Browsing by Author "Kapoor, Manav"

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    A meta-analysis of two genome-wide association studies to identify novel loci for maximum number of alcoholic drinks
    (Springer, 2013) Kapoor, Manav; Wang, Jen-Chyong; Wetherill, Leah; Le, Nhung; Bertelsen, Sarah; Hinrichs, Anthony L.; Budde, John; Agrawal, Arpana; Bucholz, Kathleen; Dick, Danielle; Harari, Oscar; Hesselbrock, Victor; Kramer, John; Nurnberger, John I., Jr.; Rice, John; Saccone, Nancy; Schuckit, Marc; Tischfield, Jay; Porjesz, Bernice; Edenberg, Howard J.; Bierut, Laura; Foroud, Tatiana; Goate, Alison; Medical and Molecular Genetics, School of Medicine
    Maximum number of alcoholic drinks consumed in a 24-h period (maxdrinks) is a heritable (>50 %) trait and is strongly correlated with vulnerability to excessive alcohol consumption and subsequent alcohol dependence (AD). Several genome-wide association studies (GWAS) have studied alcohol dependence, but few have concentrated on excessive alcohol consumption. We performed two GWAS using maxdrinks as an excessive alcohol consumption phenotype: one in 118 extended families (N = 2,322) selected from the Collaborative Study on the Genetics of Alcoholism (COGA), and the other in a case-control sample (N = 2,593) derived from the Study of Addiction: Genes and Environment (SAGE). The strongest association in the COGA families was detected with rs9523562 (p = 2.1 × 10(-6)) located in an intergenic region on chromosome 13q31.1; the strongest association in the SAGE dataset was with rs67666182 (p = 7.1 × 10(-7)), located in an intergenic region on chromosome 8. We also performed a meta-analysis with these two GWAS and demonstrated evidence of association in both datasets for the LMO1 (p = 7.2 × 10(-7)) and PLCL1 genes (p = 4.1 × 10(-6)) with maxdrinks. A variant in AUTS2 and variants in INADL, C15orf32 and HIP1 that were associated with measures of alcohol consumption in a meta-analysis of GWAS studies and a GWAS of alcohol consumption factor score also showed nominal association in the current meta-analysis. The present study has identified several loci that warrant further examination in independent samples. Among the top SNPs in each of the dataset (p ≤ 10(-4)) far more showed the same direction of effect in the other dataset than would be expected by chance (p = 2 × 10(-3), 3 × 10(-6)), suggesting that there are true signals among these top SNPs, even though no SNP reached genome-wide levels of significance.
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    Allele-specific expression and high-throughput reporter assay reveal functional genetic variants associated with alcohol use disorders
    (Springer Nature, 2021-04) Rao, Xi; Thapa, Kriti S.; Chen, Andy B.; Lin, Hai; Gao, Hongyu; Reiter, Jill L.; Hargreaves, Katherine A.; Ipe, Joseph; Lai, Dongbing; Xuei, Xiaoling; Wang, Yue; Gu, Hongmei; Kapoor, Manav; Farris, Sean P.; Tischfield, Jay; Foroud, Tatiana; Goate, Alison M.; Skaar, Todd C.; Mayfield, R. Dayne; Edenberg, Howard J.; Liu, Yunlong; Medical and Molecular Genetics, School of Medicine
    Genome-wide association studies (GWAS) of complex traits, such as alcohol use disorders (AUD), usually identify variants in non-coding regions and cannot by themselves distinguish whether the associated variants are functional or in linkage disequilibrium with the functional variants. Transcriptome studies can identify genes whose expression differs between alcoholics and controls. To test which variants associated with AUD may cause expression differences, we integrated data from deep RNA-seq and GWAS of four postmortem brain regions from 30 subjects with AUD and 30 controls to analyze allele-specific expression (ASE). We identified 88 genes with differential ASE in subjects with AUD compared to controls. Next, to test one potential mechanism contributing to the differential ASE, we analyzed single nucleotide polymorphisms (SNPs) in the 3′ untranslated regions (3′UTR) of these genes. Of the 88 genes with differential ASE, 61 genes contained 437 SNPs in the 3′UTR with at least one heterozygote among the subjects studied. Using a modified PASSPORT-seq (parallel assessment of polymorphisms in miRNA target-sites by sequencing) assay, we identified 25 SNPs that affected RNA levels in a consistent manner in two neuroblastoma cell lines, SH-SY5Y and SK-N-BE(2). Many of these SNPs are in binding sites of miRNAs and RNA-binding proteins, indicating that these SNPs are likely causal variants of AUD-associated differential ASE. In sum, we demonstrate that a combination of computational and experimental approaches provides a powerful strategy to uncover functionally relevant variants associated with the risk for AUD.
