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Viewing April 2006 — 71 paper(s) from the local store. (Local view only — run without --view to fetch new papers.)
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Also flagged:nucleoplasminschaperonechromatinfertilizationnuclear basic proteinsprotamine
Journal Article 2006-04-28 ✓ 1 Snippet Frehlick LJ, Eirín-López JM, Jeffery ED, Hunt DF, Ausió J.
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…of highly specificlinker histoneshistones with similar…

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<h4>Background</h4>Nucleoplasmin is a nuclear chaperone protein that has been shown to participate in the remodeling of sperm chromatin immediately after fertilization by displacing highly specialized sperm nuclear basic proteins (SNBPs), such as protamine (P type) and protamine-like (PL type) proteins, from the sperm chromatin and by the transfer of histone H2A-H2B. The presence of SNBPs of the histone type (H type) in some organisms (very similar to the histones found in somatic tissues) raises uncertainty about the need for a nucleoplasmin-mediated removal process in such cases and poses a very interesting question regarding the appearance and further differentiation of the sperm chromatin remodeling function of nucleoplasmin and the implicit relationship with SNBP diversity The amphibians represent an unique opportunity to address this issue as they contain genera with SNBPs representative of each of the three main types: Rana (H type); Xenopus (PL type) and Bufo (P type).<h4>Results</h4>In this work, the presence of nucleoplasmin in oocyte extracts from these three organisms has been assessed using Western Blotting. We have used mass spectrometry and cloning techniques to characterize the full-length cDNA sequences of Rana catesbeiana and Bufo marinus nucleoplasmin. Northern dot blot analysis shows that nucleoplasmin is mainly transcribed in the egg of the former species. Phylogenetic analysis of nucleoplasmin family members from various metazoans suggests that amphibian nucleoplasmins group closely with mammalian NPM2 proteins.<h4>Conclusion</h4>We have shown that these organisms, in striking contrast to their SNBPs, all contain nucleoplasmins with very similar primary structures. This result has important implications as it suggests that nucleoplasmin's role in chromatin assembly during early zygote development could have been complemented by the acquisition of a new function of non-specifically removing SNBPs in sperm chromatin remodeling. This acquired function would have been strongly determined by the constraints imposed by the appearance and differentiation of SNBPs in the sperm.

Also flagged:Cannabinoid receptorsendocannabinoidsCB1 receptorsCB2 receptorsarachidonoylethanolamide2-arachidonoylglycerol
Journal Article 2006-04-28 No Snippets Mackie K, Stella N.
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It is now well established that the psychoactive effects of Cannabis sativa are primarily mediated through neuronal CB1 receptors, while its therapeutic immune properties are primarily mediated through CB2 receptors. Two endocannabinoids, arachidonoylethanolamide and 2-arachidonoylglycerol, have been identified, their action on CB1 and CB2 thoroughly characterized, and their production and inactivation elucidated. However, many significant exceptions to these rules exist. Here we review the evidence suggesting that cannabinoids can modulate synaptic transmission, the cardiovascular system, and the immune system through receptors distinct from CB1 and CB2, and that an additional "independent" endocannabinoid signaling system that involves palmitoylethanolamide may exist.

Also flagged:caffeineglycineserotoninenitric oxideextracellularadrenaline
Journal Article 2006-04-27 No Snippets Ellwanger K, Nickel M.
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<h4>Background</h4>Sponges (Porifera) are nerve- and muscleless metazoa, but display coordinated motor reactions. Therefore, they represent a valuable phylum to investigate coordination systems, which evolved in a hypothetical Urmetazoon prior to the central nervous system (CNS) of later metazoa. We have chosen the contractile and locomotive species Tethya wilhelma (Demospongiae, Hadromerida) as a model system for our research, using quantitative analysis based on digital time lapse imaging. In order to evaluate candidate coordination pathways, we extracorporeally tested a number of chemical messengers, agonists and antagonists known from chemical signalling pathways in animals with CNS.<h4>Results</h4>Sponge body contraction of T. wilhelma was induced by caffeine, glycine, serotonine, nitric oxide (NO) and extracellular cyclic adenosine monophosphate (cAMP). The induction by glycine and cAMP followed patterns varying from other substances. Induction by cAMP was delayed, while glycine lead to a bi-phasic contraction response. The frequency of the endogenous contraction rhythm of T. wilhelma was significantly decreased by adrenaline and NO, with the same tendency for cAMP and acetylcholine. In contrast, caffeine and glycine increased the contraction frequency. The endogenous rhythm appeared irregular during application of caffeine, adrenaline, NO and cAMP. Caffeine, glycine and NO attenuated the contraction amplitude. All effects on the endogenous rhythm were neutralised by the washout of the substances from the experimental reactor system.<h4>Conclusion</h4>Our study demonstrates that a number of chemical messengers, agonists and antagonists induce contraction and/or modulate the endogenous contraction rhythm and amplitude of our nerveless model metazoon T. wilhelma. We conclude that a relatively complex system of chemical messengers regulates the contraction behaviour through auto- and paracrine signalling, which is presented in a hypothetical model. We assume that adrenergic, adenosynergic and glycinergic pathways, as well as pathways based on NO and extracellular cAMP are candidates for the regulation and timing of the endogenous contraction rhythm within pacemaker cells, while GABA, glutamate and serotonine are candidates for the direct coordination of the contractile cells.

Also flagged:iron transport proteinsironcolorectal cancercolorectal carcinomaduodenal cytochrome bDCYTB
Journal Article 2006-04-26 ✓ 1 Snippet Brookes MJ, Hughes S, Turner FE, Reynolds G, Sharma N, Ismail T, Berx G, McKie AT, Hotchin N, Anderson GJ, Iqbal T, Tselepis C.
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HFE

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<h4>Background and aims</h4>Total body iron and high dietary iron intake are risk factors for colorectal cancer. To date there is no comprehensive characterisation of iron transport proteins in progression to colorectal carcinoma. In this study, we examined expression of iron import (duodenal cytochrome b (DCYTB), divalent metal transporter 1 (DMT1), and transferrin receptor 1 (TfR1)) and export (hephaestin (HEPH) and ferroportin (FPN)) proteins in colorectal carcinoma.<h4>Methods</h4>Perl's staining was used to examine colonocyte iron content. Real time polymerase chain reaction (PCR) and western blotting were used to examine mRNA and protein levels of the molecules of interest in 11 human colorectal cancers. Semiquantitative immunohistochemistry was used to verify protein levels and information on cellular localisation. The effect of iron loading on E-cadherin expression in SW480 and Caco-2 cell lines was examined by promoter assays, real time PCR and western blotting.<h4>Results</h4>Perl's staining showed increased iron in colorectal cancers, and there was a corresponding overexpression of components of the intracellular iron import machinery (DCYTB, DMT1, and TfR1). The iron exporter FPN was also overexpressed, but its intracellular location, combined with reduced HEPH levels, suggests reduced iron efflux in the majority of colorectal cancers examined. Loss of HEPH and FPN expression was associated with more advanced disease. Iron loading Caco-2 and SW480 cells caused cellular proliferation and E-cadherin repression.<h4>Conclusions</h4>Progression to colorectal cancer is associated with increased expression in iron import proteins and a block in iron export due to decreased expression and aberrant localisation of HEPH and FPN, respectively. This results in increased intracellular iron which may induce proliferation and repress cell adhesion.

Also flagged:antithrombin IIIprotein CsepsisPCdeath
Journal Article 2006-04-25 ✓ 5 Snippets Lauterbach R, Pawlik D, Radziszewska R, Woźniak J, Rytlewski K.
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…plasma antithrombin III (ATIII) and protein C…

….<h4>Observations</h4>Both theATIIIand PC concentrations…

…values of plasmaATIIIand PC were…

…significant (respectively, forATIIIP=0.003 and for…

…However, plasmaATIIIconcentration, evaluated in…

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<h4>Objective</h4>The aim of this prospective, observational study was to establish the prognostic values of plasma antithrombin III (ATIII) and protein C (PC) functional levels, determined in 150 neonates with suspected late-onset sepsis.<h4>Observations</h4>Both the ATIII and PC concentrations were significantly lower in neonates with sepsis, either confirmed or not confirmed by blood culture, than data obtained in infants with excluded disease. The lowest values of plasma ATIII and PC were observed in neonates who had died in the course of sepsis. The differences between survivors and non-survivors were statistically significant (respectively, for ATIII P=0.003 and for PC P=0.00002). A highly statistically significant correlation (P=0.0016) between plasma PC functional level and risk of death was found in patients with sepsis. However, plasma ATIII concentration, evaluated in the same group of patients, did not correlate with the occurrence of death.<h4>Conclusion</h4>We concluded that the measurement of plasma ATIII and, especially, PC levels may facilitate the recognition of sepsis and, with respect to PC, may have a prognostic value. Plasma PC functional concentration below 10% might be the indication for supplementation of PC concentrate.

Also flagged:Hepatopulmonary syndromechronic liver diseaseliver diseasesHPSliver cirrhosischronic hepatitis
Journal Article 2006-04-25 ✓ 1 Snippet Deibert P, Allgaier HP, Loesch S, Müller C, Olschewski M, Hamm H, Maier KP, Blum HE.
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…Rare aetiologies werehemochromatosis, Wilson's disease, primary…

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<h4>Background</h4>Hepatopulmonary syndrome (HPS) is a rare complication of liver diseases of different etiologies and may indicate a poor prognosis. Therefore, a simple non-invasive screening method to detect HPS would be highly desirable. In this study pulse oximetry was evaluated to identify patients with HPS.<h4>Methods</h4>In 316 consecutive patients with liver cirrhosis (n = 245), chronic hepatitis (n = 69) or non-cirrhotic portal hypertension (n = 2) arterial oxygen saturation (SaO2) was determined using a pulse oximeter. In patients with SaO2 < or = 92% in supine position and/or a decrease of > or = 4% after change from supine to upright position further diagnostic procedures were performed, including contrast-enhanced echocardiography and perfusion lung scan.<h4>Results</h4>Seventeen patients (5.4%) had a pathological SaO2. Four patients (1.3%) had HPS. HPS patients had a significant lower mean SaO2 in supine (89.7%, SD 5.4 vs. 96.0%, SD 2.3; p = 0.003) and upright position (84.3%, SD 5.0 vs. 96.0%, SD 2.4; p = 0.001) and had a lower mean PaO2 (56.2 mm Hg, SD 15.2 vs. 71.2 mm Hg, SD 20.2; p = 0.02) as compared to patients without HPS. The mean deltaSaO2 (difference between supine and upright position) was 5.50 (SD 7) in HPS patients compared to non-HPS patients who showed no change (p = 0.001). There was a strong correlation between shunt volume and the SaO2 values (R = -0.94).<h4>Conclusion</h4>Arterial SaO2 determination in supine and upright position is a useful non-invasive screening test for HPS and correlates well with the intrapulmonary shunt volume.

Also flagged:serotoninmonoamine transportersserotonin transporter-monoamine oxidase AMAOA
Journal Article 2006-04-25 ✓ 5 Snippets Mössner R, Simantov R, Marx A, Lesch KP, Seif I.
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To assess the clearance of serotonin (5-HT) in the absence of the 5-HTT, we have generated double knockout mice lacking both the 5-HTT and the catabolizing enzyme monoamine oxidase A (MAOA).

…The serotonin transporter (5-HTT) is the molecular…

…absence of the5-HTT, we have generated…

…lacking both the5-HTTand the catabolizing…

…striatum of these MAOA/5-HTTdouble knockout mice.…

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Gene targeting approaches greatly facilitate insight into the functioning of monoamine transporters, the targets of potent antidepressants. The serotonin transporter (5-HTT) is the molecular target of a large number of antidepressants. To assess the clearance of serotonin (5-HT) in the absence of the 5-HTT, we have generated double knockout mice lacking both the 5-HTT and the catabolizing enzyme monoamine oxidase A (MAOA). We found aberrant 5-HT accumulation in the striatum of these MAOA/5-HTT double knockout mice. By additional ablation of the dopamine transporter (DAT), this aberrant 5-HT accumulation was abolished in MAOA/5-HTT/DAT triple knockout mice. Thus, aberrant uptake of 5-HT occurs in dopaminergic terminals under conditions of elevated 5-HT levels, and this aberrant uptake is mediated by the DAT. These findings have important consequences for antidepressant therapy, since during treatment of depression with selective serotonin reuptake inhibitors, clearance of 5-HT by dopaminergic neurons may reduce the desired therapeutic elevation of extracellular 5-HT levels. This provides a molecular rationale for improving antidepressant efficacy by additional pharmacological inhibition of the DAT.

Also flagged:genetic disordersautosomeschromosomeorganellesnucleusextracellular matrix
Journal Article 2006-04-25 No Snippets Franke L, van Bakel H, Fokkens L, de Jong ED, Egmont-Petersen M, Wijmenga C.
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Most common genetic disorders have a complex inheritance and may result from variants in many genes, each contributing only weak effects to the disease. Pinpointing these disease genes within the myriad of susceptibility loci identified in linkage studies is difficult because these loci may contain hundreds of genes. However, in any disorder, most of the disease genes will be involved in only a few different molecular pathways. If we know something about the relationships between the genes, we can assess whether some genes (which may reside in different loci) functionally interact with each other, indicating a joint basis for the disease etiology. There are various repositories of information on pathway relationships. To consolidate this information, we developed a functional human gene network that integrates information on genes and the functional relationships between genes, based on data from the Kyoto Encyclopedia of Genes and Genomes, the Biomolecular Interaction Network Database, Reactome, the Human Protein Reference Database, the Gene Ontology database, predicted protein-protein interactions, human yeast two-hybrid interactions, and microarray co-expressions. We applied this network to interrelate positional candidate genes from different disease loci and then tested 96 heritable disorders for which the Online Mendelian Inheritance in Man database reported at least three disease genes. Artificial susceptibility loci, each containing 100 genes, were constructed around each disease gene, and we used the network to rank these genes on the basis of their functional interactions. By following up the top five genes per artificial locus, we were able to detect at least one known disease gene in 54% of the loci studied, representing a 2.8-fold increase over random selection. This suggests that our method can significantly reduce the cost and effort of pinpointing true disease genes in analyses of disorders for which numerous loci have been reported but for which most of the genes are unknown.

