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Found 37769 matches. Displaying 4651-4660
Fava VM, Manry J, Cobat A, Orlova M, Thuc NV, Moraes MO, Sales-Marques C, Stefani MMA, Latini ACP, Belone AF, Thai VH, Abel L, Alcais A, Schurr E
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A genome wide association study identifies a lncRna as risk factor for pathological inflammatory responses in leprosy

PLOS GENETICS 2017 FEB; 13(2):? Article e1006637
Leprosy Type-1 Reactions (T1Rs) are pathological inflammatory responses that afflict a sub-group of leprosy patients and result in peripheral nerve damage. Here, we employed a family-based GWAS in 221 families with 229 T1R-affect offspring with stepwise replication to identify risk factors for T1R. We discovered, replicated and validated T1R-specific associations with SNPs located in chromosome region 10p21.2. Combined analysis across the three independent samples resulted in strong evidence of association of rs1875147 with T1R (p = 4.5x10(-8); OR = 1.54, 95% CI = 1.32-1.80). The T1R-risk locus was restricted to a lncRNA-encoding genomic interval with rs1875147 being an eQTL for the lncRNA. Since a genetic overlap between leprosy and inflammatory bowel disease (IBD) has been detected, we evaluated if the shared genetic control could be traced to the T1R endophenotype. Employing the results of a recent IBD GWAS meta-analysis we found that 10.6% of IBD SNPs available in our dataset shared a common risk-allele with T1R (p = 2.4x10(-4)). This finding points to a substantial overlap in the genetic control of clinically diverse inflammatory disorders.
Sabari BR, Zhang D, Allis CD, Zhao YM
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Metabolic regulation of gene expression through histone acylations

NATURE REVIEWS MOLECULAR CELL BIOLOGY 2017 FEB; 18(2):90-101
Eight types of short-chain Lys acylations have recently been identified on histones: propionylation, butyrylation, 2-hydroxyisobutyrylation, succinylation, malonylation, glutarylation, crotonylation and beta-hydroxybutyrylation. Emerging evidence suggests that these histone modifications affect gene expression and are structurally and functionally different from the widely studied histone Lys acetylation. In this Review, we discuss the regulation of non-acetyl histone acylation by enzymatic and metabolic mechanisms, the acylation 'reader' proteins that mediate the effects of different acylations and their physiological functions, which include signal-dependent gene activation, spermatogenesis, tissue injury and metabolic stress. We propose a model to explain our present understanding of how differential histone acylation is regulated by the metabolism of the different acyl-CoA forms, which in turn modulates the regulation of gene expression.
Keller A, Gerkin RC, Guan YF, Dhurandhar A, Turu G, Szalai B, Mainland JD, Ihara Y, Yu CW, Wolfinger R, Vens C, Schietgat L, De Grave K, Norel R, Stolovitzky G, Cecchi GA, Vosshall LB, Meyer P
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Predicting human olfactory perception from chemical features of odor molecules

SCIENCE 2017 FEB 24; 355(6327):820-826
It is still not possible to predict whether a given molecule will have a perceived odor or what olfactory percept it will produce. We therefore organized the crowd-sourced DREAM Olfaction Prediction Challenge. Using a large olfactory psychophysical data set, teams developed machine-learning algorithms to predict sensory attributes of molecules based on their chemoinformatic features. The resulting models accurately predicted odor intensity and pleasantness and also successfully predicted 8 among 19 rated semantic descriptors ("garlic," "fish," "sweet," "fruit," "burnt," "spices," "flower," and "sour"). Regularized linear models performed nearly as well as random forest-based ones, with a predictive accuracy that closely approaches a key theoretical limit. These models help to predict the perceptual qualities of virtually any molecule with high accuracy and also reverse-engineer the smell of a molecule.
Andrews CD, Bernard LS, Poon AY, Mohri H, Gettie N, Spreen WR, Gettie A, Russell-Lodrigue K, Blanchard J, Hong Z, Ho DD, Markowitz M
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Cabotegravir long acting injection protects macaques against intravenous challenge with SIVmac251

