脑创伤后NGF对神经干细胞Nestin蛋白表达的影响

Influence of NGF on neural stem cell nestin expression after traumatic brain injury

目的 研究脑创伤后外源性神经生长因子 (NGF)对神经干细胞Nestin蛋白表达的影响及其意义。方法 建立大鼠流体脑创伤模型 ,采用免疫细胞化学及图像分析等方法 ,观察脑创伤后非NGF处理组和NGF处理组Nestin蛋白表达的变化。结果 成年大鼠Nestin阳性细胞主要位于室管膜下组织 ,细胞的形态主要是胶质细胞。脑创伤后Nestin阳性细胞在室管膜下反应性增加 ,以伤后 7d明显 ,同时在创伤区域周围也可见到大量的Nestin阳性细胞 ,并在伤后 14d继续维持其反应性增加。NGF处理组伤后 7dNestin阳性细胞在伤灶周围更加明显 ,为 2 8.7± 3.8,比同时相点的非NGF处理组明显增加 (P <0 .0 1)。结论 外源性NGF能明显促进脑创伤后Nestin阳性细胞数量的增加 ,增强星形胶质细胞对脑创伤的反应并使其表现有神经干细胞的特征 ,参与神经细胞的再生和重塑。

Objective To study influence and significance of exogenous nerve growth factor (NGF) on neural stem cell nestin expression after traumatic brain injury (TBI).Methods A brain trauma model of fluid percussion in rats was established. Methods of immunocytochemical techniques and image analysis were used to observe changes of nestin protein expression after TBI in simple injury group without NGF administration as well as NGF therapeutic group.Results Nestin positive cells of adult rats mainly located in infraependyma tissues and were morphological glial cells. Nestin positive cells under ependyma increased reactively especially at 7 d posttrauma , and tissues adjacent to the injury site also had many nestin positive cells, and cells increased continuously at 14 d posttrauma. Nestin positive cells in tissues around injury site increased markedly in NGF treated group, which was 28.7±3.8, significantly higher than that in simple injury group without NGF administration at 7 d following brain trauma( P <0.01). Conclusion Exogenous NGF can markedly enhance the quantity of nestin positive cells after TBI, and increase the reactivity of astrocytes in response to brain injury, and make astrocytes show the characteristics of the neural stem cells, which may be related to neuronal regeneration and remodeling.