牛磺酸抑制糖尿病大鼠坐骨神经雪旺细胞凋亡

Taurine inhibites Schwann cell apoptosis of sciatic nerve in diabetic rats

目的观察牛磺酸对糖尿病大鼠坐骨神经雪旺细胞凋亡的影响,探讨其神经保护作用机制。方法用链脲佐菌素(STZ)诱发糖尿病模型。牛磺酸治疗8周后应用化学比色法测定坐骨神经组织中丙二醛(MDA)和谷胱甘肽(GSH)含量;用免疫组化法、RT-PCR和TUNEL法检测坐骨神经中活化的caspase-3蛋白和mRNA表达,以及雪旺细胞凋亡的情况。结果牛磺酸能降低坐骨神经中MDA水平,提高GSH水平(均P<0.05)。在正常鼠坐骨神经中,未见活化的caspase-3蛋白表达和细胞凋亡;Caspase-3 mRNA有极少量表达。模型对照组上述表达均增加,牛磺酸干预后其表达均较模型组表达明显减少(P<0.05)。结论牛磺酸抑制caspase-3 mRNA的转录与caspase-3的活化,减少细胞凋亡,与调节机体内的氧化应激状态有关,从而达到神经保护作用。

Objective To observe the effects of Taurine on Schwann cell apoptosis of sciatic nerve in diabetic rat, and to explore its mechanism of nervous protective effect. Methods The diabetic models were induced by streptozotocin. The sciatic nerve was taken out in 8th week from the beginning of treatment, and then various parameters were measured as follows ： The content of MDA and GSH in sciatic nerve were analysed by chromatometry ;caspase- 3 expression in protein and mRNA level in sciatic nerve were analysed by immunohistochemical and reverse-transeriptase polymerase chain reaction （RT-PCR） ; apoptosis of Schwann cell was examined by method of TUNEL. Results Taurine-treated control group attenuated the content of MDA in sciatic nerve, and elevated the content of GSH（P 〈0. 05）. Protein expression of actived caspase-3 and apoptosis of Schwann cell in sciatic nerve of normal control group were not found, but the caspase-3 mRNA expression was at lower level in normal group than in model group（P 〈0. 05 ）. Taurine group significantly decreased the expression of caspase-3 and apoptosis of Schwann cell （P 〈 0. 05 ）. Conclusion Taurine inhibiting transcription of caspase-3 mRNA and activation of caspase-3 and decreasing apoptosis may be mediated by adjusting the oxidative stress state of organism . This may be one of the function mechanisms of protective effects of Taurine on diabetic peripheral neuropathy.