral THA (16 of 65 or 25% versus 12 of 72 or 17% respectively). We observed a relationship between DVT and factor V Leiden mutation, antithrombin-III level, and prothrombin promoter G20210A mutation. We saw no relationship between DVT and coagulation or thrombophilic data. We conclude combinations of absent thrombophilic polymorphisms with low clinical prothrombotic risk factors led to low prevalence of DVT and virtually absent PE after THA in the current series of patients, who had not received any form of prophylactic or therapeutic treatment for DVT.
Also flagged:IronalcoholsynthesisethanolcarbonylHepcidin
Journal Article2007-12-01✓ 3 SnippetsHarrison-Findik DD, Klein E, Crist C, Evans J, Timchenko N, Gollan J.
In-Text Gene Mentions
Abstract)
…Hfe(-/-) mice were used…
Abstract)
…Hfe(-/-) mice treated with…
Abstract)
…disease and genetichemochromatosisin combination with…
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<h4>Unlabelled</h4>Alcohol reduces and iron increases liver hepcidin synthesis. This study investigates the interaction of alcohol and iron in the regulation of hepcidin messenger RNA (mRNA) expression in animal models. Mice were administered 10% ethanol for 7 days after an iron-overloaded diet. Rats were administered regular or ethanol-Lieber De Carli diets for 7 weeks with or without carbonyl iron. Hfe(-/-) mice were used as a model for genetic iron overload. Hepcidin mRNA expression was determined by real-time polymerase chain reaction (PCR) and northern blotting. Iron elevated and alcohol decreased liver hepcidin expression in mice and rats. Interestingly, despite iron overload, alcohol was capable of suppressing the up-regulation of hepcidin mRNA expression in both models. Liver iron and ferritin protein expression was elevated in alcohol-treated rats, but was not elevated further in rats treated with both iron and alcohol. Duodenal ferroportin protein expression was increased both in alcohol-treated mice and in mice treated with alcohol and iron. Hfe(-/-) mice treated with ethanol for 7 days exhibited a further decrease in hepcidin mRNA expression. The iron-induced increase in DNA-binding activity of the transcription factor CCAAT/enhancer binding protein alpha (C/EBP alpha) was also suppressed by alcohol.<h4>Conclusion</h4>Alcohol abolishes the iron-induced up-regulation of both liver hepcidin transcription and the DNA-binding activity of C/EBP alpha. Of note, hepcidin protects the body from the harmful effects of iron overload. Our findings therefore suggest that alcohol negates the protective effect of hepcidin, which may have implications for the liver injury observed in alcoholic liver disease and genetic hemochromatosis in combination with alcohol.
Also flagged:Sumoylationsmall ubiquitin-like protein modifierSUMOnucleusdegradationlocalization
Journal Article2007-12-01No SnippetsZhao J.
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Ten years after its discovery, the small ubiquitin-like protein modifier (SUMO) has emerged as a key regulator of proteins. While early studies indicated that sumoylation takes place mainly in the nucleus, an increasing number of non-nuclear substrates have recently been identified, suggesting a wider stage for sumoylation in the cell. Unlike ubiquitylation, which primarily targets a substrate for degradation, sumoylation regulates a substrate's functions mainly by altering the intracellular localization, protein-protein interactions or other types of post-translational modifications. These changes in turn affect gene expression, genomic and chromosomal stability and integrity, and signal transduction. Sumoylation is counter-balanced by desumoylation, and well-balanced sumoylation is essential for normal cellular behaviors. Loss of the balance has been associated with a number of diseases. This paper reviews recent progress in the study of SUMO pathways, substrates, and cellular functions and highlights important findings that have accelerated advances in this study field and link sumoylation to human diseases.
Also flagged:Pearson syndromemitochondrial disordersideroblastic anemialiver diseaserenal tubulopathyexocrine pancreas deficiency
Journal Article2007-12-01✓ 5 SnippetsKefala-Agoropoulou K, Roilides E, Lazaridou A, Karatza E, Farmaki E, Tsantali H, Augoustides-Savvopoulou P, Tsiouris J.
In-Text Gene Mentions
Abstract)
…The patient was heterozygous for HFE gene C282Y mutation (type I hemochromatosis).…
Abstract)
…The patient was heterozygous for HFE gene C282Y mutation ( type I hemochromatosis )…
Abstract)
…who was also heterozygous for HFE gene mutation C282Y published. It is…
Abstract)
…After an initial response to deferoxamine she presented with cutaneous zygomycosis and died after metabolic derangement and Pneumocystis jiroveci pneumonia.<h4>Conclusion</h4>This is the second case of a Pearson syndrome individual who was also heterozygous for HFE gene mutation C282Y published.…
Title)
…Pearson syndrome in an infant heterozygous for C282Y allele of HFE gene.…
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<h4>Background</h4>Pearson syndrome is a rare mitochondrial disorder characterized by sideroblastic anemia, liver disease, renal tubulopathy and exocrine pancreas deficiency.<h4>Observations</h4>We describe a female infant suffering from anemia since birth who gradually developed the complete picture of Pearson syndrome by 13 months. Iron overload was disproportionate to blood transfusions. The patient was heterozygous for HFE gene C282Y mutation (type I hemochromatosis). After an initial response to deferoxamine she presented with cutaneous zygomycosis and died after metabolic derangement and Pneumocystis jiroveci pneumonia.<h4>Conclusion</h4>This is the second case of a Pearson syndrome individual who was also heterozygous for HFE gene mutation C282Y published. It is also the second case report of a Pearson patient suffering from severe iron overload and liver disease that responded to therapy with deferoxamine.
Also flagged:ironuroporphyriaporphyrialiver diseaseUROdeferiprone
Journal Article2007-12-01✓ 3 SnippetsGorman N, Zaharia A, Trask HS, Szakacs JG, Jacobs NJ, Jacobs JM, Balestra D, Sinclair JF, Sinclair PR.
In-Text Gene Mentions
Abstract)
…Here we used Hfe(-/-) mice to compare the effects on hepatic URO accumulation of two different methods of hepatic iron depletion: iron chelation using deferiprone (L1) versus iron-deficient diets.…
Abstract)
…Here we usedHfe(-/-) mice to compare…
Abstract)
…Hfe(-/-) mice in a…
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<h4>Unlabelled</h4>Porphyria cutanea tarda is a liver disease characterized by elevated hepatic iron and excessive production of uroporphyrin (URO). Phlebotomy is an effective treatment that probably acts by reducing hepatic iron. Here we used Hfe(-/-) mice to compare the effects on hepatic URO accumulation of two different methods of hepatic iron depletion: iron chelation using deferiprone (L1) versus iron-deficient diets. Hfe(-/-) mice in a 129S6/SvEvTac background were fed 5-aminolevulinic acid (ALA), which results in hepatic URO accumulation, and increasing doses of L1 in the drinking water. Hepatic URO accumulation was completely prevented at low L1 doses, which partially depleted hepatic nonheme iron. By histological assessment, the decrease in hepatic URO accumulation was associated with greater depletion of iron from hepatocytes than from Kupffer cells. The L1 treatment had no effect on levels of hepatic cytochrome P4501A2 (CYP1A2). L1 also effectively decreased hepatic URO accumulation in C57BL/6 Hfe(-/-) mice treated with ALA and a CYP1A2 inducer. ALA-treated mice maintained on defined iron-deficient diets, rather than chow diets, did not develop uroporphyria, even when the animals were iron-supplemented either directly in the diet or by iron dextran injection.<h4>Conclusion</h4>The results suggest that dietary factors other than iron are involved in the development of uroporphyria and that a modest depletion of hepatocyte iron by L1 is sufficient to prevent URO accumulation.
