PLA2G6基因突变通过鞘脂代谢异常致自噬溶酶体通路障碍的机制研究

PLA2G6突变可致帕金森病（PD）的发生，机制尚不明确。研究提示PLA2G6突变与鞘脂异常可能相关。本团队前期发现PLA2G6突变小鼠模型中，鞘脂代谢通路多种酶及受体表达存在改变，脑部出现异常溶酶体和多泡小体，提示PLA2G6突变可导致鞘脂代谢紊乱及自噬-溶酶体通路障碍。本项目提出假说：PLA2G6突变可能导致鞘脂代谢异常，使胞内自噬-溶酶体紊乱，导致多巴胺能神经元丢失，最终导致PD发生。本项目拟利用PLA2G6基因D331Y敲入小鼠模型及相关细胞，应用液相色谱质谱串联法进行鞘脂组学分析；应用RT-PCR、Western blot、免疫荧光等方法，明确PLA2G6突变是否导致鞘脂代谢紊乱，并通过鞘脂相关信号通路导致细胞自噬异常，最终导致多巴胺能神经元丢失；应用鞘脂代谢调节剂调节鞘脂代谢，探讨是否缓解PLA2G6突变所致的自噬-溶酶体异常，为探索PLA2G6突变所致的PD发病机制拓展思路。

The mutations of PLA2G6 gene can cause Parkinson’s disease (PD), whereas the underlying mechanism remains unclear. Previous studies have indicated the important relationship between PLA2G6 gene and sphingolipid metabolism. Our team also found that, in PLA2G6 mutant mice, the mRNA level of sphingolipids-associated enzymes also altered significantly. We also found the excessive lysosomes and multivesicular bodies appeared in the brains of mice. These findings suggest that PLA2G6 gene mutation can lead to sphingolipid metabolism dysregulation and autophagy-lysosomal pathway disfunction. Thus, we hypothesize that mutations in the PLA2G6 gene can disrupt of sphingolipid metabolism and then result in autophagic impairment through sphingolipid-related signaling pathways, culminate in the loss of dopaminergic neurons. Based on the previous findings, we tends to use the PLA2G6 p.D331Y mice and related cell lines to analyze sphingolipids by tandem liquid chromatography mass spectrometry. Subsequently, we would use RT-PCR, Western blot, Immunohistochemistry and other molecular biology methods to determine whether mutations in the PLA2G6 gene cause disruption of sphingolipid metabolism and then result in autophagic impairment through sphingolipid-related signaling pathways, finally lead to dopaminergic neurons loss. On this basis, we would further use Myrinocin、DMS、Despramine、FTY720 or other related medicines to regulate sphingolipid metabolism, exploring their roles in sphingolipid metabolism and related autophagic dysfunction. The development of this study will further reveal the functions of sphingolipids in the pathogenesis of PD caused by PLA2G6 gene mutation.