血管内皮生长因子基因转染内皮祖细胞移植于大鼠缺血心肌的研究

Cell transplantation of endothelial progenitor cells transfected by VEGF gene exvivo into ischemic myocardium of the rat

目的:将编码有血管内皮生长因子基因的腺病毒(Ad.VEGF)转染诱导培养的骨髓内皮祖细胞(EPCs),移植于大鼠缺血心肌,评价其对心功能的保护和促血管再生作用。方法:Ficoll离心分离大鼠骨髓单个核细胞,诱导培养EPCs;在50倍的转染倍数(病毒数/靶细胞)下,用Ad.VEGF转染诱导的EPCs。然后将其移植于结扎冠状动脉前降支的Lewis大鼠缺血心肌内(组Ⅰ),同时设置单纯细胞移植组(组Ⅱ)和基因治疗组(组Ⅲ),以注射磷酸盐缓冲液的大鼠为对照组(组Ⅳ)。术后4周通过血流动力学指标评价其对心功能的保护作用;另外通过免疫组化染色观察移植细胞存活、分化和血管再生情况。结果:骨髓EPCs移植于缺血心肌4周后,缺血区的移植细胞部分分化为血管内皮细胞,组Ⅰ心功能明显好于组Ⅱ、组Ⅲ和组Ⅳ(P<0.01),在促血管新生方面,组Ⅰ也明显优于以上3组[组Ⅰ(32.2±3.5)、组Ⅱ(17.6±2.7)、组Ⅲ(19.4±3.3)、组Ⅳ(5.9±1.2)个/高倍视野]。结论:转染Ad.VEGF后的EPCs移植于缺血心肌后,可促进缺血心肌再血管化,更好地保护和改善心脏功能。

Objective： To study the effect of on cardiac function protection and angiogenesis transplantation of EPCs that were transfected with Ad. VEGF ex vivo into acute ischemic myocardium. Method.. Bone marrow mononeuclear cells of adult Lewis rats were isolated by gradient centrifugation on Ficoll, EPCs were induced and cultured. Then the cultured EPCs were transfected with Ad. VEGF which was recombinate adenovirus vector carrying VEGF gene, Myocardial infarction of Lewis rats was generated by ligating the left anterior descending coronary artery. All animals were randomized into four groups（Group Ⅰ , transplanted with EPCs transfected by Ad. VEGF; Group Ⅱ , transplanted with EPCs alone; GroupⅢ, injected with Ad. VEGF alone as gene theropy group; Groupiv, injected with PBS as cortrol group）. After operation, differentiation of transplantated cells and anglogenesis were assessed by pathological examination, cardiac function were assessed by examination of hemodynamics. Result：After transplantation, transplanted EPCs differentiated into vascular endothelial cells. Angiogenesis was most remarkable in group Ⅰ compared with groupⅡ , Ⅲand Ⅳ （P〈0.01） ; cardiac function in Group Ⅰ were significantly saved （ P 〈0.01）. Conclusion： The transplantation of EPCs＇transfected with Ad. VEGF has strong potency to protect cardiac function by stimulating angiogenesis. Such a strategy may be useful in the treatment of patients with ischemic heart disease.