扎里奴思方干预骨髓间充质干细胞移植对脑缺血再灌注损伤大鼠突触结构可塑性的影响

目的:观察扎里奴思方(扎方)干预骨髓间充质干细胞(BMSCs)移植对大脑中动脉阻塞(MCAO)模型大鼠突触结构可塑性的影响,并探讨其机制。方法:SD大鼠随机分为假手术组、模型组、扎方组、移植组和联合组;线栓法制备大鼠MCAO模型,体外全骨髓贴壁筛选法培养及扩增BMSCs;大鼠灌胃给药(14.6 g·kg~(-1)·d~(-1)),BMSCs悬浮液经颈内动脉移植入脑;移植后1,3,7,14 d取材,透射电镜观察神经元突触超微结构,蛋白质免疫印迹(Western blot)检测突触素(SYN),突触后致密蛋白-95(PSD-95)蛋白表达。结果:假手术组突触结构完整,前后膜轮廓及突触间隙清晰,可见多个突触小泡,均匀分布,模型各组突触数量减少,结构破坏,突触间隙模糊,突触小泡数量减少甚至消失。扎方组突触数量增多,结构接近正常,可见凹型及U型突触,3,7,14 d组突触小泡增多,14 d组突触间隙增宽。移植组突触超微结构变化与扎方组大致相同。联合组突触损伤明显减轻,突触数量增多,7,14 d可见多个凹型突触,突触小泡明显增多。模型各组SYN及PSD-95较假手术组减低(P0.01);与模型组比较,联合各组及扎方、移植各7 d组SYN表达增高(P0.01),扎方、移植各3,7,14 d组及联合各组PSD-95表达增高(P0.01);与移植组比较,联合各组SYN,PSD-95表达增高(P0.01,P0.05),扎方3 d组PSD-95表达减低(P0.01);扎方与联合组比较,联合各组SYN,PSD-95表达增高(P0.01);同组间比较,模型、扎方、移植及联合各3 d组SYN表达较其他组减低(P0.01),各7 d组PSD-95表达达高峰(P0.01),各14 d组PSD表达较3 d组增高(P0.01,P0.05),扎方及移植各14 d组SYN表达较7 d组减低(P0.01)。结论:扎方可显著提高脑缺血再灌注损伤BMSCs移植后神经元突触结构可塑性,以二者联合作用显著,其机制可能与干预损伤后SYN,PSD-95的动态表达有关。

Effect of Zhali Nusi Fang Intervening Bone Marrow Mesenchymal Stem Cells Transplantation on Synaptic Structural Plasticity in Rats After Cerebral Ischemia Reperfusion Injury

Objective: To observe the effect of Zhali Nusi Fang(ZLNF) intervening bone marrow mesenchymal stem cells (BMSCs) transplantation on synaptic structural plasticity in rats after cerebral ischemia reperfusion injury (CIRI). Method: SD rats were randomly divided into sham-operated group, model group, ZLNF group, BMSCs transplantation group and ZLNF combined with BMSCs groups. Middle cerebral artery occlusion (MCAO) model was duplicated with nylon thread, BMSCs were cultured and amplified by the whole bone marrow adherence method. Drugs were given to the rats by intragastric administration (14.6 g·kg^-1·d^-1), BMSCs suspension solution was transplanted into rat brain through carotid artery. Brain was taken out at 1, 3, 7, 14 days after transplantation. The changes of neuronal synaptic ultrastructure were observed by transmission electron microscopy, synaptophysin(SYN) and postsynaptic density protein-95(PSD-95)protein expressions were detected by Western blot. Result: The structure of synapses in sham-operated group was integrated, the presynaptic membrane and postsynaptic membrane were clear, the synaptic cleft was visible, and a lots of synaptic vesicles distributed equably. While in model group, the quantity ofsynapses were decreased, the structure was destroyed and the synaptic cleft was dim, the amount of synaptic vesicles was decreased and even disappeared. The quantity of synapses was increased, the structure was close to the normal, and the concave and U form synapses could be seen in ZLNF group, the synaptic vesicles were increased at 3, 7, 14 days in ZLNF group, the synaptic cleft became wider at 14 dayin ZLNF group, the changes of neuronal synaptic ultrastructure in transplantation groups were in keeping with ZLNF group, the damage of synapses in combination groups was significantly lower, the synapses increased, and many concave synapses could be seen at 7, 14 days in combination groups, the synaptic vesicles were significantly increased. The SYN, PSD-95 expressions in model groups were obviously decreased when compared with the sham-operated group (P<0.01). Compared with the model group, the SYN expression was increased at 7 day group in ZLNF and transplantation and in all the combination groups (P<0.01), the PSD-95 expression was increased at 3, 7, 14 days in ZLNF and transplantation and in all the combination groups (P<0.01). Compared with the transplantation groups, the SYN, PSD-95 expressions were increased in all the combination groups (P<0.01, P<0.05), the PSD-95 expression was decreased at 3 day in ZLNF group (P<0.01). Compared with the ZLNF group, the SYN, PSD-95 expressions were increased in all the combination groups (P<0.01). Compared with the same time groups, the SYN expression at 3 day group in ZLNF, transplantation and combination groups was lower than other groups (P<0.01), and the PSD-95 expression in all 7 day groups was higher than other groups (P<0.01), the PSD-95 expression in all 14 day groups was higher than any 3 day group (P<0.01, P<0.05), the SYN expression at 14 day was lower than that at 7 day in ZLNF, transplantation group (P<0.01). Conclusion: ZLNF could increase the synaptic structural plasticity obviously after the transplantation of BMSCs to CIRI, the effect was superior when using the combination of them, and its mechanism may be related to the regulation of the dynamic expressions of SYN and PSD-95.