Role of glucocorticoid receptor-mediated mRNA decay in alcohol dependence

摘要 药物抑制糖皮质激素受体(GR)信号通路可有效减少酒精摄入量和 在啮齿动物和灵长类动物中寻找大量饮酒的模型，以及在有酒精的人类受试者中寻找 使用障碍(澳元)。尽管有丰富的证据支持GR抑制对高血压的治疗潜力 AUD的治疗，其分子机制尚不清楚。除了充当 转录调节因子GR可以结合细胞质中的一部分mRNAs，并引起它们的快速降解 在配基结合时-这一过程称为GR介导的mRNA衰变(GMD)。有趣的是，我们展示了 内切核糖核酸酶RIDA是GMD复合体的关键组成部分，是最重要的 小鼠戒断过程中内侧前额叶皮质(MPFC)蛋白质的上调 过度饮酒。目前的项目将检验过度活跃的GMD有助于 酒精摄入量增加，这是GR拮抗作用减少戒断小鼠饮酒的基础 慢性间歇性酒精蒸气吸入所致。第一个目标将是确定节欲是否会增加 过量饮酒者的GMD活性。为此，我们将首先确定与GR结合的mRNAs的身份 在酒精幼稚小鼠的mPFC样本中，检测GR激活是否会导致它们的快速降解。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 用抑制来阻止它。第二个目标是确定是否通过局部RIDA阻断mPFC中的GMD 基因敲除不会影响GR的转录活性，可以复制GR拮抗作用。 过度饮酒和认知障碍。我们的方法充分利用了我们在建模方面的专业知识 小鼠的AUD和操纵大脑小区域的基因表达，以及获得最先进的 核糖核酸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 了解导致小鼠酒精摄入量增加和记忆障碍的分子机制 以及GR拮抗剂的作用机制。它将首次探讨GMD在 并可能为治疗AUD和其他与GR相关的神经和 精神障碍。

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contributes to alcohol intake escalation and underlies the ability of GR antagonism to reduce alcohol drinking in mice withdrawn from chronic intermittent alcohol vapor inhalation.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.