神经前体细胞巢蛋白在大鼠脊髓损伤后的表达

Expression of nestin of neural precursor cell after spinal cord injury in rats

目的:探讨成年大鼠脊髓损伤后损伤(SCI)区局部巢蛋白(nestin)的表达及意义。方法:应用Allen法建立大鼠SCI模型,行为学评分采用BBB评分,用病理学和免疫组织化学方法检测脊髓在不同时段的病理改变和nestin的表达变化。结果:伤后第1天,脊髓实质灶状出血,小血管栓塞,部分神经细胞细胞核碎裂,见损伤区附近、软脊髓膜下的白质和脊髓中央管区有nestin表达,BBB评分低,随后增加,1—2周恢复幅度加大。第3天后损伤灶出现大量胶质细胞,损伤组织液化。第5天后液化灶逐渐扩大,出血减少,阳性神经元和阳性反应的平均积分光密度值达到高峰(P<0.05)。第7天后神经细胞退行性变更为严重,部分神经细胞崩解仅留其轮廓,胶质细胞增生明显。2周后出血已基本吸收,以损伤处为中心,囊腔开始形成,nestin表达明显下调(P<0.05)。结论:脊髓损伤可诱导损伤区周围短暂的nestin阳性表达,nestin可能在脊髓损伤后的再生与修复中起重要作用。

Objective：To study the expression and significance of nestin in the areas adjacent to the injured site after spinal cord injury（SCI） in rats.Method：Each rat received contusion on its spinal cord at T9 with modified Allen＇ s impactor to establish SCI model.The behavioral evaluation was performed with Basso,Beattie Bresnahan locomotor rating scale（BBB scale）.The pathological study included hematoxylin and eosin（HE） staining,and immunohistology staining for nestin.Result：The spinal cord lesion as bleeding,small vessel thrombosis,some nerve cell karyorrhexis in myeloid tissue could be seen at the 1st d after injury.The expression of nestin could be seen near the damage zone,spinal cord white matter under spinal pia-mater and the central canal of spinal cord.BBB score lowered at the 1st d after injury,and the recovery range increased gradually in 1—2 weeks.There were a lot of glial cells proliferation,tissue liquefaction in damaged zone at the 3rd d after injury.Liquefaction area of damage areas expanded gradually,bleeding reduction,and the average integral optical density of nestin-immunoreactive neurons reached the peak（P〈0.05） at the 5th d after injury.Nerve cells occured serious degeneration,some nerve cells appeared necrosis,with marked hyperplasia of glial cells at the 7th d after injury.Two weeks later the bleeding absorbed basically,cysts began to form around the damage center and the nestin expression reduced significantly（P〈0.05）.Conclusion：SCI can induce the transient expression of nestin in the areas adjacent to injured site,which may play an important role in the repair and restoration of spinal cord.