Also flagged:enterovirus infectionsEnterovirusinfectionsInfectious DiseaseVP1hand-foot-and-mouth disease
Journal Article2007-12-01✓ 2 SnippetsTseng FC, Huang HC, Chi CY, Lin TL, Liu CC, Jian JW, Hsu LC, Wu HS, Yang JY, Chang YW, Wang HC, Hsu YW, Su IJ, Wang JR, CDC-Taiwan Virology Reference Laboratories and Sentinel Physician Network.
In-Text Gene Mentions
Abstract)
…Echovirus (E) 30 and E6, which are associated with aseptic meningitis, were prevalent in 2001 and 2002, CA4 and CA10, which cause herpangina, were predominant in 2004, and coxsackievirus B (CB) 4 and CB3, which are associated with neonatal febrile disease, were most common in 2004 and 2005, respectively.…
Abstract)
…2002, CA4 andCA10, which cause herpangina,…
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Enterovirus (EV) infections are common. There are more than 60 known serotypes, and each has different epidemiologic or medical importance. Over 700 physicians from 75% of basic administrative units of Taiwan participated in the "Sentinel Physician Surveillance of Infectious Disease" and reported weekly to the Center for Disease Control-Taiwan with data on various infections. Data of laboratory-confirmed EV infections from this surveillance between 2000 and 2005 was analyzed. EV serotypes were determined by immunofluorescence staining and/or viral VP1 sequence analysis. A total of 12,236 EV cases, or approximately 1,300-2,500 per year, were identified, and 52% of the cases occurred between April and July. The median age was 3 years, and 57.6% of patients were male. Coxsackievirus A (CA) 16 and EV71, which primarily manifest as hand-foot-and-mouth disease, were the most prevalent serotypes every year except 2004. Other prevalent serotypes and associated symptoms varied from year to year. Echovirus (E) 30 and E6, which are associated with aseptic meningitis, were prevalent in 2001 and 2002, CA4 and CA10, which cause herpangina, were predominant in 2004, and coxsackievirus B (CB) 4 and CB3, which are associated with neonatal febrile disease, were most common in 2004 and 2005, respectively. Some of these epidemics overlapped with outbreaks of the same serotypes in other Asian Pacific countries. Of all serotypes, EV71 was associated with the highest number of severe complications in patients. Surveying the epidemic pattern, disease spectra, and severity associated with each EV serotype provided important information for public health and medical personnel.
Also flagged:HdhdeathlacZHuntington's diseaseglial fibrillary acidic protein
Journal Article2007-12-01No SnippetsReiner A, Del Mar N, Deng YP, Meade CA, Sun Z, Goldowitz D.
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The R6/2 mouse possesses mutant exon 1 of human Hdh, and R6/2 mice with 150 CAG repeats show neurological abnormalities by 10 weeks and die by 15 weeks. Few brain abnormalities, however, are evident at death, other than widespread ubiquitinated neuronal intranuclear inclusions (NIIs). We constructed R6/2t+/t- <--> wildtype (WT) chimeric mice to prolong survival of R6/2 cells and determine if neuronal death and/or neuronal injury become evident with longer survival. ROSA26 mice (which bear a lacZ transgene) were used as WT to distinguish between R6/2 and WT neurons. Chimeric mice consisting partly of R6/2 cells lived longer than pure R6/2 mice (up to 10 months), with the survival proportional to the R6/2 contribution. Genotypically R6/2 cells formed NIIs in the chimeras, and these NIIs grew only slightly larger than in 12-week pure R6/2 mice, even after 10 months. Additionally, neuropil aggregates formed near R6/2 neurons in chimeric mice older than 15 weeks. Thus, R6/2 neurons could survive well beyond 15 weeks in chimeras. Moreover, little neuronal degeneration was evident in either cortex or striatum by routine histological stains. Nonetheless, striatal shrinkage and ventricular enlargement occurred, and striatal projection neuron markers characteristically reduced in Huntington's disease were diminished. Consistent with such abnormalities, cortex and striatum in chimeras showed increased astrocytic glial fibrillary acidic protein. These results suggest that while cortical and striatal neurons can survive nearly a year with nuclear and extranuclear aggregates of mutant huntingtin, such lengthy survival does reveal cortical and striatal abnormality brought on by the truncated mutant protein.
Also flagged:SUMOylationPost-translational protein modificationsextracellulartranslational modificationsmall ubiquitin-like modifierlysine
Journal Article2007-12-01No SnippetsMartin S, Wilkinson KA, Nishimune A, Henley JM.
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Post-translational protein modifications are integral components of signalling cascades that enable cells to efficiently, rapidly and reversibly respond to extracellular stimuli. These modifications have crucial roles in the CNS, where the communication between neurons is particularly complex. SUMOylation is a post-translational modification in which a member of the small ubiquitin-like modifier (SUMO) family of proteins is conjugated to lysine residues in target proteins. It is well established that SUMOylation controls many aspects of nuclear function, but it is now clear that it is also a key determinant in many extranuclear neuronal processes, and it has also been implicated in a wide range of neuropathological conditions.
Also flagged:nuclear transfernuclearmitochondrialMitochondriametabolismcytoplasmic
Journal Article2007-12-01✓ 2 SnippetsLee E, Song K.
In-Text Gene Mentions
Abstract)
…1%) in theDCC-derived embryos did not…
Results)
…± 2%) whenDCCwere used as…
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The objective of the present study was to examine the feasibility of the production of autologous porcine somatic cell nuclear transfer (SCNT) blastocysts using oocytes and donor cells from slaughtered ovaries. Therefore, we attempted to optimize autologous SCNT by examining the effects of electrical fusion conditions and donor cell type on cell fusion and the development of SCNT embryos. Four types of donor cells were used: 1) denuded cumulus cells (DCCs) collected from in vitro-matured (IVM) oocytes; 2) cumulus cells collected from oocytes after 22 h of IVM and cultured for 18 h (CCCs); 3) follicular cells obtained from follicular contents and cultured for 40 h (CFCs); and 4) adult skin fibroblasts. The DCCs showed a significantly (p < 0.01) lower rate of fusion than the CCCs when two pulses of 170 V/mm DC were applied for 50 microsec (19 +/- 2% vs. 77 +/-3%). The rate of DCC fusion with oocytes was increased by the application of two DC pulses of 190 V/mm for 30 microsec, although this was still lower than the rate of fusion in the CCCs (33 +/- 1% vs. 80 +/- 2%). The rates of cleavage (57 +/- 5%) and blastocyst formation (1 +/- 1%) in the DCC-derived embryos did not differ from those (55 +/- 6% and 3 +/- 1%, respectively) in the CCC- derived SCNT embryos. Autologous SCNT embryos derived from CFCs (5 +/- 2%) showed higher levels of blastocyst formation (p < 0.01) than CCC-derived autologous SCNT embryos (1 +/- 0%). In conclusion, the results of the present study show that culturing cumulus and follicular cells before SCNT enhances cell fusion with oocytes and that CFCs are superior to CCCs in the production of higher numbers of autologous SCNT blastocysts.