Also flagged:arachidonic- and docosahexaenoic- acidlong chain polyunsaturated fatty acidsmetabolismcarbohydrateamino acidcell proliferation
Journal Article 2006-04-20 No Snippets Berger A, Roberts MA, Hoff B.
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<h4>Introduction</h4>Herein, we expand our previous work on the effects of long chain polyunsaturated fatty acids (LC-PUFA) on the murine hepatic transcriptome using novel statistical and bioinformatic approaches for evaluating microarray data. The analyses focuses on key differences in the transcriptomic response that will influence metabolism following consumption of FUNG (rich in 20:4n6), FISH (rich in 20:5n3, 22:5n3, and 22:6n3) and COMB, the combination of the two.<h4>Results</h4>Using a variance-stabilized F-statistic, 371 probe sets (out of 13 K probe sets in the Affymetrix Mu11K chip set) were changed by dietary treatment (P < 0.001). Relative to other groups, COMB had unique affects on murine hepatic transcripts involved in cytoskeletal and carbohydrate metabolism; whereas FUNG affected amino acid metabolism via CTNB1 signaling. All three diets affected transcripts linked to apoptosis and cell proliferation, with evidence FISH may have increased apoptosis and decreased cell proliferation via various transcription factors, kinases, and phosphatases. The three diets affected lipid transport, lipoprotein metabolism, and bile acid metabolism through diverse pathways. Relative to other groups, FISH activated cyps that form hydroxylated fatty acids known to affect vascular tone and ion channel activity. FA synthesis and delta 9 desaturation were down regulated by COMB relative to other groups, implying that a FA mixture of 20:4n6, 20:5n3, and 22:6n3 is most effective at down regulating synthesis, via INS1, SREBP, PPAR alpha, and TNF signaling. Heme synthesis and the utilization of heme for hemoglobin production were likely affected by FUNG and FISH. Finally, relative to other groups, FISH increased numerous transcripts linked to combating oxidative such as peroxidases, an aldehyde dehydrogenase, and heat shock proteins, consistent with the major LC-PUFA in FISH (20:5n3, 22:5n3, 22:6n3) being more oxidizable than the major fatty acids in FUNG (20:4n6).<h4>Conclusion</h4>Distinct transcriptomic, signaling cascades, and predicted affects on murine liver metabolism have been elucidated for 20:4n6-rich dietary oils, 22:6n3-rich oils, and a surprisingly distinct set of genes were affected by the combination of the two. Our results emphasize that the balance of dietary n6 and n3 LC-PUFA provided for infants and in nutritional and neutraceutical applications could have profoundly different affects on metabolism and cell signaling, beyond that previously recognized.

Also flagged:Hereditary hemochromatosisiron-overload diseasesHHsynthesisironHepcidin
Journal Article 2006-04-20 ✓ 3 Snippets Swinkels DW, Janssen MC, Bergmans J, Marx JJ.
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Since the discovery of the hemochromatosis gene (HFE) in 1996, several novel gene defects have been detected, explaining the mechanism and diversity of iron-overload diseases.

…discovery of thehemochromatosisgene (HFE) in…

…the hemochromatosis gene (HFE) in 1996, several…

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Since the discovery of the hemochromatosis gene (HFE) in 1996, several novel gene defects have been detected, explaining the mechanism and diversity of iron-overload diseases. At least 4 main types of hereditary hemochromatosis (HH) have been identified. Surprisingly, genes involved in HH encode for proteins that all affect pathways centered around liver hepcidin synthesis and its interaction with ferroportin, an iron exporter in enterocytes and macrophages. Hepcidin concentrations in urine negatively correlate with the severity of HH. Cytokine-mediated increases in hepcidin appear to be an important causative factor in anemia of inflammation, which is characterized by sequestration of iron in the macrophage system. For clinicians, the challenge is now to diagnose HH before irreversible damage develops and, at the same time, to distinguish progressive iron overload from increasingly common diseases with only moderately increased body iron stores, such as the metabolic syndrome. Understanding the molecular regulation of iron homeostasis may be helpful in designing innovative and reliable DNA and protein tests for diagnosis. Subsequently, evidence-based diagnostic strategies must be developed, using both conventional and innovative laboratory tests, to differentiate between the various causes of distortions of iron metabolism. This review describes new insights in mechanisms of iron overload, which are needed to understand new developments in diagnostic medicine.

Also flagged:erythropoiesisstem cell developmenttranscription factorshigh-mobility-group (HMG) box transcription factoranemiacell condensation
Journal Article 2006-04-20 ✓ 5 Snippets Dumitriu B, Patrick MR, Petschek JP, Cherukuri S, Klingmuller U, Fox PL, Lefebvre V.
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Sox6cell-autonomously stimulates e…

…box transcription factorSox6as an important…

Sox6is highly expressed…

…and pups lackingSox6develop erythroid cells…

…hroid-specific inactivation ofSox6causes the same…

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Erythropoiesis, the essential process of hematopoietic stem cell development into erythrocytes, is controlled by lineage-specific transcription factors that determine cell fate and differentiation and by the hormone erythropoietin that stimulates cell survival and proliferation. Here we identify the Sry-related high-mobility-group (HMG) box transcription factor Sox6 as an important enhancer of definitive erythropoiesis. Sox6 is highly expressed in proerythroblasts and erythroblasts in the fetal liver, neonatal spleen, and bone marrow. Mouse fetuses and pups lacking Sox6 develop erythroid cells slowly and feature misshapen, short-lived erythrocytes. They compensate for anemia by elevating the serum level of erythropoietin and progressively enlarging their erythropoietic tissues. Erythroid-specific inactivation of Sox6 causes the same phenotype, demonstrating cell-autonomous roles for Sox6 in erythroid cells. Sox6 potentiates the ability of erythropoietin signaling to promote proerythroblast survival and has an effect additive to that of erythropoietin in stimulating proerythroblast and erythroblast proliferation. Sox6 also critically facilitates erythroblast and reticulocyte maturation, including hemoglobinization, cell condensation, and enucleation, and ensures erythrocyte cytoskeleton long-term stability. It does not control adult globin and erythrocyte cytoskeleton genes but acts by stabilizing filamentous actin (F-actin) levels. Sox6 thus enhances erythroid cell development at multiple levels and thereby ensures adequate production and quality of red blood cells.

Also flagged:chromosomearachidonate5-lipoxygenaseatherosclerosisaortic aneurysmsLipoxygenase
Journal Article 2006-04-19 No Snippets Ghazalpour A, Wang X, Lusis AJ, Mehrabian M.
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We previously mapped a locus on chromosome 6 with a large effect (LOD > 6) on aortic lesion size in a (C57BL/6J x CAST/Ei) F(2) cross and identified arachidonate 5-lipoxygenase (5LO) as a candidate gene in this region. Subsequent studies with the 5LO knockout model showed effects on atherosclerosis and aortic aneurysms. We now report detailed genetic analysis of the chromosome 6 locus. We created a panel of overlapping and reciprocal subcongenic lines from the B6.CAST Ldlr(-/-) chromosome 6 congenic strain (CON6.Ldlr(-/-)) and analyzed aortic lesion size in different subcongenic lines. Our results revealed that there are at least two subregions, designated as Ath37 and Ath38 that affect the size of aortic lesions independently of 5LO. We also showed that homozygote 5LO null mice develop smaller atherosclerotic lesions. We conclude that the relation between the mouse chromosome 6 locus and atherosclerosis is complex and is due to at least two genes with large effects within this region. This complexity should be considered when interpreting results of knockout studies.

Also flagged:axonalcopulationaxonaxon growth conessax-1synapses
Journal Article 2006-04-19 ✓ 2 Snippets Jia L, Emmons SW.
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… that the UNC-6/netrin-UNC-40/DCCpathway provides the…

DCC

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We have studied how a set of male-specific sensory neurons in Caenorhabditis elegans establish axonal connections during postembryonic development. In the adult male, 9 bilateral pairs of ray sensory neurons innervate an acellular fan that serves as a presumptive tactile and olfactory organ during copulation. We visualized ray axon commissures with a ray neuron-specific reporter gene and studied both known and new mutations that affect the establishment of connections to the pre-anal ganglion. We found that the UNC-6/netrin-UNC-40/DCC pathway provides the primary dorsoventral guidance cue to ray axon growth cones. Some axon growth cones also respond to an anteroposterior cue, following a segmented pathway, and most or all also have a tendency to fasciculate. Two newly identified genes, rax-1 and rax-4, are highly specific to the ray neurons and appear to be required for ray axon growth cones to respond to the dorsoventral cue. Among other genes we identified, rax-2 and rax-3 affect anteroposterior signaling or fate specification and rax-5 and rax-6 affect ray identities. We identified a mutation in sax-2 and show that the sax-2/Furry and sax-1/Tricornered pathway affects ectopic neurite outgrowth and establishment of normal axon synapses. Finally, we identified mutations in genes for muscle proteins that affect axon pathways by distorting the conformation of the body wall. Thus ray axon pathfinding relies on a variety of general and more ray neuron-specific genes and provides a potentially fruitful system for further studies of how migrating axon growth cones locate their targets. This system is applicable to the study of mechanisms underlying topographic mapping of sensory neurons into target circuitry where the next stage of information processing is carried out.

Also flagged:Ca2+Voltage-dependent Ca(2+) channelsCa(2+) channel-parallel fiber Purkinje cellsynapse
Journal Article 2006-04-19 No Snippets Osanai M, Saegusa H, Kazuno AA, Nagayama S, Hu Q, Zong S, Murakoshi T, Tanabe T.
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Voltage-dependent Ca(2+) channels play important roles in cerebellar functions including motor coordination and learning. Since abundant expression of Ca(V)2.3 Ca(2+) channel gene in the cerebellum was detected, we searched for possible deficits in the cerebellar functions in the Ca(V)2.3 mutant mice. Behavioral analysis detected in delayed motor learning in rotarod tests in mice heterozygous and homozygous for the Ca(V)2.3 gene disruption (Ca(V)2.3+/- and Ca(V)2.3-/-, respectively). Electrophysiological analysis of mutant mice revealed perplexing results: deficit in long-term depression (LTD) at the parallel fiber Purkinje cell synapse in Ca(V)2.3+/- mice but apparently normal LTD in Ca(V)2.3-/- mice. On the other hand, the number of spikes evoked by current injection in Purkinje cells under the current-clamp mode decreased in Ca(V)2.3 mutant mice in a gene dosage-dependent manner, suggesting that Ca(V)2.3 channel contributed to spike generation in Purkinje cells. Thus, Ca(V)2.3 channel seems to play some roles in cerebellar functions.

Also flagged:serotonin transporterSLC6A4autismHyperserotonemiaserotonintransporter
Journal Article 2006-04-17 ✓ 3 Snippets Ramoz N, Reichert JG, Corwin TE, Smith CJ, Silverman JM, Hollander E, Buxbaum JD.
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<h4>Background</h4>The serotonin transporter (5-HTT) has long been considered likely to play a role in autism.

…h4>The serotonin transporter (5-HTT) has long been…

…variants of the5-HTTgene, SLC6A4, especially…

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<h4>Background</h4>The serotonin transporter (5-HTT) has long been considered likely to play a role in autism. Hyperserotonemia has been consistently found in a proportion of autistic patients, and the use of selective serotonin reuptake inhibitors (SSRIs) can have a positive effect in treating some symptoms of autism. Specific variants of the 5-HTT gene, SLC6A4, especially the insertion-deletion 5-HTTLPR promoter locus, have been found to modulate its expression and transporter function.<h4>Methods</h4>We examined the transmission of the short or long allele of 5-HTTLPR locus to affected individuals, using a large cohort of 352 families. In addition, we screened five single nucleotide polymorphisms (SNPs) in the 5' region of SLC6A4 previously reported to be positively associated with autism, as well as 4 additional SNPs also in the 5' region.<h4>Results</h4>No association of the 5-HTTLPR locus with autism was found. Furthermore, no evidence for association of any of the nine SNPs covering the SLC6A4 gene, or any of their haplotypes, was observed in our study. Using obsessive-compulsive behaviors (OCB), severe OCBs or rigid-compulsive subsets of our cohort gave the same negative results.<h4>Conclusions</h4>SLC6A4 variants do not appear to be significantly involved in the liability to autism.

Also flagged:BSdeathventricular tachycardiaVentricular FibrillationBrugada Syndromelong QT syndrome
Journal Article 2006-04-17 No Snippets Castro Hevia J, Antzelevitch C, Antzelevitch C, Tornés Bárzaga F, Dorantes Sánchez M, Dorticós Balea F, Zayas Molina R, Quiñones Pérez MA, Fayad Rodríguez Y.
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<h4>Objectives</h4>Our objective in this study was to evaluate Tpeak-Tend interval (Tp-e) and other electrocardiographic parameters as risk factors for recurrence of life-threatening cardiac events in patients with the Brugada syndrome (BS).<h4>Background</h4>The Tp-e interval in the electrocardiogram (ECG) has been reported to predict life-threatening arrhythmias in the long QT syndrome.<h4>Methods</h4>Twenty-nine patients with the ECG pattern of BS and 29 healthy age- and gender-matched controls were studied. The follow-up period was 42.65 +/- 24.42 months (range 11 to 108 months).<h4>Results</h4>Upon presentation, five patients had suffered aborted sudden death, five syncope, and two presyncope. Eleven patients with the ECG pattern of BS had a prolonged (>460 ms) QTc in V2 but usually not in inferior or left leads. No patient had abnormally prolonged QT dispersion. Programmed electrical stimulation induced ventricular tachycardia/fibrillation in 5 out of 26 patients. Inducibility did not predict recurrence of events. Cardioverter-defibrillators were implanted in 14 patients (all symptomatic and two asymptomatic). During follow-up, nine symptomatic patients experienced recurrences. Previous cardiac events and a QTc >460 ms in V2 were significant risk factors (p = 0.00002 and p = 0.03, respectively). Tp-e and Tp-e dispersion were significantly prolonged in patients with recurrences versus patients without events (104.4 and 35.6 ms vs. 87.4 and 23.2 ms; p = 0.006 and p = 0.03, respectively) or controls (90.7 and 17.9 ms; p = 0.02 and p = 0.001, respectively).<h4>Conclusions</h4>Our study demonstrates significant correlation between previous events, QTc >460 ms in V2, Tp-e, and Tp-e dispersion and occurrence of life-threatening arrhythmic events, suggesting that these parameters may be useful in risk stratification of patients with the Brugada syndrome.

