Embryonic stem cells (ESCs) show potential prospect of wide application in establishing cardiac pharmacological model system, forming three-dimensional cardiac tissues and constructing biological pacemaker. The process of ESCs differentiating into cardiomyocytes is to simulate heart growth and development in vitro. The cases of transplanting ESCs into animal models confirm that the cardiac function is improved. Moreover, the research and exploitation of tissue engineered cardiac muscle tissue with vessel system brings hope for clinical cardiac muscle restoration. ESC-derived pacemaker can functionally integrate with quiescent ventricular muscle cells to induce rhythmic electrical and contractile activities in vitro. However, the immunological rejection limits its clinical application. Although ESCs have strong differentiation potential, the problems such as the differentiation process towards cardiomyocytes, ESC induction and signal regulatory pathway, and whether induced cardiomyocytes can substitute in vivo cardiomyocytes still need exploration.

Objective To observe the influence of human umbilical cord wharton′s jelly‐mesenchymal stem cells(WJ‐MHCs) on the tumor necrosis factorα (TNF‐α) and N‐terminal pro‐brain natriuretic peptide(NT‐proBNP) in rats with heart failure of a‐cute myocardial infarction .Methods Totally 80 male rat models of heart failure of acute myocardial infarction were made by isopre‐naline(ISO) 200 mg/kg injected subcutaneously twice at an interval of 24 hours .After one week ,24 survival rats were randomly di‐vided into WJ‐M HCs transplantation group and normal control group .Sham group was made of 12 health rats ,and then each of the three groups was subdivided into pre‐transplantation group and post‐transplantation group 4 weeks later .WJ‐MHCs transplantation group was transplanted with WJ‐MHCs with DAPI labeled after ISO injected one week .Sham group and normal group were un‐treated and normally bred .The left ventricular ejection fraction(LVEF) measured by before transplantation and post‐transplantation 4 weeks later .The injected cells and the expression of TNF‐αwas measured .Results Compared to pre‐transplantation group ,WJ‐M HCs transplantation group increased the LVEF(P<0 .05);compared to pre‐transplantation and normal control ,WJ‐M HCs trans‐plantation group reduced the TNF‐αand NT‐proBNP in the serum(P<0 .05)and the expression of TNF‐α from the heart tissue (P<0 .05);compared to normal transplantation ,WJ‐M HCs transplantation group reduced the mortality from 33 .3% to 16 .7% ;immunofluorescence demonstrated that transplanted cells were still found alive in the heart after transplantation 4 weeks later .Con‐clusion Transplantation of WJ‐MHCS down‐regulates TNF‐α and NT‐proBNP in the serum in the serum and the expression of TNF‐αfrom the heart tissue and up‐regulates the LVEF in rats with heart failure of acute myocardial infarction .