星形胶质细胞CysLT1R与抑郁症的相关性及机制研究

One of the most important reasons is that key molecules have not been confirmed why a breakthrough has not been made for low toxicity and high efficacy of new antidepressant research. Our recent studies showed that cysteinyl leukotriene receptor 1(CysLT1R) might mediate the onset of depression. This study will use GFAP-initiated CysLT1R RNA interference lentiviral vector (LV-GFAPpro-CysLT1R shRNA-EGFP) and CysLT1R RNA lentiviral vector (LV-GFAPpro-CysLT1R-EGFP) for knock-down and over-expression of CysLT1R gene in mouse hippocampal astrocytes, as well as the Cre-LoxP recombinase system for conditional knockout of CysLT1R gene in astrocytes of mouse brain, to investigate the role of CysLT1R in physiological and pathological conditions of depression and its regulation of glutamate circle, brain-derived neurotrophic factor and inflammatory factors. The correlation between astrocyte CysLT1R and depression and its underlying mechanisms will be revealed from in vivo, in vitro and molecular level, which provides an important molecular target for the study of novel antidepressants based on the regulation of astrocyte function.

低毒高效新型抗抑郁药研究至今未获得突破，重要原因之一是未确立引发抑郁症的关键分子。我们近期研究显示，星形胶质细胞半胱氨酰白三烯受体1(CysLT1R)可能介导抑郁症的发病过程。本研究拟分别采用GFAP启动的CysLT1R RNA干扰慢病毒载体（LV-GFAPpro-CysLT1R shRNA-EGFP）和CysLT1R RNA慢病毒载体（LV-GFAPpro-CysLT1R-EGFP），敲减、过表达小鼠海马星形胶质细胞CysLT1R；采用Cre-LoxP重组酶系统条件性敲除小鼠脑内星形胶质细胞CysLT1R，探究CysLT1R在生理及抑郁症病理条件下的功能及其对突触间谷氨酸循环、脑源性神经生长因子和炎症因子的调节作用，从在体、离体及分子水平证明星形胶质细胞CysLT1R与抑郁症的相关性及机制，为基于星形胶质细胞功能调节研究新型抗抑郁药提供重要的分子靶标。

抑郁症是严重危害人类健康的常见精神疾病。常用抗抑郁药主要通过增加脑内单胺类神经递质产生抗抑郁作用，但这些药物存在起效慢、有效率低、损害认知功能等诸多缺点。因此，寻找原创药物靶标、开发新型药物是该领域研究热点。本项目主要研究内容包括：星形胶质细胞半胱氨酰白三烯受体1（CysLT1R）基因条件性敲除和海马星形胶质CysLT1R敲减对抑郁模型动物抑郁样行为、谷氨酸循环、proBDNF/mBDNF 平衡及炎症反应影响；海马星形胶质CysLT1R过表达致抑郁效应及相关机制以及CysLT1R调控星形胶质细胞谷氨酸转运体（GLT-1/EAAT2）、谷氨酰胺合成酶（GS）、mBDNF/proBDNF及炎症因子生成的信号转导机制。研究结果显示，星形胶质细胞特异性敲除CysLT1R和海马星形胶质CysLT1R敲减均显著改善慢性应激诱导的小鼠抑郁样行为、增加海马GFAP+细胞数、海马齿状回BrdU+神经元数、突触数量和长时程增强电位；增加海马GLT-1、GS、PSD-95、PCSK7蛋白表达水平；降低GluN2B的表达水平和谷氨酸含量，但不影响AMPA受体亚型GluA1和GluA2表达以及5羟色胺、去甲肾上腺素和多巴胺含量。CysLT1R拮抗剂能产生相似的作用。过表达海马星形胶质细胞CysLT1R能诱导小鼠出现抑郁样行为，促进慢性应激诱导的小鼠抑郁样行为，降低海马突触可塑性，增加海马炎症反应。进一步研究显示，CysLT1R通过β-arrestin2、Clatrhin和NF-κB信号通路调控EAAT2、GS和炎症因子表达。本项目从DNA、RNA和蛋白质三个水平、上调和下调两个方面、多种应激诱导的抑郁动物模型以及离体细胞实验证明CysLT1R是治疗抑郁症的新靶点，CysLT1R拮抗剂可能是治疗抑郁症的候选药物。