内皮祖细胞和胰岛素样生长因子-1联合移植治疗急性心肌梗死的实验研究

Experimental study of endothelial progenitor cells transplantation combined with insulin-like growth factor-1 injection in the treatment of acute myocardial infarction

目的 :联合移植内皮祖细胞(endothelial progenitor cells,EPCs)和胰岛素样生长因子-1(insulin-like growth factor-1,IGF-1)治疗急性心肌梗死大鼠,观察心脏功能并探究其作用机制。方法 :体外扩增EPCs,建立大鼠心肌梗死模型,随机分为手术对照组(Control组)、EPCs组、IGF-1组和EPCs+IGF-1组。细胞移植组予注射移植EPCs或EPCs+IGF-1,Control组和IGF-1组注射等体积的PBS和IGF-1。移植后2周,采用心脏超声评价心脏功能,荧光显微镜下观察标记阳性细胞,免疫组化法检测毛细血管密度,Western Blot检测心肌组织血管内皮生长因子(vascular endothelial growth factor,VEGF)的表达。结果:与Control组相比,其他3组心脏功能均有改善(P<0.05),EPCs+IGF-1组改善最为显著(P<0.05);EPCs+IGF-1组梗死边缘区可见较多4’,6-二脒基-2-苯基吲哚(4’,6-diamidino-2-phenylindole,DAPI)标记阳性细胞(P<0.05);边缘区毛细血管密度检测示:EPCs+IGF-1组密度最高,EPCs组及IGF-1组次之(P<0.05);EPCs+IGF-1组VEGF的表达水平显著高于其他各组(P<0.05),而EPCs组和IGF-1组高于Control组(P<0.05)。结论:EPCs与IGF-1联合移植治疗大鼠心肌梗死,较单用EPCs或IGF-1移植更能改善心脏功能,其机制是增加细胞移植效率,增强旁分泌效应,增加血管新生,改善组织灌注等。

Objective： To explore the therapeutic effect and mechanism of endothelial progenitor cells（EPCs） transplantation combined with insulin-like growth factor-1（IGF-1） injection in treatment of acute myocardial infarction. Methods： The EPCs isolated from bone marrow were cultured and expanded in vitro. The successful myocardial infarction-rats were randomly allocated to Control group, EPCs group, IGF-1 group and EPCs＋IGF-1 group. After the ligation of the left anterior descending coronary artery, EPCs labeled with 4＇, 6-diamidino-2-phenylindole（DAPI） suspension with or without IGF-1 were directly injected into the infarcted hearts of cell transplantation groups, while identical volume of PBS or IGF-1 saline was delivered into the hearts of Control or IGF-1 group in same manner. Two weeks post cell delivery, cardiac function was measured by Echocardiography, and then all animals were sacrificed, cellular engraftment in infarcted heart was determined by fluorescent microscopy. The capillary density was assessed by immunohistochemical staining of CD31. The expression level of vascular endothelial growth factor（VEGF） was evaluated by Western Blot analysis. Results： Echocardiography showed that cardiac function of the other three groups improved compared with Control group, especially, EPCs＋IGF-1 group increased more significantly（P〈0.05）. DAPI labeled cells in the peri-infarct area were higher in EPCs＋IGF-1 group than EPCs group（P〈0.05）, the capillary density of peri-infarct area in EPCs＋IGF-1 group was markedly higher than that in the other groups（P〈0.05）. The highest expression of VEGF was observed in EPCs＋IGF-1 group compared with that in the other groups（P〈0.05）, meanwhile, the levels of EPCs group and IGF-1 group were higher than Control group（P〈0.05）. Conclusion： EPCs transplantation combined with IGF-1 may provide more beneficial effect on improving cardiac function in a rat AMI model than by EPCs alone via enhancing cell survival, promoting paracrine activities and the induction of therapeutic angiogenesis.