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Found 37769 matches. Displaying 6451-6460
Whitaker RC, Dearth-Wesley T, Gooze RA, Becker BD, Gallagher KC, McEwen BS
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Adverse childhood experiences, dispositional mindfulness, and adult health

PREVENTIVE MEDICINE 2014 OCT; 67(?):147-153
Objective. To determine whether greater dispositional mindfulness is associated with better adult health across a range of exposures to adverse childhood experiences (ACEs). Methods. In 2012, a web-based survey of 2160 Pennsylvania Head Start staff was conducted. We assessed ACE score (count of eight categories of childhood adversity), dispositional mindfulness (Cognitive and Affective Mindfulness Scale Revised), and the prevalence of three outcomes: multiple health conditions of (>= 3 of 7 conditions), poor health behavior (>= 2 of 5 behaviors), and poor health-related quality of life (HRQOL) (>= 2 of 5 indicators). Results. Respondents were 97% females, and 23% reported >= 3 ACEs. The prevalences of multiple health conditions, poor health behavior, and poor HRQOL were 29%, 21%, and 13%, respectively. At each level of ACE exposure, health outcomes were better in those with greater mindfulness. For example, among persons reporting >= 3 ACES, those in the highest quartile of mindfulness had a prevalence of multiple health conditions two-thirds that of those in the lowest quartile (adjusted prevalence ratio (95% confidence interval) = 0.66(0.51, 0.86)); for those reporting no ACEs, the ratio was 0.62 (0.41, 0.94). Conclusion. Across a range of exposures to ACEs, greater dispositional mindfulness was associated with fewer health conditions, better health behavior, and better HRQOL. (C) 2014 Elsevier Inc. All rights reserved.
Brown ZZ, Muller MM, Jain SU, Allis CD, Lewis PW, Muir TW
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Strategy for "Detoxification" of a Cancer-Derived Histone Mutant Based on Mapping Its Interaction with the Methyltransferase PRC2

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 2014 OCT 1; 136(39):13498-13501
The histone methyltransferase PRC2 plays a central role in genomic stability and cellular development. Consequently, its misregulation has been implicated in several cancers. Recent work has shown that a histone H3 mutant, where the PRC2 substrate residue Lys27 is replaced by methionine, is also associated with cancer phenotypes and functions as an inhibitor of PRC2. Here we investigate the mechanism of this PRC2 inhibition through kinetic studies and photo-cross-linking. Efficient inhibition is dependent on (1) hydrophobic lysine isosteres blocking the active site, (2) proximal residues, and (3) the H3 tail forming extensive contacts with the EZH2 subunit of PRC2. We further show that naturally occurring post-translational modifications of the same H3 tail, both proximal and distal to K27M, can greatly diminish the inhibition of PRC2. These results suggest that this potent gain of function mutation may be detoxified by modulating alternate chromatin modification pathways.
Zignego AL, Wojcik GL, Cacoub P, Visentini M, Casato M, Mangia A, Latanich R, Charles ED, Gragnani L, Terrier B, Piazzole V, Dustin LB, Khakoon SI, Busch MP, Lauer GM, Kim AY, Alric L, Thomas DL, Duggal P
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Genome-wide association study of hepatitis C virus- and cryoglobulin-related vasculitis

GENES AND IMMUNITY 2014 OCT-NOV; 15(7):500-505
The host genetic basis of mixed cryoglobulin vasculitis is not well understood and has not been studied in large cohorts. A genome-wide association study was conducted among 356 hepatitis C virus (HCV) RNA-positive individuals with cryoglobulin-related vasculitis and 447 ethnically matched, HCV RNA-positive controls. All cases had both serum cryoglobulins and a vasculitis syndrome. A total of 899 641 markers from the Illunnina HumanOmni1-Quad chip were analyzed using logistic regression adjusted for sex, as well as genetically determined ancestry. Replication of select single-nucleotide polymorphisms (SNPs) was conducted using 91 cases and 180 controls, adjusting for sex and country of origin. The most significant associations were identified on chromosome 6 near the NOTCH4 and MHC class II genes. A genome-wide significant association was detected on chromosome 6 at SNP rs9461776 (odds ratio = 2.16, P= 1.16E - 07) between HLA-DRB1 and DQA1: this association was further replicated in additional independent samples (meta-analysis P=7.1 x 10(-9)). A genome-wide significant association with cryoglobulin-related vasculitis was identified with SNPs near NOTCH4 and MHC Class II genes. The two regions are correlated and it is difficult to disentangle which gene is responsible for the association with mixed cryoglobulinemia vasculitis in this extended major histocompatibility complex region.
Hite RK, Butterwick JA, MacKinnon R
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Phosphatidic acid modulation of Kv channel voltage sensor function