Also flagged:Huntington's diseaseHDCushingsyndromemuscular atrophymineral
Journal Article 2006-04-13 No Snippets Björkqvist M, Petersén A, Bacos K, Isaacs J, Norlén P, Gil J, Popovic N, Sundler F, Bates GP, Tabrizi SJ, Brundin P, Mulder H.
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Huntington's disease (HD) is characterized by a triad of motor, psychiatric and cognitive symptoms. Although many of these symptoms are likely to be related to central nervous system pathology, others may be due to changes in peripheral tissues. The R6/2 mouse, a transgenic model of HD expressing exon 1 of the human HD gene, develops progressive alterations in the hypothalamic-pituitary-adrenal axis, reminiscent of a Cushing-like syndrome. We observed muscular atrophy, reduced bone mineral density, abdominal fat accumulation and insulin resistance in the mice. All these changes could be consequences of increased glucocorticoid levels. Indeed, hypertrophy of the adrenal cortex and a progressive increase in serum and urine corticosterone levels were found in R6/2 mice. In addition, the intermediate pituitary lobe was markedly enlarged and circulating adreno-corticotrophic hormone (ACTH) increased. Under normal conditions dopamine represses the ACTH expression. In the R6/2 mice, however, the expression of pituitary dopamine D2 receptors was reduced by half, possibly explaining the increase in ACTH. Urinary samples from 82 HD patients and 68 control subjects were analysed for cortisol: in accord with the observations in the R6/2 mice, urinary cortisol increased in parallel with disease progression. This progressive increase in cortisol may contribute to the clinical symptoms, such as muscular wasting, mood changes and some of the cognitive deficits that occur in HD.

Also flagged:5-hydroxytryptamine transporterpulmonary hypertensionidiopathic pulmonary hypertensionserotonin5-HT transporter5
Journal Article 2006-04-13 ✓ 5 Snippets Guignabert C, Izikki M, Tu LI, Li Z, Zadigue P, Barlier-Mur AM, Hanoun N, Rodman D, Hamon M, Adnot S, Eddahibi S.
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One intrinsic abnormality of pulmonary artery smooth muscle cells (PA-SMCs) in human idiopathic pulmonary hypertension (iPH) is an exaggerated proliferative response to internalized serotonin (5-HT) caused by increased expression of the 5-HT transporter (5-HTT).

These results show that increased 5-HTT expression in PA-SMCs, to a level close to that found in human iPH, lead to PH in mice.

They further support a central role for 5-HTT in the pathogenesis of PH, making 5-HTT a potential therapeutic target.

To investigate whether 5-HTT overexpression in PA-SMCs is sufficient to produce PH, we generated transgenic mice overexpressing 5-HTT under the control of the SM22 promoter.

…the 5-HT transporter (5-HTT).…

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One intrinsic abnormality of pulmonary artery smooth muscle cells (PA-SMCs) in human idiopathic pulmonary hypertension (iPH) is an exaggerated proliferative response to internalized serotonin (5-HT) caused by increased expression of the 5-HT transporter (5-HTT). To investigate whether 5-HTT overexpression in PA-SMCs is sufficient to produce PH, we generated transgenic mice overexpressing 5-HTT under the control of the SM22 promoter. Studies in SM22-LacZ(+) mice showed that the transgene was expressed predominantly in SMCs of pulmonary and systemic vessels. Compared with wild-type mice, SM22-5-HTT(+) mice exhibited a 3- to 4-fold increase in lung 5-HTT mRNA and protein, together with increased lung 5-HT uptake activity, but no changes in platelet 5-HTT activity or blood 5-HT levels. At 8 weeks of age, SM22-5-HTT(+) mice exhibited PH, with marked increases in right ventricular systolic pressure (RVSP), right ventricle/left ventricle+septum ratio, and muscularization of distal pulmonary vessels, but no changes in systemic arterial pressure. PH worsened with age. Except a marked decrease in Kv channels, no changes in the lung expression of mediators of pulmonary vascular remodeling were observed in SM22-5-HTT(+) mice. Compared with wild-type mice, SM22-5-HTT(+) mice showed depressed hypoxic pulmonary vasoconstriction contrasting with greater severity of hypoxia- or monocrotaline-induced PH. These results show that increased 5-HTT expression in PA-SMCs, to a level close to that found in human iPH, lead to PH in mice. They further support a central role for 5-HTT in the pathogenesis of PH, making 5-HTT a potential therapeutic target.

Also flagged:Netrin-1angiogenesisERK1axonaleNOSantibody
Journal Article 2006-04-12 ✓ 5 Snippets Nguyen A, Cai H.
In-Text Gene Mentions

…angiogenesis via aDCC-dependent ERK1/2-eNOS feed-fo…

…occurs via aDCC-dependent, ERK1/2-eNOS feed-f…

…was inhibited byDCCantibody, DCC small…

…by DCC antibody,DCCsmall interfering RNA…

DCC

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Netrin-1 is critical for axonal pathfinding which shares similarities with formation of vascular network. Here we report that netrin-1 induction of angiogenesis is mediated by an increase in endothelial nitric oxide (NO*) production, which occurs via a DCC-dependent, ERK1/2-eNOS feed-forward mechanism. Exposure of mature aortic endothelial cells to netrin-1 resulted in a potent, dose-dependent increase in NO* production, detected by electron spin resonance. Scavenging NO* with 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO) abolished netrin-1 stimulated angiogenesis. Netrin-1-stimulated NO* production or angiogenesis was inhibited by DCC antibody, DCC small interfering RNA (siRNA), specific inhibitors (PD98059, U0126), or siRNAs for MEK1/2. PTIO attenuated ERK1/2 phosphorylation, indicating a feed-forward mechanism. Netrin-1 induced a time-dependent phosphorylation of eNOS(s1179, s116) and a rapid dephosphorylation of eNOS(t497). Only eNOS(s1179) was sensitive to U0126 or PTIO. These data characterized a mechanism whereby netrin-1 promotes angiogenesis, which may broadly relate to cardiovascular, neuronal and cancer physiology.

Also flagged:tumorsporadic breast cancercancerhereditary breast/ovarian cancer syndromebreast cancersBRCA1
Journal Article 2006-04-12 No Snippets Weber F, Shen L, Fukino K, Patocs A, Mutter GL, Caldes T, Eng C.
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We have shown that the tumor microenvironment of sporadic breast cancer is diverse in genetic alterations and contributes to the cancer phenotype. The dynamic morphology of the mammary gland might be of special interest in hereditary breast/ovarian cancer syndrome (HBOC). We hypothesized that hotspots of loss of heterozygosity or allelic imbalance (LOH/AI) within the tumor stroma of BRCA1/2-related breast cancers provide an impaired mammary stroma that could facilitate later malignant transformation of the breast epithelium. We conducted a total genome LOH/AI scan of DNA derived from the epithelium and stroma of 51 BRCA1/2-related breast cancers, using 372 microsatellite markers. We compared these data with those from a set of 134 sporadic breast cancers. HBOC-related breast cancers accumulated significantly more genetic alterations than did sporadic breast cancers. BRCA1/2-related breast cancer stroma showed LOH/AI at 59.7% of all loci analyzed, similar to the average frequency of LOH/AI observed in the epithelium (66.2%). This is remarkably different from sporadic breast cancers, for which the average epithelial LOH/AI frequency (36.7%) far exceeds the average stromal LOH/AI frequency (28.4%) (P=.03). We identified 11 hotspot loci of LOH/AI in the BRCA1/2 stroma, encompassing genes such as POLD1, which functions in DNA replication, and SDHB. In a subset of samples, enriched for BRCA1 cases, we found 45.0% overall LOH/AI in the stroma, which was significantly higher than the 41.8% LOH/AI observed in corresponding epithelium (P=.04). Together, our data indicate that, in HBOC-related breast cancers, the accumulation of genomic instability in the cancer stroma coincides with that in the neoplastic epithelium, and we postulate that such a genetically unstable stroma might facilitate a microenvironment that functions as a landscaper that promotes genomic instability in the epithelium and, subsequently, neoplastic transformation.

Also flagged:ribosomal protein L15cell proliferationribosomeRPL15gastric cancerCyclin D1
Journal Article 2006-04-11 ✓ 2 Snippets Wang H, Zhao LN, Li KZ, Ling R, Li XJ, Wang L.
In-Text Gene Mentions

It was believed that mutation or amplification of oncogenes c-ras, c-erbB-2, K-sam, c-met, and c-myc and inactivation of tumor suppressor genes p53, adenomatosis polyposis coli (APC), deleted in colorectal carcinomas (DCC), and retinoblastoma (RBI) are related to the development of gastric cancer.

…in colorectal carcinomas (DCC), and retinoblastoma (RBI)…

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<h4>Background</h4>Ribosomal proteins are the components of ribosome, which also exhibit various secondary functions in DNA repair, apoptosis, drug resistance and proliferation. In our previous study of microarray, ribosomal protein L15 (RPL15) was identified as an upregulated gene in gastric cancer.<h4>Methods</h4>We investigated the expression of ribosomal protein L15 in gastric cancer and the effect of RPL15 on proliferation of gastric cancer.<h4>Results</h4>It was found that the expression of RPL15 was markedly up-regulated in gastric cancer tissues. RPL15 was also highly expressed in gastric cancer cell lines AGS, MKN45, MKN28, SGC7901 and KATOIII. Inhibition of RPL15 expression by siRNA vector transfection suppressed the growth of SGC7901 cells significantly, which was independent of the expression of Cyclin D1 and B1. Down-regulation of RPL15 expression inhibited SGC7901 cell growth in soft agar and its tumorigenicity in nude mice.<h4>Conclusion</h4>RPL15 promotes cell proliferation and may be a potential target for anticancer therapy of gastric cancer.

Also flagged:SteapIroncoppertransmembraneferrireductaseSteap3
Journal Article 2006-04-11 ✓ 1 Snippet Ohgami RS, Campagna DR, McDonald A, Fleming MD.
In-Text Gene Mentions

hemochromatosis

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Iron and copper are essential for all organisms, assuming critical roles as cofactors in many enzymes. In eukaryotes, the transmembrane transport of these elements is a highly regulated process facilitated by the single electron reduction of each metal. Previously, we identified a mammalian ferrireductase, Steap3, critical for erythroid iron homeostasis. Now, through homology, expression, and functional studies, we characterize all 4 members of this protein family and demonstrate that 3 of them, Steap2, Steap3, and Steap4, are not only ferrireductases but also cupric reductases that stimulate cellular uptake of both iron and copper in vitro. Finally, the pattern of tissue expression and subcellular localization of these proteins suggest they are physiologically relevant cupric reductases and ferrireductases in vivo.

Also flagged:Bone morphogenetic proteinHepcidinironanemiaHFE2HJV
Journal Article 2006-04-09 ✓ 2 Snippets Babitt JL, Huang FW, Wrighting DM, Xia Y, Sidis Y, Samad TA, Campagna JA, Chung RT, Schneyer AL, Woolf CJ, Andrews NC, Lin HY.
In-Text Gene Mentions

…mutants associated withhemochromatosishave impaired BMP…

…HFE2 mutations causehemochromatosis: hemojuvelin dysfunction decr…

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Hepcidin is a key regulator of systemic iron homeostasis. Hepcidin deficiency induces iron overload, whereas hepcidin excess induces anemia. Mutations in the gene encoding hemojuvelin (HFE2, also known as HJV) cause severe iron overload and correlate with low hepcidin levels, suggesting that hemojuvelin positively regulates hepcidin expression. Hemojuvelin is a member of the repulsive guidance molecule (RGM) family, which also includes the bone morphogenetic protein (BMP) coreceptors RGMA and DRAGON (RGMB). Here, we report that hemojuvelin is a BMP coreceptor and that hemojuvelin mutants associated with hemochromatosis have impaired BMP signaling ability. Furthermore, BMP upregulates hepatocyte hepcidin expression, a process enhanced by hemojuvelin and blunted in Hfe2-/- hepatocytes. Our data suggest a mechanism by which HFE2 mutations cause hemochromatosis: hemojuvelin dysfunction decreases BMP signaling, thereby lowering hepcidin expression.

Also flagged:L-type Ca2+ironoverloadhemosiderosisPrimary hemochromatosis
Journal Article 2006-04-08 ✓ 3 Snippets Oudit GY, Trivieri MG, Khaper N, Liu PP, Backx PH.
In-Text Gene Mentions

Next to mutations in HFE, mutations in ferroportin are the most common cause of hemochromatosis [7, 38, 39].

…as primary (hereditary)hemochromatosisand secondary iron…

…mortality in primaryhemochromatosispatients.…

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Excessive body iron or iron overload occurs under conditions such as primary (hereditary) hemochromatosis and secondary iron overload (hemosiderosis), which are reaching epidemic levels worldwide. Primary hemochromatosis is the most common genetic disorder with an allele frequency greater than 10% in individuals of European ancestry, while hemosiderosis is less common but associated with a much higher morbidity and mortality. Iron overload leads to iron deposition in many tissues especially the liver, brain, heart and endocrine tissues. Elevated cardiac iron leads to diastolic dysfunction, arrhythmias and dilated cardiomyopathy, and is the primary determinant of survival in patients with secondary iron overload as well as a leading cause of morbidity and mortality in primary hemochromatosis patients. In addition, iron-induced cardiac injury plays a role in acute iron toxicosis (iron poisoning), myocardial ischemia-reperfusion injury, Friedreich ataxia and neurodegenerative diseases. Patients with iron overload also routinely suffer from a range of endocrinopathies, including diabetes mellitus and anterior pituitary dysfunction. Despite clear connections between elevated iron and clinical disease, iron transport remains poorly understood. While low-capacity divalent metal and transferrin-bound transporters are critical under normal physiological conditions, L-type Ca2+ channels (LTCC) are high-capacity pathways of ferrous iron (Fe2+) uptake into cardiomyocytes especially under iron overload conditions. Fe2+ uptake through L-type Ca2+ channels may also be crucial in other excitable cells such as pancreatic beta cells, anterior pituitary cells and neurons. Consequently, LTCC blockers represent a potential new therapy to reduce the toxic effects of excess iron.

