Center for Alcohol Research in Epigenetics, Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois; Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois.
Center for Alcohol Research in Epigenetics, Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois; Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, Illinois; Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois.
Biol Psychiatry. 2019 Jun 1;85(11):904-914. doi: 10.1016/j.biopsych.2018.12.021. Epub 2019 Jan 14.
Adolescent intermittent ethanol (AIE) exposure is an emerging risk factor for adult psychopathology, such as anxiety disorders. Enhancer RNAs (eRNAs) are short noncoding RNAs transcribed from enhancer regions that regulate synaptic plasticity-associated gene expression, including Arc, but their role in AIE-induced susceptibility to anxiety in adulthood is unknown.
Rats were exposed to AIE (ethanol exposure 2 days on/off) or intermittent normal saline during postnatal days 28 to 41 and allowed to grow to adulthood for analysis of behavior and biochemical measures. Some AIE rats and rats with intermittent normal saline exposure were exposed to an acute challenge with ethanol in adulthood. Cohorts of alcohol-naïve adult rats were cannulated in the central nucleus of amygdala and infused with either Kdm6b small interfering RNA or an antisense locked nucleic acid oligonucleotide specific to Arc eRNA before behavioral and biochemical analysis.
AIE adult rats displayed heightened anxiety and decreased Arc eRNA expression, which is regulated epigenetically through decreased Kdm6b expression. This triggered condensed chromatin at the synaptic activity response element site and promoter of the Arc gene, facilitating increased negative elongation factor binding to the Arc promoter and decreasing Arc expression in the amygdala. Knockdown of Kdm6b or Arc eRNA expression in the central nucleus of amygdala provoked anxiety in alcohol-naïve adult rats and recapitulated the molecular and epigenetic phenotypes of AIE.
These data suggest that eRNA regulation via epigenetic reprogramming in the amygdala, particularly at the Arc synaptic activity response element site, contributes to adult anxiety after adolescent alcohol exposure.
青少年间歇性乙醇（AIE）暴露是成年期精神病理学（如焦虑障碍）的新兴风险因素。增强子 RNA（eRNA）是从增强子区域转录的短非编码 RNA，可调节与突触可塑性相关的基因表达，包括 Arc，但它们在 AIE 诱导的成年期焦虑易感性中的作用尚不清楚。
大鼠在出生后第 28 至 41 天期间接受 AIE（乙醇暴露 2 天/停 2 天）或间歇性生理盐水暴露，然后成年期进行行为和生化分析。一些 AIE 大鼠和接受间歇性生理盐水暴露的大鼠在成年期接受急性乙醇挑战。一组酒精-naïve 成年大鼠在杏仁中央核内进行套管，并在行为和生化分析之前，用 Kdm6b 小干扰 RNA 或 Arc eRNA 的反义锁核酸寡核苷酸进行灌注。
AIE 成年大鼠表现出焦虑增加和 Arc eRNA 表达减少，这是通过减少 Kdm6b 表达进行表观遗传调控的。这触发了突触活性反应元件位点和 Arc 基因启动子处的染色质浓缩，促进了负延伸因子与 Arc 启动子的结合增加，并减少了杏仁核中的 Arc 表达。杏仁中央核中的 Kdm6b 或 Arc eRNA 表达敲低会引起酒精-naïve 成年大鼠的焦虑，并重现了 AIE 的分子和表观遗传表型。
这些数据表明，通过表观遗传重编程在杏仁核中调节 eRNA，特别是在 Arc 突触活性反应元件位点，可导致青少年期酒精暴露后的成年期焦虑。