Brevetoxins are neurotoxic compounds produced by the dinoflagellate Karenia brevis. Extensive blooms induce neurotoxic shellfish poisoning (NSP) and asthma-like symptoms in humans. beta-naphthoyl-brevetoxin, the first semisynthetic brevetoxin antagonist, has been defined as the lead compound in the investigation of the mechanisms of bronchoconstriction induced by inhaled brevetoxins and relaxation or reversal of those effects by selected derivatives. In pursuit of more potent and effective brevetoxin antagonists, a series of beta-naphthoyl-brevetoxin analogues have been synthesized. Activities were determined by competitive displacement of tritiated brevetoxin-3 from rat brain synaptosomes and by lung resistance measurements in sheep. Additionally, preliminary computational structural studies have been performed. All analogues bound to rat brain synaptosomes with affinities similar to beta-naphthoyl-brevetoxin but exhibited very different responses in sheep. The biological evaluations along with computational studies suggest that the brevetoxin binding site in rat brain synaptosome might be different from the ones in lung tissue and both steric and electrostatic factors contribute to the efficacy of brevetoxin antagonism.
Also flagged:OX40blindnessTNF receptorbindingOX40Lantibody
Journal Article2007-12-01No SnippetsHattori T, Usui Y, Okunuki Y, Sonoda Y, Usui M, Takada E, Mizuguchi J, Yagita H, Okumura K, Akiba H, Takeuchi M.
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Although corneal transplantation is one of the most common tissue transplantations and is known to have a high graft acceptance rate, occasional corneal graft rejection remains a cause of blindness. OX40, a member of the TNF receptor superfamily, is expressed on activated T cells, and transmits a costimulatory signal by binding to OX40 ligand (OX40L) expressed on several cells with antigen-presenting functions. Using a blocking monoclonal antibody (mAb) against murine OX40L, we investigated the role of OX40 in a murine model of corneal transplantation. C3H/He mouse corneas were transplanted to BALB/c mice orthotopically. Administration of anti-OX40L mAb significantly reduced allograft rejection, and increased graft survival rate to 40% at 8 weeks after transplantation, while all corneas were rejected within 5 weeks in control IgG-treated mice. Similar reduced rejection was observed when wild-type donor corneas were transplanted to OX40L-deficient recipients. In vitro study revealed that the anti-OX40L mAb treatment reduced proliferative response and IFN-gamma production of draining lymph node cells in response to stimulation with donor alloantigen. These results demonstrate that OX40L blockade is effective for prolongation of corneal allograft survival by inhibiting recipient T cell activation.
Also flagged:hepatic aneurysmhereditary hemorrhagic telangiectasiaOsler-Weber-Rendu diseasebiliary enzymeanemiaaneurysm
Journal Article2007-12-01No SnippetsMiyabe K, Akita S, Kitajima Y, Hirai M, Naitoh I, Hayashi K, Okamoto T, Okayama Y, Gotoh K, Ohara H, Joh T, Yokoyama Y, Itoh M.
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A 74-year-old woman was transferred to our hospital for further examinations because of abdominal fullness and abnormal levels of serum liver/biliary enzyme persisting for 3 weeks. She had anemia and dilatation of many capillary vessels in her fingers, palms, and tongue in addition to reporting frequent incidences of nasal bleeding in herself and her family. Abdominal ultrasonography detected a cystic lesion in the right hepatic lobe, connected to a dilated tortuous hepatic artery. A low-echoic hepatic phyma was also detected in the back of the cystic lesion. Abdominal computed tomography and magnetic resonance imaging indicated that the cystic lesion was an aneurysm and the low-echoic phyma was a hematoma. Hepatic arteriography confirmed a hepatic aneurysm, tortuous dilatation of the hepatic artery, and the complication of an arteriovenous shunt in the liver. Taking all of these findings into consideration, this case was diagnosed as hereditary hemorrhagic telangiectasia (HTT) complicated by a hepatic aneurysm causing intrahepatic hematoma. To prevent re-rupture of the aneurysm, we performed a hepatic arterial coil embolization. After therapy, no blood flow to the aneurysm was detected by ultrasonic color Doppler method and the hematoma gradually diminished. There have been no reports of a case in which hepatic arterial embolization was effective for HHT-associated hepatic aneurysm causing intrahepatic hematoma. This very rare case provides important clinical information regarding abdominal vascular complications of HTT and a less invasive treatment for them.
Also flagged:colonic polypscolon cancercanceradenomasAPCadenoma
Journal Article2007-12-01✓ 2 SnippetsCappell MS.
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…Progression from adenomas to colon cancer is a multistep process, involving mutations of the DCC, k-ras, and p53 genes; loss of heterozygosity in which cells loose one allele of some genes from chromosomal loss; and DNA methylation which can silence DNA expression.…
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…mutations of theDCC, k-ras, and p53…
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<h4>Unlabelled</h4>Colon cancer is the most common nondermatologic cancer in Italy and throughout Europe, with about 250,000 cases annually in Europe, about half of whom die. Yet, colon cancer is largely preventable through intensive, mass screening programs to remove premalignant colonic polyps. The persistently high incidence and mortality is largely due to ineffective implementation of established screening protocols due to patient fears about screening tests, physician under-referral for screening, and test costs. Colon cancer mostly arises from adenomas, recognized as colonic polyps, but may occasionally arise from the sessile serrated adenoma. Adenomatous polyposis coli (APC) gene mutation is the key molecular step in adenoma formation. Mismatch repair gene mutation is a less common alternative pathway. Progression from adenomas to colon cancer is a multistep process, involving mutations of the DCC, k-ras, and p53 genes; loss of heterozygosity in which cells loose one allele of some genes from chromosomal loss; and DNA methylation which can silence DNA expression. Numerous environmental factors can increase the risk of colon cancer, presumably by modulating these molecular pathways. While colon cancer in an advanced and incurable stage often produces clinical findings, premalignant adenomatous polyps and early, highly curable, colon cancer are often asymptomatic. This phenomenon renders adenomas or early cancers difficult to detect by clinical presentation and provides the rationale for mass screening of asymptomatic adults over 50 years old for early detection and prevention of colon cancer. Colonoscopy is the primary screening test. All polyps identified at colonoscopy are removed by colonoscopic polypectomy. Endoscopic mucosal resection is required for deeply penetrating noncancerous polyps. Colonoscopy is repeated every ten years if the index colonoscopy revealed no lesions, but is repeated more frequently if adenomatous polyps were identified at this colonoscopy due to an increased risk of subsequent polyps or colon cancer. Flexible sigmoidoscopy every few years with annual fecal occult blood testing is a significantly less sensitive screening protocol. Virtual colonoscopy is controversial as a screening test due to widely variable reported<h4>Results</h4>Computerized tomography is standardly used to preoperatively detect distant colon cancer metastases, while endosonography is being increasingly used for locoregional staging of rectal cancer. Stool genetic markers and videocapsule endoscopy are promising, but currently experimental, screening tests.