AIDS 2017 FEB 20; 31(4):461-467
Objective: We evaluated the effectiveness of cabotegravir (CAB; GSK1265744 or GSK744) long acting as preexposure prophylaxis (PrEP) against intravenous simian immunodeficiency virus (SIV) challenge in a model that mimics blood transfusions based on the per-act probability of infection. Design: Clong acting is an integrase strand transfer inhibitor formulated as a 200 mg/ml injectable nanoparticle suspension that is an effective PrEP agent against rectal and vaginal simian/human immunodeficiency virus transmission in macaques. Methods: Three groups of rhesus macaques (n = 8 per group) were injected intramus-cularly with Clong acting and challenged intravenously with 17 animal infectious dose 50% SIVmac251 on week 2. Group 1 was injected with 50 mg/kg on week 0 and 4 to evaluate the protective efficacy of the Clong-acting dose used in macaque studies mimicking sexual transmission. Group 2 was injected with 50 mg/kg on week 0 to evaluate the necessity of the second injection of Clong acting for protection against intravenous challenge. Group 3 was injected with 25 mg/kg on week 0 and 50 mg/kg on week 4 to correlate Cplasma concentrations at the time of challenge with protection. Five additional macaques remained untreated as controls. Results: Clong acting was highly protective with 21 of the 24 Clong-actingtreated macaques remaining aviremic, resulting in 88% protection. The plasma Cconcentration at the time of virus challenge appeared to be more important for protection than sustaining therapeutic plasma concentrations with the second Clong acting injection. Conclusion: These results support the clinical investigation of Clong acting as PrEP in people who inject drugs. Copyright (C) 2017 Wolters Kluwer Health, Inc. All rights reserved.
Schwabe T, Li XL, Gaul U
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Dynamic analysis of the mesenchymal-epithelial transition of blood-brain barrier forming glia in Drosophila

BIOLOGY OPEN 2017 FEB 15; 6(2):232-243
During development, many epithelia are formed by a mesenchymal-epithelial transition (MET). Here, we examine the major stages and underlying mechanisms of MET during blood-brain barrier formation in Drosophila. We show that contact with the basal lamina is essential for the growth of the barrier-forming subperineurial glia (SPG). Septate junctions (SJs), which provide insulation of the paracellular space, are not required for MET, but are necessary for the establishment of polarized SPG membrane compartments. In vivo time-lapse imaging reveals that the Moody GPCR signaling pathway regulates SPG cell growth and shape, with different levels of signaling causing distinct phenotypes. Timely, well-coordinated SPG growth is essential for the uniform insertion of SJs and thus the insulating function of the barrier. To our knowledge, this is the first dynamic in vivo analysis of all stages in the formation of a secondary epithelium, and of the key role trimeric G protein signaling plays in this important morphogenetic process.
Fava VM, Sales-Marques C, Alcais A, Moraes MO, Schurr E
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Age-Dependent Association of TNFSF15/TNFSF8 Variants and Leprosy Type 1 Reaction