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    Allele-specific expression and high-throughput reporter assay reveal functional genetic variants associated with alcohol use disorders.
    (Springer, 2021-04) Rao, Xi; Thapa, Kriti S.; Chen, Andy B.; Lin, Hai; Gao, Hongyu; Reiter, Jill L.; Hargreaves, Katherine A.; Ipe, Joseph; Lai, Dongbing; Xuei, Xiaoling; Wang, Yue; Gu, Hongmei; Kapoor, Manav; Farris, Sean P.; Tischfield, Jay; Foroud, Tatiana; Goate, Alison M.; Skaar, Todd C.; Mayfield, R. Dayne; Edenberg, Howard J.; Liu, Yunlong
    Genome-wide association studies (GWAS) of complex traits, such as alcohol use disorders (AUD), usually identify variants in non-coding regions and cannot by themselves distinguish whether the associated variants are functional or in linkage disequilibrium with the functional variants. Transcriptome studies can identify genes whose expression differs between alcoholics and controls. To test which variants associated with AUD may cause expression differences, we integrated data from deep RNA-seq and GWAS of four postmortem brain regions from 30 subjects with AUD and 30 controls to analyze allele-specific expression (ASE). We identified 88 genes with differential ASE in subjects with AUD compared to controls. Next, to test one potential mechanism contributing to the differential ASE, we analyzed single nucleotide polymorphisms (SNPs) in the 3' untranslated regions (3'UTR) of these genes. Of the 88 genes with differential ASE, 61 genes contained 437 SNPs in the 3'UTR with at least one heterozygote among the subjects studied. Using a modified PASSPORT-seq (parallel assessment of polymorphisms in miRNA target-sites by sequencing) assay, we identified 25 SNPs that affected RNA levels in a consistent manner in two neuroblastoma cell lines, SH-SY5Y and SK-N-BE(2). Many of these SNPs are in binding sites of miRNAs and RNA-binding proteins, indicating that these SNPs are likely causal variants of AUD-associated differential ASE. In sum, we demonstrate that a combination of computational and experimental approaches provides a powerful strategy to uncover functionally relevant variants associated with the risk for AUD.