Also flagged:alcoholliver diseaseliver damagemetabolismalcohol-metabolizing enzymesalcohol dehydrogenase
Journal Article2007-12-01✓ 1 SnippetZakhari S, Li TK.
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…type 2 diabetes,hemochromatosis, or obesity and…
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<h4>Unlabelled</h4>More than 70% of alcohol is consumed by 10% of the population in the United States. Implicit in this statistic is that tremendous variation in the pattern of drinking (quantity, frequency, and duration) exists among alcohol consumers. Individuals who are binge or chronic drinkers will have different health outcomes than social drinkers. Therefore, knowing the pattern of drinking will shed light on how severely individuals are alcohol-dependent and on the extent of liver damage. Thus, these parameters assume particular relevance for the treatment-providing physician. Genetic factors contribute substantially to differences in alcohol metabolism. Variations in the activities of the alcohol-metabolizing enzymes, cytosolic alcohol dehydrogenase and mitochondrial aldehyde dehydrogenase, in part determine blood alcohol concentration, thereby contributing to the predisposition to becoming alcohol-dependent and to susceptibility to alcohol-induced liver damage. Chronic alcohol consumption induces cytochrome P450 2E1, a microsomal enzyme that metabolizes alcohol at high concentrations and also metabolizes medications such as acetaminophen and protease inhibitors. Alcohol metabolism changes the redox state of the liver, which leads to alterations in hepatic lipid, carbohydrate, protein, lactate, and uric acid metabolism. The quantity and frequency of alcohol consumption severely impact the liver in the presence of comorbid conditions such as infection with hepatitis B or C and/or human immunodeficiency virus, type 2 diabetes, hemochromatosis, or obesity and thus have implications with respect to the extent of injury and response to medications.<h4>Conclusion</h4>Knowledge of the relationships between the quantity, frequency, and patterns of drinking and alcoholic liver disease is limited. A better understanding of these relationships will guide hepatologists in managing alcoholic liver disease.
Also flagged:dopamine receptorindolizidinoneallylprolinebindingN
Journal Article2007-12-01No SnippetsVartak AP, Skoblenick K, Thomas N, Mishra RK, Johnson RL.
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A peptidomimetic of Pro-Leu-Pro-NH2, 7, possessing an indolizidinone type VI beta-turn mimic was synthesized via improved high-yielding protocols for the preparation and Cbz protection of alpha-allylproline. Bicyclic peptidomimetic 7 and spirobicylic peptidomimetic 8 enhanced the binding of [3H] N-propylnorapomorphine to dopamine receptors indicating that a type VI beta-turn is a possible bioactive conformation of the homochiral Pro-Leu-Pro-NH2 and Pro-Pro-Pro-NH 2 analogues of Pro-Leu-Gly-NH2 at the dopamine receptor allosteric regulatory site.
Also flagged:neuropilin-1axonscell-surfaceaxonaxonalbehavioral
Journal Article2007-12-01✓ 2 SnippetsChauvet S, Cohen S, Yoshida Y, Fekrane L, Livet J, Gayet O, Segu L, Buhot MC, Jessell TM, Henderson CE, Mann F.
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The establishment of functional neural circuits requires the guidance of axons in response to the actions of secreted and cell-surface molecules such as the semaphorins. Semaphorin 3E and its receptor PlexinD1 are expressed in the brain, but their functions are unknown. Here, we show that Sema3E/PlexinD1 signaling plays an important role in initial development of descending axon tracts in the forebrain. Early errors in axonal projections are reflected in behavioral deficits in Sema3E null mutant mice. Two distinct signaling mechanisms can be distinguished downstream of Sema3E. On corticofugal and striatonigral neurons expressing PlexinD1 but not Neuropilin-1, Sema3E acts as a repellent. In contrast, on subiculo-mammillary neurons coexpressing PlexinD1 and Neuropilin-1, Sema3E acts as an attractant. The extracellular domain of Neuropilin-1 is sufficient to convert repulsive signaling by PlexinD1 to attraction. Our data therefore reveal a "gating" function of neuropilins in semaphorin-plexin signaling during the assembly of forebrain neuronal circuits.
Also flagged:cancerHMG1HMG17CalgizzarinSaltOvarian Cancer
Journal Article2007-12-01✓ 1 SnippetWisniewski JR, Zougman A, Mann M.
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…Inlinker histoneshistones and high…
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Post-translational modification of histones and other chromosomal proteins regulates chromatin conformation and gene activity. Methylation and acetylation of lysyl residues are among the most frequently described modifications in these proteins. Whereas these modifications have been studied in detail, very little is known about a recently discovered chemical modification, the N(epsilon)-lysine formylation, in histones and other nuclear proteins. Here we mapped, for the first time, the sites of lysine formylation in histones and several other nuclear proteins. We found that core and linker histones are formylated at multiple lysyl residues located both in the tails and globular domains of histones. In core histones, formylation was found at lysyl residues known to be involved in organization of nucleosomal particles that are frequently acetylated and methylated. In linker histones and high mobility group proteins, multiple formylation sites were mapped to residues with important role in DNA binding. N(epsilon)-lysine formylation in chromosomal proteins is relatively abundant, suggesting that it may interfere with epigenetic mechanisms governing chromatin function, which could lead to deregulation of the cell and disease.
Also flagged:bindingpositronserotonin transporterserotoninmajor depressiondepression
Journal Article2007-12-01✓ 5 SnippetsBhagwagar Z, Murthy N, Selvaraj S, Hinz R, Taylor M, Fancy S, Grasby P, Cowen P.
