Construction of cardiac atrioventricular electrical conduction pathway by rabbit bone marrow mesenchymal stem cells / 中国组织工程研究

ABSTRACT

BACKGROUND:Autologous stem celltransplantation to the heart is a research direction of heart failure treatment, but there are relatively few of studies about autologous bone marrow mesenchymal stem celltransplantation targeting the cardiac conduction system. OBJECTIVE:To evaluate the potential of rabbit bone marrow mesenchymal stem cells for treatment of heart block. METHODS:Rabbit bone marrow mesenchymal stem cells were induced by 5-azacytidine to differentiate into cardiomyocyte-like cells. After thoracotomy, the left atrium-left ventricular anterior wal was sutured in 14 New Zealand white rabbits (8 in the experimental group and 6 in the control group). One month after the surgery, in the experimental group, autologous bone marrow mesenchymal stem cells induced by 5-azacytidine for 4 weeks were labeled with 4',6-diamidino-2-phenylindole and then injected into the suture area when opening the thoracic again. In the control group, cells cultured in medium were used. One month after celltransplantation, the third thoracotomy was done to insert electrodes into the left atrium and left ventricular anterior wal , for cardiac electrophysiological detection. Whether atrioventricular pathway formed in the suture area was observed. RESULTS AND CONCLUSION:After cells were transplanted into the sutured area, two rabbits in the experimental group were discovered to form the atrioventricular pathway in the sutured area through cardiac electrophysiological examination. After transplantation, transplanted cells were visible on the heart frozen sections under fluorescence microscope in the left ventricle and sutured area, but there was no cellin the control group. In the experimental group, bone marrow mesenchymal stem cells expressed Cx43 and formed gap junction intercellular communication with cardiomyocytes, which was presented as formation of the atrioventricular pathway on cardiac electrophysiology examination. These findings indicate that bone marrow mesenchymal stem cells can be used to treat cardiac conduction system block diseases.