糖尿病大鼠坐骨神经calpainⅡ的动态表达

CalpainⅡexpression in sciatic nerves of diabetic rats

目的观察早期糖尿病(DM)大鼠坐骨神经calpainⅡ的动态表达,探讨其在糖尿病多发性神经病(DPN)发病中的作用。方法以链佐星(STZ)诱导DM大鼠模型,通过原位杂交和免疫组化技术观察不同病程DM大鼠坐骨神经calpainⅡmRNA和蛋白的表达;并通过光镜和电镜观察坐骨神经形态,免疫组化观察坐骨神经中神经丝(NF)的表达。结果DM4和8周大鼠坐骨神经calpainⅡmRNA均较正常组明显减少[(2.64±0.78)%vs(5.44±0.36)%,P<0.001;(1.97±0.31)%vs(5.18±0.69)%,P<0.001];蛋白表达也较正常组明显减少[(3.35±0.57)%vs(7.79±1.42)%,P<0.001;(2.82±0.77)%vs(6.47±1.12)%,P<0.001]。DM4周时坐骨神经仅有超微结构改变,NF含量无明显改变;DM8周时神经形态明显改变,NF含量明显减少。结论DM大鼠坐骨神经calpainⅡ表达减少,其参与DPN的发病。

Purpose To observe the expressions of calpainI] in sciatic nerves of diabetic rats,and its implication in the pathogenesis of diabetic polyneuropathy（DPN）. Methods Diabetes mellitus（DM） were induced by single intraperitoneal injection of strepzocin （STZ）. The expressions of calpain Ⅱ mR- NA and protein in sciatic nerve of DM in 4 weeks or 8 weeks rats were observed by in situ hybridization and immunohistochemistry. Morphological findings were also observed under light and electron microscopy, and neurofilament （NF） expression was detected by immunohistochemistry. Results Calpain Ⅱ mRNA expressions were reduced significantly both in DM 4 weeks [（2. 64 ± 0. 78）% vs （5.44 ± 0.36） % ,P〈0, 001] and bM 8 weeks [（1.97 ± 0.31） % -as （5.18 ± 0.69） %, P〈0. 001）] rats. CalpainlI protein were also decreased significantly in DM 4 weeks [（3.35 ± 0.57） % vs （7.79 ± 1, 42） % ,P 〈0. 001）] and DM 8 weeks [（2.82 ± 0.77）% vs （6.47 ± 1.12） % ,P〈0. 001）]. At DM 4 weeks, only ultrastructural lesions was observed, NF expression did not changed. At DM 8 weeks, morphological abnormalities were obvious, and NF expression was decreased. Conclusions Calpain Ⅱ expressions were decreased in the sciatic nerves of DM rats, which may be involved in the pathogenesis of DPN.