Atg5在肌萎缩侧索硬化症转基因小鼠纹状体和脑干中表达降低

Decreased expression of Atg5 in the striatum and brainstem of amyotrophic lateral sclerosis transgenic mice

目的研究自噬相关基因Atg5在肌萎缩侧索硬化症(ALS)转基因小鼠纹状体和脑干中的表达情况,探讨Atg5与ALS发病的关系。方法分别取ALS转基因小鼠和同窝野生型小鼠95d、108d和122d的纹状体和脑干,应用免疫荧光技术检测Atg5在纹状体和脑干中的表达及与神经元的共定位关系,应用q RT-PCR技术检测Atg5 m RNA表达情况,应用Western blot技术检测蛋白表达的改变。结果免疫荧光双标染色检测发现,ALS转基因小鼠和野生型小鼠纹状体和脑干中Atg5阳性细胞与β-tubulinⅢ标记的神经元共表达;与野生型小鼠比较,ALS转基因小鼠纹状体和脑干内舌下神经核和面神经核中Atg5免疫反应性降低;q RT-PCR分析显示,ALS转基因小鼠纹状体内Atg5 m RNA表达水平在95d、108d和122d时均显著低于同窝野生型小鼠纹状体内Atg5 m RNA表达水平;脑干内Atg5 m RNA表达水平在108d和122d时均显著低于同窝野生型小鼠脑干内Atg5 m RNA表达水平;Western bot分析显示,与野生型小鼠比较,ALS转基因小鼠纹状体和脑干内Atg5蛋白表达水平在108d和122d时显著降低。结论 ALS转基因小鼠纹状体和脑干中Atg5的表达降低,提示Atg5调控的自噬改变与ALS发病关系密切。

Objective To explore the relationship between autophagy-related gene 5(Atg5)and amyotrophic lateral sclerosis(ALS)by detecting Atg5 expression in the striatum and brainstem o f ALS transgenic mice.Methods The striatum and brainstem o f ALS transgenic mice and w ild-type mice were dissected out at day 95,108 and 122 after birth.The tissue distribution and neuronal localization o f Atg5 in the striaton and brainstem were detected using in m皿ofluorescence.The expression o f Atg5 was detem h^by qRT-PCR at mRNA level and by Western blot at protein level.Results Atg5 co-localized w ith neuronal marker P-tubulin m in the striatum and brainstem o f ALS transgenic mice and w ild-type mice.Compared w ith w ild-type mice,Atg5 immunofluorescent intensity in the striatum,brainstem hypoglossal nerve nucleus and facial nerve nucleus o f ALS transgenic mice decreased at day 108 and 122.Both qRT-PCR and WB results confirmed that Atg5 expression was significantly lower in the striatum and brainstem o f ALS transgenic mice.The mRNA reduction appeared earlier at day 95,while the reduction o f protein started at day 108.Conclusion The decreased Atg5 expression in striatum and brainstem o f ALS transgenic mice suggested Atg5 regulated autophagy may be related to the pathogenesis o f ALS.