创伤性脑损伤后PHB2表达变化及其与星形胶质细胞增殖的相关性研究

Prohibitin2 expression and its relation with astrocyte proliferation in rats after traumatic brain injury

目的研究PHB2在创伤性脑损伤（TBI）大鼠大脑中的表达变化以及细胞定位情况，探究其与神经元凋亡、星形胶质细胞增殖之间的关系。方法通过使用刀片在脑部形成损伤缺口建立大鼠TBI模型，随后采用Westernblotting实验检测PHB2在损伤后大鼠脑皮层中随时间的变化趋势。通过免疫组织化学染色检测PHB2在脑损伤大鼠大脑皮层中的表达分布变化。通过免疫荧光染色检测PHB2在脑损伤大鼠神经细胞中的定位，以及与神经元凋亡、星形胶质细胞增殖间的关系。结果（1）成功构建TBI大鼠模型，PHB2表达量在TBI后12h开始明显增高，5d后达到最高，随后逐渐下降，总体差异有统计学意义（P〈0．05）。（2）TBI大鼠损伤口附近皮层中PHB2表达量明显高于假手术组、对照组大鼠及损伤对侧。（3）TBI大鼠PHB2主要分布于脑皮层的星形胶质细胞及神经元中。（4）TBI大鼠损伤口附近的星形胶质细胞与细胞增殖标记物PCNA存在共定位，而且PHB2与PCNA同样也存在共定位。提示损伤口附近的星形胶质细胞发生了增殖，而且PHB2与增殖存在一定联系。（5）TBI大鼠损伤口附近的神经元与细胞凋亡标记物活化caspase-3存在共定位，PHB2与活化caspase-3同样存在共定位，提示TBI可以引起神经元凋亡，而且PHB2与该凋亡存在一定程度上的关联。结论PHB2在创伤性脑损伤大鼠脑皮层中表达增高，这种表达变化与神经细胞的增殖与凋亡存在相关性。

Objective To research the prohibitin2 （PHB2） expression and cellular localization in the rat brain cortex after traumatic brain injury （TBI）, and explore its relationship with astrocyte proliferation and neuron apoptosis. Methods TBI rat models were established by knife injurying the brain. Western blotting was used to detect the PHB2 expression variation trend in the brain cortex. Immunohistochemical method was used to detect the distribution of PHB2 in damaged cerebral cortex, and immunofluorescence was applied to research the PHB2 expression changes and cellular localization in the rat brain cortex after TBI, and explore its relationship with astrocyte proliferation and neuron apoptosis. Results （1） The TBI models were established successfully; 12 h after TBI, the PHB2 expression started to increase obviously, and PHB2 expression reached to its peak level 5 d aider TBI. （2） The PHB2 expression in the cortex of TBI rats was significantly increased as compared with that in the sham-operated group, control group and contralateral side of TBI rats. （3） PHB2 mainly located at the astrocytes and neurons of the cerebral cortex after TBI. （4） Co-localization was noted in astrocytes and cell proliferation marker PCNA, and in PHB2 and PCNA, which indicated that proliferation of astrocytes existed and PHB2 involved in the proliferation. （5） Co-localization was noted in astrocytes and cell apoptosis marker A-caspase-3, and in PHB2 and A-caspase-3, which indicated that TBI induced cell apoptosis, and PHB2 involved in the apoptosis. Conclusion PHB2 has a high expression in the cerebral cortex of rats after TBI, and these changes are related to astrocyte proliferation and neuronal apoptosis.