Also flagged:histonenucleosomesaltchromatingene expressionOligonucleosome
Journal Article 2006-04-07 ✓ 1 Snippet Arya G, Zhang Q, Schlick T.
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linker histones

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We describe a new mesoscopic model of oligonucleosomes that incorporates flexible histone tails. The nucleosome cores are modeled using the discrete surface-charge optimization model, which treats the nucleosome as an electrostatic surface represented by hundreds of point charges; the linker DNAs are treated using a discrete elastic chain model; and the histone tails are modeled using a bead/chain hydrodynamic approach as chains of connected beads where each bead represents five protein residues. Appropriate charges and force fields are assigned to each histone chain so as to reproduce the electrostatic potential, structure, and dynamics of the corresponding atomistic histone tails at different salt conditions. The dynamics of resulting oligonucleosomes at different sizes and varying salt concentrations are simulated by Brownian dynamics with complete hydrodynamic interactions. The analyses demonstrate that the new mesoscopic model reproduces experimental results better than its predecessors, which modeled histone tails as rigid entities. In particular, our model with flexible histone tails: correctly accounts for salt-dependent conformational changes in the histone tails; yields the experimentally obtained values of histone-tail mediated core/core attraction energies; and considers the partial shielding of electrostatic repulsion between DNA linkers as a result of the spatial distribution of histone tails. These effects are crucial for regulating chromatin structure but are absent or improperly treated in models with rigid histone tails. The development of this model of oligonucleosomes thus opens new avenues for studying the role of histone tails and their variants in mediating gene expression through modulation of chromatin structure.

Also flagged:malariaATPasenucleic acidsamino acidp68DNA helicase 60
Journal Article 2006-04-07 No Snippets Tuteja R, Pradhan A.
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The causative agent for the most fatal form of malaria, Plasmodium falciparum, has developed insecticide and drug resistance with time. Therefore combating this disease is becoming increasingly difficult and this calls for finding alternate ways to control malaria. One of the feasible ways could be to find out inhibitors/drugs specific for the indispensable enzymes of malaria parasite such as helicases. These helicases, which contain intrinsic nucleic acid-dependent ATPase activity, are capable of enzymatically unwinding energetically stable duplex nucleic acids into single-stranded templates and are required for all the nucleic acid transactions. Most of the helicases contain a set of nine extremely conserved amino acid sequences, which are called 'helicase motifs'. Due to the presence of the DEAD (Asp-Glu-Ala-Asp) in one of the conserved motifs, this family is also known as the 'DEAD-box' family. In this review, using bioinformatic approach, we describe the 'DEAD-box' helicases of malaria parasite P. falciparum. An in depth analysis shows that the parasite contains 22 full-length genes, some of which are homologues of well-characterized helicases of this family from other organisms. Recently we have cloned and characterized the first member of this family, which is a homologue of p68 and is expressed during the schizont stage of the development of the parasite [Pradhan, A., Chauhan, V.S., Tuteja, R., 2005a. A novel 'DEAD-box' DNA helicase from Plasmodium falciparum is homologous to p68. Mol. Biochem. Parasitol. 140, 55-60.; Pradhan A., Chauhan V.S., Tuteja R., 2005b. Plasmodium falciparum DNA helicase 60 is a schizont stage specific, bipolar and dual helicase stimulated by PKC phosphorylation. Mol. Biochem. Parasitol. 144, 133-141.]. It will be really interesting to clone and characterize other members of the 'DEAD-box' family and understand their role in the replication and transmission of the parasite. These detailed studies may help to identify a parasite-specific enzyme, which could be a potential drug target to treat malaria. The various steps at which this probable drug can act are also discussed.

Also flagged:CystaminecysteamineBDNFHuntington diseaseneurodegenerative disorderHD
Journal Article 2006-04-06 ✓ 1 Snippet Borrell-Pagès M, Canals JM, Cordelières FP, Parker JA, Pineda JR, Grange G, Bryson EA, Guillermier M, Hirsch E, Hantraye P, Cheetham ME, Néri C, Alberch J, Brouillet E, Saudou F, Humbert S.
In-Text Gene Mentions

htt

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There is no treatment for the neurodegenerative disorder Huntington disease (HD). Cystamine is a candidate drug; however, the mechanisms by which it operates remain unclear. We show here that cystamine increases levels of the heat shock DnaJ-containing protein 1b (HSJ1b) that are low in HD patients. HSJ1b inhibits polyQ-huntingtin-induced death of striatal neurons and neuronal dysfunction in Caenorhabditis elegans. This neuroprotective effect involves stimulation of the secretory pathway through formation of clathrin-coated vesicles containing brain-derived neurotrophic factor (BDNF). Cystamine increases BDNF secretion from the Golgi region that is blocked by reducing HSJ1b levels or by overexpressing transglutaminase. We demonstrate that cysteamine, the FDA-approved reduced form of cystamine, is neuroprotective in HD mice by increasing BDNF levels in brain. Finally, cysteamine increases serum levels of BDNF in mouse and primate models of HD. Therefore, cysteamine is a potential treatment for HD, and serum BDNF levels can be used as a biomarker for drug efficacy.

Also flagged:glycopeptidevancomycineremomycinteicoplaninristocetin Acarbohydrate
Journal Article 2006-04-06 No Snippets Balzarini J, Keyaerts E, Vijgen L, Egberink H, De Clercq E, Van Ranst M, Printsevskaya SS, Olsufyeva EN, Solovieva SE, Preobrazhenskaya MN.
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Various semisynthetic derivatives of glycopeptide antibiotics including vancomycin, eremomycin, teicoplanin, ristocetin A and DA-40926 have been evaluated for their inhibitory activity against feline infectious peritonitis virus (FIPV) and human (SARS-CoV, Frankfurt-1 strain) coronavirus in cell culture in comparison with their activity against human immunodeficiency virus (HIV). Several glycopeptide derivatives modified with hydrophobic substituents showed selective antiviral activity. For the most active compounds, the 50% effective concentrations (EC(50)) were in the lower micromolar range. In general, removal of the carbohydrate parts of the molecules did not affect the antiviral activity of the compounds. Some compounds showed inhibitory activity against both, whereas other compounds proved inhibitory to either, FIPV or SARS-CoV. There was no close correlation between the EC(50) values of the glycopeptide derivatives for FIPV or SARS-CoV.

Also flagged:Inositolautophagylithiuminositol monophosphataseIMPasemammalian target of rapamycin
Journal Article 2006-04-06 No Snippets Sarkar S, Rubinsztein DC.
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We recently showed that lithium induces autophagy via inositol monophosphatase (IMPase) inhibition, leading to free inositol depletion and reduced myo-inositol-1,4, 5-triphosphate (IP3) levels. This represents a novel way of regulating mammalian autophagy, independent of the mammalian target of rapamycin (mTOR). Induction of autophagy by lithium led to enhanced clearance of autophagy substrates, like mutant huntingtin fragments and mutant alpha-synucleins, associated with Huntington's disease (HD) and some autosomal dominant forms of Parkinson's disease (PD), respectively. Similar effects were observed with a specific IMPase inhibitor and mood-stabilizing drugs that decrease inositol levels. This may represent a new therapeutic strategy for upregulating autophagy in the treatment of neurodegenerative disorders, where the mutant protein is an autophagy substrate. In this Addendum, we review these findings, and some of the speculative possibilities they raise.

Also flagged:NucleotideCancerTNFIL13FGL2PROCR
Journal Article 2006-04-05 No Snippets Cousin E, Deleuze JF, Genin E.
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<h4>Background</h4>The recent advances in genotyping and molecular techniques have greatly increased the knowledge of the human genome structure. Millions of polymorphisms are reported and freely available in public databases. As a result, there is now a need to identify among all these data, the relevant markers for genetic association studies. Recently, several methods have been published to select subsets of markers, usually Single Nucleotide Polymorphisms (SNPs), that best represent genetic polymorphisms in the studied candidate gene or region.<h4>Results</h4>In this paper, we compared four of these selection methods, two based on haplotype information and two based on pairwise linkage disequilibrium (LD). The methods were applied to the genotype data on twenty genes with different patterns of LD and different numbers of SNPs. A measure of the efficiency of the different methods to select SNPs was obtained by comparing, for each gene and under several single disease susceptibility models, the power to detect an association that will be achieved with the selected SNP subsets.<h4>Conclusion</h4>None of the four selection methods stands out systematically from the others. Methods based on pairwise LD information turn out to be the most interesting methods in a context of association study in candidate gene. In a context where the number of SNPs to be tested in a given region needs to be more limited, as in large-scale studies or wide genome scans, one of the two methods based on haplotype information, would be more suitable.

Also flagged:ALK1angiogenesisSmad2Smad3Smad1Smad5
Journal Article 2006-04-04 ✓ 1 Snippet Lux A, Salway F, Dressman HK, Kröner-Lux G, Hafner M, Day PJ, Marchuk DA, Garland J.
In-Text Gene Mentions

…, NF2 ,PLCL1).…

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<h4>Background</h4>TGF-beta1 is an important angiogenic factor involved in the different aspects of angiogenesis and vessel maintenance. TGF-beta signalling is mediated by the TbetaRII/ALK5 receptor complex activating the Smad2/Smad3 pathway. In endothelial cells TGF-beta utilizes a second type I receptor, ALK1, activating the Smad1/Smad5 pathway. Consequently, a perturbance of ALK1, ALK5 or TbetaRII activity leads to vascular defects. Mutations in ALK1 cause the vascular disorder hereditary hemorrhagic telangiectasia (HHT).<h4>Methods</h4>The identification of ALK1 and not ALK5 regulated genes in endothelial cells, might help to better understand the development of HHT. Therefore, the human microvascular endothelial cell line HMEC-1 was infected with a recombinant constitutively active ALK1 adenovirus, and gene expression was studied by using gene arrays and quantitative real-time PCR analysis.<h4>Results</h4>After 24 hours, 34 genes were identified to be up-regulated by ALK1 signalling. Analysing ALK1 regulated gene expression after 4 hours revealed 13 genes to be up- and 2 to be down-regulated. Several of these genes, including IL-8, ET-1, ID1, HPTPeta and TEAD4 are reported to be involved in angiogenesis. Evaluation of ALK1 regulated gene expression in different human endothelial cell types was not in complete agreement. Further on, disparity between constitutively active ALK1 and TGF-beta1 induced gene expression in HMEC-1 cells and primary HUVECs was observed.<h4>Conclusion</h4>Gene array analysis identified 49 genes to be regulated by ALK1 signalling and at least 14 genes are reported to be involved in angiogenesis. There was substantial agreement between the gene array and quantitative real-time PCR data. The angiogenesis related genes might be potential HHT modifier genes. In addition, the results suggest endothelial cell type specific ALK1 and TGF-beta signalling.

Also flagged:Sp1Huntington diseasetranscription factorsspecificitySpHD
Journal Article 2006-04-04 ✓ 5 Snippets Qiu Z, Norflus F, Singh B, Swindell MK, Buzescu R, Bejarano M, Chopra R, Zucker B, Benn CL, DiRocco DP, Cha JH, Ferrante RJ, Hersch SM.
In-Text Gene Mentions

…of Sp1 to Htt protein aggregation and neuronal cell death. We…

Interactions between mutant huntingtin (Htt) and a variety of transcription factors including specificity proteins (Sp) have been suggested as a central mechanism in Huntington disease (HD).

…between mutant huntingtin (Htt) and a variety…

…activity induced byHttin neurons that…

…of Sp1 toHttprotein aggregation and…

Show Full Abstract

Interactions between mutant huntingtin (Htt) and a variety of transcription factors including specificity proteins (Sp) have been suggested as a central mechanism in Huntington disease (HD). However, the transcriptional activity induced by Htt in neurons that triggers neuronal death has yet to be fully elucidated. In the current study, we characterized the relationship of Sp1 to Htt protein aggregation and neuronal cell death. We found increased levels of Sp1 in neuronal-like PC12 cells expressing mutant Htt, primary striatal neurons, and brain tissue of HD transgenic mice. Sp1 levels were also elevated when 3-nitropropionate (3-NP) was used to induce cell death in PC12 cells. To assess the effects of knocking down Sp1 in HD pathology, we used Sp1 siRNA, a heterozygous Sp1 knock-out mouse, and mithramycin A, a DNA-intercalating agent that inhibits Sp1 function. The three approaches consistently yielded reduced levels of Sp1 which ameliorated toxicity caused by either mutant Htt or 3-NP. In addition, when HD mice were crossed with Sp1 heterozygous knock-out mice, the resulting offspring did not experience the loss of dopamine D2 receptor mRNA characteristic of HD mice, and survived longer than their HD counterparts. Our data suggest that enhancement of transcription factor Sp1 contributes to the pathology of HD and demonstrates that its suppression is beneficial.

Also flagged:Huntington diseaseneurodegenerative disorderpolyglutamine
Journal Article 2006-04-04 ✓ 5 Snippets Li W, Serpell LC, Carter WJ, Rubinsztein DC, Huntington JA.
In-Text Gene Mentions

Huntington disease is an inherited neurodegenerative disorder that is caused by expanded CAG trinucleotide repeats, resulting in a polyglutamine stretch of >37 on the N terminus of the protein huntingtin (htt).

…the protein huntingtin (htt).…

httis a large…

…precise functions ofhttare not clear,…

…lethal phenotype inhttknock-out mice.…

Show Full Abstract

Huntington disease is an inherited neurodegenerative disorder that is caused by expanded CAG trinucleotide repeats, resulting in a polyglutamine stretch of >37 on the N terminus of the protein huntingtin (htt). htt is a large (347 kDa), ubiquitously expressed protein. The precise functions of htt are not clear, but its importance is underscored by the embryonic lethal phenotype in htt knock-out mice. Despite the fact that the htt gene was cloned 13 years ago, little is known about the properties of the full-length protein. Here we report the expression and preliminary characterization of recombinant full-length wild-type human htt. Our results support a model of htt composed entirely of HEAT repeats that stack to form an elongated superhelix.

Also flagged:ofgene expressionaxoncocaineaxon guidanceG-protein-coupled receptors
Journal Article 2006-04-04 ✓ 1 Snippet Jassen AK, Yang H, Miller GM, Calder E, Madras BK.
In-Text Gene Mentions

…EphrinA1, EphrinA5, EphB1,DCC, and Semaphorin3C, whereas…

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Axon guidance molecules, critical for neurodevelopment, are also implicated in morphological and other neurodaptative changes mediated by physiological or pharmacological events in adult brain. As an example, the psychostimulant cocaine markedly alters axon guidance molecules in adult brain of cocaine-treated rats. To decipher a potential link between drug-induced activation of G-protein-coupled receptors (GPCRs) and modulation of axon guidance molecules, we investigated whether GPCR activity in a SK-N-MC human neuroepithelioma cell line (which expresses low levels of D1 dopamine receptors) affects gene expression of axon guidance molecules (semaphorins, ephrins, netrins, and their receptors). Using real-time polymerase chain reaction, we identified 17 of 26 axon guidance molecules in these cells, with varying levels of expression. Forskolin, which raised intracellular cAMP levels 340%, increased EphA5, EphB2, and Neuropilin1 expression, paralleling reported changes in the rat hippocampus after cocaine treatment. The dopamine receptor agonist dihydrexidine, which raised cAMP levels 22%, promoted regulatory changes in EphrinA1, EphrinA5, EphB1, DCC, and Semaphorin3C, whereas (+/-)-6-chloro-7,8-dihydroxy-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine hydrobromide (SKF81297) altered EphA5, EphrinA1, EphrinA5, and neuropilin1. cAMP and other signal transduction pathways may regulate gene expression of axon guidance molecules, potentially linking monoamine receptor activation to signal transduction cascades, transcriptional regulation of axon guidance molecules, and alterations in neural networks.

