Abstract:

BACKGROUND: Umbilical cord blood (UCB)-derived mesenchymal stem cells (MSCs) have multi-differentiation potentials, and can repair myocardial tissue following homing or implantation into the heart. However, transplantation safety and whether the transplantation can inhibit apoptosis of human cardiomyocytes under coculture of human cardiomyocytes deserve further investigations.
OBJECTIVE: To study the safety and apoptosis inhibition of the UCB-derived MSCs with co-culture on human cardiomyocytes.
METHODS: Human UCB-derived MSCs were collected at the time of delivery, and treated with 5-azacytidine for 24 hours and further introduced differentiation into cardiomyocytes. Cells at passages 3-5 and induced cells were obtained to detect the telomerase activation, tumor-related gene RNA levels, chromosome karyotype G typing, cell surface antigen expression, tumor formation in nude mice, and cell apoptosis under coculture.
RESULTS AND CONCLUSION: MSCs derived from UCB were differentiated into cardiomyocytes in vitro following induced by 5-azacytidine. Telomerase activity, p53, cyclin A, cdk2, β-actin, c-fos, h-TERT and c-myc expression was similar before and after induction. No abnormal chromosomal karyotypes were observed. Immunophenotype did not significantly change. Cells were negative for CD34, but positive for CD44 and CD90 (Thy-1). There was no tumor formation in nude mice. UCB-derived MSCs significantly inhibited apoptosis of human cardiomyocytes under co-culture conditions compared with cardiomyocytes (P < 0.05). Results have suggested that human UCB-derived MSCs are a valuable safe and effective source of cell-transplantation treatment, and can inhibit the apoptosis of human cardiomyocytes under co-cultured conditions.