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    Analysis of whole genome-transcriptomic organization in brain to identify genes associated with alcoholism
    (Springer Nature, 2019-02-14) Kapoor, Manav; Wang, Jen-Chyong; Farris, Sean P.; Liu, Yunlong; McClintick, Jeanette; Gupta, Ishaan; Meyers, Jacquelyn L.; Bertelsen, Sarah; Chao, Michael; Nurnberger, John; Tischfield, Jay; Harari, Oscar; Zeran, Li; Hesselbrock, Victor; Bauer, Lance; Raj, Towfique; Porjesz, Bernice; Agrawal, Arpana; Foroud, Tatiana; Edenberg, Howard J.; Mayfield, R. Dayne; Goate, Alison; Medical and Molecular Genetics, School of Medicine
    Alcohol exposure triggers changes in gene expression and biological pathways in human brain. We explored alterations in gene expression in the Pre-Frontal Cortex (PFC) of 65 alcoholics and 73 controls of European descent, and identified 129 genes that showed altered expression (FDR < 0.05) in subjects with alcohol dependence. Differentially expressed genes were enriched for pathways related to interferon signaling and Growth Arrest and DNA Damage-inducible 45 (GADD45) signaling. A coexpression module (thistle2) identified by weighted gene co-expression network analysis (WGCNA) was significantly correlated with alcohol dependence, alcohol consumption, and AUDIT scores. Genes in the thistle2 module were enriched with genes related to calcium signaling pathways and showed significant downregulation of these pathways, as well as enrichment for biological processes related to nicotine response and opioid signaling. A second module (brown4) showed significant upregulation of pathways related to immune signaling. Expression quantitative trait loci (eQTLs) for genes in the brown4 module were also enriched for genetic associations with alcohol dependence and alcohol consumption in large genome-wide studies included in the Psychiatric Genetic Consortium and the UK Biobank's alcohol consumption dataset. By leveraging multi-omics data, this transcriptome analysis has identified genes and biological pathways that could provide insight for identifying therapeutic targets for alcohol dependence.
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    Association of Polygenic Liability for Alcohol Dependence and EEG Connectivity in Adolescence and Young Adulthood
    (MDPI, 2019-10-17) Meyers, Jacquelyn L.; Chorlian, David B.; Johnson, Emma C.; Pandey, Ashwini K.; Kamarajan, Chella; Salvatore, Jessica E.; Aliev, Fazil; Subbie-Saenz de Viteri, Stacey; Zhang, Jian; Chao, Michael; Kapoor, Manav; Hesselbrock, Victor; Kramer, John; Kuperman, Samuel; Nurnberger, John; Tischfield, Jay; Goate, Alison; Foroud, Tatiana; Dick, Danielle M.; Edenberg, Howard J.; Agrawal, Arpana; Porjesz, Bernice; Medical and Molecular Genetics, School of Medicine
    Differences in the connectivity of large-scale functional brain networks among individuals with alcohol use disorders (AUD), as well as those at risk for AUD, point to dysfunctional neural communication and related cognitive impairments. In this study, we examined how polygenic risk scores (PRS), derived from a recent GWAS of DSM-IV Alcohol Dependence (AD) conducted by the Psychiatric Genomics Consortium, relate to longitudinal measures of interhemispheric and intrahemispheric EEG connectivity (alpha, theta, and beta frequencies) in adolescent and young adult offspring from the Collaborative Study on the Genetics of Alcoholism (COGA) assessed between ages 12 and 31. Our findings indicate that AD PRS (p-threshold < 0.001) was associated with increased fronto-central, tempo-parietal, centro-parietal, and parietal-occipital interhemispheric theta and alpha connectivity in males only from ages 18-31 (beta coefficients ranged from 0.02-0.06, p-values ranged from 10-6-10-12), but not in females. Individuals with higher AD PRS also demonstrated more performance deficits on neuropsychological tasks (Tower of London task, visual span test) as well as increased risk for lifetime DSM-5 alcohol and opioid use disorders. We conclude that measures of neural connectivity, together with neurocognitive performance and substance use behavior, can be used to further understanding of how genetic risk variants from large GWAS of AUD may influence brain function. In addition, these data indicate the importance of examining sex and developmental effects, which otherwise may be masked. Understanding of neural mechanisms linking genetic variants emerging from GWAS to risk for AUD throughout development may help to identify specific points when neurocognitive prevention and intervention efforts may be most effective.