ELIFE 2014 OCT 29; 3(?):? Article e04366
Membrane phospholipids can function as potent regulators of ion channel function. This study uncovers and investigates the effect of phosphatidic acid on Kv channel gating. Using the method of reconstitution into planar lipid bilayers, in which protein and lipid components are defined and controlled, we characterize two effects of phosphatidic acid. The first is a non-specific electrostatic influence on activation mediated by electric charge density on the extracellular and intracellular membrane surfaces. The second is specific to the presence of a primary phosphate group, acts only through the intracellular membrane leaflet and depends on the presence of a particular arginine residue in the voltage sensor. Intracellular phosphatidic acid accounts for a nearly 50 mV shift in the midpoint of the activation curve in a direction consistent with stabilization of the voltage sensor's closed conformation. These findings support a novel mechanism of voltage sensor regulation by the signaling lipid phosphatidic acid.
Jacobo A, Hudspeth AJ
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Reaction-diffusion model of hair-bundle morphogenesis

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 2014 OCT 28; 111(43):15444-15449
The hair bundle, an apical specialization of the hair cell composed of several rows of regularly organized stereocilia and a kinocilium, is essential for mechanotransduction in the ear. Its precise organization allows the hair bundle to convert mechanical stimuli to electrical signals; mutations that alter the bundle's morphology often cause deafness. However, little is known about the proteins involved in the process of morphogenesis and how the structure of the bundle arises through interactions between these molecules. We present a mathematical model based on simple reaction-diffusion mechanisms that can reproduce the shape and organization of the hair bundle. This model suggests that the boundary of the cell and the kinocilium act as signaling centers that establish the bundle's shape. The interaction of two proteins forms a hexagonal Turing patterna periodic modulation of the concentrations of the morphogens, sustained by local activation and long-range inhibition of the reactants that sets a blueprint for the location of the stereocilia. Finally we use this model to predict how different alterations to the system might impact the shape and organization of the hair bundle.
Sandrone S, Wiesel T
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Torsten Wiesel Progress in sight

NATURE 2014 OCT 16; 514(7522):S11-S12
Perez-Jimenez R, Alonso-Caballero A, Berkovich R, Franco D, Chen MW, Richard P, Badilla CL, Fernandez JM
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Probing the Effect of Force on HIV-1 Receptor CD4

ACS NANO 2014 OCT; 8(10):10313-10320
Cell-surface proteins are central for the interaction of cells with their surroundings and are also associated with numerous diseases. These molecules are exposed to mechanical forces, but the exact relation between force and the functions and pathologies associated with cell-surface proteins is unclear. An important cell-surface protein is CD4, the primary receptor of HIV-1. Here we show that mechanical force activates conformational and chemical changes on CD4 that may be important during viral attachment. We have used single-molecule force spectroscopy and analysis on HIV-1 infectivity to demonstrate that the mechanical extension of CD4 occurs in a time-dependent manner and correlates with HIV-1 infectivity. We show that Ibalizumab, a monoclonal antibody that blocks HIV-1, prevents the mechanical extension of CD4 domains 1 and 2. Furthermore, we demonstrate that thiol/disulfide exchange in CD4 requires force for exposure of cryptic disulfide bonds. This mechanical perspective provides unprecedented information that can change our understanding on how viruses interact with their hosts.
Tubbs E, Theurey P, Vial G, Bendridi N, Bravard A, Chauvin MA, Ji-Cao J, Zoulim F, Bartosch B, Ovize M, Vidal H, Rieusset J
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Mitochondria-Associated Endoplasmic Reticulum Membrane (MAM) Integrity Is Required for Insulin Signaling and Is Implicated in Hepatic Insulin Resistance

