自噬及自噬相关蛋白在帕金森病模型大鼠黑质纹状体中的表达及意义

Autophagy and autophagy-related protein expressions in the substantia nigra and striatum of rat models of Parkinson's disease

目的观察自噬及自噬相关蛋白Beclin1及微管相关蛋白1轻链3(microtubule-associated protein 1light chain 3,MAPlLC3,简称LC3)在帕金森病(Parkinson disease,PD)模型大鼠黑质纹状体中的表达及变化,探讨自噬在PD发病中的作用。方法将90只SD大鼠随机分为正常组、假手术组、PD模型组(模型组),每组又分为模型制备后4d、8d两个亚组,每个亚组各15只。采用颈背部皮下注射鱼藤酮制作PD模型,透射电镜观察自噬体的形成,免疫组化法和Western blotting法检测黑质纹状体自噬相关蛋白Beclin1和LC3的表达水平。结果 (1)电子显微镜下PD模型组黑质纹状体中出现自噬体,呈圆形,大多位于细胞核旁,溶酶体数量增多。8d时,自噬体、溶酶体数量显著增多。(2)与正常组比较,假手术组黑质纹状体中Beclin1和LC3表达略增多,但差异无统计学意义(均P>0.05);与假手术组比较,模型组黑质纹状体Beclin1和LC3的表达明显增多(均P<0.01),8d高于4d,差异有统计学意义(均P<0.05)。结论 PD模型大鼠黑质纹状体中自噬活性被激活,自噬可能参与了PD的发病过程。

Objective To observe the expression and variation of autophagy, Beclinl and microtubule- associated protein 1 light chain 3 （LC3） in substantia nigra and striatum of rat models of Parkinson＇ s disease （PD）, and to explore the role of autophagy in the pathogenesis of PD. Methods Ninety rats were randomly divided into the normal control group, the sham operation group, and the model group. Each group was divided into 4 days and 8 days subgroups after successful model preparation （n 15）. PD rat model was established by injecting rotenone subcutaneously. The autophagy was observed by transmission electron microscope. The expression of Beclinl and LC3 in substantia nigra and striatum was detected by immunohistochemistry and western blotting. Results （1） Under the electron microscope autophagosomes appeared in substantia nigra and striatum of the model group. They were round, mostly located beside the nucleus, and the number of lysosomes increased . Both of them significantly increased in 8 d. （2） The expression of Beclinl and LC3 in substantia nigra and striatum slightly increased in the sham operation group compared with that in the normal group, but the difference was not statistically significant （all P〉0.05）. The expression of Beclinl and LC3 in substantia nigra and striatum increased in the model group compared with that in the sham operation group （all P〈0.01）, and there were more expression of Beclinl and LCS at 8 d compared with those at 4 d, and it has significant difference （all P〈0.05）. Cenclusiens Autophagy is activated in substantia nigra and striatum of rat models of PD and it may be involved in the palhogenesis of PD.