骨髓基质细胞与bcl-2基因对脑缺血大鼠疗效以及IGF-1表达影响的研究

目的:探讨联合应用骨髓基质细胞与bcl-2基因治疗大鼠脑缺血的疗效,以及对IGF-1表达的影响。方法:40只Wistar大鼠采用改良栓线法制成大鼠大脑中动脉闭塞(MCAO)再灌注模型,随机分成空白对照组、bcl-2组、MSC组和MSC bcl-2组,每组10只。各组于再灌注后1、3、7及14d进行神经功能评分;于3d及14d分别处死5只大鼠,采用免疫组化法检测BrdU、IGF-1及bcl-2蛋白的表达;通过TUNEL法检测细胞凋亡情况。结果:再灌注7、14d后各治疗组神经功能评分明显低于空白对照组(P<0.05),而14d时MSC bcl-2组神经功能评分明显低于bcl-2组及MSC组(P<0.05);MSC bcl-2组梗死半球BrdU阳性细胞明显多于MSC组(P<0.05);MSC bcl-2组梗死灶侧皮层表达IGF-1和bcl-2的阳性细胞明显多于bcl-2组及MSC组(P<0.05);MSC bcl-2组凋亡细胞明显少于bcl-2组及MSCs组(P<0.05)。结论:bcl-2基因可抑制MSCs移植后的凋亡,增加其治疗脑缺血的疗效,二者联合应用可产生叠加效应;增加IGF-1的表达可能是MSC治疗脑缺血的机制之一。

Effect of combination of marrow stromal cell and bcl-2 gene on neurological deficit and IGF-1 expression in rats with cerebral ischemia

Objective: To explore the effect of the combination of marrow stromal cell (MSC) and bcl-2 gene on neurological deficit and insulin-like growth factor-1 (IGF-1) expression in rats with cerebral ischemia. Methods: The models of middle cerebral artery occlusion were established in 40 Wistar rats by occluding the middle cerebral artery for 2 hours and then performing reperfusion. The rats were randomly and equally divided into 4 groups: control group,bcl-2 group,MSC group,and MSC bcl-2 group. The neurological scores were assessed 1,3,7,and 14 days after the reperfusion,and the expressions of bromodeoxyuridine (BrdU),IGF-1,and bcl-2 protein were detected by immunohistochemical method. The apoptosis of neural cells were detected by TUNEL method. Results: Compared with control group,the neurological scores were significantly lower in other 3 groups after 7 and 14 days of the reperfusion. The neurological scores in MSC bcl-2 group were significantly lower than those in bcl-2 and MSC groups after 14 days of the reperfusion. The number of BrdU-positive cells in the infarct hemisphere in MSC bcl-2 group was significantly higher than that in MSC group. Compared with the MSC and bcl-2 groups,the expression of IGF-1 and bcl-2 protein in the infarct hemisphere significantly increased and the apoptosis of neural cells significantly decreased in MSC bcl-2 group. Conclusion: bcl-2 gene could inhibit MSC apoptosis and enhance the therapeutic effect of MSC on cerebral ischemia. The combination of MSC and bcl-2 has a synergistic effect in treating cerebral ischemia. Enhancing IGF-1 expression might be one of the mechanisms of MSC in treating rats with cerebral ischemia.