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90 result(s) for "Choquet, Helene"
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Meta-analysis of 542,934 subjects of European ancestry identifies new genes and mechanisms predisposing to refractive error and myopia
Refractive errors, in particular myopia, are a leading cause of morbidity and disability worldwide. Genetic investigation can improve understanding of the molecular mechanisms that underlie abnormal eye development and impaired vision. We conducted a meta-analysis of genome-wide association studies (GWAS) that involved 542,934 European participants and identified 336 novel genetic loci associated with refractive error. Collectively, all associated genetic variants explain 18.4% of heritability and improve the accuracy of myopia prediction (area under the curve (AUC) = 0.75). Our results suggest that refractive error is genetically heterogeneous, driven by genes that participate in the development of every anatomical component of the eye. In addition, our analyses suggest that genetic factors controlling circadian rhythm and pigmentation are also involved in the development of myopia and refractive error. These results may enable the prediction of refractive error and the development of personalized myopia prevention strategies in the future. Meta-analysis of genome-wide association studies of 542,934 individuals identifies 336 novel loci associated with refractive error and implicates eye development, circadian rhythm and pigmentation pathways in controlling myopia.
A large multiethnic GWAS meta-analysis of cataract identifies new risk loci and sex-specific effects
Cataract is the leading cause of blindness among the elderly worldwide and cataract surgery is one of the most common operations performed in the United States. As the genetic etiology of cataract formation remains unclear, we conducted a multiethnic genome-wide association meta-analysis, combining results from the GERA and UK Biobank cohorts, and tested for replication in the 23andMe research cohort. We report 54 genome-wide significant loci, 37 of which were novel. Sex-stratified analyses identified CASP7 as an additional novel locus specific to women. We show that genes within or near 80% of the cataract-associated loci are significantly expressed and/or enriched-expressed in the mouse lens across various spatiotemporal stages as per iSyTE analysis. Furthermore, iSyTE shows 32 candidate genes in the associated loci have altered gene expression in 9 different gene perturbation mouse models of lens defects/cataract, suggesting their relevance to lens biology. Our work provides further insight into the complex genetic architecture of cataract susceptibility. The genetic basis of cataract is not well understood. Here, the authors perform a genome-wide association multiethnic meta-analysis of cataract, finding 37 new loci and replicating known and new loci. They additionally perform sex-specific analyses, identifying new associations specific to women.
A Large Multiethnic Genome-Wide Association Study of Adult Body Mass Index Identifies Novel Loci
Body mass index (BMI), a proxy measure for obesity, is determined by both environmental (including ethnicity, age, and sex) and genetic factors, with > 400 BMI-associated loci identified to date. However, the impact, interplay, and underlying biological mechanisms among BMI, environment, genetics, and ancestry are not completely understood. To further examine these relationships, we utilized 427,509 calendar year-averaged BMI measurements from 100,418 adults from the single large multiethnic Genetic Epidemiology Research on Adult Health and Aging (GERA) cohort. We observed substantial independent ancestry and nationality differences, including ancestry principal component interactions and nonlinear effects. To increase the list of BMI-associated variants before assessing other differences, we conducted a genome-wide association study (GWAS) in GERA, with replication in the Genetic Investigation of Anthropomorphic Traits (GIANT) consortium combined with the UK Biobank (UKB), followed by GWAS in GERA combined with GIANT, with replication in the UKB. We discovered 30 novel independent BMI loci (P < 5.0 × 10−8) that replicated. We then assessed the proportion of BMI variance explained by sex in the UKB using previously identified loci compared to previously and newly identified loci and found slight increases: from 3.0 to 3.3% for males and from 2.7 to 3.0% for females. Further, the variance explained by previously and newly identified variants decreased with increasing age in the GERA and UKB cohorts, echoed in the variance explained by the entire genome, which also showed gene–age interaction effects. Finally, we conducted a tissue expression QTL enrichment analysis, which revealed that GWAS BMI-associated variants were enriched in the cerebellum, consistent with prior work in humans and mice.
