骨髓间充质干细胞移植对脑缺血大鼠脑组织凋亡相关蛋白的影响

目的 探讨经静脉移植的骨髓间充质干细胞(MSCs)在脑缺血大鼠脑组织的分布情况及对凋亡相关蛋白半胱氨酸天冬氨酸蛋白酶3(Caspase 3)及Bcl-2蛋白表达的影响.方法 体外培养及扩增MSCs后,用绿色荧光染料羟基荧光素二醋酸盐琥珀酰亚胺脂(CFSE)标记,通过静脉途径移植给大脑中动脉缺血2 h再灌注的SD大鼠,按不同时间点取材,荧光显微镜下观察MSCs在脑内的分布,免疫组化染色检测大鼠脑内Caspase 3、Bcl-2蛋白表达情况.结果 移植组6、12、24、72 h及7 d时,Caspase 3免疫组化阳性目标面密度分别为(2.81±0.35)%、(3.98±0.67)%、(5.58±0.92)%、(3.51±0.63)%、(1.64±0.29)%,明显低于对照组[(3.92±0.44)%、(5.23±0.30)%、(6.89±0.57)%、(4.39±0.57)%、(2.29±0.21)%],两组比较差异有统计学意义(t值分别为4.37、3.34、2.60、2.32、3.90,P＜0.05或＜0.01);移植组6、12 h及7 d,Bcl-2阳性目标面密度分别为(4.70±0.16)%、(5.61±0.26)%、(3.00±0.28)%,明显高于对照组[(3.28±0.27)%、(4.54±0.59)%、(2.15±0.62)%],两组比较差异有统计学意义(t值分别为8.32、3.25、2.54,P＜0.05或＜0.01).结论 MSCs可能通过下调Caspase 3蛋白表达、上调Bcl-2蛋白表达的方式对脑缺血再灌注损伤起保护作用.

Effects of bone marrow mesenchymal stem cells on apoptosis relative proteins of cerebral tissue in brain ischemic rat

Objective To observe the distribution of bone marrow mesenchymal stem cells(MSCs) and the effects on expression of apoptosis relative proteins Caspase 3 and Bcl-2 after intravenous transplanted into ischemic rat brains.Methods MSCs from SD rats were cultivated and proliferated in vitro and marked with CFSE.MSCs were then intravenously transplanted into middle cerebral artery occlusion(MCAO)models of SD rats.The rats were killed at different time points to observe the distribution of MSCs under fluorescence microscoDe as well as the effects on expression of apoptosis relative proteins Caspase 3 and Bcl-2 using immunohistochemical method.Results Density of Caspase 3 in immunohistochemically positive area in transplantion group were(2.81±0.35)%,(3.98±0.67)%,(5.58±0.92)%,(3.51±0.63)%,(1.64±0.29)%in 6,12,24,72 hours and in 7 days,respectively,and decreased significantly compared with those of control group[(3.92±0.44)%,(5.23±0.30)%,(6.89±0.57)%,(4.39±0.57)%,(2.29±0.21)%],the difference being significant(t=4.37,3.34,2.60,2.32,3.90,P＜0.05 or＜0.01).The density of Bcl-2 in immunohistochemically positive area in transplantation group were(4.70±0.16)%,(5.61±0.26)%,(3.00±0.28)%respectively in 6,12 hours and in 7 days,which had improved significantly compared with those of control group[(3.28±0.27)%,(4.54±0.59)%,(2.15±0.62)%],the difference being significant(t=8.32,3.25,2.54,P＜0.05 or＜0.01).Conclusions Bone marrow MSCs can exert protective effects on brain ischemia and reperfusion injury possibly by down-regulating Caspase 3 and up-regulating Bcl-2.