FRONTIERS IN IMMUNOLOGY 2017 FEB 14; 8(?):? Article 155
A current major challenge in leprosy control is the prevention of permanent disabilities. Host pathological inflammatory responses termed type 1 reaction (T1R) are a leading cause of nerve damage for leprosy patients. The environmental or inherited factors that predispose leprosy cases to undergo T1R are not known. However, studies have shown an important contribution of host genetics for susceptibility to T1R. We have previously identified variants encompassing the TNFSF15/TNFSF8 genes as T1R risk factors in a Vietnamese sample and replicated this association in a Brazilian sample. However, we failed to validate in Brazilian patients the strong association of TNFSF15/TNFSF8 markers rs6478108 and rs7863183 with T1R that we had observed in Vietnamese patients. Here, we investigated if the lack of validation of these variants was due to age-dependent effects on association using four independent population samples, two from Brazil and two from Vietnam. In the combined analysis across the four samples, we observed a strong association of the TNFSF15/TNFSF8 variants rs6478108, rs7863183, and rs3181348 with T1R (p(combined) = 1.5E-05, p(combined) = 1.8E-05, and p(combined) = 6.5E-06, respectively). However, the association of rs6478108 with T1R was more pronounced in leprosy cases under 30 years of age compared to the global sample [odds ratio (OR) = 1.95, 95% confidence interval (CI) = 1.54-2.46, p(combined) = 2.5E-08 versus OR = 1.46, 95% CI = 1.23-1.73, p(combined) = 1.5E-05]. A multivariable analysis indicated that the association of rs6478108 with T1R was independent of either rs7863183 or rs3181348. These three variants are known regulators of the TNFSF8 gene transcription level in multiple tissues. The age dependency of association of rs6478108 and T1R suggests that the genetic control of gene expression varies across the human life span.
Hong SG, Zhou WJ, Fang B, Lu WY, Loro E, Damle M, Ding GL, Jager J, Zhang SS, Zhang YX, Feng D, Chug QW, Dill BD, Molina H, Khurana TS, Rabinowitz JD, Lazar MA, Sun Z
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Dissociation of muscle insulin sensitivity from exercise endurance in mice by HDAC3 depletion

NATURE MEDICINE 2017 FEB; 23(2):223-234
Type 2 diabetes and insulin resistance are associated with reduced glucose utilization in the muscle and poor exercise performance. Here we find that depletion of the epigenome modifier histone deacetylase 3 (HDAC3) specifically in skeletal muscle causes severe systemic insulin resistance in mice but markedly enhances endurance and resistance to muscle fatigue, despite reducing muscle force. This seemingly paradoxical phenotype is due to lower glucose utilization and greater lipid oxidation in HDAC3-depleted muscles, a fuel switch caused by the activation of anaplerotic reactions driven by AMP deaminase 3 (Ampd3) and catabolism of branched-chain amino acids. These findings highlight the pivotal role of amino acid catabolism in muscle fatigue and type 2 diabetes pathogenesis. Further, as genome occupancy of HDAC3 in skeletal muscle is controlled by the circadian clock, these results delineate an epigenomic regulatory mechanism through which the circadian clock governs skeletal muscle bioenergetics. These findings suggest that physical exercise at certain times of the day or pharmacological targeting of HDAC3 could potentially be harnessed to alter systemic fuel metabolism and exercise performance.
Caskey M, Schoofs T, Gruell H, Settler A, Karagounis T, Kreider EF, Murrell B, Pfeifer N, Nogueira L, Oliveira TY, Learn GH, Cohen YZ, Lehmann C, Gillor D, Shimeliovich I, Unson-O'Brien C, Weiland D, Robles A, Kummerle T, Wyen C, Levin R, Witmer-Pack M, Eren K, Ignacio C, Kiss S, West AP, Mouquet H, Zingman BS, Gulick RM, Keler T, Bjorkman PJ, Seaman MS, Hahn BH, Fatkenheuer G, Schlesinger SJ, Nussenzweig MC, Kleine F
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Antibody 10-1074 suppresses viremia in HIV-1-infected individuals