Clinical implications of recent advances in primary open-angle glaucoma genetics
Over the last decade, genetic studies, including genome-wide association studies (GWAS), have accelerated the discovery of genes and genomic regions contributing to primary open-angle glaucoma (POAG), a leading cause of irreversible vision loss. Here, we review the findings of genetic studies of POAG published in English prior to September 2019. In total, 74 genomic regions have been associated at a genome-wide level of significance with POAG susceptibility. Recent POAG GWAS provide not only insight into global and ethnic-specific genetic risk factors for POAG susceptibility across populations of diverse ancestry, but also important functional insights underlying biological mechanisms of glaucoma pathogenesis. In this review, we also summarize the genetic overlap between POAG, glaucoma endophenotypes, such as intraocular pressure and vertical cup–disc ratio (VCDR), and other eye disorders. We also discuss approaches recently developed to increase power for POAG locus discovery and to predict POAG risk. Finally, we discuss the recent development of POAG gene-based therapies and future strategies to treat glaucoma effectively. Understanding the genetic architecture of POAG is essential for an earlier diagnosis of this common eye disorder, predictive testing of at-risk patients, and design of gene-based targeted medical therapies none of which are currently available.
Cigarette smoking behaviors and the importance of ethnicity and genetic ancestry
Cigarette smoking contributes to numerous diseases and is one of the leading causes of death in the United States. Smoking behaviors vary widely across race/ethnicity, but it is not clear why. Here, we examine the contribution of genetic ancestry to variation in two smoking-related traits in 43,485 individuals from four race/ethnicity groups (non-Hispanic white, Hispanic/Latino, East Asian, and African American) from a single U.S. healthcare plan. Smoking prevalence was the lowest among East Asians (22.7%) and the highest among non-Hispanic whites (38.5%). We observed significant associations between genetic ancestry and smoking-related traits. Within East Asians, we observed higher smoking prevalence with greater European (versus Asian) ancestry (P = 9.95 × 10−12). Within Hispanic/Latinos, higher cigarettes per day (CPD) was associated with greater European ancestry (P = 3.34 × 10−25). Within non-Hispanic whites, the lowest number of CPD was observed for individuals of southeastern European ancestry (P = 9.06 × 10−5). These associations remained after considering known smoking-associated loci, education, socioeconomic factors, and marital status. Our findings support the role of genetic ancestry and socioeconomic factors in cigarette smoking behaviors in non-Hispanic whites, Hispanic/Latinos, and East Asians.
A multiethnic genome-wide association study of primary open-angle glaucoma identifies novel risk loci
Primary open-angle glaucoma (POAG) is a leading cause of irreversible vision loss, yet much of the genetic risk remains unaccounted for, especially in African-Americans who have a higher risk for developing POAG. We conduct a multiethnic genome-wide association study (GWAS) of POAG in the GERA cohort, with replication in the UK Biobank (UKB), and vice versa, GWAS in UKB with replication in GERA. We identify 24 loci ( P  < 5.0 × 10 −8 ), including 14 novel, of which 9 replicate (near FMNL2 , PDE7B , TMTC2 , IKZF2 , CADM2 , DGKG , ANKH , EXOC2 , and LMX1B ). Functional studies support intraocular pressure-related influences of FMNL2 and LMX1B , with certain Lmx1b mutations causing high IOP and glaucoma resembling POAG in mice. The newly identified loci increase the proportion of variance explained in each GERA race/ethnicity group, with the largest gain in African-Americans (0.5–3.1%). A meta-analysis combining GERA and UKB identifies 24 additional loci. Our study provides important insights into glaucoma pathogenesis. Primary open-angle glaucoma (POAG) leads to progressive vision loss. Here, Choquet et al. perform genome-wide association analysis for POAG in a multi-ethnic cohort, identify a total of nine novel genetic loci and show relevant function of FMNL2 and LMX1B using cell line and mouse experiments.
A large multi-ethnic genome-wide association study identifies novel genetic loci for intraocular pressure
Elevated intraocular pressure (IOP) is a major risk factor for glaucoma, a leading cause of blindness. IOP heritability has been estimated to up to 67%, and to date only 11 IOP loci have been reported, accounting for 1.5% of IOP variability. Here, we conduct a genome-wide association study of IOP in 69,756 untreated individuals of European, Latino, Asian, and African ancestry. Multiple longitudinal IOP measurements were collected through electronic health records and, in total, 356,987 measurements were included. We identify 47 genome-wide significant IOP-associated loci ( P  < 5 × 10 −8 ); of the 40 novel loci, 14 replicate at Bonferroni significance in an external genome-wide association study analysis of 37,930 individuals of European and Asian descent. We further examine their effect on the risk of glaucoma within our discovery sample. Using longitudinal IOP measurements from electronic health records improves our power to identify new variants, which together explain 3.7% of IOP variation. Intraocular pressure (IOP) is a major risk factor for glaucoma. Here, Choquet and co-authors perform a multi-ethnic genome-wide association study of repeat IOP measurements in 69,756 individuals and identify 40 novel loci, 36 of which show directionally consistent effects in glaucoma.
