过度训练可部分通过上调TLR4的表达激活死亡受体凋亡通路诱导大鼠肾小管上皮细胞凋亡

摘要

Objective: To investigate the changes of the expression of renal tissue TLR4, Fas, Caspase - 8 and the influences of TLR4 in death receptor signal pathway. Methods: Forty - eight male SD rats were randomly divided into three groups: control ( CN, re =8 ),exhaustive swimming ( ES, re =24 ) and Anisodamine ( AD, re = 16 ) . The rats of CN were quiet without swimming. The rats of ES swam to exhaustive state and were sacrificed at immediately ( ESI ) ,6 hour ( ES 6 h ) and 24 hour ( ES 24 h ) after exhaustive swimming respectively. The rats of AD received intraperitoneal injection of Anisodamine at the dose of 10 mg/kg body weight at 20 minutes before swimming and then swam to exhaustive condition. The rats of AD group were sacrificed at 6 hour ( AD 6 h ) and 24 hour ( AD 24 h ) after exhaustive swimming. The expression of TLR4 and Fas protein in renal tissue were examined by Western Blotting. The expression of Caspase - 8 in renal tissue was observed by immunohistochemistry. Results: The expression of TLR4 and Fas and Caspase - 8 were significantly increased in group ES as compared with control group. Respectively, TLR4 had significantly positive correlation with the value of Fas and Caspase - 8 and renal tubular cell apoptosis ( r = 0. 848 ,P＜0. 05; r = 0. 916 ,P＜0. 05; t = 0. 95, P＜0.05 )in ES rats. Pretreatment with Anisodamine inhibited the up - regulation of TLR4, Fas, Caspase - 8 and cell apoptosis in renal tublar cells induced by exhaustive swimming. Conclusion: Overtraining can induce renal tubular cells apoptosis through activating Fas - Caspase - 8 signal pathway by impairing TLR4.%目的:观察过度训练大鼠肾组织TLR4、Fas及 Caspase-8表达的变化,探讨TLR4在死亡受体凋亡通路中的作用.方法:将48只雄性SD大鼠按随机数字表法分为对照组(CN)、力竭运动组(ES)、山莨菪碱干预组(AD).CN组为安静对照;ES组又根据力竭后恢复时间分为力竭后即刻(ESI)、力竭后6 h(ES 6 h)和力竭后24 h(ES 24 h);AD组于力竭运动前20 min腹腔注射山莨菪碱10 mg/kg后进行力竭运动,分为AD 6 h和AD 24 h组.采用大鼠游泳至力竭建立过度训练模型.采用Western印记测定肾组织TLR4和Fas的表达,免疫组织化学法检测肾组织Caspase-8的表达,并分别对TLR4与Fas、Caspase-8、肾组织细胞凋亡率进行相关性分析.结果:Western印记测定结果显示,过度训练大鼠肾组织TLR4及Fas的表达于力竭后即刻、6 h及24 h逐渐增高,均显著高于对照组(P<0.05).免疫组化显示,过度训练大鼠肾组织Caspase-8的表达于力竭后即刻、6 h及24 h逐渐增强,均显著高于对照组(P<0.05).过度训练大鼠肾组织TLR4与Fas、Caspase-8和细胞凋亡率的表达均呈正相关性(r=0.848,P＜0.05;r=0.916,P＜0.05;r=0.95,P＜0.05).用山莨菪碱干预后,过度训练引起的肾组织TLR4、Fas及Caspase-8的过度表达均被显著抑制(均P<0.05).结论:过度训练可通过上调TLR4强化死亡受体凋亡通路,进而诱导大鼠肾小管上皮细胞凋亡.