NATURE MEDICINE 2017 FEB; 23(2):185-191
Monoclonal antibody 10-1074 targets the V3 glycan supersite on the HIV-1 envelope (Env) protein. It is among the most potent anti-HIV-1 neutralizing antibodies isolated so far. Here we report on its safety and activity in 33 individuals who received a single intravenous infusion of the antibody. 10-1074 was well tolerated and had a half-life of 24.0 d in participants without HIV-1 infection and 12.8 d in individuals with HIV-1 infection. Thirteen individuals with viremia received the highest dose of 30 mg/kg 10-1074. Eleven of these participants were 10-1074-sensitive and showed a rapid decline in viremia by a mean of 1.52 logic copies/ml. Virologic analysis revealed the emergence of multiple independent 10-1074-resistant viruses in the first weeks after infusion. Emerging escape variants were generally resistant to the related V3-specific antibody PGT121, but remained sensitive to antibodies targeting nonoverlapping epitopes, such as the anti-CD4-binding-site antibodies 3BNC117 and VRC01. The results demonstrate the safety and activity of 10-1074 in humans and support the idea that antibodies targeting the V3 glycan supersite might be useful for the treatment and prevention of HIV-1 infection.
Netzer WJ, Bettayeb K, Sinha SC, Flajolet M, Greengard P, Bustos V
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Gleevec shifts APP processing from a beta-cleavage to a nonamyloidogenic cleavage

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 2017 FEB 7; 114(6):1389-1394
Neurotoxic amyloid-beta peptides (A beta) are major drivers of Alzheimer's disease (AD) and are formed by sequential cleavage of the amyloid precursor protein (APP) by beta-secretase (BACE) and gamma-secretase. Our previous study showed that the anticancer drug Gleevec lowers A beta levels through indirect inhibition of gamma-secretase activity. Here we report that Gleevec also achieves its A beta-lowering effects through an additional cellular mechanism. It renders APP less susceptible to proteolysis by BACE without inhibiting BACE enzymatic activity or the processing of other BACE substrates. This effect closely mimics the phenotype of APP A673T, a recently discovered mutation that protects carriers against AD and age- related cognitive decline. In addition, Gleevec induces formation of a specific set of APP C-terminal fragments, also observed in cells expressing the APP protective mutation and in cells exposed to a conventional BACE inhibitor. These Gleevec phenotypes require an intracellular acidic pH and are independent of tyrosine kinase inhibition, given that a related compound lacking tyrosine kinase inhibitory activity, DV2-103, exerts similar effects on APP metabolism. In addition, DV2-103 accumulates at high concentrations in the rodent brain, where it rapidly lowers A beta levels. This study suggests that long-term treatment with drugs that indirectly modulate BACE processing of APP but spare other BACE substrates and achieve therapeutic concentrations in the brain might be effective in preventing or delaying the onset of AD and could be safer than nonselective BACE inhibitor drugs.
Schaafsma SM, Gagnidze K, Reyes A, Norstedt N, Mansson K, Francis K, Pfaff DW
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Sex-specific gene-environment interactions underlying ASD-like behaviors

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 2017 FEB 7; 114(6):1383-1388
The male bias in the incidence of autism spectrum disorders (ASDs) is one of the most notable characteristics of this group of neurodevelopmental disorders. The etiology of this sex bias is far from known, but pivotal for understanding the etiology of ASDs in general. Here we investigate whether a "three-hit" (genetic load x environmental factor x sex) theory of autism may help explain the male predominance. We found that LPS-induced maternal immune activation caused male-specific deficits in certain social responses in the contactin-associated protein-like 2 (Cntnap2) mouse model for ASD. The three " hits" had cumulative effects on ultrasonic vocalizations at postnatal day 3. Hits synergistically affected social recognition in adulthood: only mice exposed to all three hits showed deficits in this aspect of social behavior. In brains of the same mice we found a significant three-way interaction on corticotropin-releasing hormone receptor-1 (Crhr1) gene expression, in the left hippocampus specifically, which co-occurred with epigenetic alterations in histone H3 N-terminal lysine 4 trimethylation (H3K4me3) over the Crhr1 promoter. Although it is highly likely that multiple (synergistic) interactions may be at work, change in the expression of genes in the hypothalamic-pituitary-adrenal/stress system (e. g., Crhr1) is one of them. The data provide proof-of-principle that genetic and environmental factors interact to cause sex-specific effects that may help explain the male bias in ASD incidence.