大鼠脑损伤后COX-2表达变化的时间规律性研究

目的探讨大鼠脑损伤后环氧合酶2(COX-2)在神经元、神经胶质细胞中表达变化的时间规律性。方法以冲击应力σd为355.09kPa致大鼠脑损伤后,于不同时间段分别应用原位杂交、免疫组化、免疫组化双染色技术检测COX-2mRNA和蛋白的表达强度,用图像分析系统测定阳性反应物平均灰度,进行统计学处理。结果正常对照组COX-2mRNA和蛋白弱表达,伤后15min开始表达呈增强趋势,分别于伤后1,2d,表达达到峰值,平均灰度值分别为126.38±1.36、124.77±3.20,与对照组、邻近上组比较均具有显著性差异(P<0.05),于伤后3,4d,表达达到另一峰值,平均灰度值分别为127.18±1.96、120.14±3.52,并维持高水平表达分别至伤后7,15d,平均灰度值分别为110.03±2.61、111.27±2.83,与对照组比较具有显著性差异(P<0.05)。阳性细胞多为神经元。结论脑损伤后COX-2mRNA及蛋白的表达具有时间规律性,可作为法医学推断脑损伤形成时间的指标。

The dynamically changes of COX-2 and the gene expression of COX-2 mRNA after traumatic brain injury in rats

Objective To illuminate the pathology of traumatic brain injury(TBI)and to better understand the re-lationship between the expression of COX-2and the time course of TBI.Methods Immunocytochemical staining,double-labeled with the anti-COX-2antibody and either the neuron-specific antibody NeuN or the astroglial-spe cific marker GFAP,in situ hybridization and computer image analysis were used.Re sults Results from im-munohistochemistry indicated time-dependent staining chan ges of neuronal plasma.The immunostained cells were faint at control cortex,most ly were neurons.The immunostained cells appeared to be darkly stained30min after TBI for extended periods of time and reached the maximum at2d after injury,reac hed another peak(P<0.05)at4d post-injury.The darker cells persisted in a high le vel,significant differences(P<0.05)even presented between control and15d post-in jury.The COX-2mRNA expression was faint at control cortex.The expressions of COX-2mRNA appeared to be darkly stained15min after TBI for extended periods of time and reached the maximum(P<0.05)at1d post-injury,reached another peak(P<0.05)at3 d post-in-jury,and significant differences(P<0.05)even presented between contro l and7d post-injury,but not15d post-injury.Conclusion The results of this study indicated that the expression of COX-2mRNA and protein had a possible relationsh ip with the extended periods of time after TBI.It might have some relationship b e-tween the expression of COX-2and secondary brain injury after TBI.