Also flagged:Wnt5acell growthWntbindingnucleusT-cell factor
Journal Article 2006-04-04 ✓ 2 Snippets Mikels AJ, Nusse R.
In-Text Gene Mentions

This example is formed by the Netrins, ligands that can either attract or repel axons depending on whether they interact with the DCC (deleted in colorectal carcinoma) or UNC5 (UNCoordinated family member 5) families of receptors [54–56].

…interact with theDCC(deleted in colorectal…

Show Full Abstract

The Wnts comprise a large class of secreted proteins that control essential developmental processes such as embryonic patterning, cell growth, migration, and differentiation. In the most well-understood "canonical" Wnt signaling pathway, Wnt binding to Frizzled receptors induces beta-catenin protein stabilization and entry into the nucleus, where it complexes with T-cell factor/lymphoid enhancer factor transcription factors to affect the transcription of target genes. In addition to the canonical pathway, evidence for several other Wnt signaling pathways has accumulated, in particular for Wnt5a, which has therefore been classified as a noncanonical Wnt family member. To study the alternative mechanisms by which Wnt proteins signal, we purified the Wnt5a protein to homogeneity. We find that purified Wnt5a inhibits Wnt3a protein-induced canonical Wnt signaling in a dose-dependent manner, not by influencing beta-catenin levels but by downregulating beta-catenin-induced reporter gene expression. The Wnt5a signal is mediated by the orphan tyrosine kinase Ror2, is pertussis toxin insensitive, and does not influence cellular calcium levels. We show that in addition to its inhibitory function, Wnt5a can also activate beta-catenin signaling in the presence of the appropriate Frizzled receptor, Frizzled 4. Thus, this study shows for the first time that a single Wnt ligand can initiate discrete signaling pathways through the activation of two distinct receptors. Based on these and additional observations, we propose a model wherein receptor context dictates Wnt signaling output. In this model, signaling by different Wnt family members is not intrinsically regulated by the Wnt proteins themselves but by receptor availability.

Also flagged:oxygenchondrogenesisinsulinextracellularproteoglycanssynthesis
Journal Article 2006-04-03 ✓ 5 Snippets Chen L, Fink T, Ebbesen P, Zachar V.
In-Text Gene Mentions

hypoxia, including Ak4, Akt3, Col X, Fmod, Ier3, IGFbp4, MafF, Mxi1, Rcor2, Rras, Sox6, Tnni2

hypoxia, including Ak4, Akt3, Col X, Fmod, Ier3, IGFbp4, MafF, Mxi1, Rcor2, Rras, Sox6, Tnni2, Wnt5a, and Zfp313

hypoxia, including Ak4, Akt3, Col X, Fmod, Ier3, IGFbp4, MafF, Mxi1, Rcor2, Rras, Sox6, Tnni2, Wnt5a

hypoxia, including Ak4, Akt3, Col X, Fmod, Ier3, IGFbp4, MafF, Mxi1, Rcor2, Rras, Sox6

…Mxi1, Rcor2, Rras,Sox6, Tnni2, Wnt5a, and…

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The formation of cartilage takes place in vivo in an environment of reduced oxygen tension. To study the effect of hypoxia on the process of chondrogenesis, ATDC5 mouse chondroprogenitor cells were induced to differentiate by the addition of insulin and cultured under ambient and hypoxic conditions corresponding to 21% and 1% O2 in the gas phase, respectively. The production of extracellular proteoglycans as well as the transcriptional profile of 104 selected genes was determined by real-time RT-PCR. Hypoxia alone induced early chondrogenesis as evidenced by the synthesis of glycosaminoglycans and expression of aggrecan and collagen type II genes. Surprisingly, however, hypoxic incubation of insulin-treated cells delayed and suppressed the insulin-mediated early chondrogenesis and almost completely blocked hypertrophic differentiation. Analysis of the gene expression yielded several clues as to the mechanisms involved. In addition, a group of genes was identified that have not previously been associated with hypoxia, including Ak4, Akt3, Col X, Fmod, Ier3, IGFbp4, MafF, Mxi1, Rcor2, Rras, Sox6, Tnni2, Wnt5a, and Zfp313.

Also flagged:neogeninratpeptideCSTaxonsaxonal growth
Journal Article 2006-04-03 ✓ 1 Snippet Hata K, Fujitani M, Yasuda Y, Doya H, Saito T, Yamagishi S, Mueller BK, Yamashita T.
In-Text Gene Mentions

…and homologue ofDCC(deleted in colorectal…

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Repulsive guidance molecule (RGM) is a protein implicated in both axonal guidance and neural tube closure. We report RGMa as a potent inhibitor of axon regeneration in the adult central nervous system (CNS). RGMa inhibits mammalian CNS neurite outgrowth by a mechanism dependent on the activation of the RhoA-Rho kinase pathway. RGMa expression is observed in oligodendrocytes, myelinated fibers, and neurons of the adult rat spinal cord and is induced around the injury site after spinal cord injury. We developed an antibody to RGMa that efficiently blocks the effect of RGMa in vitro. Intrathecal administration of the antibody to rats with thoracic spinal cord hemisection results in significant axonal growth of the corticospinal tract and improves functional recovery. Thus, RGMa plays an important role in limiting axonal regeneration after CNS injury and the RGMa antibody offers a possible therapeutic agent in clinical conditions characterized by a failure of CNS regeneration.

Also flagged:HDACsneurodegenerative diseaseshistone acetyltransferaseshistone deacetylasesnucleusHAT
Journal Article 2006-04-01 No Snippets Saha RN, Pahan K.
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Gradual disclosure of the molecular basis of selective neuronal apoptosis during neurodegenerative diseases reveals active participation of acetylating and deacetylating agents during the process. Several studies have now successfully manipulated neuronal vulnerability by influencing the dose and enzymatic activity of histone acetyltransferases (HATs) and histone deacetylases (HDACs), enzymes regulating acetylation homeostasis within the nucleus, thus focusing on the importance of balanced acetylation status in neuronal vitality. It is now increasingly becoming clear that acetylation balance is greatly impaired during neurodegenerative conditions. Herein, we attempt to illuminate molecular means by which such impairment is manifested and how the compromised acetylation homeostasis is intimately coupled to neurodegeneration. Finally, we discuss the therapeutic potential of reinstating the HAT-HDAC balance to ameliorate neurodegenerative diseases.

Also flagged:prothrombinpeptideangiogenesisLewis lung carcinomamembranecell proliferation
Journal Article 2006-04-01 No Snippets Hwang HS, Kim DW, Kim SS.
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The human prothrombin kringle-2 protein inhibits angiogenesis and LLC (Lewis lung carcinoma) growth and metastasis in mice. Additionally, the NSA9 peptide (NSAVQLVEN) derived from human prothrombin kringle-2 has been reported to inhibit the proliferation of BCE (bovine capillary endothelial) cells and CAM (chorioallantoic membrane) angiogenesis. In the present study, we examined the structure-activity relationships of the NSA9 peptide in inhibiting the proliferation of endothelial cells lines e.g. BCE and HUVE (human umbilical vein endothelial). N- or C-terminal truncated derivatives and reverse sequence analogues of NSA9 were prepared and their anti-proliferative activities were assessed using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide] assay. This cell proliferation assay demonstrated that both the N-terminal region and sequence orientation of NSA9 are important for inhibiting the proliferation of endothelial cells. In particular 2 C-terminal truncation derivatives of NSA9 [NSA7 (NSAVQLV) and NSA8 (NSAVQLVE)] inhibited cellular proliferation to a greater extent than did NSA9. The heptapeptide NSA7, was found to be more potent than NSA9 in inhibiting CAM angiogenesis, and tubular formation and migration of HUVE cells. In addition NSA9, NSA8 and NSA7 peptides exhibited considerable inhibitory effects on the proliferation of tumour cells such as B16F10 (murine melanoma), LLC and L929 (murine fibroblast). Also, cellular internalization studies demonstrated that NSA7 was internalized into both endothelial and tumour cells more easily than was NSA9. In conclusion, these results suggest that NSA7, residing within the full sequence of NSA9, contains the required sequence for anti-proliferative activity and cellular internalization.

Also flagged:tumorCD55beta-glucanComplement (C) regulatory proteinscancerantibodies
Journal Article 2006-04-01 ✓ 5 Snippets Gelderman KA, Lam S, Sier CF, Gorter A.
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These data imply that the effectiveness of mAb immunotherapy can be improved using anti-tumor antigen*anti-CD55 bi-mAb and beta-glucan, thereby initiating CR3-DCC as an additional effector mechanism that is efficient for eradication of tumor cells with lower antigen expression.

This CR3-DCC was dependent on the binding of the anti-CD55 arm of tumor-bound anti-Ep-CAM*anti-CD55 bi-mAb to effector cell CD55, CR3 priming by beta-glucan and the presence of iC3b on the target cell.

…nt cellular cytotoxicity (CR3-DCC) by CR3-positive effector…

…than threefold higher CR3-DCC(71%) of human…

…This CR3-DCCwas dependent on…

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Complement (C) regulatory proteins decrease the effectiveness of immunotherapeutic anti-cancer antibodies. Bispecific mAb (bi-mAb) that target a tumor antigen and simultaneously inhibit a C regulator increase the effectiveness of such a therapy. Here we investigated the mechanism by which bi-mAb increase tumor cell lysis. Apart from C-dependent cytotoxicity, C activation can lead to complement receptor 3 (CR3)-dependent cellular cytotoxicity (CR3-DCC) by CR3-positive effector cells in the presence of beta-glucan. Here we show that an anti-Ep-CAM*anti-CD55 bi-mAb induced more than threefold higher CR3-DCC (71%) of human colorectal cancer cells compared with anti-Ep-CAM alone (20%). This CR3-DCC was dependent on the binding of the anti-CD55 arm of tumor-bound anti-Ep-CAM*anti-CD55 bi-mAb to effector cell CD55, CR3 priming by beta-glucan and the presence of iC3b on the target cell. Comparable lysis could be obtained in the absence of iC3b, when CR3 and CD55 were cross-linked on the effector cells, suggesting cooperation between CD55 and CR3 in signal transduction. Tumor cells with low antigen expression were effectively lysed via this mechanism in contrast to direct C-dependent cytotoxicity. These data imply that the effectiveness of mAb immunotherapy can be improved using anti-tumor antigen*anti-CD55 bi-mAb and beta-glucan, thereby initiating CR3-DCC as an additional effector mechanism that is efficient for eradication of tumor cells with lower antigen expression.

Also flagged:strokepneumoniaswallowingdysphagic strokeacute anterior circulation strokecapsaicin
Journal Article 2006-04-01 No Snippets Unknown Authors
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No abstract available.

Also flagged:pathogenesishereditary haemochromatosisHCironFPNhyperferritinaemia
Journal Article 2006-04-01 ✓ 1 Snippet Pietrangelo A.
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HFE

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No abstract available.

Also flagged:Ironoverload
Journal Article 2006-04-01 ✓ 2 Snippets Fleming RE, Britton RS.
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…mutations in theHFEgene.…

…primary role ofHFEin the liver…

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The majority of clinical cases of iron overload is caused by mutations in the HFE gene. However, the role that HFE plays in the physiology of intestinal iron absorption remains enigmatic. Two major models have been proposed: 1) HFE exerts its effects on iron homeostasis indirectly, by modulating the expression of hepcidin; and 2) HFE exerts its effects directly, by changing the iron status (and therefore the iron absorptive activity) of intestinal enterocytes. The first model places the primary role of HFE in the liver (hepatocytes and/or Kupffer cells). The second model places the primary role in the duodenum (crypt cells or villus enterocytes). These models are not mutually exclusive, and it is possible that HFE influences the iron status in each of these cell populations, leading to cell type-specific downstream effects on intestinal iron absorption and body iron distribution.

Also flagged:membranesneurodegenerative disordersAgingneurodegenerative disordermetabolismsignal transduction
Journal Article 2006-04-01 ✓ 1 Snippet Mattson MP, Magnus T.
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Htt

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Everyone ages, but only some will develop a neurodegenerative disorder in the process. Disease might occur when cells fail to respond adaptively to age-related increases in oxidative, metabolic and ionic stress, thereby resulting in the accumulation of damaged proteins, DNA and membranes. Determinants of neuronal vulnerability might include cell size and location, metabolism of disease-specific proteins and a repertoire of signal transduction pathways and stress resistance mechanisms. Emerging evidence on protein interaction networks that monitor and respond to the normal ageing process suggests that successful neural ageing is possible for most people, but also cautions that cures for neurodegenerative disorders are unlikely in the near future.

Also flagged:Net1Gastric adenocarcinomaGANET 1MYEOVtumour
Journal Article 2006-04-01 No Snippets Leyden J, Murray D, Moss A, Arumuguma M, Doyle E, McEntee G, O'Keane C, Doran P, MacMathuna P.
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Gastric adenocarcinoma (GA) is a significant cause of mortality worldwide. The molecular mechanisms of GA remain poorly characterised. Our aim was to characterise the functional activity of the computationally identified genes, NET 1 and MYEOV in GA. Digital Differential Display was used to identify genes altered expression in GA-derived EST libraries. mRNA levels of a subset of genes were quantitated by qPCR in a panel of cell lines and tumour tissue. The effect of pro- and anti-inflammatory stimuli on gene expression was investigated. Cell proliferation and invasion were measured using in an in-vitro GA model following inhibition of expression using siRNA. In all, 23 genes not previously reported in association with GA were identified. Two genes, Net1 and Myeov, were selected for further analysis and increased expression was detected in GA tissue compared to paired normal tissue using quantitative PCR. siRNA-mediated downregulation of Net1 and Myeov resulted in decreased proliferation and invasion of gastric cancer cells in vitro. These functional studies highlight a putative role for NET1 and Myeov in the development and progression of gastric cancer. These genes may provide important targets for intervention in GA, evidenced by their role in promoting invasion and proliferation, key phenotypic hallmarks of cancer cells.

