大鼠脑创伤后caspase-3的过度表达与细胞凋亡的关系

目的:探讨大鼠脑创伤后海马神经组织中casepase-3表达及其在细胞凋亡中的机制。方法:雄性Wistar大鼠72只随机分成对照组和创伤组,用Marmarou方法造成大鼠重型弥漫性颅脑创伤,采用免疫组织化学检测海马CA1区神经细胞casepase-3蛋白表达情况,原位细胞DNA断裂检测末端标记(TUNEL)法观察大鼠海马CA1区神经细胞凋亡动态变化。同时行TUNEL与caspase-3双标染色。结果:对照组海马区神经细胞casepase-3未见明显表达,创伤组海马CA1区神经细胞casepase-3表达在伤后3小时开始升高,伤后3天达高峰(P0.01),伤后7天下降明显。对照组海马区未见TUNEL阳性细胞,创伤组海马区TUNEL阳性细胞伤后3小时开始增多,伤后3天达高峰(P0.01),伤后7天下降。可见创伤组TUNEL染色与caspase-3免疫染色双标阳性的细胞伤后6小时细胞数量逐渐增多,于伤后3天达高峰(P0.01),伤后7天双标阳性细胞数量下降。Casepase-3表达与TUNEL阳性细胞明显相关(P0.01)。结论:大鼠脑创伤后casepase-3的过度表达是影响大鼠脑创伤后神经细胞凋亡原因之一,抑制casepase-3活性表达对神经组织起保护作用。

The Excessive Expression of Caspase-3 and the Apoptosis after Traumatic Brain Injury in Rats

Objective:To explore casepase-3 expression and the role of casepase-3 in apoptosis following traumatic brain injury (TBI) in rats .Methods:85 male Wistar rats were randomly divided into 2 groups. According to Marmarou, severe closed brain injury was made. After that, immunohistochemical staining with caspase-3 were performed. TUNEL in situ was applied. At last, double staining with caspase-3 and TUNEL were performed.Results:Caspase-3 immunoreactivity in trauma group began to increase at 3h following injury, peaked at 3d (P<0.01) and began to decline at 7d. At 3h in trauma group, a little TUNEL positive cell appeared in hippocampus, peaked at 3d (P<0.01) and began to decline at 7d. The double positive cell in trauma group began to increase at 6h following injury, peaked at 3d (P<0.01) and began to decline at 7d. The expression of casepase-3 was correlated with TUNEL positive cells (P<0.01).Conclusion:Excessive expressed and activated caspase-3 related to apoptosis, which plays an important part in the mechanism of nerve cell death. Certain neroprotective effect may be obtained by inhibiting excessive expression of caspase-3 caused by TBI.