骨髓基质细胞源神经干细胞对大鼠局灶性脑缺血神经细胞凋亡及相关蛋白表达的动态影响

Effects of bone marrow stromal cells derived neural stem cells on the dynamic changes of apoptosis and correlative proteins in rats after focal cerebral ischemia and reperfusion

目的探讨骨髓基质细胞源神经干细胞对大鼠局灶性脑缺血神经细胞凋亡及相关蛋白表达的影响。方法建立大鼠大脑中动脉缺血再灌注模型。32只健康Sprague-Dawley(SD)大鼠分为假手术组、缺血对照组、缺血骨髓基质细胞移植组和缺血骨髓基质细胞源神经干细胞移植组。分别在移植后7d和14d行脑灌注固定取材,应用免疫组化染色及原位细胞凋亡检测脑组织Bcl-2、Bax蛋白表达及凋亡细胞数。结果缺血移植组各时点的凋亡细胞数均少于缺血对照组(P<0.01),缺血移植14d组凋亡细胞数明显少于缺血移植7d组(P<0.01),骨髓基质细胞源神经干细胞移植组凋亡细胞明显少于骨髓基质细胞移植组(P<0.05)。缺血移植组Bcl-2表达显著高于缺血对照组(P<0.01)。缺血移植组Bax蛋白表达明显低于缺血对照组(P<0.01)。结论骨髓基质细胞源神经干细胞可能通过上调Bcl-2蛋白表达,下调Bax蛋白表达,对脑缺血再灌注损伤起保护作用。

Objective To study the effects of bone marrow stromal cells derived neural stem cells（BMSCs） on apoptosis and the expression of Bcl-2 and Bax after focal cerebral ischemia and reperfusion. Methods The model of middle cerebral artery occlusion（MCAO） and reperfusion was set up. 32 Sprague-Dawley rats were divided into sham-operated group,ischemia control group,BMSCs transplanted group and BMSCs derived neural stem cells transplanted group. The rats were killed on 7,14d after transplantation. The brain sections were used for terminal deoxynucleotidyl transferase dUTP mickend labeling（TUNEL） staining and Bcl-2 ,Bax immunohistochemical staining. Result The number of apoptotic cells in the ischemia transplanted groups decreased compared with that of ischemia control group （P〈0.01）. The number of apoptotic cells in the group of 14d after transplantation decreased compared with that of the group 7d after transplantation（P〈0.01）. The number of apoptotic cells in the group of BMSCs derived neural stem cells transplantation group decreased compared with that of the bone marrow stromal cells transplantation group（P〈0.05）. The differences of bal-2 and bax positive cells between ischemia transplantation group and ischemia control group were evidently（P〈0.01）. Conclusion BMSCs derived neural stem cells can decrease the number of apoptotic cells after cerebral ischemia and reperfusion by up-regulating Bcl-2 and down-regulating Bax.