Project description:Although genome-wide association studies (GWAS) have identified loci associated with alcohol consumption and alcohol use disorder (AUD), they do not identify which variants are functional. To approach this, we evaluated the impact of variants in 3’ untranslated regions (3’-UTRs) of genes in loci associated with substance use and neurological disorders using a massively parallel reporter assay (MPRA) in neuroblastoma and microglia cells. We identified genes whose 3’-UTR activities are associated with AUD and alcohol consumption by combining variant effects from MPRA with GWAS results. We examined their effects by evaluating gene expression after CRISPR inhibition of neuronal cells.
Project description:Alcohol use disorder (AUD) has a profound public health impact and understanding of the molecular mechanisms underlying the development and progression of AUD remain limited. Many genetic risk loci have been identified for AUD or alcohol consumption, though the neurobiological mechanisms underlying these loci remain largely unknown. DNA methylation (DNAm) differences between individuals with and without AUD can provide insight into the mechanisms that predispose to AUD and consequences of AUD itself. Here, we provide Illumina HumanMethylation EPIC array data generated in nucleus accumbens and dorsolateral prefrontal cortex, both addiction relevant brain tissues, from 119 decedents of European ancestry: 61 controls and 58 cases. From these data we have conducted an epigenome-wide association study (EWAS) and identified several CpG associations with AUD. A subset of the identified CpGs map to genes that were previoulsy identified as associated with substance use behaviors in genetic studies, but the other CpGs map to genes previoulsy unassociated with substance use behaviors and are novel.