Abstract: Objective To investigate Effects of Transplantation of mesenchymal stem cells combining with two different gene transfection on the treatment of myocardial infarction in rats. Methods MSCs were isolated and expanded using the preplating method. Ad-ADM or Ad-HGF expression in MSCs and its secretion in culture medium were measured by ELISA. The left anterior descending branch of rats was ligated to establish a myocardial infarction model. Then the pretreated MSCs were labeled by DAPI, and were injected directly into the infarcted myocardium at open thorax surgery. Four weeks later, cardiac function was evaluated using echocardiography. Hearts were harvested. Immunohistochemistry staining of factor Ⅷ was used to evaluate the density of capillary vessels in infarction area. Immunohistochemistry staining of Troponin I (TNI) and connexin 43 were used to evaluate the differentiation and expression of implanted MSCs. Fluorescence microscope was used to identify the DAPI-labeled cells. Results The expression of ADM or HGF was traced in culture medium and has the time-effect relationship. DAPI-labeled transplantion MSCs were founded in the hearts of the recipients and expressed TNI in all MSCs transplantation groups. Immunohistochemical studies demonstrated that intense immunostaining for connexin 43 was higher in Ad-ADM plus MSCs group and Ad-HGF plus MSCs group, compared with MSCs group. A combination of Ad-ADM or Ad-HGF trensfection and MSCs transplantation demonstrated a further increase in capillary density and further improved LVEF compared with MSCs alone. There is no statistics significance between Ad-ADM plus MSCs group or Ad-HGF plus MSCs group in all index. Conclusion Ad-ADM or Ad-HGF transfection enhanced the angiogenic potency of MSCs transplantation and improved cardiac function. The treatment of myocardial infarction in rats in both Ad-ADM plus MSCs group and Ad-HGF plus MSCs group is no statistics significance.

Key words: adrenomedullin, hepatocyte growth factor, mesenchymal stem cells, myocardial infarction, cell transplantation