Experimental Study On Combining BMP-2 With Myocardial Cell Lysate To Induce Marrow Mesenchymal Stem Cells For The Improvement Of Cardiac Function After Myocardial Infarction

Objective: In this experiment, We adopt Myocardial cell lysate to simulate cardiomyocyte microenvironment in vitro. we Combine BMP-2 and Myocardial cell lysate to induce MSCs transdifferentiate to cardiomyocyte-like cells to study the induce effect on MSCs.Then,we transplate the MSCs that induced by different induction factors to study the Improvement effect on Cardiac Function. Moreover,we will observe the induction ability and characteristics of BMP-2 as compared with the traditional Inducer 5-Aza.Methods: 6-8 weeks old SD rats femoral marrows mesenchymal stem cells were cultured to the third generation, then divided into five groups. group A: DMEM/F12 medium group; group B: BMP-2 induction group; group C: 5-azacytidine induction group; group D: myocardial cell lysate induction group; group E: BMP-2 and myocardial cell lysate induction group. According to each experimental condition, the MSCs were induced for one week. Using real time PCR to investigate the relative expression of GATA-4, NKX2.5 so as to clear the strength of the performance of different induction conditions.Ligating Left anterior descending coronary artery to make the Model of Myocardial Infarction in rat.Then,the vivo Transplantation experiment is also divided into five groups: Group A, (control group), only to inject DMEM/F12 medium; Group B,to transplant Uninduced MSCs; Group C,to transplant MSCs induced by BMP-2; Group D,to transplant MSCs induced by myocardial cell lysate; Group E: to transplant MSCs induced by BMP-2 and myocardial cell lysate.The echocardiographic studies were performed to measure cardiac function in the preoperative and 4 weeks postoperative. In addition, the vascular perfusion function will be assessed in the infarct zone and infarct border zone in each group.Results: The experimental results detected by real time PCR: There were conspicuous expression of GATA-4, NKX2.5 in the experimental groups. From the density and brightness of the bands to analyze the expression of GATA4 and NKX2.5, the differences of the four experimental groups had statistic significance (P<0.05).Group E has more obvious induction performance Compared with the Group D (P <0.05).The induction effect in group C is more obvious than Group B (P <0.05). but there are no differences between experimental Groups C and D(P>0.05).Myocardial infarction was defined by echocardiography as any segmental wall motion abnormality,Left ventricular end-diastolic diameter (LVEDd) increase and contractility decreased significantly after MI (P<0.05). After intravenously injected MSCs, the cardiac function in B, C, D and E group improved compared with control group (P<0.05).the cardiac function improvement in Group E is more obvious than the other three groups. the cardiac function improvement in Group D is more obvious than Group C ,and the cardiac function improvement in Group C is better than Group B. there are Significant difference between the four experimental Groups (P<0.05).Compared with the control group, The infarct zone capillary density in B and C group was significantly increased (P <0.05), Group D have more significant capillary density than Group B and Group C (P <0.05),but there are no significant differences between Groups B and C(P>0.05).the number of blood perfusion capillary of group E is the most highest in experimental groups (P <0.05).Conclusions: BMP-2 that is at the current 10μg/L induction concentration could induces bone mesenchymal stem cells differentiate to cardiomyocyte-like cell,but the induction effect is weaker than the traditional Inducer agent 5-Aza; The improvement of cardiac function in induced MSCs groups is better Compared with that of Uninduced MSCs; The Joint induction group Played a more obvious and effective induction effect to promote marrow mesenchymal stem cells to Differentiate and Develop Compared with other groups; Transplantion of MSCs induced by BMP-2 and Myocardial cell lysate can improve the cardiac function more Significantly than any other groups,and the more obvious induction effect is,the better the cardiac function improves.