Role of glucocorticoid receptor-mediated mRNA decay in alcohol dependence

总结 糖皮质激素受体（GR）信号传导的药理学抑制可以有效地减少酒精摄入， 在大量饮酒的啮齿动物和灵长类动物模型以及饮酒的人类受试者中寻找 使用障碍（AUD）。尽管有大量证据支持GR抑制对糖尿病的治疗潜力， 尽管目前对AUD的治疗尚不清楚，但介导这种效应的分子机制仍不清楚。除了扮演一个 作为转录调节因子，GR可以结合细胞质中的一部分mRNA，并引起它们的快速降解 在配体结合-一个过程称为GR介导的mRNA衰变（GMD）。有趣的是，我们证明了 核糖核酸内切酶RIDA是GMD复合物的关键组分，是最显著的 上调蛋白质在小鼠内侧前额叶皮质（mPFC）在禁欲的历史后， 过量饮酒。本项目将测试假设，过度活跃的GMD有助于 酒精摄入量增加，并强调GR拮抗作用减少戒断小鼠饮酒的能力 慢性间歇性酒精蒸汽吸入所致第一个目标将是确定禁欲是否会增加 过量饮酒者的GMD活性。为此，我们将首先确定与GR结合的mRNA的身份， 在来自酒精未处理小鼠的mPFC样品中，测试GR激活是否导致其快速降解。我们 然后将研究酒精戒断对这些潜在的GMD底物的影响以及GR的能力。 第二个目的是确定是否通过局部RIDA阻断mPFC中的GMD， 不会影响GR转录活性的敲低可以复制GR拮抗作用， 过度饮酒和认知障碍。我们的方法利用了我们在建模方面的专业知识 小鼠中的AUD和操纵小大脑区域中的基因表达，结合最先进的 RNA测序和生物信息学分析的核心资源。拟议的工作将加强我们的 了解驱动小鼠酒精摄入量增加和记忆缺陷的分子机制， 以及GR拮抗剂的作用机制。它将首次探讨GMD在 并可能确定一个新的分子靶点，用于治疗AUD和其他GR相关的神经和 精神疾病

SUMMARY Pharmacological inhibition of glucocorticoid receptor (GR) signaling can efficiently reduce alcohol intake and seeking in rodent and primate models of heavy alcohol drinking, as well as in human subjects with an alcohol use disorder (AUD). Despite the wealth of evidence supporting the therapeutic potential of GR inhibition for the treatment of AUD, the molecular mechanism mediating this effect remains unknown. Aside from acting as a transcriptional regulator, GR can bind a subset of mRNAs in the cytoplasm and elicit their rapid degradation upon ligand binding – a process called GR-mediated mRNA decay (GMD). Intriguingly, we demonstrated that the endoribonuclease RIDA, a critical component of the GMD complex, is among the most significantly upregulated proteins in the mouse medial prefrontal cortex (mPFC) during abstinence following a history of excessive alcohol drinking. The present project will test the hypothesis that hyperactive GMD contributes to alcohol intake escalation and underlies the ability of GR antagonism to reduce alcohol drinking in mice withdrawn from chronic intermittent alcohol vapor inhalation. A first aim will be to determine whether abstinence increases GMD activity in excessive alcohol drinkers. To do so, we will first determine the identity of mRNAs bound to GR in mPFC samples from alcohol-naïve mice and test whether GR activation causes their rapid degradation. We will then examine the effect of alcohol withdrawal on these potential GMD substrates and the ability of GR inhibition to prevent it. A second aim will be to determine whether blocking GMD in the mPFC via local RIDA knockdown, which will not impact GR transcriptional activity, can replicate the effect of GR antagonism on excessive alcohol consumption and cognitive impairment. Our approach capitalizes on our expertise in modeling AUD in mice and manipulating gene expression in small brain regions, combined with access to state-of-the-art core resources for RNA sequencing and bioinformatic analysis. The proposed work will enhance our understanding of the molecular mechanisms driving alcohol intake escalation and memory deficits in mice, as well as the mechanism of action of GR antagonists. It will probe for the first time the relevance of GMD in the brain and may identify a new molecular target for the treatment of AUD and other GR-related neurological and psychiatric disorders.