Also flagged:Carbazolebiodegradationwaterdegradationcarbonnitrogen
Journal Article 2006-04-01 ✓ 1 Snippet Castorena G, Mugica V, Le Borgne S, Acuña ME, Bustos-Jaimes I, Aburto J.
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…those reported inPseudomonas resinovorans CA10resinovorans CA10.…

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<h4>Aim</h4>To select carbazole-degrading bacteria able to survive and metabolize carbazole in biphasic organic-water media and to study the factors affecting carbazole degradation in such conditions.<h4>Methods and results</h4>In this research a new carbazole-degrading strain was isolated from hot springs in Mexico. This bacterium was preliminary identified as Burkholderia sp. IMP5GC and was able to grow using carbazole as sole carbon and nitrogen source. Genetic analysis showed that this bacterium carries carA genes identical to those reported in Pseudomonas resinovorans CA10. Burkholderia IMP5GC efficiently degraded carbazole in aqueous media as well as in biphasic media with n-hexadecane. Furthermore, the strain IMPGC5 efficiently reduced the concentration of carbazole and monomethyl carbazole species in gas oil-water biphasic media.<h4>Conclusions</h4>This study demonstrates the biodegradation of carbazole in biphasic gas oil/water media (1 : 1), regardless of the highly toxic effects of this petroleum distillate.<h4>Significance and impact of the study</h4>Biodegradation of carbazole in biphasic media contributes to the understanding and design of bioprocesses for carbazole removal from petroleum-upgrading fractions and other carbazole-rich organic mixtures.

Also flagged:dentinogenesis imperfectadentin dysplasiaDDdentinDSPPdentin sialophospho-protein
Journal Article 2006-04-01 ✓ 1 Snippet Beattie ML, Kim JW, Gong SG, Murdoch-Kinch CA, Simmer JP, Hu JC.
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DGI-III

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Dentinogenesis imperfecta (DGI) and dentin dysplasia (DD) are allelic disorders that primarily affect the formation of tooth dentin. Both conditions are autosomal-dominant and can be caused by mutations in the dentin sialophosphoprotein gene (DSPP, 4q21.3). We recruited 23 members of a four-generation kindred, including ten persons with dentin defects, and tested the hypothesis that these defects are linked to DSPP. The primary dentition showed amber discoloration, pulp obliteration, and severe attrition. The secondary dentition showed either pulp obliteration with bulbous crowns and gray discoloration or thistle-tube pulp configurations, normal crowns, and mild gray discoloration. Haplotype analyses showed no recombination between three 4q21-q24 markers and the disease locus. Mutational analyses identified no coding or intron junction sequence variations associated with affection status in DMP1, MEPE, or the DSP portion of DSPP. The defects in the permanent dentition were typically mild and consistent with a diagnosis of DD-II, but some dental features associated with DGI-II were also present. We conclude that DD-II and DGI-II are milder and more severe forms, respectively, of the same disease.

Also flagged:Purpurameningococcal sepsispurpura fulminanscoagulation deficiencyrenal failureseptic shock
Journal Article 2006-04-01 ✓ 1 Snippet Belloni G, Ramello P, Salcuni MR, Scavone L, Girotto M, Di Bassiano F.
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…endogenous protein C,ATIIIand calcium were…

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A male patient, 29 years old, was admitted to our unit with purpura fulminans, coagulation deficiency, renal failure and subsequent septic shock accompanied by respiratory insufficiency in the absence of meningeal signs. The serum levels of endogenous protein C, ATIII and calcium were well below the norm. The bacteriological examination revealed the presence of gram-negative diplococci. The onset of adult respiratory distress syndrome (ARDS) revealed aa early complication of the meningococcal sepsis. Forty-eight hours after being admitted, the recombinant protein C infusion was started at a dose of 24 microg/kg/h for the duration of 96 h. The skin lesions regressed, starting from the ecchymosis and the edema of the face, trunk and auricular pavilions. A week after the onset of the symptomatology the chest X-ray appeared clear, the renal function had normalised, and the signs of shock had disappeared.

Also flagged:anandamidesynthesisamideN-arachidonoylethanolamineN-oleoylethanolaminepalmitoylethanolamine
Journal Article 2006-04-01 No Snippets Appendino G, Minassi A, Berton L, Moriello AS, Cascio MG, De Petrocellis L, Di Marzo V.
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The three amide oxyhomologues of the endolipids N-arachidonoylethanolamine (anandamide, AEA, 1a), N-oleoylethanolamine (OEA, 2a), and N-palmitoylethanolamine (PEA, 3a) have been prepared in a chemoselective way, capitalizing on the easy availability of O-[2-(triisopropylsilyoxy)ethyl]hydroxylamine (6) and the surprising complementary selectivity observed in the acylation of N-[2-(tert-butyldiphenylsilyloxy)ethyl]hydroxylamine (7) with the PPAA and the DCC/HOBT protocols. Reversal of the cannabinoid CB(1)/CB(2) receptor affinity ratio was observed for the first time in a derivative of anandamide (the O-alkyl-N-acyl hydroxylamine 1b), while the other oxyhomologues (1c and 1d) showed only marginal cannabimimetic activity. Compounds with unsaturated acyl chains generally retained vanilloid activity and showed an increased stability toward FAAH compared to their corresponding ethanolamides. Taken together, these observation show that oxyhomologation has a pronounced effect on both the pharmacodynamic and the pharmacokinetic properties of endogenous ethanolamides, suggesting a general relevance of this maneuver for the modification of amide pharmacophores.

Also flagged:osteoarthritisprimary osteoarthritisOAhemochromatotic arthropathy
Journal Article 2006-04-01 ✓ 5 Snippets Carroll GJ.
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.To test the hypothesis that possession of either C282Y or H63D mutations in the HFE gene is associated with primary osteoarthritis (OA) in joints commonly affected in hemochromatotic arthropathy.

HFE gene mutations are associated with osteoarthritis in the index or middle finger metacarpophalangeal joints.

A statistically significant association between HFE mutations and OA was observed for the MCP2,3 joints (p = 0.0001) and the ankle/IT/TMT joint group (p = 0.002) as well as for the 3 joint regions collectively (p = 0.0001), but not for the elbow joints (p = 0.062).

HFE gene mutations are associated with OA in the MCP2,3 joints.

HFE gene mutations are associated wit

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<h4>Objective</h4>. To test the hypothesis that possession of either C282Y or H63D mutations in the HFE gene is associated with primary osteoarthritis (OA) in joints commonly affected in hemochromatotic arthropathy.<h4>Methods</h4>HFE genotyping was performed in 87 patients with radiologically proven OA in 3 joint regions: index or middle finger metacarpophalangeal joints (MCP2,3; n = 52), elbow joints (n = 8), ankle, intertarsal or tarsometatarsal joints (ankle/IT/TMT; n = 27); and in 56 patients with radiologically proven OA in finger interphalangeal (IP) joints, but not MCP2,3 joints (IP OA control group). HFE mutation frequencies in these groups were also compared to those in a similar population (Busselton population control group).<h4>Results</h4>A statistically significant association between HFE mutations and OA was observed for the MCP2,3 joints (p = 0.0001) and the ankle/IT/TMT joint group (p = 0.002) as well as for the 3 joint regions collectively (p = 0.0001), but not for the elbow joints (p = 0.062). Comparison with the Busselton population controls showed similar statistically significant associations, except for the elbow and ankle/IT/TMT groups, where similar trends were observed.<h4>Conclusion</h4>HFE gene mutations are associated with OA in the MCP2,3 joints. These mutations may be markers for a polyarticular OA phenotype.

Also flagged:srp-3serine peptidaseschymotrypsincathepsin GGFPchymotrypsin-like serine peptidases
Journal Article 2006-04-01 No Snippets Pak SC, Tsu C, Luke CJ, Askew YS, Silverman GA.
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Members of the intracellular serpin family may help regulate apoptosis, tumor progression, and metastasis. However, their in vivo functions in the context of a whole organism have not been easily defined. To better understand the biology of these serpins, we initiated a comparative genomics study using Caenorhabditis elegans as a model organism. Previous in silico analysis suggested that the C. elegans genome harbors nine serpin-like sequences bearing significant similarities to the human clade B intracellular serpins. However, only five genes appear to encode full-length serpins with intact reactive site loops. To determine if this was the case, we have cloned and expressed a putative inhibitory-type C. elegans serpin, srp-3. Analysis of SRP-3 inhibitory activity indicated that SRP-3 was a potent inhibitor of the serine peptidases, chymotrypsin and cathepsin G. Spatial and temporal expression studies using GFP and LacZ promoter fusions indicated that SRP-3 was expressed primarily in the anterior body wall muscles, suggesting that it may play a role in muscle cell homeostasis. Combined with previous studies showing that SRP-2 is an inhibitor of the serine peptidase, granzyme B, and lysosomal cysteine peptidases, these data suggested that C. elegans expressed at least two inhibitory-type serpins with nonoverlapping expression and inhibitory profiles. Moreover, the profiles of these clade L serpins in C. elegans share significant similarities with the profiles of clade B intracellular serpin members in higher vertebrates. This degree of conservation suggests that C. elegans should prove to be a valuable resource in the study of metazoan intracellular serpin function.

Also flagged:sepsisbronchopulmonary dysplasianecrotizing enterocolitisgestationmaternal illnessesplacenta abruption
Journal Article 2006-04-01 No Snippets Mercer JS, Vohr BR, McGrath MM, Padbury JF, Wallach M, Oh W.
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<h4>Objective</h4>This study compared the effects of immediate (ICC) and delayed (DCC) cord clamping on very low birth weight (VLBW) infants on 2 primary variables: bronchopulmonary dysplasia (BPD) and suspected necrotizing enterocolitis (SNEC). Other outcome variables were late-onset sepsis (LOS) and intraventricular hemorrhage (IVH).<h4>Study design</h4>This was a randomized, controlled unmasked trial in which women in labor with singleton fetuses <32 weeks' gestation were randomly assigned to ICC (cord clamped at 5-10 seconds) or DCC (30-45 seconds) groups. Women were excluded for the following reasons: their obstetrician refused to participate, major congenital anomalies, multiple gestations, intent to withhold care, severe maternal illnesses, placenta abruption or previa, or rapid delivery after admission.<h4>Results</h4>Seventy-two mother/infant pairs were randomized. Infants in the ICC and DCC groups weighed 1151 and 1175 g, and mean gestational ages were 28.2 and 28.3 weeks, respectively. Analyses revealed no difference in maternal and infant demographic, clinical, and safety variables. There were no differences in the incidence of our primary outcomes (BPD and suspected NEC). However, significant differences were found between the ICC and DCC groups in the rates of IVH and LOS. Two of the 23 male infants in the DCC group had IVH versus 8 of the 19 in the ICC group. No cases of sepsis occurred in the 23 boys in the DCC group, whereas 6 of the 19 boys in the ICC group had confirmed sepsis. There was a trend toward higher initial hematocrit in the infants in the DCC group.<h4>Conclusions</h4>Delayed cord clamping seems to protect VLBW infants from IVH and LOS, especially for male infants.

Also flagged:Chlorophenol hydroxylasesPhenoxyalkanoic compoundschloroether2,4-dichlorophenolmethylphenol
Journal Article 2006-04-01 No Snippets Ledger T, Pieper DH, González B.
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Phenoxyalkanoic compounds are used worldwide as herbicides. Cupriavidus necator JMP134(pJP4) catabolizes 2,4-dichlorophenoxyacetate (2,4-D) and 4-chloro-2-methylphenoxyacetate (MCPA), using tfd functions carried on plasmid pJP4. TfdA cleaves the ether bonds of these herbicides to produce 2,4-dichlorophenol (2,4-DCP) and 4-chloro-2-methylphenol (MCP), respectively. These intermediates can be degraded by two chlorophenol hydroxylases encoded by the tfdB(I) and tfdB(II) genes to produce the respective chlorocatechols. We studied the specific contribution of each of the TfdB enzymes to the 2,4-D/MCPA degradation pathway. To accomplish this, the tfdB(I) and tfdB(II) genes were independently inactivated, and growth on each chlorophenoxyacetate and total chlorophenol hydroxylase activity were measured for the mutant strains. The phenotype of these mutants shows that both TfdB enzymes are used for growth on 2,4-D or MCPA but that TfdB(I) contributes to a significantly higher extent than TfdB(II). Both enzymes showed similar specificity profiles, with 2,4-DCP, MCP, and 4-chlorophenol being the best substrates. An accumulation of chlorophenol was found to inhibit chlorophenoxyacetate degradation, and inactivation of the tfdB genes enhanced the toxic effect of 2,4-DCP on C. necator cells. Furthermore, increased chlorophenol production by overexpression of TfdA also had a negative effect on 2,4-D degradation by C. necator JMP134 and by a different host, Burkholderia xenovorans LB400, harboring plasmid pJP4. The results of this work indicate that codification and expression of the two tfdB genes in pJP4 are important to avoid toxic accumulations of chlorophenols during phenoxyacetic acid degradation and that a balance between chlorophenol-producing and chlorophenol-consuming reactions is necessary for growth on these compounds.

Also flagged:perchloric acidhistone H1HMG proteinshistonebreast cancerHMG
Journal Article 2006-04-01 ✓ 1 Snippet Zougman A, Wiśniewski JR.
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…Beyondlinker histoneshistones and high…

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Extraction with HClO(4) provides an easy method for efficient enrichment of both histone H1 and HMG proteins from a variety of tissues. Usually, the histone and the HMG proteins are the most abundant components of the extracts, however, other proteins have frequently been observed but only seldom studied in more detail. Here we describe a study aimed at global characterization of HClO(4) extractable proteins from breast cancer cell lines. We report identification of 150 unique proteins by liquid chromatography tandem mass spectrometry including almost all major histone H1 variants and canonical members of the HMG protein families. In the extracts, diverse proteins with HMG-like amino acid composition were identified and their post-translational modifications were mapped. Importantly, those include multiple proteins known or supposed to be related to cell proliferation and cancer. Since purification of these proteins as well as low abundant variants of histone and HMG proteins is difficult due to their metabolic instability, characterization of these proteins from crude extracts can facilitate studies aimed at better understanding of their function.

