新生鼠缺血脑组织MMP-9、TIMP1表达及其意义

目的:观察新生大鼠缺血脑组织基质金属蛋白酶-9(matrix metallo proteinase system-9,MMP-9)、基质金属蛋白酶组织抑制物1(TIMP1)表达情况及其作用。方法:75只7 d龄Wistar大鼠随机分为正常对照组、缺氧缺血组(模型组)、假手术组。采用左侧大脑中动脉结扎术建立脑缺氧缺血组模型,24 h后用免疫组化法观察新生大鼠缺血脑组织MMP-9、TIMP1表达水平。结果:MMP-9、TIMP1在三组脑组织中均有表达,但组间差异有统计学意义(P<0.01);模型组缺血脑组织MMP-9、TIMP1表达水平较假手术组及对照组均显著升高(P<0.01)。其中模型组缺血脑组织MMP-9与TIMP1表达水平呈显著正相关(P<0.01);正常对照组和假手术组脑组织MMP-9与TIMP表达水平之间无显著相关性(P>0.05)。结论:MMP-9、TIMP1在新生鼠缺血脑组织表达明显增加,可能参与新生鼠缺血脑组织损伤的发生。

Expression and significance of MMP-9 and TIMP1 in newborn rat brain after ischemia injury

Objective:To study the effects of the matrix metalloproteinase-9(MMP-9) and tissue inhibitors of metalloproteinases 1(TIMP1) in cerebral tissues of newborn rats after brain ischemia injury.Methods:Seventy-five,seven-day-old rats were classified into three groups randomly:normal control group(n= 25),hypoxia-ischemia group(25),and sham operation group(25).The rats in the hypoxia-ischemia group were subjected to right carotid artery occusion,and the cerebral MMP-9 and TIMP1 levels were detected by immuno-histochemistry method 24 hours later.Results:MMP-9 and TIMP1 were expressed in the three groups,but there were significant differences among the three groups.The cerebral MMP-9 and TIMP1 levels were increased in the hypoxia-ischemia group compared with those in the normal control and sham operation group(P<0.01),and the cerebral MMP-9 level showed positive correlation with TIMP1 level in the hypoxia-ischemia group(P<0.01),whereas no correlation was founded in the normal control or the sham operation group(P>0.05).Conclusion:The expression of MMP-9 and TIMP1 is increased in newborn ischemic brain and may contribute to the brain injury after ischemia condition.