In-Text Gene Mentions
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…<h4>Objective</h4>The serotonin transporter (5-HTT) is a key target for selective serotonin reuptake inhibitors and may be involved in the pathophysiology of major depression.…
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…5-HTTbinding in recovered…
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…h4>The serotonin transporter (5-HTT) is a key…
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…possible to image5-HTTdirectly in the…
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…whether abnormalities in5-HTTmight be present…
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<h4>Objective</h4>The serotonin transporter (5-HTT) is a key target for selective serotonin reuptake inhibitors and may be involved in the pathophysiology of major depression. It is now possible to image 5-HTT directly in the human brain, but results from studies of acutely depressed patients have been inconsistent. The purpose of this study was to determine whether abnormalities in 5-HTT might be present in recovered depressed patients.<h4>Method</h4>The authors measured the binding potential of 5-HTT using [11C]DASB in conjunction with positron emission tomography (PET) in 24 medication-free, recovered depressed male patients and 20 healthy male comparison subjects. The regional estimates of binding potential were obtained using a metabolite-corrected plasma input function method followed by Logan analysis, with the cerebellum as a reference region.<h4>Results</h4>The authors found no significant difference in the binding potential of [11C]DASB between the recovered depressed patients and healthy comparison subjects in any of the brain regions (amygdala, anterior cingulate cortex, caudate nucleus, frontal cortex, hippocampus, insula, thalamus, and dorsal raphe) studied.<h4>Conclusions</h4>Men who recover from depression have normal availability of 5-HTT in brain regions thought to be involved in the pathophysiology of depression. The findings therefore do not support the proposal that recurrent depression is associated with long-standing deficits in 5-HTT.
Also flagged:OX40thymic stromal lymphopoietinTSLPallergic inflammatory diseasesasthmaatopic dermatitis
Journal Article2007-12-01✓ 1 SnippetSeshasayee D, Lee WP, Zhou M, Shu J, Suto E, Zhang J, Diehl L, Austin CD, Meng YG, Tan M, Bullens SL, Seeber S, Fuentes ME, Labrijn AF, Graus YM, Miller LA, Schelegle ES, Hyde DM, Wu LC, Hymowitz SG, Martin F.
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Abstract)
…OX40L-blocking antibodies also inhibited antigen-driven Th2 inflammation in mouse and nonhuman primate models of asthma.…
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Thymic stromal lymphopoietin (TSLP) potently induces deregulation of Th2 responses, a hallmark feature of allergic inflammatory diseases such as asthma, atopic dermatitis, and allergic rhinitis. However, direct downstream in vivo mediators in the TSLP-induced atopic immune cascade have not been identified. In our current study, we have shown that OX40 ligand (OX40L) is a critical in vivo mediator of TSLP-mediated Th2 responses. Treating mice with OX40L-blocking antibodies substantially inhibited immune responses induced by TSLP in the lung and skin, including Th2 inflammatory cell infiltration, cytokine secretion, and IgE production. OX40L-blocking antibodies also inhibited antigen-driven Th2 inflammation in mouse and nonhuman primate models of asthma. This treatment resulted in both blockade of the OX40-OX40L receptor-ligand interaction and depletion of OX40L-positive cells. The use of a blocking, OX40L-specific mAb thus presents a promising strategy for the treatment of allergic diseases associated with pathologic Th2 immune responses.
Also flagged:dopamineserotoninserotonin transporterserotonin receptor 2Adopamine D2 receptorDRD2
Journal Article2007-12-01✓ 2 SnippetsEmanuele E, Brondino N, Pesenti S, Re S, Geroldi D.
In-Text Gene Mentions
Abstract)
…To address this issue, we looked for associations between markers in neurotransmitter genes (the serotonin transporter gene, 5-HTT; the serotonin receptor 2A, 5HT2A; the dopamine D2 receptor gene, DRD2; and the dopamine D4 receptor gene, DRD4) and the six styles of love as conceptualized by Lee (Eros, Ludus, Storge, Pragma, Mania and Agape).…
Abstract)
…serotonin transporter gene,5-HTT; the serotonin receptor…
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<h4>Objectives</h4>It has been hypothesized that cerebral neurotransmitters such as dopamine and serotonin could play a role in human romantic bonding. However, no data on the genetic basis of human romantic love are currently available. To address this issue, we looked for associations between markers in neurotransmitter genes (the serotonin transporter gene, 5-HTT; the serotonin receptor 2A, 5HT2A; the dopamine D2 receptor gene, DRD2; and the dopamine D4 receptor gene, DRD4) and the six styles of love as conceptualized by Lee (Eros, Ludus, Storge, Pragma, Mania and Agape).<h4>Design</h4>A total of 350 healthy young adults (165 males and 185 females, mean age: 24.1+/-3.9 years, range 18-32 years) filled the 24-item Love Attitudes Scale (LAS) and were genotyped for the following six polymorphic markers: the serotonin transporter-linked polymorphic region (5-HTTLPR), the 5HT2A T102C and C516T polymorphisms, the DRD2 TaqI A and TaqI B variants, and the DRD4 exon 3 VNTR polymorphism.<h4>Results</h4>Statistical analysis revealed a significant association between the DRD2 TaqI A genotypes and "Eros" (a loving style characterized by a tendency to develop intense emotional experiences based on the physical attraction to the partner), as well as between the C516T 5HT2A polymorphism and "Mania" (a possessive and dependent romantic attachment, characterized by self-defeating emotions). These associations were present in both sexes and remained significant even after adjustment for potential confounders.<h4>Conclusions</h4>Our data provide the first evidence of a possible genetic loading on human loving styles.
Also flagged:ChromatincancertumourigenesishistonephosphorylationH2AX
Journal Article2007-12-01✓ 1 SnippetDowns JA.
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Abstract)
…subset of these proteins--linker histoneshistones and high-mobility…
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Defects in the detection and repair of DNA double-strand breaks (DSBs) have been causatively linked to tumourigenesis. Moreover, inhibition of DNA damage responses (DDR) can increase the efficacy of cancer therapies that rely on generation of damaged DNA. DDR must occur within the context of chromatin, and there have been significant advances in recent years in understanding how the modulation and manipulation of chromatin contribute to this activity. One particular covalent modification of a histone variant--the phosphorylation of H2AX--has been investigated in great detail and has been shown to have important roles in DNA DSB responses and in preventing tumourigenesis. These studies are reviewed here in the context of their relevance to cancer therapy and diagnostics. In addition, there is emerging evidence for contributions by proteins involved in mediating higher order structure to DNA DSB responses. The contributions of a subset of these proteins--linker histones and high-mobility group box (HMGB) proteins--to DDR and their potential significance in tumourigenesis are discussed.
Also flagged:OX40OX40Lallergic diseasesallergicthymic stromal lymphopoietinTSLP
Journal Article2007-12-01No SnippetsWang YH, Liu YJ.
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Recent advances in understanding the cellular and molecular mechanisms of atopy have shed light on potential targets for the development of new therapies for allergic diseases. In this issue of the JCI, Seshasayee et al. provide direct in vivo evidence that OX40 has critical roles in allergic inflammation mediated by thymic stromal lymphopoietin (TSLP) (see the related article beginning on page 3868). Blockade of interactions between OX40 on Th2 cells and OX40 ligand (OX40L) on TSLP-activated DCs using an OX40L-specific monoclonal antibody, inhibited Th2 cell-mediated immune responses in both mouse and nonhuman primate models of allergic inflammation. The results point to potential therapeutic approaches to targeting the cellular and molecular mechanism underlying TSLP-mediated allergic inflammation.