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    Association of substance dependence phenotypes in the COGA sample
    (Wiley, 2015-05) Wetherill, Leah; Agrawal, Arpana; Kapoor, Manav; Bertelsen, Sarah; Bierut, Laura J.; Brooks, Andrew; Dick, Danielle; Hesselbrock, Michie; Hesselbrock, Victor; Koller, Daniel L.; Le, Nhung; Nurnberger Jr., John I.; Salvatore, Jessica E.; Schuckit, Marc; Tischfield, Jay A.; Wang, Jen-Chyong; Xuei, Xiaoling; Edenberg, Howard J.; Porjesz, Bernice; Bucholz, Kathleen; Goate, Alison M.; Foroud, Tatiana; Department of Medical & Molecular Genetics, IU School of Medicine
    Alcohol and drug use disorders are individually heritable (50%). Twin studies indicate that alcohol and substance use disorders share common genetic influences, and therefore may represent a more heritable form of addiction and thus be more powerful for genetic studies. This study utilized data from 2322 subjects from 118 European-American families in the Collaborative Study on the Genetics of Alcoholism sample to conduct genome-wide association analysis of a binary and a continuous index of general substance dependence liability. The binary phenotype (ANYDEP) was based on meeting lifetime criteria for any DSM-IV dependence on alcohol, cannabis, cocaine or opioids. The quantitative trait (QUANTDEP) was constructed from factor analysis based on endorsement across the seven DSM-IV criteria for each of the four substances. Heritability was estimated to be 54% for ANYDEP and 86% for QUANTDEP. One single-nucleotide polymorphism (SNP), rs2952621 in the uncharacterized gene LOC151121 on chromosome 2, was associated with ANYDEP (P = 1.8 × 10(-8) ), with support from surrounding imputed SNPs and replication in an independent sample [Study of Addiction: Genetics and Environment (SAGE); P = 0.02]. One SNP, rs2567261 in ARHGAP28 (Rho GTPase-activating protein 28), was associated with QUANTDEP (P = 3.8 × 10(-8) ), and supported by imputed SNPs in the region, but did not replicate in an independent sample (SAGE; P = 0.29). The results of this study provide evidence that there are common variants that contribute to the risk for a general liability to substance dependence.
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    Cis-Regulatory Variants Affect CHRNA5 mRNA Expression in Populations of African and European Ancestry
    (Public Library of Science, 2013-11-26) Wang, Jen-Chyong; Spiegel, Noah; Bertelsen, Sarah; Le, Nhung; McKenna, Nicholas; Budde, John P.; Harari, Oscar; Kapoor, Manav; Brooks, Andrew; Hancock, Dana; Tischfield, Jay; Foroud, Tatiana; Bierut, Laura J.; Steinbach, Joe Henry; Edenberg, Howard J.; Traynor, Bryan J.; Goate, Alison M.; Medical and Molecular Genetics, School of Medicine
    Variants within the gene cluster encoding α3, α5, and β4 nicotinic receptor subunits are major risk factors for substance dependence. The strongest impact on risk is associated with variation in the CHRNA5 gene, where at least two mechanisms are at work: amino acid variation and altered mRNA expression levels. The risk allele of the non-synonymous variant (rs16969968; D398N) primarily occurs on the haplotype containing the low mRNA expression allele. In populations of European ancestry, there are approximately 50 highly correlated variants in the CHRNA5-CHRNA3-CHRNB4 gene cluster and the adjacent PSMA4 gene region that are associated with CHRNA5 mRNA levels. It is not clear which of these variants contribute to the changes in CHRNA5 transcript level. Because populations of African ancestry have reduced linkage disequilibrium among variants spanning this gene cluster, eQTL mapping in subjects of African ancestry could potentially aid in defining the functional variants that affect CHRNA5 mRNA levels. We performed quantitative allele specific gene expression using frontal cortices derived from 49 subjects of African ancestry and 111 subjects of European ancestry. This method measures allele-specific transcript levels in the same individual, which eliminates other biological variation that occurs when comparing expression levels between different samples. This analysis confirmed that substance dependence associated variants have a direct cis-regulatory effect on CHRNA5 transcript levels in human frontal cortices of African and European ancestry and identified 10 highly correlated variants, located in a 9 kb region, that are potential functional variants modifying CHRNA5 mRNA expression levels.
