GAPDH降解途径在鱼藤酮诱导多巴胺能神经元损伤中的作用

The role of GAPDH degradation pathway in rotenone-induced dopaminergic cell injury

目的探讨GAPDH降解途径在鱼藤酮(rotenone)诱导的多巴胺能神经元损伤中的作用。方法用鱼藤酮诱导多巴胺能神经细胞SH-SY5Y建立帕金森病(Parkinson’s disease,PD)细胞模型,并分别加入蛋白酶体和自噬抑制剂和激活剂,显微镜观察细胞形态,MTT法检测细胞活性,Western blot检测GAPDH的表达及降解。结果鱼藤酮、蛋白酶体和自噬途径抑制剂可导致细胞活性下降,各药物组细胞生长受抑制;在鱼藤酮诱导的SH-SY5Y细胞内GAPDH水平上调,加入蛋白酶体和自噬途径抑制剂能够进一步上调GAPDH水平,而加入两个降解途径的激活剂则显著抑制鱼藤酮对GAPDH水平的上调作用。结论蛋白酶体和自噬溶酶体途径功能异常在GAPDH代谢中发挥重要作用,两者均参与GAPDH的降解。激活这两条降解途径可增加过表达的GAPDH的清除,可能成为PD治疗潜在的新靶点。

Objective To investigate the role of GAPDH degradation pathway in rotenone-induced dopaminergic cell injury. Methods Parkinson＇s disease （PD） cell model was established through inducing SH-SYSY dopaminergic neuron-like cells by rotenone. Cells were then treated with inhibitors or activators ofproteasome and autophagy pathways. Cell morphology under light microscopy was recorded and viability was measured by MTT assay. The protein expression and degradation of GAPDH was detected by Western blot. Results Both rotenone treatment and the inhibition of proteasome and autophagy pathways lead to decreased cell viability and cell growth inhibition. GAPDH level was up-regulated by rotenone treatment as well as by the inhibition of proteasome and autophagy pathways, while it was down-regulated in response to the activation of the two protein degradation pathways. Conclusion Both proteasome and autophagy pathways are involved in the metabolism of GAPDH. Activation of the two pathways increases the clearance of GAPDH and provides a potential therapeutic strategy for Parkinson＇s disease.