大鼠创伤性脑损伤中内皮性脂酶表达变化

Expression of endothelial lipase in rat traumatic brain injuried

目的探讨内皮性脂酶(EL)在创伤性脑损伤(TBI)后的表达变化及定位情况。方法应用健康成年SD大鼠40只,成功制备TBI模型31只。通过Western blotting检测脑损伤后EL表达的时相变化,免疫荧光化学方法检测EL在脑组织中的细胞定位。结果 Western blotting显示,大鼠脑损伤后,EL表达逐步增高,伤后3d升至最高点,之后逐渐下降,于损伤后2周时降至最低水平;免疫荧光双标记结果显示EL与神经元的标记物NeuN共定位。与凋亡相关的蛋白Caspase-3和Bcl-2在TBI后表达发生变化,并且细胞凋亡趋势与EL表达变化趋势基本一致。结论大鼠TBI后,EL表达增加,推测EL可能参与脑损伤后神经再生及神经元凋亡过程。

Objeetive To investigate the expression of Endothelial Lipase （EL） in rat brains after being injuried. Methods Forty healthy adult SD rats were used, thirty one rats were successfully prepared as traumatic brain injury （TBI） model. The expression of EL was tested by Western blotting at various time points after injury. Double immunofluorescent staining was used to observe the cell distribution of EL as well as changes in expression levels after injury. Results Western blotting data showed that EL proteins in lesion site increased gradually and reached a peak on the 3rd day post injury, and it decreased to the lowest level until 2 weeks after the injury. EL was localized in neurons as shown by co-localization with neuronal nuclei （NeuN）. Intensity of immunofluorescence was weak in intact brain but greatly enhanced on the 3rd day after the injury. In addition, temporal expression pattern of Caspase-3, a key protein involved in apoptosis, was similar to that of EL, and expression of Bcl-2, which is involved in anti-apoptosis was also temporally regulated. Conclusion The brain injury results in up-regulation of EL expression in traumatic brain sites suggesting that it may participate in brain injury-induced apoptosis as well as neuronal regeneration processes.