睫状神经营养因子对坐骨神经切断吻合后大鼠脊髓前角胶质纤维酸性蛋白表达的影响

Effects of ciliary neurotrophic factor on the expression of glia fibrillary acidic protein in the anterior horn after anastomosing apocoptic sciatic nerve in rats

背景:睫状神经营养因子具有多种生物活性,在神经系统发育、分化和损伤修复中具有重要意义。目的:观察睫状神经营养因子对坐骨神经切断吻合后大鼠相应脊髓节段前角星形胶质细胞的特异标记物胶质纤维酸性蛋白表达的影响。方法:将SD大鼠随机分为对照组、模型组、生理盐水组及药物组。除对照组外,对所有大鼠实施双侧坐骨神经切断吻合术,药物组手术区局部注射睫状神经营养因子100ng/kg,1次/d,生理盐水组局部注射等量生理盐水。术后1,3,7,14,21,28d取相应脊髓节段,免疫组织化学染色观察胶质纤维酸性蛋白的表达,苏木精-伊红染色、TUNEL染色对脊髓前角神经元进行计数。结果与结论:大鼠坐骨神经切断吻合后相应脊髓节段星形胶质细胞胞体大,突起分枝多且粗大,神经元数目逐渐减少,凋亡神经元增多,胶质纤维酸性蛋白表达增高。与模型组和生理盐水组比较,药物组神经元存活数目增多,凋亡减少,胶质纤维酸性蛋白表达明显增加(P<0.05或P<0.01)。同时,药物组大鼠的运动功能障碍较轻,恢复较快。说明睫状神经营养因子可以通过促进大鼠脊髓前角胶质纤维酸性蛋白的表达起到神经保护作用。

BACKGROUND： Ciliary neurotrophic factor （CNTF） has multiple biological activities, which has significance in development, differentiation and damage repair of nervous system. OBJECTIVE： To study the effects of CNTF on the expression of glia fibrillary acidic protein （GFAP） in the corresponding segment spinal anterior horn astrocytes after anastomosing apocoptic sciatic nerve in rats. METHODS： Sprague Dawley rats were randomly divided into control, model, saline and medicine groups. All rats were performed anastomosing apocoptic operation at both sciatic nerves except that in the control group. CNTF and saline were injected into rats in the medicine and saline groups, 100 ng/kg, once per day. The corresponding spinal segments were obtained at 1, 3, 7, 14, 21 and 28 days after the operation, and the expression of GFAP was observed by immunohistochemistry, and the number of neurons in the anterior horn of spinal cord was counted by hematoxylin-eosin staining and TUNEL staining. RESULTS AND CONCLUSION： The astrocytes in the anterior horn of spinal cord became bigger after anastomosing apocoptic both sciatic nerves operation, neurites increased and became thickening, neurons apoptosis less, the expression of GFAP increased. Compared with the model and saline groups, the survival neurons were increased, apoptotic neurons decreased, and the expression of GFAP protein were greater in the medicine group （P0.05 or P0.01）. Simultaneously, the rats in the medicine group were suffered slightly motor dysfunction and recovered faster those of other groups. The results illustrate that CNTF has neuroprotective effect via promoting the high expression of GFAP in the anterior horn of spinal cord after anastomosing apocoptic sciatic nerve in rats.