兔骨髓间充质干细胞自体移植治疗扩张型心肌病的实验研究

目的 研究骨髓间充质干细胞(MSCs)自体移植于扩张型心肌病后的增殖分化情况和对心功能的保护作用。方法 日本大耳白兔随机分为4组:(1)扩张型心肌病(DCM)细胞移植组(n=12);(2)DCM对照组(n=12);(3)DCM假手术组(n=12);(4)正常对照组(n=10)。分离培养DCM细胞移植组MSCs后,前3组动物用盐酸阿霉素建立兔DCM模型,第4组注射等量生理盐水。模型建立成功后第3周,将5溴脱氧尿嘧啶(BrdU)标记的MSCs自体移植到细胞移植组心肌内,对照组注射培养基,假手术组只开胸,不做注射。4周后采用超声心动图和血流动力学参数评价各组动物的心脏结构和功能,并取移植区心肌组织行免疫荧光染色以观察移植细胞的增殖分化情况。另选部分心肌组织做HE染色查看心肌组织形态学改变。结果 与正常对照组相比,DCM各组心功能明显受损。细胞移植4周后,可以在移植组心肌内找到BrdU标记的阳性细胞,且一部分表现为心肌特异性肌钙蛋白T染色阳性,一部分Ⅷ因子相关抗原染色阳性并参与形成新生血管,其他组中没有发现。且细胞移植组心功能较对照组和假手术组有明显改善。组织学检查示前3组均有心肌细胞变性坏死。结论 MSCs自体移植到DCM后有可能增殖分化为心肌样细胞和血管内皮样细胞并改善心功能。

Experimental studies on rabbit bone marrow mesenchymal stem cells autologous transplantation into dilated cardiomyopathy

Objective Bone marrow mesenchymal stem cell (MSCs) has been shown to replace infarcted myocardium and improve cardiac performance in acute myocardial infarction. The present study was designed to investigate the effects of autologous MSCs implantation into dilated cardiomyopathy on cardiac function. Methods Forty six rabbits were randomized into four groups: (1) DCM cell implantation group (n = 12) ; (2) DCM control group (n = 12) ; (3) DCM sham-operated rabbits (n = 12); (4) normal rabbits (n = 10). Adriamycin was applied to create rabbit DCM model . Animals for cell implantation were received intramyocardial injection of autologous MSCs . The echocardiography and hemodynamic studies were performed to evaluate cardiac function at 28th day after implantation. Histologic sections of the implanted sites were examined under fluorescent microscope to identify the transplanted MSCs and to investigate its differentiation. Results At 4 weeks after the cells transplantation, the implanted cells were found in the histologic sections of experiment group and some of them differentiated into cardiomyocytes and vascular endothelial cells. The implanted cells were not found in the other groups. Compared with the normal rabbits, left ventricle end-systolic diameters (LVDs) , left ventricle end-diastolic diameters (LVDd) and the left ventricle end diastolic pressure (LVEDP) were significantly increased (P < 0. 05) , and ejection fraction (EF) , left ventricle systolic pressure (LVSP) and maximum LV pressure rising rates (dp/dtmax) were all significantly reduced (all P < 0. 05) in all DCM model groups , which changes indicated that LV functions of DCM groups were impaired. The comparison among all DCM groups showed that impaired LV functions were improved by autologous MSCs implantation, as revealed by decreased LVEDP and increased EF, LVSP and dp/dtmax(all P <0. 05). Pathological examination demonstrated that the cardiac muscular tissue of all DCM groups were harmed. Conclusions MSCs may differentiate into cardiomyocytes and vascularendothelial cells after autologous implantation into DCM and improve impaired cardiac function.