Empirical Study Of Bone Mesenchymal Stem Cells Differentiation Into Cardiac Cells Induced By BMP-2

Objective: Coronary heart disease remains the first cause of morbidity and mortality worldwide. It is known that Cardiomyocytes can not regenerate after birth. Loss of cardiomyocytes leads to regional contractile dysfunction and necrosis .cardiomyocytes in infarcted ventricular tissues are progressively replaced by fibroblasts and form scar tissues, which leads the contractile function disorder and heart function decrease ,then induces congestive heart failure. This experiment will aimed to improve the heart function, amendment cardiomyocytes reconstitution, increase cell number and promote neogenesis blood vessel through transplanting Mesenchymal Stem Cell treated by BMP-2.Methods: The bone marrow stem cells were taken from Meishan- swines respectively.The 4th generation BMSCs were induced for 24 hours differentiation into cardiomyopathy with BMP-2, and immunocytochemistry signed BMSCs by cTnT, CX-43 and MHC.15 healthy male meishan swines were randomly devided into 3 groups, and heart infarction model were established with gelatin sponge through intervention. Group A was control group, and DMEM of 5mL was transplanted into infarction area though intervention 4 weeks after infarction. In Group B 1×107 MSCs were transplanted into infarction zone. In Group C 1×107 induced MSCs were transplanted.The heart function were measured through Powerlab after transplanting, the number of neogenesis blood capillary was counted using facterⅧstaining, detected the expression of GATA-4 in all groups through the method of Western blot,observed the change of myocardial ischemia by ECT, calculated the change of infarction area by the method of TTC.Results: Shape and arrangement of the cells changed after induction with BMP-2. cTnT and Cx-43 were expressed three weeks after induction.Expression of cTnT was obvious 4 weeks after induction,the structure was dense and striation-like.Cx-43 was located beneath the membrane 3 weeks after induction,in 4 weeks,the protein was observed at cell conjunctions,it was granular and dense and located at conjunctions between cells of my tube-like structure ; MHC was expressed in endochylema and nucelus three weeks after induction . before transplantation, Powerlab showed hemodynamic LVDP and±dp / dtmax dropped significantly in cardiac infarction model,after transplanted induced cells to infarcted area, as the time gone by, cardiac function of B, C group has improved (P<0.05), this improvement in cardiac function ingroup C is more obvious (vs. the B group, P<0.05). Compared with group A, B, the number of capillaries increased and infarction size dicreased significantly in group C (P <0.05). 4 weeks after transplantation, GATA-4 expressed significantly in group C (vs. the A, B group, P<0.05), ECT also showed ischemic area obviously decreased in group C.Conclusions: BMP-2 can induce MSCs differentiation into cardiomyocytes via and expresse myocardium specificity protein in vitro, transplantion of MSCs induced by BMP-2 can more promot the blood capillary micrangium eregeneration which to amendment heart muscle ischemia and and improve the cardiac function.