MiR-9 regulation of beta-catenin mediated alcohol tolerance and EtOH consumption

项目总结 MiRNA调节Wnt/β-catenin触发BK通道酒精耐受 促进消费 研究发现，大电导电压和钙激活通道(BK)是 神经元兴奋性的关键调节因子与行为酒精耐受遗传相关 无脊椎动物。同样，在哺乳动物中，通过敲除BK通道的酒精敏感性 它的4个亚基导致小鼠自愿饮酒增加。对乙醇的敏感度 分子水平的特征是通道活动的急性增强。然而，不同的 BK通道的异构体在酒精敏感性上表现出不同的变化，并且是不同的分布 在质膜表面对长时间暴露的反应，也称为持久性 酒精耐量(PMT)。结合活性的酒精敏感异构体的miRNA靶向 乙醇对BK通道的内化被认为是建立 在纹状体内产生持续变化的动态平衡适应。这些 机制可以独立运行，相同的终点是增加 表示酒精不敏感的BK通道或交互以协调和优化这些通道 在法规的翻译和贩运层面上持续不断的适应性变化。 我们目前项目的结果已经确定Wnt/β-连环蛋白信号通路是一个关键 乙醇暴露6小时后BK通道表面重分布的调节因子。我们有 将其描述为一种长期的神经元可塑性，这需要蛋白质合成 结果，在超过24小时的停药后，ç-连环蛋白的表达和持久性增加。激活 ？？连环蛋白信号与人类癌细胞中miR-9的上调有关， MiRNA在抑郁症复原性小鼠中的表达。值得注意的是，miR-9在 纹状体是PMT介导BK通道急性无水乙醇脱敏的关键事件。因此， 这一建议的主要假设是，持续地进行一次类似狂欢的6小时暴露 通过miRNA调节的Wnt/β连接蛋白改变BK通道在NAc内的表面分布 发出信号，影响随后的饮酒。我们将使用电生理学、分子生物学 生物学、行为分析和成像技术确定Wnt/？连环蛋白的作用 在纹状体内BK运输和miRNA调节中的信号转导，其目标是 确定新的治疗靶点，以防止从最初到 强迫性饮酒行为。

PROJECT SUMMARY miRNA regulation of Wnt/beta-catenin triggers BK channel alcohol tolerance and facilitated consumption Research has identified the large conductance voltage- and calcium-activated channel (BK) as a key regulator of neuronal excitability genetically associated to behavioral alcohol tolerance in invertebrates. Similarly in mammals, decreasing BK channel alcohol sensitivity by knocking out its ß4 subunit leads to increased alcohol voluntary consumption in mice. Sensitivity to ethanol at the molecular level is characterized by acute potentiation of channel activity. However, different isoforms of the BK channel show variations in alcohol sensitivity and are differentially distributed on the plasma membrane surface in response to prolonged exposure, also known as persistent alcohol tolerance (PMT). miRNA targeting of alcohol-sensitive isoforms coupled with active internalization of BK channels in response to ethanol are believed to be key in establishing homeostatic adaptations that produce persistent changes within the striatum. These mechanisms may operate independently, with the same end point of increasing the representation of alcohol insensitive BK channels or interact to orchestrate and optimize these persistent adaptive changes at the translational and trafficking level of regulation. Results from our current project have identified the Wnt/β-catenin signaling pathway as a key regulator of BK channel surface redistribution in response to 6hr ethanol exposure. We have characterized this as a form of long-term neuronal plasticity, which requires protein synthesis resulting in increased ß-catenin expression and persistence, past 24hr withdrawal. Activation of ß-catenin signaling has been linked to miR-9 upregulation in human cancer cells, as well as, miRNA expression in depression-resilient mice. Notably, miR-9 upregulated expression in the striatum is a key event in PMT mediating acute EtOH desensitization of BK channels. Thus, the overarching hypothesis of this proposal is that a single “binge-like” 6hr exposure persistently alters BK channel surface distribution within the NAc via miRNA regulated Wnt/β-catenin signaling, impacting subsequent alcohol consumption. We will use electrophysiology, molecular biology, behavioral assays and imaging techniques to determine the role of Wnt/ß-catenin signaling in both BK trafficking and miRNA regulation within the striatum with the goal of identifying novel therapeutic targets involved in preventing the transition from initial to compulsive drinking behavior.