Also flagged:calciumHuntington's diseaseHDNMDA-type glutamate receptorsmitochondrialglutamine
Journal Article2007-12-01✓ 1 SnippetFernandes HB, Baimbridge KG, Church J, Hayden MR, Raymond LA.
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Expansion of a CAG repeat in the Huntington's disease (HD) gene results in progressive neuronal loss, particularly of striatal medium-sized spiny neurons (MSNs). Studies in human HD autopsy brain tissue, as well as cellular and animal models of HD, suggest that increased activity of NMDA-type glutamate receptors and altered mitochondrial function contribute to selective neuronal degeneration. In this regard, the YAC128 mouse model, expressing full-length human huntingtin with 128 glutamine repeats, has been the focus of much interest. Although NMDA-induced apoptosis is enhanced in YAC128 MSNs, here we report that the initial steps in the death signaling pathway, including NMDA receptor (NMDAR) current and cytosolic Ca2+ loading, are similar to those observed in wild-type MSNs. In contrast, we found that the NMDAR-mediated Ca2+ load triggered a strikingly enhanced loss of mitochondrial membrane potential in YAC128 MSNs, suggesting that NMDAR signaling via the mitochondrial apoptotic pathway is altered. This effect was accompanied by impaired cytosolic Ca2+ clearance after removal of NMDA, a difference that was not apparent after high potassium-evoked depolarization-mediated Ca2+ entry. Inhibition of the mitochondrial permeability transition (mPT) reduced peak cytosolic Ca2+ and mitochondrial depolarization evoked by NMDA in YAC128 MSNs but not wild-type MSNs. Hence, in contrast to YAC models with moderate CAG expansions, the enhanced NMDA-induced apoptosis in YAC128 MSNs is predominantly determined by augmented mitochondrial sensitivity to Ca2+-induced activation of the mPT. These results suggest that the CAG repeat length influences the mechanism by which mHtt enhances NMDAR-mediated excitotoxicity.
Also flagged:NR2B receptorCaMKIINR2BNMDA receptorcalcium/calmodulin-dependent protein kinase IIcarboxy
Journal Article2007-12-01✓ 1 SnippetZhou Y, Takahashi E, Li W, Halt A, Wiltgen B, Ehninger D, Li GD, Hell JW, Kennedy MB, Silva AJ.
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…Densin-180…
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The NR2B subunit of the NMDA receptor interacts with several prominent proteins in the postsynaptic density, including calcium/calmodulin-dependent protein kinase II (CaMKII). To determine the function of these interactions, we derived transgenic mice expressing a ligand-activated carboxy-terminal NR2B fragment (cNR2B) by fusing this fragment to a tamoxifen (TAM)-dependent mutant of the estrogen receptor ligand-binding domain LBD(G521R). Here, we show that induction by TAM allows the transgenic cNR2B fragment to bind to endogenous CaMKII in neurons. Activation of the LBD(G521R)-cNR2B transgenic protein in mice leads to the disruption of CaMKII/NR2B interactions at synapses. The disruption decreases Thr286 phosphorylation of alphaCaMKII, lowers phosphorylation of a key CaMKII substrate in the postsynaptic membrane (AMPA receptor subunit glutamate receptor 1), and produces deficits in hippocampal long-term potentiation and spatial learning. Together our results demonstrate the importance of interactions between CaMKII and NR2B for CaMKII activity, synaptic plasticity, and learning.
Also flagged:hereditary haemochromatosisHHiron overload diseaseironmetabolismiron regulatory hormone
Journal Article2007-12-01✓ 5 SnippetsJacobs EM, Verbeek AL, Kreeftenberg HG, van Deursen CT, Marx JJ, Stalenhoef AF, Swinkels DW, de Vries RA.
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Abstract)
…HFE-related hereditary haemochromatosis (HH) is an iron overload disease attributed to the highly prevalent homozygosity for the C282Y mutation in the HFE gene.…
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…HFE-related HH include liver failure, arthralgia, chronic fatigue, diabetes mellitus…
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…HFE-related HH include liver failure, arthralgia, chronic fatigue, diabetes mellitus and congestive heart failure…
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…HFE-related HH include liver failure…
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…HFE-related HH include liver failure, arthralgia, chronic fatigue…
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HFE-related hereditary haemochromatosis (HH) is an iron overload disease attributed to the highly prevalent homozygosity for the C282Y mutation in the HFE gene. The pathophysiology of this error in iron metabolism is not completely elucidated yet, although deficiency of the iron regulatory hormone hepcidin appears to play a role. Ways of diagnosing iron overload include measurement of the serum iron parameters, i.e. serum transferrin saturation and serum ferritin, by a liver biopsy or by calculating the amount of mobilisable body iron withdrawn by phlebotomies. Clinical signs attributed to HFE-related HH include liver failure, arthralgia, chronic fatigue, diabetes mellitus and congestive heart failure. organ failure can be prevented by phlebotomies starting before irreversible damage has occurred. Therefore, screening to facilitate early diagnosis is desirable in individuals at risk of developing HFE-related iron overload. over time it appeared that the clinical penetrance of the HFE mutations was much lower than had previously been thought. This changed the opinion about a suitable screening modality from case detection, via population screening, to family screening as the most appropriate method to prevent HFE-related disease. However, before the implementation of family screening it is vital to have thorough information on the relevance of the specific health problem involved, on the clinical penetrance of C282Y homozygosity and on the effectiveness of the screening approach.
…participating in theHEmochromatosisfAmily study (HEfAs).…
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…the C282Y mutatedHFE-gene and elevated serum…
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<h4>Background</h4>Family screening has been suggested as a sophisticated model for the early detection of HFE-related hereditary haemochromatosis (HH). However, until now, controlled studies on the morbidity and mortality in families with HH are lacking.<h4>Methods</h4>Data on iron parameters, morbidity and mortality were collected from 224 dutch C282Y-homozygous probands with clinically overt HH and 735 of their first-degree family members, all participating in the HEmochromatosis fAmily study (HEfAs). These data were compared with results obtained from an age- and gender-matched normal population. HEfAs and controls filled in similar questionnaires on demographics, lifestyle factors, health, morbidity and mortality.<h4>Results</h4>A significantly higher proportion of the HEfAs first-degree family members reported to be diagnosed with haemochromatosis-related diseases: 45.7 vs 19.4% of the matched normal population (McNemar p<0.001). Mortality among siblings, children and parents in the HEFAS population was similar to that in the relatives of matched control.<h4>Conclusion</h4>In this study we show that, morbidity among first-degree family members of C282Y-homozygous probands previously diagnosed with clinically proven HH is higher than that in an age- and gender-matched normal population. Further studies are needed to definitely connect these increase morbidity figures to increase prevalenc of the C282Y mutated HFE-gene and elevated serum iron indices.
