ABSTRACT Alcohol is one of the most widely used addictive drugs in adolescence, and continued use can lead to the development of psychiatric disorders, including alcoholism, in adulthood. Epigenetic processes, such as histone acetylation and DNA methylation mechanisms, have been shown to play a role in neuromaturation by contributing to the stability of gene expression during brain development. The Neurobiology of Adolescent Drinking in Adulthood (NADIA) consortium has revealed that adolescent intermittent ethanol (AIE) exposure produces epigenetic reprogramming in several brain circuits (prefrontal cortex, basal forebrain, hippocampus and amygdala) that persists until adulthood and might be responsible for adult psychopathology. These findings prompt determination of the global epigenome to determine AIE altered specific gene loci within key brain regions. The Epigenetic/Molecular Core is developed to evaluate epigenetic mechanisms in specific brain regions linked to key AIE phenotypes in adulthood. The Epigenetic/Molecular Core will also develop tools for CRISPR/dCas9 approaches for epigenetic editing of target genes to directly link AIE-induced behavioral phenotypes with molecular mechanisms. The objectives of the Core are to provide tools and scientific expertise to test NADIA’s hypotheses that perturbations of epigenetic targets due to AIE may lead to dynamic changes in epigenetic programming leading to transcriptomic changes in key brain areas (prefrontal cortex, amygdala, hippocampus, hypothalamus, and basal forebrain) which are responsible for persistent behavioral and molecular phenotypes in adulthood. These objectives will be achieved with the following proposed work: 1) To examine the status of the epigenome at the whole genome level. We will perform Assay for Transposase-Accessible Chromatin sequencing (ATAC-seq) to determine the locations of open and closed chromatin domains in different brain regions studied across NADIA. The core will provide information on global chromatin states during AIE to each component and identify “hub” genes related to the component’s hypotheses for functional studies. 2) To determine gene specific AIE-induced epigenetic modifications (histone acetylation/methylation/DNA methylation) associated with changes in gene expression. 3) To provide gene specific CRISPR/dCas9 tools for NADIA components. The core will develop and test CRISPR/dCas9 technologies to make epigenetic editing (activating or silencing) at specific gene locations and evaluate both functional and behavioral consequences. These studies will provide a better understanding of AIE-mediated changes in gene expression via epigenetic reprogramming across NADIA components. In addition, we will be able to identify mechanisms that may lead to the development of novel treatment strategies for adult psychopathologies resulting from adolescent binge drinking.

Public Health Relevance: Binge drinking is very common in adolescents and continued alcohol abuse by this population can lead to the development of psychiatric disorders including alcohol use disorder (AUD) in adulthood. The proposed studies will continue to elucidate the molecular mechanisms of adolescent intermittent ethanol (AIE) induced behavioral phenotypes in adulthood that are under investigation by the NADIA consortium. These studies will lead to the development of epigenetic-based therapies for adolescent binge drinking induced adult psychopathology.