Cocaine self-administration and cholesterol metabolism

项目摘要 疾病控制和预防中心报告说，涉及可卡因的死亡率正在上升。 可卡因使用障碍（CUD）目前尚无有效的药物治疗方法。辅酶A结合到 多巴胺转运蛋白（DAT），抑制多巴胺（DA）再摄取，从而提高细胞外DA水平， 纹状体纹状体DA升高与人类主观欣快体验相关。最近 对CUD患者神经影像学的荟萃分析表明，急性可卡因诱导的DA升高是 钝的这种失调可能导致可卡因寻求和服用行为的重复循环， 意外过量一个关键的知识缺口是可卡因-DAT相互作用如何被慢性 可卡因暴露DAT在富含胆固醇的膜中采用面向外的构象 环境以适应高亲和力可卡因结合。胆固醇稳态的扰动 细胞和离体破坏可卡因-DAT相互作用。我们的初步数据显示可卡因SA 纹状体胆固醇含量，重要的是，离体胆固醇补充到纹状体突触体 提高可卡因抑制DA再摄取的能力。根据这些意见，本提案将 研究可卡因调节脑胆固醇的一种以前未知的分子机制 代谢介导可卡因-DAT相互作用。我们将探讨是否药理学和遗传学 调节胆固醇含量是减轻可卡因-DAT相互作用中断的新途径， 减少可卡因自我给药。

Project Summary The Center for Disease Control and Prevention reports that death rates involving cocaine are on the rise. There is still no effective pharmacological treatment for cocaine use disorder (CUD). Cocaine binds to the dopamine transporter (DAT), inhibiting dopamine (DA) reuptake and thus elevating extracellular DA levels in the striatum. Striatal DA elevation is associated with subjective experience of euphoria in humans. Recent meta-analysis of neuroimaging in patients with CUD indicates that acute cocaine-induced elevation of DA is blunted. This dysregulation likely contributes to repeated cycles of cocaine-seeking and taking behavior and accidental overdoses. A critical knowledge gap is how cocaine-DAT interactions are disrupted by chronic cocaine exposure. DAT adopts an outward-facing conformation in a cholesterol-enriched membrane environment to accommodate high-affinity cocaine binding. Perturbation of cholesterol homeostasis in cultured cells and ex vivo disrupts cocaine-DAT interactions. Our preliminary data show that cocaine SA reduces striatal cholesterol content and importantly, ex vivo cholesterol replenishment to striatal synaptosomes improves the ability of cocaine to inhibit DA reuptake. Based on these observations, this proposal will investigate a previously unknown molecular mechanism whereby cocaine modulation of brain cholesterol metabolism mediates cocaine-DAT interactions. We will explore whether pharmacological and genetic modulation of cholesterol content is a new avenue to mitigate disrupted cocaine-DAT interactions and attenuate cocaine self-administration.