…Liver biopsy is recommended when ferritin exceeds 1000 microg/l to establish the presence or absence of cirrhosis, which will affect prognosis and management. iron accumulation confirmed by magnetic resonance imaging (MRI) in the absence of the homozygous C282Y mutation or the combined C282Y/H63d genotype may justify a search for rare hereditary forms of non-HFE HH in a specialised centre.…
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…cirrhosis, which will affect prognosis and management. iron accumulation confirmed by magnetic resonance imaging (MRI) in the absence of the homozygous C282Y mutation or the combined C282Y/H63d genotype may justify a search for rare hereditary forms of non-HFE…
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…mutations in theHFEgene and can…
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…local reference ranges,HFEmutations should be…
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…the diagnosis ofHFE-related HH.…
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Hereditary haemochromatosis (HH) is a disease related to mutations in the HFE gene and can lead to progressive iron accumulation, especially in the liver, eventually resulting in organ damage. We have developed guidelines for the diagnosis and treatment of this disease according to CBO methodology (dutch institute for Healthcare Quality). The prevalence of clinical symptoms such as fatigue, arthropathies, impotence and diabetes mellitus among homozygotes was similar to that in a control population. Nevertheless, we recommend the assessment of serum iron indices when these symptoms remain unexplained. When transferrin saturation is >45% and ferritin exceeds local reference ranges, HFE mutations should be investigated. Homozygosity for the C282Y mutation or combined C282Y/H63d mutation confirms the diagnosis of HFE-related HH. Liver biopsy is recommended when ferritin exceeds 1000 microg/l to establish the presence or absence of cirrhosis, which will affect prognosis and management. iron accumulation confirmed by magnetic resonance imaging (MRI) in the absence of the homozygous C282Y mutation or the combined C282Y/H63d genotype may justify a search for rare hereditary forms of non-HFE HH in a specialised centre. The literature supports the benefits of adequate phlebotomy and the screening of first-degree relatives of index patients with clinically overt HH. overall, the guidelines presented here are to a great extent based on the expert opinion of the working party, as the quantity of evidence that met predefined criteria posed by the evidence-based approach was small. We therefore recommend world-wide efforts to collaboratively address these remaining issues.
Also flagged:RIN1Breast cancergene expressionRASbreast tumortranscription repressor
Journal Article2007-12-01✓ 1 SnippetMilstein M, Mooser CK, Hu H, Fejzo M, Slamon D, Goodglick L, Dry S, Colicelli J.
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…PEBP1…
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Breast cancer progression is driven by altered gene expression. We show that the RIN1 gene, which encodes a RAS effector regulating epithelial cell properties, is silenced in breast tumor cell lines compared with cultured human mammary epithelial cells. We also report that RIN1 is often reduced in human breast tumor cells compared with morphologically normal breast glandular cells. At least two silencing mechanisms seem to be involved. Overexpression of the transcription repressor SNAI1 (Snail) was observed in ZR75-1 cells, and SNAI1 knockdown restored RIN1 expression. In addition, DNA methylation within the RIN1 promoter and the first exon in KPL-1 cells suggested that epigenetic modifications may contribute to silencing, and demethylation was shown to restore RIN1 expression. Reexpression of RIN1 was shown to inhibit anchorage-independent growth in soft agar. In addition, RIN1 expression inhibited both the initiation and progression of tumorigenesis for two breast tumor cell lines in a mouse model, consistent with a tumor suppressor function. We also show that RIN1 acts as a negative regulator of tumor cell invasive growth and that this requires the ABL kinase-signaling function of RIN1, suggesting a mechanism through which RIN1 silencing may contribute to breast cancer progression.
Also flagged:proteolysisHuntington's diseasepathogenesisHuntingtinamino acidsprotease
Journal Article2007-12-01No SnippetsRatovitski T, Nakamura M, D'Ambola J, Chighladze E, Liang Y, Wang W, Graham R, Hayden MR, Borchelt DR, Hirschhorn RR, Ross CA.
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Proteolytic cleavage of mutant huntingtin may play a key role in the pathogenesis of Huntington's disease; however the steps in huntingtin proteolysis are not fully understood. Huntingtin was shown to be cleaved by caspases and calpains within a region between 460-600 amino acids from the N-terminus. Two smaller N-terminal fragments produced by unknown protease have been previously described as cp-A and cp-B. To further investigate the huntingtin proteolytic pathway, we used an inducible PC12 cell model expressing full-length huntingtin with either normal or expanded polyglutamine. This cell model recapitulates several steps of huntingtin proteolysis: proteolysis mediated by caspases within the region previously mapped for caspase cleavage, and cleavage generating two novel N-terminal fragments (cp-1 approximately 90-105 residues long and cp-2 extending beyond 115-129 epitope of huntingtin). Interestingly, the deletion of amino acids 105-114 (mapped previously as a cleavage site for cp-A) failed to affect the production of cp-1 or cp-2. Therefore, we conclude that these new fragments are distinct from previously described cp-A and cp-B. We demonstrate that cp-1 and cp-2 fragments are produced and accumulate within nuclear and cytoplasmic inclusions prior to huntingtin-induced cell toxicity, and these fragments can be formed by caspase-independent proteolytic cleavage of huntingtin in PC12 cells. In addition, inhibition of calpains leads to decreased subsequent degradation of cp-1 and cp-2 fragments, and accelerated formation of inclusions. Further delineation of huntingtin cleavage events may lead to novel therapeutic targets for HD.
A defining feature of centromeres is the presence of the histone H3 variant CENP-A(Cnp1). It is not known how CENP-A(Cnp1) is specifically delivered to, and assembled into, centromeric chromatin. Through a screen for factors involved in kinetochore integrity in fission yeast, we identified Sim3. Sim3 is homologous to known histone binding proteins NASP(Human) and N1/N2(Xenopus) and aligns with Hif1(S. cerevisiae), defining the SHNi-TPR family. Sim3 is distributed throughout the nucleoplasm, yet it associates with CENP-A(Cnp1) and also binds H3. Cells defective in Sim3 function have reduced levels of CENP-A(Cnp1) at centromeres (and increased H3) and display chromosome segregation defects. Sim3 is required to allow newly synthesized CENP-A(Cnp1) to accumulate at centromeres in S and G2 phase-arrested cells in a replication-independent mechanism. We propose that one function of Sim3 is to act as an escort that hands off CENP-A(Cnp1) to chromatin assembly factors, allowing its incorporation into centromeric chromatin.
