溶酶体贮积症细胞内胆固醇累积导致患者神经元死亡的细胞与分子机制

溶酶体贮积症（LSDs）是严重威胁我国人民身体健康的一组可遗传代谢性疾病。多数LSDs病患伴有类似于神经退行性疾病的临床表现，这可能是由大脑神经元死亡所导致。胆固醇作为LSDs溶酶体内一种常见的累积底物，可导致溶酶体贮积症患者神经元死亡，然而其细胞与分子生物学机制仍不清楚。申请人前期鉴定出溶酶体表达的一种新型氯离子通道Lyso-VRAC，并揭示此通道既能够调控溶酶体体积又能够缓解损伤刺激诱导的细胞死亡。进一步研究显示，胆固醇是Lyso-VRAC氯离子通道内源性抑制剂。因此基于上述研究，申请人提出一个科学假说：Lyso-VRAC氯通道可能参与调控溶酶体内胆固醇累积导致的LSDs患者脑内神经元死亡的过程。本项目拟运用电生理技术、分子动力学模拟、定点突变及其它细胞分子生物学方法，从细胞内部细胞器角度探讨胆固醇累积导致神经元死亡的细胞与分子机制，并为溶酶体贮积症药物治疗提供新的干预靶点。

Lysosome Storage Disorders (LSDs) is a group of metabolic and inherited disorders, which threatens our health badly. To date, major patients with LSDs can not get effictive drugs clinically. The majourity of LSDs patients are accompanied with neurodegenerative symptoms probably caused by the aggressive neuronal cell death. As one of the common substrated accumulated in lysosomes, Cholesterol would pathologically lead to the neuronal cell death abbrently. However, the underlying cellular and molecular mechanims forneuronal cell death caused by lysosomal cholestrol accumulation are still obscure. Our previous work found that a novel chloride channel, Lyso-VRAC, on the lysosomal membranes is capable of regulating the volume of lysosome, and defenses cell from various physiological stress. Notably, cholesterol is an endogeneous inhibitor for the Lyso-VRAC channel. Based on these conclusions, we proposed a scientific question that whether Lyso-VRAC is engaged in the process of neuronal cell death resulted from cholesterol accumulation in the LSDs patients? We are going to utilize the whole-lysosome patch-clamp recording technique, molecular dynamic simulation, site-directed mutagenesis with cholesterol detect methods and cell death analysis to test our hypothesis about cholestrol accumulation in lysosome and neuronal cell death. Hopefully, our work would provide a potential drug target for LSDs.