血管内皮生长因子基因转染的心肌细胞移植对心肌梗死大鼠心功能的影响

目的：探讨腺病毒介导血管内皮生长因子165基因（AdVEGF165）转染乳鼠心肌细胞后血管内皮生长因子（VEGF）的表达及移植于大鼠急性心肌梗死（MI）模型后对心功能的影响。方法:体外培养新生大鼠心室肌细胞、标记BrdU、共培养法转染AdVEGF165基因；收集培养液上清，ELISA法检测转染细胞VEGF的表达。结扎同种大鼠前降支建立心肌梗死模型，4周后将心肌梗死大鼠随机分为4组，分别注射移植转染心肌细胞(组Ⅰ)、单纯心肌细胞（组Ⅱ）、AdVEGF165（组Ⅲ）和DMEM培养基（组Ⅳ）。超声心动图检测移植前及移植4周后的心功能。处死大鼠，留取心脏标本作HE病理染色及免疫组化检测，并计数血管密度。结果:AdVEGF165基因转染的心肌细胞表达VEGF高于对照组(P<0.01)；超声检测心功能提示转染细胞组(组Ⅰ)心功能障碍轻于其它3组（P<0.01）；免疫组化检测显示，移植细胞在移植区存活；HE染色血管计数显示转染组(组Ⅰ)有更多的新生血管形成（P<0.01） 。结论：AdVEGF165基因转染心肌细胞后表达分泌VEGF增加，可促进梗死区新生血管形成，改善心肌血供，有利于移植细胞的存活，能更好地减轻心功能障碍。

Effect of cell transplantation for the treatment of acute myocardial infarction using vascular endothelial growth factor gene transferred neonatal cardiomyocytes

AIM:To observe the secretion of vascular endothelial growth factor (VEGF) when adenovirus induced VEGF165 (AdVEGF165) gene transferred into neonatal cardiomyocytes in vitro,and to investigate the impact on heart function after transplanted the transferred cardiomyocytes into infarct myocardium in rats.METHODS:Neonatal cardiomyocytes were cultured in vitro and labeled with BrdU,then transferred by AdVEGF165.ELISA was applied to assay the expression and secretion of VEGF.Wistar rats,in which left descending branch of coronary artery was ligated,were randomly divided into four groups and transplanted into MI area with transferred cardiomyocytes (group Ⅰ),untransferred cardiomyocytes (group Ⅱ),AdVEGF165 (group Ⅲ) and culture medium (group Ⅳ),respectively.The echocardiograph was applied to evaluate the heart function before and after cell transplantation.Then the rats were executed and the hearts were harvested for histological (hematoxylin-eosin) and immunohistological (anti-BrdU dyeing) examinations.The vessels were also counted in injected area.RESULTS:ELISA indicated that the expression and secretion of VEGF in groupⅠwere higher than those in the rest (P<0.01).Echocardiograph revealed that the improvement of ejection fraction (EF) in groupⅠwas greater than that in other groups (P<0.01).Immunohistological study showed that the implanted cardiomyocytes survived in MI area.More blood vessels in groupⅠthan other groups were observed (P<0.01) by vessel-counting.CONCLUSIONS:AdVEGF165 gene transfer increased the VEGF-production,accelerated neovascularization in MI area and increased the blood flow.The method makes favor for the survival of implanted cells and greatly improves the heart function.