Sensorimotor gating commonly occurs at sensory neuron synapses onto motor circuit neurons and motor neurons. Here, using the crab stomatogastric nervous system, we show that sensorimotor gating also occurs at the level of the projection neurons that activate motor circuits. We compared the influence of the gastro-pyloric receptor (GPR) muscle stretch-sensitive neuron on two projection neurons, modulatory commissural neuron 1 (MCN1) and commissural projection neuron 2 (CPN2), with and without a preceding activation of the mechanosensory ventral cardiac neurons (VCNs). MCN1 and CPN2 project from the paired commissural ganglia (CoGs) to the stomatogastric ganglion (STG), where they activate the gastric mill (chewing) motor circuit. When stimulated separately, the GPR and VCN neurons each elicit the gastric mill rhythm by coactivating MCN1 and CPN2. When GPR is instead stimulated during the VCN-gastric mill rhythm, it slows this rhythm. This effect results from a second GPR synapse onto MCN1 that presynaptically inhibits its STG terminals. Here, we show that, during the VCN-triggered rhythm, the GPR excitation of MCN1 and CPN2 in the CoGs is gated out, leaving only its influence in the STG. This gating effect appears to occur within the CoG and does not result from a ceiling effect on projection neuron firing frequency. Additionally, this gating action enables GPR to either activate rhythmic motor activity or act as a phasic sensorimotor feedback system. These results also indicate that the site of sensorimotor gating can occur at the level of the projection neurons that activate a motor circuit.
Also flagged:tirofibanplatelet activationComplement activationGPIIb/IIIacreatine phosphokinasecomplement factors
Journal Article2007-12-01✓ 2 SnippetsBrandl U, Jöckle H, Erhardt M, Michel S, Burdorf L, Brenner P, Bittmann I, Rössle M, Mordstein V, Hammer C, Thein E, Reichart B, Schmoeckel M.
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Abstract)
…C4), platelets, fibrinogen,ATIII, and graft histology.<h4>Resu…
Abstract)
…ATIIIconsumption was most…
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<h4>Background</h4>Solid organ xenograft rejection is associated with vascular injury resulting at least in part in platelet activation, and rejected xenografts invariably demonstrate intravascular thrombosis and interstitial hemorrhage. Complement activation plays a prominent role in platelet-endothelial interaction. We tested the effects of platelet GPIIb/IIIa inhibitor tirofiban during perfusion of hDAF pig hearts.<h4>Methods</h4>Using a working-heart model, nontransgenic and hDAF pig hearts were perfused with tirofiban or human blood only. Myocardial damage was determined by hemodynamic parameters (cardiac output, stroke work index) and creatine phosphokinase. Further monitoring included the assessment of complement factors (C3, C4), platelets, fibrinogen, ATIII, and graft histology.<h4>Results</h4>Tirofiban increased cardiac output (CO) and stroke work index (SWI) of nontransgenic pig hearts and improved superior CO and SWI of hDAF pig hearts. Although perfusion time of nontransgenic pig hearts was prolonged by tirofiban (196+/-65 min vs. 162+/-122 min), a similar effect in hDAF pig hearts (218+/-116 min vs. 222+/-30 min) could not be demonstrated. Tirofiban reduced consumption of C3 and C4 independently from hDAF. Depletion of fibrinogen was equally diminished by tirofiban and hDAF; the combination of both agents obtained no further reduction. ATIII consumption was most effectively inhibited by this combination. Intravascular fibrin deposition was reduced by tirofiban and hDAF, but particularly by the combination of the two agents.<h4>Conclusions</h4>Improvement of heart performance and reduction of myocardial damage and intravascular thrombosis confirm a role of the GPIIb/IIIa inhibitor tirofiban for the prevention of hDAF pig heart rejection and xenograft function.
Also flagged:Multidrug resistance associated proteinsMRP1MRP2MRP3MRP4MRP5
Journal Article2007-12-01No SnippetsYu XQ, Xue CC, Wang G, Zhou SF.
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The multidrug resistance associated proteins (MRP1, MRP2, MRP3, MRP4, MRP5, MRP6, MRP7, MRP8 and MRP9) belong to the ATP-binding cassette superfamily (ABCC family) of transporters. They are expressed differentially in the liver, kidney, intestine, brain and other tissues. These transporters are localized to the apical and/or basolateral membrane of the hepatocytes, enterocytes, renal proximal tubule cells and endothelial cells of the blood-brain barrier. Several MRPs (mainly MRP1-3) are associated with tumor resistance which is often caused by an increased efflux and decreased intracellular accumulation of natural product anticancer drugs and other anticancer agents. MRPs transport a structurally diverse array of important endogenous substances and xenobiotics and their metabolites (in particular conjugates) with different substrate specificity and transport kinetics. Most MRPs are subject to induction and inhibition by a variety of compounds. Several nuclear receptors, including pregnane X receptor (PXR), liver X receptor (LXR), and farnesoid receptor (FXR) participate in the regulation of MRPs. MRPs play an important role in the absorption, distribution and elimination of various drugs in the body and thus may affect their efficacy and toxicity and cause drug-drug interactions. MRPs located in the blood-brain barrier can restrict the penetration of compounds into the central nervous system. Mutation of MRP2 causes Dubin-Johnson syndrome, while mutations in MRP6 are responsible for pseudoxanthoma elasticum. More recently, mutations in mouse Mrp6/Abcc6 gene is associated with dystrophic cardiac calcification (DCC), a disease characterized by hydroxyapatite deposition in necrotic myocytes. A single nucleotide polymorphism, 538G>A in the MRP8/ABCC11 gene, is responsible for determination of earwax type. A better understanding of the function and regulating mechanism of MRPs can help minimize and avoid drug toxicity, unfavourable drug-drug interactions, and to overcome drug resistance.
The study assesses absolute and relative errors in the calculation of cytochemical indices in a precise patient. At present, the semiquantitative index (the mean cytochemical coefficient (MCC) after G. Astaldi and L. Verg) is widely used to evaluate the cytochemical activity of leukocytes. At the same time other indices, such as differentiating cytochemical coefficient (DCC) after I. G. Bondarenko, occasionally find application. Analysis of the results of simulation of an array containing 500 leukograms has demonstrated that the individual relative detection error for MCC ranges from 13 to 21% and that for DCC 20 to 51%. The results of the study enable an adequate estimation of the ways of expressing the cytochemical findings, which are proposed by different authors.
Also flagged:cholangiocarcinomaprimaryliver cancercollision tumorhepatocellular carcinomaschistosomiasis
Journal Article2007-12-01✓ 1 SnippetHong CK, Yang JM, Kang BK, Kim JD, Kim YC, Chang UI, Yoo JY.
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…alcohol intake orhemochromatosis1) .…
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Combined hepatocellular-cholangiocarcinoma is a rare form of primary liver cancer showing features of both hepatocellular and biliary epithelial differentiation. We report here on a case with collision tumor, which apparently was the coincidental occurrence of both hepatocellular carcinoma and cholangiocarcinoma underlying schistosomiasis. A 39-year-old-Philippine female was transferred to our hospital for evaluation of a liver mass that was found on ultrasonography at a local hospital. HBsAg and Anti-HCV were negative and serum alpha-fetoprotein (AFP) level was normal. The tumor mass was histologically diagnosed as adenocarcinoma by sono-guided biopsy before the operation. Partial lobectomy was performed and we histologically identified the concurrent occurrence of hepatocellular carcinoma and cholangiocarcinoma, (a "collision type carcinoma").