突触后密度蛋白-93在大鼠脊髓损伤后的表达变化

目的 探讨突触后密度蛋白-93(PSD-93)在脊髓损伤(SCI)后的表达变化以及定位情况.方法 使用改良Allen法制备大鼠急性脊髓损伤模型,致大鼠脊髓(T9、T10)重度撞击伤.采用实时定量PCR(Real-time PCR)和Western blotting测定损伤后各时间段PSD-93 mRNA及其蛋白水平在脊髓中的表达变化.采用免疫荧光双标方法检测PSD-93在正常脊髓中的分布以及损伤后的定位改变.结果 PSD-93 mRNA水平在SCI后呈现逐渐下降的趋势,在3d降到最低水平;蛋白水平则在SCI后显著上调,于1d达高峰.免疫荧光双标显示,PSD-93在SCI后除与神经型一氧化氮合酶(nNOS)存在着共定位之外,还高表达于损伤局部活化的小胶质细胞和星形胶质细胞.结论 脊髓损伤后PSD-93在基因和蛋白水平呈现明显的时相变化,并且与nNOS、活化的胶质细胞存在共定位,提示PSD-93参与了脊髓继发性损伤过程.

EXPRESSION OF POSTSYNAPTIC DENSITY PROTEIN-93 IN INJURIED SPINAL CORD OF RAT

Objective To study the expression and distribution of postsynaptic density protein-93(PSD-93) after spinal cord injury(SCI). Methods With improved Allen's method,acute rats SCI models were established.Real-time PCR and Western blotting were used to detect the changes of PSD-93 mRNA and protein expression after SCI.The changes of PSD-93 localization after injury were investigated by immunofluorescence double staining. Results The expression of PSD-93 mRNA had a gradually decrease trend after SCI.The minimal mRNA was present at 3days;whereas the protein levels up-regulated significantly and peaked at 1day after injury.Immunofluorescence double staining indictated that PSD-93 was highly expressed on the activated microglias and astrocytes except that it co-localized with nNOS in the impaired spinal cord.Conclusion The time course of PSD-93 and its mRNA is vary significantly after SCI,and colocalized with nNOS and activated glias.These results indicate that PSD-93 may participate in the following response after SCI.