HGF基因转染脂肪来源干细胞移植改善兔急性心肌梗死后心功能的研究

hHGF gene-transfected adipose-derived stem cells improves heart function after myocardial infarction in rabbits

目的探讨脂肪来源干细胞(adipose-derived stem cells,ADSC)移植和肝细胞生长因子(hepatocyte growthfactor,HGF)基因联合治疗兔急性心肌梗死(acute myocardial infarction,AMI)的疗效及机制。方法家兔30只,复制急性心肌梗死模型。随机分为3组:AMI/ADSC+hHGF组、AMI/ADSC组、AMI未治疗组,每组10只,另外随机选取10只兔作为假手术组。AMI术后3 d,取兔腿部脂肪,分离ADSC培养,流式细胞术鉴定其表面标记。构建pcDNA3.1-hHGF重组表达载体,移植前用脂质体包裹表达载体转染ADSCs,孵育24 h。AMI术后14 d,自体细胞移植,AMI未治疗组接受等量的无血清培养基注射,假手术组只开胸,不注射。细胞移植后28 d,超声心动图检测左室功能指标;取心肌组织,酶联免疫吸附法(ELISA)测定心肌组织中HGF的含量;计算心肌血管密度和纤维化面积。结果移植后28 d,超声心动图测定显示AMI/ADSC+hHGF组心功能改善明显优于AMI/ADSC组;AMI/ADSC+hHGF组HGF含量高于AMI/ADSC组以及AMI组。AMI/ADSC+hHGF组梗死区血管的数量及心肌纤维化面积等参数明显优于AMI/ADSC组。结论转染肝细胞生长因子基因的脂肪来源干细胞移植可改善兔心肌梗死后的心功能,其疗效明显优于单纯干细胞移植,其可能通过促进血管新生、改善梗死区的血供及抗纤维化效应而起作用。

Objective To evaluate the transplantation of human hepatocyte growth factor （hHGF） gene-transfected adipose-derived stem cells （ADSCs） in treatment of acute myocardial infarction （AMI） in rabbits. Methods Acute myocardial infarction was induced in 30 male New Zealand rabbits, which were randomly divided into three groups （ n = 10 in each） ： AMI/ADSC ＋ hHGF group, AMI/ADSCs group and AMI group; another 10 rabbits served as sham operation group （sham）. ADSCs were isolated from the rabbits and cultured in vitro, pcDNA3.1-hHGF recombinant plasmid was constructed and transfect into ADSCs by liposome transfection method. Subsequently ADSCs orhHGF-transfected ADSCs were transplanted to the ischemic zone of rabbit hearts at d14 after AMI induced. Echocardiography was performed at 4 weeks later, ejection fraction （ % EF） was calculated using standard formulas and HGF content in the infarct myocardium was detected by ELISA. Vascular density and fibrotic area in the heart were also evaluated. Results The functional parameters of left ventricle （LV） 28d after transplantation were improved more markedly in AMI/ADSC ＋ hHG.F group than in ADSCs and AMI group. The content of HGF in infarct myocardium was significantly decreased; but the level of HGF was increased in AMI/ADSC ＋ hHGF group. Increased vascular density and decreased fibrotic area in infarct area was found in AMI/ADSC ＋ hHGF group, compared to AMI/ADSC group. Conclusion HGF gene-transfected ADSCs transplantation improves heart function after myocardial infarction more effectively than sole ADSC transplantation. Increasing capillary density in the ischemic myocardium, ameliorating blood supply to infarct-zone and anti- fibrotic effect might be involved in the mechanisms.