颅脑创伤后自噬表达的变化及bFGF保护作用的研究

The change of autophagy expression and the protective effect of bFGF after traumatic brain injury

目的探索颅脑创伤后神经细胞自噬表达的变化及碱性成纤维细胞生长因子(basic fibroblast growth factor,b FGF)的保护作用,为临床治疗脑外伤提供实验依据。方法用雷帕霉素制作体外神经细胞自噬模型,观察在体外培养神经细胞中b FGF对自噬表达的影响。将150只健康成年雄性SD大鼠随机分为3组(假手术组、颅脑创伤组、b FGF治疗组),每组50只。精密颅脑损伤撞击器制作大鼠创伤性脑损伤模型,假手术组暴露硬脑膜而不撞击,b FGF治疗组于建模后10分钟由右侧侧脑室注入b FGF,而假手术组和创伤组在建模后10分钟由右侧侧脑室注入等量的生理盐水。应用大鼠行为学评分观察大鼠脑损伤后神经功能的变化;用干湿法测脑组织含水量;用免疫荧光显微镜观察神经细胞自噬表达的变化。结果在体外培养细胞中,b FGF组能明显抑制雷帕霉素引起的LC3-Ⅱ表达增高(P<0.05)。与假手术组相比,颅脑创伤组大鼠和b FGF治疗组的行为学评分明显降低(P<0.05),但b FGF治疗组的评分恢复快于颅脑创伤组(P<0.05)。b FGF治疗组脑组织的含水量明显小于颅脑创伤组(P<0.05)。与假手术组相比相比,颅脑创伤组和b FGF治疗组伤后LC3-Ⅱ蛋白表达均明显提高(P<0.05);与颅脑创伤组相比,b FGF治疗组LC3-Ⅱ的上调被明显抑制(P<0.05)。结论 b FGF能明显抑制颅脑创伤后过度的自噬反应,减轻脑水肿,并改善大鼠神经功能。

Objective To explore the change of autophagy expression and the protective effect of basic fibroblast growth faetor（bFGF）after traumatic brain injury. Methods The autophagy model were made by rapamyein in vitro neural cell,and the change of autophage expression by bFGF were observed. 150 male SD rats were randomly divided into three groups： the sham operation group,the traumatic brain injury group and the bFGF group. Precision cortical impactor was used to establish traumatic brain injury model. In the sham operation group the dura of rat was exposed, but not got the impact. The rats were injected with a single intracerebroventricular of bFGF in bFGF group 10 minutes after brain injury ,while normal saline was injected in sham operation group and traumatic brain injury group. The change of neurologie function was detected by the rat behavioral score. Water content was detected by dry-wet analysis. The change of autophagy expression was observed by immunoiluorescence microscopy. Results The bFGF group can obviously inhibit the expression of LC3-Ⅱ caused by rapamycin in vitro cultured cells （P〈0.05）. The rat behavioral score in traumatic brain injury group and bFGF group were much lower than that in sham operation group （P〈0.05）, but the recover of score in bFGF group was much faster than that in traumatic brain injury group （P〈0.05）. The water content of brain tissue in bFGF group was less than that in traumatic brain injury group（P〈0.05）. The expression of LC3-Ⅱ was significantly increased in traumatic brain injury group and bFGF group relative to sham operation group（P〈0.05）. The up-regulation of LC3- Ⅱ which induced by trauma were inhibited in bFGF group relative to traumatic brain injury group. Conclusion The bFGF should be able to blocking-up the excessive expression of autophagy induced by trauma, reduce the brain edema, improve the neurological function in rats.