Also flagged:chromosomeCharcot-Marie-Tooth disease type 2LCMT2LRAB35RPLP0PXN
Journal Article 2006-04-01 ✓ 2 Snippets Zhang RX, Tang BS, Zi XH, Luo W, Xia K, Pan Q, Hu ZM, Zhao GH, Guo K.
In-Text Gene Mentions

All the variations showed no co-segregation with disease phenotype.<h4>Conclusion</h4>Ten candidate genes(TAOK3, RAB35, RPLP0, PXN, RNF10, RHOF, VPS33A, RSN, DENR, RNP24) were ruled out as the disease-causing gene for CMT2L.

…usion</h4>Ten candidate genes(TAOK3, RAB35, RPLP0, PXN,…

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<h4>Objective</h4>To clone the disease-causing genes possibly existing in 6.8 cM distance between microsatellite markers D12S1720 and D12S1611 in chromosome 12q24 for Charcot-Marie-Tooth disease type 2L (CMT2L).<h4>Methods</h4>Ten positional and functional candidate genes were chosen among all known genes in this locus region by bioinformatics inqury. Mutation detection was performed by sequencing the exons and intron-exon junctions of the candidate genes.<h4>Results</h4>Eleven sequence variations, that included 5 heterozygous and 6 homozygous variations, were detected in the exons and flanking areas of the 10 candidate genes. All the variations showed no co-segregation with disease phenotype.<h4>Conclusion</h4>Ten candidate genes(TAOK3, RAB35, RPLP0, PXN, RNF10, RHOF, VPS33A, RSN, DENR, RNP24) were ruled out as the disease-causing gene for CMT2L. Ten single nucleotide polymorphisms (SNP) were reported for the first time.

Also flagged:silicagene expressionethylene glycolsilanedeathcell cycle
Journal Article 2006-04-01 ✓ 1 Snippet Zhang T, Stilwell JL, Gerion D, Ding L, Elboudwarej O, Cooke PA, Gray JW, Alivisatos AP, Chen FF.
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PTGIS

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Quantum dots (Qdots) are now used extensively for labeling in biomedical research, and this use is predicted to grow because of their many advantages over alternative labeling methods. Uncoated Qdots made of core/shell CdSe/ZnS are toxic to cells because of the release of Cd2+ ions into the cellular environment. This problem has been partially overcome by coating Qdots with polymers, poly(ethylene glycol) (PEG), or other inert molecules. The most promising coating to date, for reducing toxicity, appears to be PEG. When PEG-coated silanized Qdots (PEG-silane-Qdots) are used to treat cells, toxicity is not observed, even at dosages above 10-20 nM, a concentration inducing death when cells are treated with polymer or mercaptoacid coated Qdots. Because of the importance of Qdots in current and future biomedical and clinical applications, we believe it is essential to more completely understand and verify this negative global response from cells treated with PEG-silane-Qdots. Consequently, we examined the molecular and cellular response of cells treated with two different dosages of PEG-silane-Qdots. Human fibroblasts were exposed to 8 and 80 nM of these Qdots, and both phenotypic as well as whole genome expression measurements were made. PEG-silane-Qdots did not induce any statistically significant cell cycle changes and minimal apoptosis/necrosis in lung fibroblasts (IMR-90) as measured by high content image analysis, regardless of the treatment dosage. A slight increase in apoptosis/necrosis was observed in treated human skin fibroblasts (HSF-42) at both the low and the high dosages. We performed genome-wide expression array analysis of HSF-42 exposed to doses 8 and 80 nM to link the global cell response to a molecular and genetic phenotype. We used a gene array containing approximately 22,000 total probe sets, containing 18,400 probe sets from known genes. Only approximately 50 genes (approximately 0.2% of all the genes tested) exhibited a statistically significant change in expression level of greater than 2-fold. Genes activated in treated cells included those involved in carbohydrate binding, intracellular vesicle formation, and cellular response to stress. Conversely, PEG-silane-Qdots induce a down-regulation of genes involved in controlling the M-phase progression of mitosis, spindle formation, and cytokinesis. Promoter analysis of these results reveals that expression changes may be attributed to the down-regulation of FOXM and BHLB2 transcription factors. Remarkably, PEG-silane-Qdots, unlike carbon nanotubes, do not activate genes indicative of a strong immune and inflammatory response or heavy-metal-related toxicity. The experimental evidence shows that CdSe/ZnS Qdots, if appropriately protected, induce negligible toxicity to the model cell system studied here, even when exposed to high dosages. This study indicates that PEG-coated silanized Qdots pose minimal impact to cells and are a very promising alternative to uncoated Qdots.

Also flagged:cirrhosishereditary hemochromatosishepatocellular carcinomadeathcarcinomaliver disease
Journal Article 2006-04-01 ✓ 1 Snippet Beaton MD, Adams PC.
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hemochromatosis

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<h4>Objectives</h4>The survival of treated, noncirrhotic patients with hereditary hemochromatosis is similar to that of the general population. Less is known about the outcome of cirrhotic hereditary hemochromatosis patients. The present study evaluated the survival of patients with hereditary hemochromatosis and cirrhosis.<h4>Methods</h4>From an established hereditary hemochromatosis database, all cirrhotic patients diagnosed from January 1972 to August 2004 were identified. Factors associated with survival were determined using univariate and multivariate regression. Survival differences were assessed using the Kaplan-Meier life table method.<h4>Results</h4>Ninety-five patients were identified. Sixty patients had genetic testing, 52 patients (87%) were C282Y homozygotes. Median follow-up was 9.2 years (range 0 to 30 years). Nineteen patients (20%) developed hepatocellular carcinoma, one of whom was still living following transplantation. Cumulative survival for all patients was 88% at one year, 69% at five years and 56% at 20 years. Factors associated with death on multivariate analysis included advanced Child-Pugh score and hepatocellular carcinoma. Patients with hepatocellular carcinoma were older at the time of diagnosis of cirrhosis (mean age 61 and 54.6 years, respectively; P=0.03). The mean age at the time of diagnosis of hepatocellular carcinoma was 70 years (range 48 to 79 years). No other differences were found between the groups.<h4>Conclusions</h4>Patients with hereditary hemochromatosis and cirrhosis are at significant risk of developing hepatocellular carcinoma. These patients are older when diagnosed with carcinoma and may have poorer survival following transplantation than patients with other causes of liver disease. Early diagnosis and treatment of hereditary hemochromatosis by preventing the development of cirrhosis may reduce the incidence of hepatocellular carcinoma in the future.

Also flagged:Cryptogenic cirrhosisobesityCCnon-alcoholic steatohepatitishypertriglyceridemiainsulin resistance
Journal Article 2006-04-01 ✓ 1 Snippet Kojima H, Sakurai S, Matsumura M, Umemoto N, Uemura M, Morimoto H, Tamagawa Y, Fukui H.
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hemochromatosis

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<h4>Aim</h4>Recent studies have demonstrated that obesity is the common feature of cryptogenic cirrhosis (CC) and non-alcoholic steatohepatitis. However, there is little information on CC in the region where obesity is not prevalent.<h4>Methods</h4>The clinical features, and the liver-related morbidity and mortality of CC were analyzed in Japan where the prevalence of obesity is low. Among 652 cirrhotic patients, we identified 29 patients (4.4%) with CC. Of these, 24 CC patients who were followed up for more than 6 months were compared in a case-control study with age-, sex-, and Child-Pugh score-matched controls having cirrhosis of viral etiology.<h4>Results</h4>Obesity (BMI>or=25 kg/m(2)), diabetes mellitus, and hypertriglyceridemia were more frequent, and the visceral fat area was larger in the CC patients than in the controls. The indices of insulin resistance were higher and the serum aminotransferase levels were lower in the CC patients than in the controls. Logistic regression analysis identified the elevated hemoglobin A1c, BMI>or=25 kg/m(2), and normal aminotransferase levels as independent predictors of CC. Kaplan-Meier analysis demonstrated lower occurrence of hepatocellular carcinoma and higher survival rate in the CC than in the controls in contrast to the similar cumulative probability of liver-related morbidity between those groups.<h4>Conclusion</h4>CC more frequently presents with the clinical features suggestive of non-alcoholic steatohepatitis compared with controls even in the region where obesity is not prevalent. The lower occurrence of hepatocellular carcinoma and higher survival rate may indicate an indolent clinical course in CC as compared with viral cirrhosis.

Also flagged:ironaspartate aminotransferaseASTalanine aminotransferaseALT
Journal Article 2006-04-01 ✓ 4 Snippets Samarasena J, Winsor W, Lush R, Duggan P, Xie Y, Borgaonkar M.
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…mutations of theHFEgene with a…

…subjects who underwentHFEmutational testing for…

…included age, gender,HFEgenotype, and values…

…genotype, no abnormalHFEgenotypes had significantly…

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Our objective was to assess the iron indexes of patients with one or more mutations of the HFE gene with a specific interest in studying the effect of the H63D/H63D genotype. Eight hundred twenty subjects who underwent HFE mutational testing for C282Y and H63D mutations were retrospectively identified. Data collected included age, gender, HFE genotype, and values for serum ferritin, iron saturation, aspartate aminotransferase (AST), and alanine aminotransferase (ALT). Compared to the Wild/Wild genotype (0.34 +/- 0.17), genotypes H63D/C282Y (0.44 +/- 0.14 P < 0.01), H63D/H63D (0.51 +/- 0.21 P < 0.01), and C282Y/C282Y (0.64 +/- 0.20 P < 0.01) had significantly higher transferrin saturation levels and were independent predictors of higher iron saturation in multivariate regression analysis. Compared to the Wild/Wild genotype, no abnormal HFE genotypes had significantly higher ferritin levels, although the genotype H63D/H63D was an independent predictor of higher serum ferritin (P = 0.02) in regression analysis. There was no significant difference in the proportion of patients with abnormally elevated AST (P = 0.64) or ALT (P = 0.80) between groups. H63D homozygotes have elevated transferrin saturation compared to the Wild genotype, comparable to that of C282Y homozygotes and compound heterozygotes. The clinical significance of this finding is unclear but warrants further study.

Also flagged:venlafaxinedepressionneurotransmitterFluvoxaminesexual dysfunctionsleep
Journal Article 2006-04-01 ✓ 1 Snippet Westenberg HG, Sandner C.
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Venlafaxine, for instance, is one of the most potent antidepressants at blocking the dopamine transporter, and paroxetine, although the most potent blocker of 5-HTT, also has appreciable affinity for the noradrenaline transporter (NAT) (1).

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Selective serotonin [5-hydroxytryptamine (5-HT)] reuptake inhibitors (SSRIs) and the 5-HT noradrenaline reuptake inhibitor, venlafaxine, are mainstays in treatment for depression. The highly specific actions of SSRIs of enhancing serotonergic neurotransmission appears to explain their benefit, while lack of direct actions on other neurotransmitter systems is responsible for their superior safety profile compared with tricyclic antidepressants. Although SSRIs (and venlafaxine) have similar adverse effects, certain differences are emerging. Fluvoxamine may have fewer effects on sexual dysfunction and sleep pattern. SSRIs have a cardiovascular safety profile superior to that of tricyclic antidepressants for patients with cardiovascular disease; fluvoxamine is safe in patients with cardiovascular disease and in the elderly. A discontinuation syndrome may develop upon abrupt SSRI cessation. SSRIs are more tolerable than tricyclic antidepressants in overdose, and there is no conclusive evidence to suggest that they are associated with an increased risk of suicide. Although the literature suggests that there are no clinically significant differences in efficacy amongst SSRIs, treatment decisions need to be based on considerations such as patient acceptability, response history and toxicity.

Journal Article 2006-04-01 ✓ 3 Snippets McNaughton BR, Miller BL.
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…natorial chemistry (DCC) is a promising tec…

… termed resin-bound DCC (RB-DCC), which pro…

…resin-bound DCC (RB-DCC), which provides a …

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[reaction: see text] Dynamic combinatorial chemistry (DCC) is a promising technique for receptor-aided selection of high-affinity ligands from equilibrating combinatorial libraries. Identification of the specific ligand(s) selected is often challenging, however, due to difficulties associated with chromatographic separation and/or mass degeneracy within the library. Herein, we describe proof-of-concept experiments demonstrating a new technique termed resin-bound DCC (RB-DCC), which provides a solution to this problem.

Also flagged:CystaminecysteaminemitochondrialdepolarizationHuntington's diseaseHD
Journal Article 2006-04-01 No Snippets Mao Z, Choo YS, Lesort M.
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Abstract Cystamine significantly improved motor deficits and extended survival in mouse models of Huntington's disease (HD); however, the precise mechanism(s) by which cystamine and the related compound cysteamine are beneficial remain to be elucidated. Using clonal striatal cell lines from wild-type (STHdhQ7/HdhQ7) and mutant huntingtin knock-in (STHdhQ111/HdhQ111) mice, we have tested the hypothesis that cystamine and cysteamine could be beneficial by preventing the depolarization of mitochondria in cell cultures. Treatment with 3-nitroproprionic acid (3-NP), a mitochondrial complex II inhibitor, induces mitochondrial depolarization and cell death of mutant HD striatal cells but not of wild-type cells. The 3-NP-mediated decrease in the mitochondrial membrane potential was attenuated by 50 microm cystamine and completely inhibited by 250 microm cystamine. Similar results were obtained using cysteamine (50-500 microm). In addition, both cystamine and cysteamine significantly attenuated the 3-NP-induced cell death. Treatment of mutant HD striatal cells with 3-NP resulted in a robust decrease in the cellular and mitochondrial levels of glutathione (GSH) compared with cells exposed to the vehicle alone. Pre-treatment of the cells with cystamine and cysteamine completely prevented the 3-NP-mediated decrease in cellular and mitochondrial GSH levels. Incubation with L-buthionine (S,R) sulfoximine (BSO) 250 microm in combination with cystamine (250 microm) or cysteamine (250 microm) prior to being treated with 3-NP completely prevented the beneficial effects of cystamine and cysteamine on the 3-NP-mediated mitochondrial depolarization. These results demonstrate that cystamine and cysteamine prevent the 3-NP-induced mitochondrial depolarization of HD striatal cell cultures.