GLIS1 regulates trabecular meshwork function and intraocular pressure and is associated with glaucoma in humans
Chronically elevated intraocular pressure (IOP) is the major risk factor of primary open-angle glaucoma, a leading cause of blindness. Dysfunction of the trabecular meshwork (TM), which controls the outflow of aqueous humor (AqH) from the anterior chamber, is the major cause of elevated IOP. Here, we demonstrate that mice deficient in the Krüppel-like zinc finger transcriptional factor GLI-similar-1 (GLIS1) develop chronically elevated IOP. Magnetic resonance imaging and histopathological analysis reveal that deficiency in GLIS1 expression induces progressive degeneration of the TM, leading to inefficient AqH drainage from the anterior chamber and elevated IOP. Transcriptome and cistrome analyses identified several glaucoma- and extracellular matrix-associated genes as direct transcriptional targets of GLIS1. We also identified a significant association between GLIS1 variant rs941125 and glaucoma in humans ( P = 4.73 × 10 −6 ), further supporting a role for GLIS1 into glaucoma etiology. Our study identifies GLIS1 as a critical regulator of TM function and maintenance, AqH dynamics, and IOP. Dysfunction of the trabecular meshwork (TM) is the chief cause of elevated intraocular pressure, the major risk factor of glaucoma. Here, the authors identify the transcription factor, GLIS1, as a critical regulator of TM maintenance and intraocular pressure, and as a glaucoma risk gene.
Dysfunction of lipid sensor GPR120 leads to obesity in both mouse and human
Mice deficient in the lipid sensor GPR120 develop obesity, glucose intolerance and fatty liver when fed a high-fat diet, and a loss-of-function variant in the GPR120 gene strongly contributes to increased obesity in human. A signal for obesity The G-protein-coupled receptor GPR120 is a receptor for free fatty acids, and is involved in homeostasis mechanisms such as fat-cell generation and the regulation of appetite. Here it is shown that without GPR120, mice on a high-fat diet develop obesity, glucose intolerance and fatty liver. In humans, GPR120 expression in adipose tissue is shown to be significantly elevated in obesity. The authors also identify a mutation that inhibits GPR120 signalling activity and is associated with an increased risk for obesity in Europeans. Free fatty acids provide an important energy source as nutrients, and act as signalling molecules in various cellular processes 1 , 2 , 3 , 4 . Several G-protein-coupled receptors have been identified as free-fatty-acid receptors important in physiology as well as in several diseases 3 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 . GPR120 (also known as O3FAR1) functions as a receptor for unsaturated long-chain free fatty acids and has a critical role in various physiological homeostasis mechanisms such as adipogenesis, regulation of appetite and food preference 5 , 6 , 14 , 15 , 16 . Here we show that GPR120-deficient mice fed a high-fat diet develop obesity, glucose intolerance and fatty liver with decreased adipocyte differentiation and lipogenesis and enhanced hepatic lipogenesis. Insulin resistance in such mice is associated with reduced insulin signalling and enhanced inflammation in adipose tissue. In human, we show that GPR120 expression in adipose tissue is significantly higher in obese individuals than in lean controls. GPR120 exon sequencing in obese subjects reveals a deleterious non-synonymous mutation (p.R270H) that inhibits GPR120 signalling activity. Furthermore, the p.R270H variant increases the risk of obesity in European populations. Overall, this study demonstrates that the lipid sensor GPR120 has a key role in sensing dietary fat and, therefore, in the control of energy balance in both humans and rodents.
New and sex-specific migraine susceptibility loci identified from a multiethnic genome-wide meta-analysis
Migraine is a common disabling primary headache disorder that is ranked as the most common neurological cause of disability worldwide. Women present with migraine much more frequently than men, but the reasons for this difference are unknown. Migraine heritability is estimated to up to 57%, yet much of the genetic risk remains unaccounted for, especially in non-European ancestry populations. To elucidate the etiology of this common disorder, we conduct a multiethnic genome-wide association meta-analysis of migraine, combining results from the GERA and UK Biobank cohorts, followed by a European-ancestry meta-analysis using public summary statistics. We report 79 loci associated with migraine, of which 45 were novel. Sex-stratified analyses identify three additional novel loci (CPS1, PBRM1, and SLC25A21) specific to women. This large multiethnic migraine study provides important information that may substantially improve our understanding of the etiology of migraine susceptibility.Hélène Choquet et al. identify novel loci associated with migraine in a large multiethnic genome-wide meta-analysis. They find 79 loci associated with migraine, including 45 which have not been previously reported and 3 that were specific to women, and which may lead to an improved understanding of migraine etiology.