DIABETES 2014 OCT; 63(10):3279-3294
Mitochondria-associated endoplasmic reticulum (ER) membranes (MAMs) are functional domains between both organelles involved in Ca2+ exchange, through the voltage-dependent anion channel (VDAC)-1/glucose-regulated protein 75 (Grp75)/inositol 1,4,5-triphosphate receptor (IP3R)-1 complex, and regulating energy metabolism. Whereas mitochondria! dysfunction, ER stress, and altered Ca2+ homeostasis are associated with altered insulin signaling, the implication of MAM dysfunctions in insulin resistance is unknown. Here we validated an approach based on in situ proximity ligation assay to detect and quantify VDAC1/IP3R1 and Grp75/IP3R1 interactions at the MAM interface. We demonstrated that MAM integrity is required for insulin signaling and that induction of MAM prevented palmitate-induced alterations of insulin signaling in HuH7 cells. Disruption of MAM integrity by genetic or pharmacological inhibition of the mitochondrial MAM protein, cyclophilin D (CypD), altered insulin signaling in mouse and human primary hepatocytes and treatment of CypD knockout mice with mefformin improved both insulin sensitivity and MAM integrity. Furthermore, ER-mitochondria interactions are altered in liver of both ob/ob and diet-induced insulin-resistant mice and improved by rosiglitazone treatment in the latter. Finally, increasing organelle contacts by overexpressing CypD enhanced insulin action in primary hepatocytes of diabetic mice. Collectively, our data reveal a new role of MAM integrity in hepatic insulin action and resistance, providing a novel target for the modulation of insulin action.
Cheung IY, Farazi TA, Ostrovnaya I, Xu H, Tran H, Mihailovic A, Tuschl T, Cheung NKV
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Deep MicroRNA Sequencing Reveals Downregulation of miR-29a in Neuroblastoma Central Nervous System Metastasis

GENES CHROMOSOMES & CANCER 2014 OCT; 53(10):803-814
Central nervous system (CNS) is an increasingly common site of isolated metastasis for patients with Stage 4 neuroblastoma. To explore the microRNA (miRNA) profile of this metastatic process, miRNA sequencing was performed to identify miRNA sequence families with differential expression between tumor pairs (pre-CNS primary and CNS metastasis) from 13 patients with Stage 4 neuroblastoma. Seven miRNA sequence families had distinct expression in CNS metastases when compared with their corresponding pre-CNS primaries. MiR-7 was upregulated (3.75-fold), and miR-21, miR-22, miR-29a, miR-143, miR-199a-1-3p, and miR-199a-1-5p were downregulated (3.5-6.1-fold), all confirmed by quantitative reverse transcription-PCR. MiR-29a, previously shown to be downregulated in a broad spectrum of solid tumors including neuroblastoma, had the most significant decrease in all 13 CNS metastases (P=0.001). Its known onco-targets CDC6, CDK6, and DNMT3A, as well as B7-H3, an inhibitory ligand for T cells, and natural killer cells, were found to have higher differential expression in these 13 CNS metastases when compared with their paired primaries. Additionally, miR-29a expression in primary tumors was significantly lower among patients who eventually relapsed in the CNS. Irrespective of the amplification status of MYCN, which is known to be associated with metastasis, pre-CNS primaries, and CNS metastases had significantly lower miR-29a expression than non-CNS primary tumors. Among MYCN amplified cell lines, those from CNS relapse also had lower miR-29a expression than non-CNS relapse. These findings raised the hypothesis that miR-29a could be a biomarker for neuroblastoma CNS metastasis, and its downregulation may play a pivotal role in CNS progression. (C) 2014 Wiley Periodicals, Inc.
Judd LL, Schettler PJ, Brown ES, Wolkowitz OM, Sternberg EM, Bender BG, Bulloch K, Cidlowski JA, de Kloet ER, Fardet L, Joels M, Leung DYM, McEwen BS, Roozendaal B, Van Rossum EFC, Ahn J, Brown DW, Plitt A, Singh G
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Adverse Consequences of Glucocorticoid Medication: Psychological, Cognitive, and Behavioral Effects

AMERICAN JOURNAL OF PSYCHIATRY 2014 OCT; 171(10):1045-1051
Glucocorticoids are the most commonly prescribed anti-inflammatory/immunosuppressant medications worldwide. This article highlights the risk of clinically significant and sometimes severe psychological, cognitive, and behavioral disturbances that may be associated with glucocorticoid use, as well as ways to prevent and treat these disturbances. An illustrative case vignette is presented describing a patient's experience of cycles of manic-like behavior and depression while on high-dosage prednisone, with long-term cognitive disorganization, vulnerability to stress, and personality changes. Severe neuropsychiatric consequences (including suicide, suicide attempt, psychosis, mania, depression, panic disorder, and delirium, confusion, or disorientation) have been reported to occur in 15.7 per 100 person-years at risk for all glucocorticoid courses, and 22.2 per 100 person-years at risk for first courses. The majority of patients experience less severe but distressing and possibly persistent changes in mood, cognition, memory, or behavior during glucocorticoid treatment or withdrawal. Although prediction of such effects is difficult, risks vary with age, gender, dosage, prior psychiatric history, and several biological markers. Key mechanisms thought to underlie these risk factors are briefly described. Recommendations are given for identifying individual risk factors and for monitoring and managing adverse neuropsychiatric effects of glucocorticoids.