Also flagged:cAMP-dependent protein kinaseprotein kinase APKAsynapseorganizationphosphorylation
Journal Article 2006-04-01 ✓ 1 Snippet Inan M, Lu HC, Albright MJ, She WC, Crair MC.
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5-HTT

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The cellular and molecular mechanisms mediating the activity-dependent development of brain circuitry are still incompletely understood. Here, we examine the role of cAMP-dependent protein kinase [protein kinase A (PKA)] signaling in cortical development and plasticity, focusing on its role in thalamocortical synapse and barrel map development. We provide direct evidence that PKA activity mediates barrel map formation using knock-out mice that lack type IIbeta regulatory subunits of PKA (PKARIIbeta). We show that PKARIIbeta-mediated PKA function is required for proper dendritogenesis and the organization of cortical layer IV neurons into barrels, but not for the development and plasticity of thalamocortical afferent clustering into a barrel pattern. We localize PKARIIbeta function to postsynaptic processes in barrel cortex and show that postsynaptic PKA targets, but not presynaptic PKA targets, have decreased phosphorylation in pkar2b knock-out (PKARIIbeta(-/-)) mice. We also show that long-term potentiation at TC synapses and the associated developmental increase in AMPA receptor function at these synapses, which normally occurs as barrels form, is absent in PKARIIbeta(-/-) mice. Together, these experiments support an activity-dependent model for barrel map development in which the selective addition and elimination of thalamocortical synapses based on Hebbian mechanisms for synapse formation is mediated by a cAMP/PKA-dependent pathway that relies on PKARIIbeta function.

Also flagged:fluvoxaminebindingserotoninreuptakeserotonin transporterpositron
Journal Article 2006-04-01 ✓ 2 Snippets Takano A, Suhara T, Ichimiya T, Yasuno F, Suzuki K.
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…of in vivo5-HTT transportertransporter occupancy by…

…on serotonin transporter (5-HTT) occupancy by positron…

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The pharmacokinetics of drugs with specific binding sites in the brain needs to be evaluated at these sites. In this study, we measured the time course of the selective serotonin reuptake inhibitor fluvoxamine in the human brain based on serotonin transporter (5-HTT) occupancy by positron emission tomography. Consecutive positron emission tomography scans were performed using [11C]3-amino-4-(2-dimethylaminomethyl-phenylsulfanyl)-benzonitrile before, 5 hours, 26 hours, and 53 hours after 50 mg of fluvoxamine administration in 6 healthy male volunteers (mean, 24.3 +/- 4.8 years). Quantification was performed using the multilinear reference tissue model 2. Mean 5-HTT occupancies were 72.9% +/- 4.9% at 5 hours, 50.3% +/- 11.0% at 26 hours, and 24.7% +/- 15.3% at 53 hours, and plasma concentrations were 13.9 +/- 5.5 ng/mL at 5 hours, 5.1 +/- 3.2 ng/mL at 26 hours, and 1.5 +/- 1.7 ng/mL at 53 hours. The relationship between the plasma concentration of fluvoxamine and 5-HTT occupancy at these different time points was fitted to the law of mass action.

Also flagged:Nonalcoholic fatty liver diseaseNAFLDliver diseasecirrhosisportal hypertensionaminotransferases
Journal Article 2006-04-01 ✓ 1 Snippet Alfire ME, Treem WR.
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…hepatitis, Wilson's disease,hemochromatosis, or alpha-1-antitrypsin defic…

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NAFLD likely is the most common liver disease in children and is responsible for significant progression to cirrhosis, portal hypertension, and the need for liver transplantation in adults and even in some adolescents. Early diagnosis and lifestyle interventions appear to be our best hope for controlling progression of disease. The pediatrician is responsible for screening all obese children with measurement of aminotransferases. Those with elevated enzymes (particularly ALT) for longer than 3 months, in the absence of markers of hepatitis B or C, autoimmune chronic active hepatitis, Wilson's disease, hemochromatosis, or alpha-1-antitrypsin deficiency, should follow up with an abdominal ultrasound. In patients with a BMI in the morbidly obese range, an ultrasound to search for a diffusely echogenic liver should be performed even if the liver enzymes are normal. Findings suggestive of NAFLD should prompt the institution of appropriate dietary and exercise regimens. If these are unsuccessful after a 3-month trial, the patient should be referred to a pediatric gastroenterologist and hepatologist for further work-up and treatment, preferably in the context of a controlled therapeutic trial. Only by aggressively engaging this current epidemic will we be able to decrease the mounting human cost of NAFLD.

Also flagged:deathHuntington's diseaseHDpathogenesistranscriptional regulatorCA150
Journal Article 2006-04-01 ✓ 5 Snippets Arango M, Holbert S, Zala D, Brouillet E, Pearson J, Régulier E, Thakur AK, Aebischer P, Wetzel R, Déglon N, Néri C.
In-Text Gene Mentions

Together, our data indicate that mutant htt may induce CA150 dysfunction in striatal neurons and suggest that the restoration of nuclear protein cooperativity may be neuroprotective.

Transcriptional dysregulation caused by expanded polyglutamines (polyGlns) in huntingtin (htt) may be central to cell-autonomous mechanisms for neuronal cell death in Huntington's disease (HD) pathogenesis.

We hypothesized that these mechanisms may involve the dysfunction of the transcriptional regulator CA150, a putative modifier of onset age in HD, because it binds to htt and accumulates in an HD grade-dependent manner in striatal and cortical neurons.

…(polyGlns) in huntingtin (htt) may be central…

…it binds tohttand accumulates in…

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Transcriptional dysregulation caused by expanded polyglutamines (polyGlns) in huntingtin (htt) may be central to cell-autonomous mechanisms for neuronal cell death in Huntington's disease (HD) pathogenesis. We hypothesized that these mechanisms may involve the dysfunction of the transcriptional regulator CA150, a putative modifier of onset age in HD, because it binds to htt and accumulates in an HD grade-dependent manner in striatal and cortical neurons. Consistently, we report herein that CA150 expression rescues striatal cell death in lentiviral overexpression (rats) and knock-in (mouse cells) conditions for mutant htt neurotoxicity. In both systems, rescue was dependent on the (Gln-Ala)38 repeat normally found in CA150. We excluded the possibility that rescue may be caused by the (Gln-Ala)38 repeat interacting with polyGlns and, by doing so, blocking mutant htt toxicity. In contrast, we found the (Gln-Ala)38 repeat is required for the nuclear restriction of exogenous CA150, suggesting that rescue requires nuclear CA150. Additionally, we found the (Gln-Ala)38 repeat was dispensable for CA150 transcriptional repression ability, suggesting further that CA150 localization is critical to rescue. Finally, rescue was associated with increased neuritic aggregation, with no reduction of nuclear inclusions, suggesting the solubilization and nuclear export of mutant htt. Together, our data indicate that mutant htt may induce CA150 dysfunction in striatal neurons and suggest that the restoration of nuclear protein cooperativity may be neuroprotective.

Also flagged:methanolvanillinphthalidesbindingSerotonin receptorphenolic ester
Journal Article 2006-04-01 No Snippets Deng S, Chen SN, Yao P, Nikolic D, van Breemen RB, Bolton JL, Fong HH, Farnsworth NR, Pauli GF.
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Serotonin receptor (5-HT(7)) binding assay-directed fractionation of a methanol extract of the dried roots of Angelica sinensis led to the isolation and identification of 21 compounds including a new phenolic ester, angeliferulate (1), and three new phthalides, 10-angeloylbutylphthalide (2), sinaspirolide (3), and ansaspirolide (4), along with 17 known compounds, p-hydroxyphenethyl trans-ferulate (5), Z-ligustilide (6), Z-butylidenephthalide (7), senkyunolide I (8), Z-6-hydroxy-7-methoxydihydroligustilide (9), N-butylbenzenesulfonamide (10), 11(S),16(R)-dihydroxyoctadeca-9Z,17-diene-12,14-diyn-1-yl acetate (11), (3R,8S)-falcarindiol (12), heptadeca-1-en-9,10-epoxy-4,6-diyne-3,8-diol (13), oplopandiol (14), 8-hydroxy-1-methoxy-, Z-9-heptadecene-4,6-diyn-3-one (15), imperatorin, ferulic acid, vanillin, stigmasterol, sucrose, and 1,3-dilinolenin. This is the first report of a sulfonamide (10) identified from a higher plant source, although its presence needs further investigation. Biosynthetic pathways for dimeric phthalides 3 and 4 are proposed. Compounds 5, 7, 11, 12, 15, and imperatorin exhibited affinity toward 5-HT(7) receptors in a competitive binding assay.

Also flagged:gene expressionChromosomecancertumoroligonucleotideERBB2
Journal Article 2006-04-01 No Snippets Bussey KJ, Chin K, Lababidi S, Reimers M, Reinhold WC, Kuo WL, Gwadry F, Ajay, Kouros-Mehr H, Fridlyand J, Jain A, Collins C, Nishizuka S, Tonon G, Roschke A, Gehlhaus K, Kirsch I, Scudiero DA, Gray JW, Weinstein JN.
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Chromosome rearrangement, a hallmark of cancer, has profound effects on carcinogenesis and tumor phenotype. We used a panel of 60 human cancer cell lines (the NCI-60) as a model system to identify relationships among DNA copy number, mRNA expression level, and drug sensitivity. For each of 64 cancer-relevant genes, we calculated all 4,096 possible Pearson's correlation coefficients relating DNA copy number (assessed by comparative genomic hybridization using bacterial artificial chromosome microarrays) and mRNA expression level (determined using both cDNA and Affymetrix oligonucleotide microarrays). The analysis identified an association of ERBB2 overexpression with 3p copy number, a finding supported by data from human tumors and a mouse model of ERBB2-induced carcinogenesis. When we examined the correlation between DNA copy number for all 353 unique loci on the bacterial artificial chromosome microarray and drug sensitivity for 118 drugs with putatively known mechanisms of action, we found a striking negative correlation (-0.983; 95% bootstrap confidence interval, -0.999 to -0.899) between activity of the enzyme drug L-asparaginase and DNA copy number of genes near asparagine synthetase in the ovarian cancer cells. Previous analysis of drug sensitivity and mRNA expression had suggested an inverse relationship between mRNA levels of asparagine synthetase and L-asparaginase sensitivity in the NCI-60. The concordance of pharmacogenomic findings at the DNA and mRNA levels strongly suggests further study of L-asparaginase for possible treatment of a low-synthetase subset of clinical ovarian cancers. The DNA copy number database presented here will enable other investigators to explore DNA transcript-drug relationships in their own domains of research focus.

Also flagged:Serotoninpulmonary arterial hypertensionSerotonin transporterCOPDBMPR2
Journal Article 2006-04-01 ✓ 5 Snippets Eddahibi S, Adnot S.
In-Text Gene Mentions

Serotonin transporter (5-HTT), the mediator of the mitogenic activity of serotonin, and the expression of which is increased in the course of idiopathic or secondary PAH, is the basis of these effects.

Treatment with selective 5-HTT inhibitors prevents or leads to complete reversal of experimental hypoxic or inflammatory PAH.

The overexpression of 5-HTT, selectively induced in vascular smooth muscle by transgenesis in the mouse, leads to the development of PAH.

The presence of polymorphism of the gene causing over expression of the protein and proliferation of PA-SMCs seems to determine the severity of certain types of human PAH, notably that complicating COPD.<h4>Viewpoint</h4>There is a potential therapeutic application of 5-HTT inhibitors in human PAH.

A clinical study is currently taking place in France.<h4>Conclusion</h4>The exploration of the role of 5-HTT and the mechanisms leading to its overexpression in PAH, as well as the interactions between 5-HTT and the BMPR2 gene, should lead to a significant increase in the understanding of the pathophysiology of the disease.

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<h4>Introduction</h4>Pulmonary arterial hypertension (PAH) is related to hypertrophic remodelling of the pulmonary vessels. Proliferation of pulmonary vascular smooth muscle cells (PA-SMCs) plays a key role in these changes.<h4>Background</h4>The PA-SMCs of patients suffering from idiopathic or secondary PAH are characterized by abnormally increased in vitro proliferation in response to serotonin or serum. Serotonin transporter (5-HTT), the mediator of the mitogenic activity of serotonin, and the expression of which is increased in the course of idiopathic or secondary PAH, is the basis of these effects. The overexpression of 5-HTT, selectively induced in vascular smooth muscle by transgenesis in the mouse, leads to the development of PAH. Treatment with selective 5-HTT inhibitors prevents or leads to complete reversal of experimental hypoxic or inflammatory PAH. The presence of polymorphism of the gene causing over expression of the protein and proliferation of PA-SMCs seems to determine the severity of certain types of human PAH, notably that complicating COPD.<h4>Viewpoint</h4>There is a potential therapeutic application of 5-HTT inhibitors in human PAH. A clinical study is currently taking place in France.<h4>Conclusion</h4>The exploration of the role of 5-HTT and the mechanisms leading to its overexpression in PAH, as well as the interactions between 5-HTT and the BMPR2 gene, should lead to a significant increase in the understanding of the pathophysiology of the disease.

Also flagged:Infectionalcoholethanolisopropyl alcoholchlorineinfections
Journal Article 2006-04-01 No Snippets Unknown Authors
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No abstract available.

Also flagged:Gene expressionhepatocellular carcinomaliver cancerHBV infectioncalciumcell cycle
Journal Article 2006-04-01 ✓ 1 Snippet Barone M, Spano D, D'Apolito M, Centra M, Lasalandra C, Capasso M, Di Leo A, Volinia S, Arcelli D, Rosso N, Francavilla A, Tiribelli C, Iolascon A.
In-Text Gene Mentions

hemochromatosis

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Hepatitis B virus (HBV) is one of the major etiological factors responsible for the development of hepatocellular carcinoma (HCC). We used a transgenic mouse, containing HBV sequences, as a model system to unravel the molecular mechanisms of hepatocarcinogenesis induced by HBV. We chose this animal model because it consistently develops liver cancer after intermediate steps that mimic the natural history of HBV infection in humans. In this study, we focus our attention on the early events leading to liver cancer. We compared the gene expression profile of 3-month-old transgenic mice with that of 3-month-old wild-type (wt) animals. In the transgenic mouse, microarray data analysis showed a total of 45 significantly differentially expressed genes, 25 highly expressed (fold change > or =2; P = 0.0025), and 20 downregulated (fold change < or =0.5; P = 0.0025). These genes belong to several different functional categories such as the regulation of immunological response, transcription, intracellular calcium ion mobilization, regulation of cell cycle and proliferation, NF-kappab signal transduction cascades, and apoptosis. In particular, the upregulation of the antiapoptotic gene NuprI and the downregulation of the proapoptotic gene Bnip3 were found. This observation was supported by an in vitro apoptosis assay that showed downregulation of apoptosis in hepatocytes of HBV transgenic mouse compared with wt mice treated with staurosporine. In conclusion, our experimental approach allowed identification of new genes modulated by HBV and showed that the apoptotic process was deregulated in transgenic mouse hepatocytes. These data shed light on one possible mechanism by which HBV induces hepatocarcinogenesis.