TY - JOUR T1 - Ethanol exposure regulates <em>Gabra1</em> expression via histone deacetylation at the promoter in cultured cortical neurons JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther DO - 10.1124/jpet.117.242446 SP - jpet.117.242446 AU - John Peyton Bohnsack AU - Vraj K Patel AU - A. Leslie Morrow Y1 - 2017/01/01 UR - http://jpet.aspetjournals.org/content/early/2017/08/10/jpet.117.242446.abstract N2 - GABAA-Rs mediate the majority of inhibitory neurotransmission in the adult brain. α1-containing GABAA-Rs are the most prominent subtype in the adult brain, and are important in both homeostatic function and several disease pathologies including alcohol dependence, epilepsy, and stress. Ethanol exposure causes a decrease of α1 transcription and peptide expression both in vivo and in vitro, but the mechanism that controls the transcriptional regulation is unknown. Since ethanol is known to activate epigenetic regulation of gene expression, we tested the hypothesis that ethanol regulates α1 expression through histone modifications in cerebral cortical cultured neurons. We found that class I histone deacetylases (HDACs) regulate ethanol-induced changes in α1 gene and protein expression as pharmacological inhibition or knockdown of HDAC1-3 prevent effects of ethanol exposure. Targeted acetylation of the Gabra1 promoter using CRISPR dCas9-P300 (a nuclease-null Cas9 fused with a histone acetyltransferase) increases acetylation and prevents the decrease of Gabra1 expression. In contrast, there was no effect of a mutant histone acetyltransferase or generic transcriptional activator or targeting P300 to a distant exon. Conversely, using a dCas9-KRAB construct that increases repressive methylation (H3K9me3) does not interfere with ethanol-induced deacetylation. Overall our results indicate that ethanol deacetylates the Gabra1 promoter through class I HDACs and that pharmacological, genetic, or epigenetic intervention prevents decreases in α1 expression in cultured cortical neurons. ER -