突触后密度蛋白-95在大鼠坐骨神经损伤后的表达

为了探讨突触后密度蛋白-95(PSD-95)在周围神经损伤过程中的表达变化,本实验建立大鼠坐骨神经夹伤模型,采用荧光定量PCR(real-timePCR)和Western blotting对PSD-95 mRNA及其蛋白水平进行定量检测,应用免疫荧光双标技术观察PSD-95与神经型一氧化氮合酶(nNOS)的共定位情况。结果显示,PSD-95 mRNA及其蛋白在正常坐骨神经中度表达,损伤后迅速下降;PSD-95 mRNA从损伤后2d开始表达上调;而其蛋白水平于损伤后1周明显升高。免疫荧光双标染色证实在坐骨神经损伤后1周PSD-95与nNOS共定位于Schwann细胞上,而与神经丝蛋白NF-200共定位不明显。本研究结果提示PSD-95通过nNOS参与了周围神经损伤修复过程。

EXPRESSION OF POSTSYNAPTIC DESENTY PROTEIN-95 IN INJURIED SCIATIC NERVE OF THE RAT

In order to study the expression of postsynaptic density protein-95 (PSD-95) in the injuried sciatic nerve of rat, constructed rat models with extrusion wound at the sciatic nerves was established. Real time-PCR and Western blotting were used to investigate the changes of PSD-95 expression at the mRNA and protein levels. The association of PSD-95 and neuronal nitric oxide synthase (nNOS) was investigated by immunofluorescence double staining. The results indictated that the expression of PSD-95 was middle levels in the normal sciatic nerve, and deceased significantly after injury, followed by the increase from the second day at mRNA level and upregulation from the first week at protein level. Immunofluorescence double staining results showed that PSD-95 colocalized with nNOS, but not with NF-200. The present results suggest that PSD-95 and nNOS may participate in the injury and recovery process of sciatic nerves.