康复训练促进大鼠脑缺血半暗带区星形胶质细胞向神经元转化的作用研究

Effects of rehabilitation training on the transformation of astrocytes into neurons in the ischemic penumbra region

目的:观察不同时间点康复训练对大脑中动脉栓塞(MCAO)模型大鼠脑缺血半暗带区星形胶质细胞(AS)及新生神经元的影响,研究康复训练对星形胶质细胞转化为神经元的作用及可能机制。方法:选用雄性Wistar大鼠42只,随机分为空白组、1d康复组、1d对照组、7d康复组、7d对照组、14d康复组、14d对照组。各组大鼠造模后进行神经功能评分,评分结果作为各自的0d组。脑缺血后24h开始对大鼠实施康复训练,20min/次/d,于训练后1d、7d、14d进行大鼠运动功能检测和脑组织取材。通过神经功能评分评定大鼠运动功能改善情况;免疫荧光染色法和Western Blot检测缺血半暗带区胶质纤维酸性蛋白(GFAP)、双皮质素(DCX)及神经源性分化因子(NeuroD1)的表达。结果:比较各组前后行为学评分发现,7d康复组、7d对照组、14d康复组、14d对照组有差异性,训练后较0d组评分明显降低(P<0.001);组间比较提示7d康复组行为学评分较7d对照组有明显改善(P<0.05)。免疫荧光法和Western Blot检测GFAP表达发现,14d康复组较14d对照组GFAP表达明显减少(P<0.01);与空白组相比,1d康复组GFAP表达明显增高(P<0.001),14d康复组GFAP表达明显降低(P<0.05)。免疫荧光法和Western Blot检测DCX表达发现,14d康复组DCX表达较14d对照组明显升高;与空白组比较,14d康复组DCX表达明显升高(P<0.05)。Western Blot检测NeuroD1表达发现,1d、7d康复组较相应对照组NeuroD1表达明显升高(P<0.05);与空白组比较,1d、7d、14d康复组NeuroD1表达均明显升高(P<0.05)。结论:康复训练可有效改善MCAO大鼠的运动功能,活化缺血半暗带区的星形胶质细胞,并使局部新生神经元增多,且新生的神经元有可能是在神经源性分化因子NeuroD1的调控下由星形胶质细胞转化而来的。

Objective:Observing the effects of rehabilitation training at different time points on astrocyte(AS)and neonatal neurons in the cerebral ischemic penumbra of rats with middle cerebral artery occlusion(MCAO)model.Studying the role and possible mechanisms in AS transforming into neurons.Method:Forty-two male Wistar rats were randomly divided into blank group,1 d rehabilitation group,1 d control group,7 d rehabilitation group,7 d control group,14 d rehabilitation group and 14 d control group.Neurological function of rats in each group was evaluated after modeling,and the scoring results were taken as their 0 d group.24 hours after cerebral ischemia,rehabilitation training for rats started daily,20 min/d.Motor function test and brain tissue were taken at day 1,day 7 and day 14.4 kind scores were taken for ethological evaluation.The expression of glial fibrillary acidic protein(GFAP),double cortisol(DCX)and neurogenic differentiation factor(Neuro D1)in the ischemic penumbra was detected by immunofluorescence staining and Western Blot.Result:The ethological scores decreased gradually in both groups,but the rehabilitation group decreased even more(P<0.001).Immunofluorescence and Western Blot detection showed that expression of GFAP in rehabilitation group was significantly lower than control group at day 14(P<0.01).Comparing with the blank group,the expression of GFAP in the 1 d rehabilitation group was significantly higher(P<0.001),and significantly lower in14 d rehabilitation group(P<0.05).Immunofluorescence and Western Blot detection showed that the DCX expression in the 14 d rehabilitation group was significantly higher than the 14 d control group and blank group(P<0.05).The expression of Neuro D1 in the rehabilitation group was significantly higher than that in the control group at day 1 and day 7(P<0.05),and significantly higher than that in blank group at day 1,7 and 14(P<0.05).Conclusion:Rehabilitation training can effectively improve the motor function of MCAO rats,activate astrocytes in the ischemic penumbra,and increase local neonatal neurons.Neonatal neurons may be transformed from the astrocyte glial cells under the control of neurogenic differentiation factors Neuro D1.