Intravenous transplantation of bone marrow mesenchymal stem cells in combination with recombinant human growth hormone repairs myocardium and vascular tissues in rats with congestive cardiomyopathy / 中国组织工程研究

ABSTRACT

BACKGROUND: It is controversial whether bone marrow mesenchymal stem cells can retain in cardiac injured position, or differentiate into cardiomyocytes or not. OBJECTIVE: To study the effects of recombinant human growth hormone and bone marrow mesenchymal stem cells (BMSCs) intravenous transplantation on myocardium and angiogenesis in rats with congestive cardiomyopathy. METHODS: BMSCs were collected from rats by density gradient centrifugation and adhesive-screening method. Models of cardiac failure were established using adriamycin induction in the model, cell transplantation, growth hormone and combination groups. Following model establishment, cell transplantation group received BrdU-labeled BMSCs (8×10~(13)/L) via vein. Growth hormone group underwent subcutaneous injection of human growth hormone 2 U/kg per day, for 14 consecutive days. Combination group received injection of human growth hormone and BMSC transplantation. At week 4, samples were collected. Immunohistochemical staining for BrdU+MHC and BrdU+Actin was used to determine homing of BMSCs to evaluate the differentiation of transplanted cells into cardiomyocytes and vascular endothelia cells. Hematoxylin-eosin staining was utilized to detect vascular density. RESULTS AND CONCLUSION: Compared with the cell transplantation group, positive rate of Brdu immunohistochemistry was increased in the combination group (P < 0.001). The number of cardiomyocytes and vascular endothelia cells was significantly increased following Brdu+MHC and Brdu+Actin staining (P < 0.001). Compared with the model group, total vascular density, microvessel density and capillary density were significantly increased in the growth hormone, cell transplantation and combination groups (P < 0.001). No significant difference was determined among growth hormone, cell transplantation and combination groups (P > 0.05). Intravenous transplantation of BMSCs could repair cardiomyocytes and vascular endothelial cells by homing into the heart. BMSCs could survive in damaged area and differentiate into cardiomyocytes or vascular endothelial cells and increase the vascular density significantly. Growth hormone could improve microenvironment and raise rates of differentiating into cardiomyocytes or vascular endothelial cells.