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    Ethanol Activates Immune Response In Lymphoblastoid Cells
    (Elsevier, 2019) McClintick, Jeanette N.; Tischfield, Jay A.; Deng, Li; Kapoor, Manav; Xuei, Xiaoling; Edenberg, Howard J.; Biochemistry and Molecular Biology, School of Medicine
    The short term effects of alcohol on gene expression in brain tissue cannot directly be studied in humans. Because neuroimmune signaling is altered by alcohol, immune cells are a logical, accessible choice to study and might provide biomarkers. RNAseq was used to study the effects of 48 h exposure to ethanol on lymphoblastoid cell lines (LCLs) from 21 alcoholics and 21 controls. Ethanol exposure resulted in differential expression of 4,577 of the 12,526 genes detectably expressed in the LCLs (FDR ≤ 0.05); 55% of these showed increased expression. Cells from alcoholics and controls responded similarly. The genes whose expression changed fell into many pathways. NFκB, neuroinflammation, IL-6, and dendritic cell maturation pathways were activated, consistent with increased signaling by NFκB, TNF, TGFβ, IL1, IL4, IL18, TLR4, and LPS. Signaling by Interferons A and B decreased, which may be responsible for a slightly blunted immune response compared to 24 h ethanol treatment. EIF2, phospholipase C and VEGF signaling were decreased. Baseline gene expression patterns were similar in LCLs from alcoholics and controls. At relaxed stringency (p<0.05), 1164 genes differed, 340 of which were also affected by ethanol. There was a suggestion of compensation, with 77% showing opposing fold changes. Aldosterone signaling and phospholipase C signaling differed. The pattern of expression was consistent with increased signaling by several cytokines and TLR2 in alcoholics. The cholesterol biosynthesis pathway was lower in alcoholics, including a decrease in the rate-limiting enzyme HMGCR. LCLs show many effects of ethanol exposure, some of which might provide biomarkers for AUD and aid in interpreting the effects of genes identified by GWAS.
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    Exome chip meta-analysis fine maps causal variants and elucidates the genetic architecture of rare coding variants in smoking and alcohol use
    (Elsevier, 2018) Brazel, David M.; Jiang, Yu; Hughey, Jordan M.; Turcot, Valérie; Zhan, Xiaowei; Gong, Jian; Batini, Chiara; Weissenkampen, J. Dylan; Liu, MengZhen; Barnes, Daniel R.; Bertelsen, Sarah; Chou, Yi-Ling; Erzurumluoglu, A. Mesut; Faul, Jessica D.; Haessler, Jeff; Hammerschlag, Anke R.; Hsu, Chris; Kapoor, Manav; Lai, Dongbing; Le, Nhung; de Leeuw, Christiaan A.; Loukola, Anu; Mangino, Massimo; Melbourne, Carl A.; Pistis, Giorgio; Qaiser, Beenish; Rohde, Rebecca; Shao, Yaming; Stringham, Heather; Wetherill, Leah; Zhao, Wei; Agrawal, Arpana; Bierut, Laura; Chen, Chu; Eaton, Charles B.; Goate, Alison; Haiman, Christopher; Heath, Andrew; Iacono, William G.; Martin, Nicholas G.; Polderman, Tinca J.; Reiner, Alex; Rice, John; Schlessinger, David; Scholte, H. Steven; Smith, Jennifer A.; Tardif, Jean-Claude; Tindle, Hilary A.; van der Leij, Andries R.; Boehnke, Michael; Chang-Claude, Jenny; Cucca, Francesco; David, Sean P.; Foroud, Tatiana; Howson, Joanna M. M.; Kardia, Sharon L. R.; Kooperberg, Charles; Laakso, Markku; Lettre, Guillaume; Madden, Pamela; McGue, Matt; North, Kari; Posthuma, Danielle; Spector, Timothy; Stram, Daniel; Tobin, Martin D.; Weir, David R.; Kaprio, Jaakko; Abecasis, Gonçalo R.; Liu, Dajiang J.; Vrieze, Scott; Medical and Molecular Genetics, School of Medicine
