5-氮胞苷与内皮素-1联合诱导大鼠骨髓间质干细胞移植治疗心肌梗死的实验研究

Autogenous transplantation of rat bone mesenchymal stem cells induced with 5-aza and ET-1 for treatment of myocardial infarction

目的 将单纯 5 -氮胞苷 (5 -aza)诱导、5 -aza与内皮素 - 1(ET - 1)联合诱导的骨髓间质干细胞 (BM SCs)所分化的心肌样细胞移植于大鼠心肌梗死区 ,探讨其对缺血心肌的病理学及功能的影响。方法 SD大鼠 2 4只 ,随机分为 3组 :组Ⅰ为对照组 ,组Ⅱ为单纯 5 -aza诱导组 (5 μmol/L) ,组Ⅲ为 5 -aza及ET - 1联合诱导组 (5 -aza 5 μmol/L +ET - 110 -10 mol/L)。组Ⅱ、组Ⅲ动物取胫骨BMSCs进行培养 ,体外诱导后行自体细胞移植。采用冷冻法建立心肌梗死模型 ,采用直接注射法将标记BrdU的待移植BMSCs移植入心肌梗死区 ,对照组注射等量无血清培养基。移植 4周后 ,测定左室血流动力学改变 ,大鼠梗死区免疫组化染色观察移植细胞存活、分化和新生血管形成特征。结果 BMSCs移植 4周后 ,梗死区内可见部分心肌样移植细胞 ,其中 ,组Ⅱ移植细胞胞质内TroponinⅠ染色较浅 ,而组Ⅲ移植细胞胞质内TroponinⅠ染色较深。血流动力学测定结果显示 ,组Ⅱ、组Ⅲ左心室舒张末压 (LVEDP)均显著低于对照组 (P <0 .0 5 ) ;左心室压力变化速率 (+dp/dtmax、-dp/dtmax)则明显高于对照组 (P <0 .0 5或P <0 .0 1)。与组Ⅱ相比 ,组Ⅲ +dp/dtmax显著增高 (P <0 .0 5 )。形态学观察显示 ,移植实验组梗死区内新生血管增多。组Ⅱ、组Ⅲ微血?

Objective To investigate the effects of augogenous transplantation of cardiac-like cells, generated from rat bone mesenchymal stem cells (BMSCs)under the induction of 5-azacytidine (5-aza) and 5-aza plus endothelin-1 (ET-1), on the pathology and function of ischemic infracted myocardium.Methods A cryoinjury-derived scar was made in the left ventricular front wall. At 4 weeks after myocardial injury, 24 rats were randomly divided into three groups: groupⅠ, culture medium (control),groupⅡ, 5-aza-induced BMSCs (5 μmol/L), groupⅢ, 5-aza (5 μmol/L) plus ET-1(10 -10 mmol/L)-induced BMSCs. The induced BMSCs were labeled with BrdU and autogenously transplanted into the myocardial scar. Heart function was measured 4 weeks after BMSCs transplantation. The transplanted BMSCs' survival, differentiation, as well as the angiogenesis in ischemic scar, were studied by immunohistochemistry.Results Cardiac-like cells, which were stained positively with BrdU and Troponin Ⅰ, were observed in the myocardial scar tissue of the transplanted hearts. The heart diastolic and systolic functions in group Ⅱ and group Ⅲ were significantly improved, compared with that in the control, with regard to LVEDP, +dp/dt max and -dp/dt max (P<0.05).The +dp/dt max was significantly higher in group Ⅲ than in group Ⅱ (P<0.05). The angiogenesis in ischemic scar was also found in all transplanted BMSCs animals, with the density of angiogenesis being higher than that in control group(22±4.6 and 24±4.2 vs 5±1.6,P<0.01).Conclusions Myocardial cellular transplantation with induced-BMSCs can not only improve ischemic heart function, but also induce angiogenesis in the infarcted area. The improvement of cardiac function after transplanting BMSCs induced with 5-aza plus ET-1 is better than that with 5-aza alone.