星形胶质细胞AQP4调控胆固醇合成障碍介导少突胶质细胞MBP途径异常在1,2-二氯乙烷致大脑中毒性脱髓鞘中的作用机制研究

1,2-二氯乙烷（1,2-DCE）中毒性脑病严重危害我国职业工人健康，防治关键在于阐明中毒机制和寻找早期生物学标志。我们发现1,2-DCE除致脑水肿，还可致脑中毒性脱髓鞘。星形胶质细胞水通道蛋白4（AQP4）和固醇通路（SCAP/SREBP）影响胆固醇合成并调控少突胶质细胞髓鞘碱性蛋白（MBP）表达，参与1,2-DCE中毒性脱髓鞘发生发展仍鲜见报道。本项目在构建1,2-DCE中毒性脱髓鞘动物模型的基础上，应用AQP4、SCAP高表达质粒或缺陷的星形胶质与少突胶质细胞共培养体系，野生型和AQP4、SCAP基因工程小鼠及不同1,2-DCE暴露水平的人群和病例，从正向和反向在细胞、动物和人群三个水平探讨星形胶质细胞AQP4调控胆固醇合成障碍介导少突胶质细胞MBP途径异常在1,2-DCE致大脑中毒性脱髓鞘及脑病中的作用机制，为防控1,2-DCE中毒性脱髓鞘和发展早期生物标志和治疗靶点提供科学依据。

1,2-Dichloroethane (1,2-DCE) causes toxic encephalopathy in occupational workers in China. The key to preventing and controlling this occupational disease is to elucidate the poisoning mechanisms and to find early biomarkers. Not only brain edema, we also found 1,2-DCE could cause demyelination in the central nervous system. Aquaporin 4 (AQP4) and sterol synthesis pathway (SCAP/SREBP) of astrocyte regulate MBP expression in oligodendrocyte. However, the mechanism of abnormal oligodendrocyte MBP pathway mediated by AQP4 regulating cholesterol synthesis disorder in astrocyte in the occurrence and progression of 1,2-DCE-induced brain toxic demyelination remain to be elucidated. We have established animal models of 1,2-DCE-induced brain toxic demyelination in our preliminary studies. We are going to study the mechanism of abnormal oligodendrocyte MBP pathway mediated by AQP4 regulating cholesterol synthesis disorder in astrocyte in the 1,2-DCE-induced brain toxic demyelination on three levels of cell, animal, exposure population and poisoning cases, respectively. First, an in vitro cell model was applied to analyze the pattern of AQP4 and SCAP/SREBP regulations on MBP and its function in the 1,2-DCE-induced brain edema in the presence or absence of high expression plasmid of AQP4 and SCAP or CRISPR-Cas9 application, respectively. Then, AQP4 and SCAP wild type and knockout mice were used to confirm the pattern of MBP expression and its regulation by AQP4 and SCAP/SREBP, as well as to explore the key molecular pathways between the AQP4 and SCAP/SREBP alteration and pathological change in brain toxic demyelination induced by 1,2-DCE by using proteomic analysis. Finally, an occupational epidemiology study with healthy exposed subjects and poisoning cases was carried out to develop and validate MBP as an early biomarker of 1,2-DCE-induced brain toxic demyelination. This study will shed light on the mechanism of abnormal oligodendrocyte MBP pathway mediated by AQP4 regulating cholesterol synthesis disorder in astrocyte in 1,2-DCE-induced brain toxic demyelination. It will also provide scientific evidence on targets for the development of early biomarkers and treatment of this occupational hazard.