    Background Smoking and alcohol use have been associated with common genetic variants in multiple loci. Rare variants within these loci hold promise in the identification of biological mechanisms in substance use. Exome arrays and genotype imputation can now efficiently genotype rare nonsynonymous and loss of function variants. Such variants are expected to have deleterious functional consequences, and contribute to disease risk. Methods We analyzed ∼250,000 rare variants from 16 independent studies genotyped with exome arrays and augmented this dataset with imputed data from the UK Biobank. Associations were tested for five phenotypes: cigarettes per day, pack years, smoking initiation, age of smoking initiation, and alcoholic drinks per week. We conducted stratified heritability analyses, single-variant tests, and gene-based burden tests of nonsynonymous/loss of function coding variants. We performed a novel fine mapping analysis to winnow the number of putative causal variants within associated loci. Results Meta-analytic sample sizes ranged from 152,348-433,216, depending on the phenotype. Rare coding variation explained 1.1-2.2% of phenotypic variance, reflecting 11%-18% of the total SNP heritability of these phenotypes. We identified 171 genome-wide associated loci across all phenotypes. Fine mapping identified putative causal variants with double base-pair resolution at 24 of these loci, and between 3 and 10 variants for 65 loci. 20 loci contained rare coding variants in the 95% credible intervals. Conclusions Rare coding variation significantly contributes to the heritability of smoking and alcohol use. Fine mapping GWAS loci identifies specific variants contributing to the biological etiology of substance use behavior.
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    Family-based association analysis of alcohol dependence criteria and severity
    (Wiley Blackwell (Blackwell Publishing), 2014-02) Wetherill, Leah; Kapoor, Manav; Agrawal, Arpana; Bucholz, Kathleen; Koller, Daniel; Bertelsen, Sarah E.; Le, Nhung; Wang, Jen-Chyong; Almasy, Laura; Hesselbrock, Victor; Kramer, John; Nurnberger, John I.; Schuckit, Marc; Tischfield, Jay A.; Xuei, Xiaoling; Porjesz, Bernice; Edenberg, Howard J.; Goate, Alison M.; Foroud, Tatiana; Department of Medical and Molecular Genetics, IU School of Medicine
    Background Despite the high heritability of alcohol dependence (AD), the genes found to be associated with it account for only a small proportion of its total variability. The goal of this study was to identify and analyze phenotypes based on homogeneous classes of individuals to increase the power to detect genetic risk factors contributing to the risk of AD. Methods The 7 individual DSM-IV criteria for AD were analyzed using latent class analysis (LCA) to identify classes defined by the pattern of endorsement of the criteria. A genome-wide association study was performed in 118 extended European American families (n = 2,322 individuals) densely affected with AD to identify genes associated with AD, with each of the seven DSM-IV criteria, and with the probability of belonging to two of three latent classes. Results Heritability for DSM-IV AD was 61%, and ranged from 17-60% for the other phenotypes. A SNP in the olfactory receptor OR51L1 was significantly associated (7.3 × 10−8) with the DSM-IV criterion of persistent desire to, or inability to, cut down on drinking. LCA revealed a three-class model: the “low risk” class (50%) rarely endorsed any criteria, and none met criteria for AD; the “moderate risk” class (33) endorsed primarily 4 DSM-IV criteria, and 48% met criteria for AD; the “high risk” class (17%) manifested high endorsement probabilities for most criteria and nearly all (99%) met criteria for AD One single nucleotide polymorphism (SNP) in a sodium leak channel NALCN demonstrated genome-wide significance with the high risk class (p=4.1 × 10−8). Analyses in an independent sample did not replicate these associations. Conclusion We explored the genetic contribution to several phenotypes derived from the DSM-IV alcohol dependence criteria. The strongest evidence of association was with SNPs in NALCN and OR51L1.