Experimental Studies On The Effects Of Bone Marrow Mesenchymal Stem Cell And Bone Marrow Mononuclear Cell Transplantation And Bone Marrow Mobilization On Adriamycin-Induced Cardiomyopathy In Rats

Part Ⅰ and ⅡDilated cardiomyopathy (DCM) is characterized by cardiac enlargement with an impairment of systolic function in one or both ventricles for unknown reasons. DCM is major in nonischemic cardiomyopathy . Nonischemic cardiomyopathy accounts for approximately one-third of the heart failure cases. Cell therapy is becoming increasing important as a potential new therapy for patients with DCM accompanied by advanced heart failure. Bone marrow mesenchymal stem cell(MSC) and bone marrow mononuclear cell (BMMNC) have been testified to have benefical effects on cardiac pump function and regenerated cardiomyocytes .But which is the better one is still unknown. In this study , we compare the effects of MSC transplantation and BMMNC transplantation on the cardiac function and cardiomyocytes regenerations and apoptosis in the rat model of Adriamycin-induced cardiomyopathy.Method:Adriamycin (2.5mg/kg, three times a week for 2 weeks, IP) was introduced into Lewis rats. They were randomly divided into 4 groups at 2 weeks after injection: MSC transplantation group(MSC group, MSC [5><106] implantation, n=10),BMMNC transplantation group(BMMNC group,BMMNC [5×10~6] implantation, n=10), control group (DMEM injection, n=10) and sham group(thoracotomy,n=10).At 4 weeks after implantation, the cardiac function were evaluated by echocardiography and cardiac cathetenzation. Cardiomyocytes apoptosis, apoptosis related protein Bcl-2 and Bax were detected by in situ terminal deoxynucleotidyl transferase assay(TUNEL method) and Western blot respectively ,VIII-factor stained and histologic study including electron-microscopic study were also performed.Result:The MSC group and BMMNC group showed a significant reduction in systolic left ventricular diameter(LVDs), diastolic left ventricular diameter (LVDd) and left ventricular end-diastolic pressure(LVEDP),whereas fractional shortening(FS),ejection fraction(EF),left ventricular systolic pressure(LVSP), the maximum rate of LV systolic pressure rise(+dp/dtmax) and the maximum rate of LV systolic pressure descend(-dp/dtmax) increased greatly compared with the control group(all PO.05). In comparison with the BMMNC group, the MSC group show a significant redunction in LVDs,LVDd,LVEDP and a significant increase in FS, EF, LVSP, +dp/dtmax, -dp/dtmax.(all P<0.05). Compared to the control group ,the apoptosis of cardiomyocytes in the MSC group and BMMNC group was significantly inhibited(P<0.05).Bcl-2 protein expression was evidently upregulated and Bax protein expression was evidently downregulated in the MSC group and BMMNC group than that in the control group.Conclusion:MSC transplantation and BMMNC transplantation can both contribute to the improvement of cardiac function in ADR-induced cardiomyopathy. MSC transplantation had more benefical effects on cardiac function than BMMNC transplantation. Both MSC transplantation and BMMNC transplantation inhibited the cardiomycytes apoptosis and affected the expression of Bcl-2 and Bax protein ,which contributes to improve cardiac pump function in vivo in ADR-induced DCM rat model.Part IIINonischemic dilated cardiomyopathy (DCM) accounts for almost one half of new cases of heart failure encountered in clinical practice. Cardiomyocytes apoptosis was reported participating in the occurrence and progression of DCM. Recent reports showed that mobilization with granulocyte colony-stimulating factor (G-CSF) enhanced bone marrow cells migrate to the damaged heart tissue and regenerated cardiomyocytes in the DCM model, however, its influence on both cardiac pump function in vivo and cardiomyocytes apoptosis has not been studied.Method: Lewis rats were randomly grouped into ADR+N.S, ADR+G-CSF group (n=10). Adriamycin(2.5 mg/kg, three times a week for 2 weeks) was administered intraperitoneally in all rats . After a two weeks wash-off period, G-CSF (50 M-g/kg/day for 8 days) was administered subcutaneously in ADR+G-CSF group and was replaced by N.S in ADR+N.S group. Four weeks later, the cardiac functions were evaluated by echocardiography and cardiac catheterization. Cardiomyocytes apoptosis, apoptosis related protein Fas were detected by in situ terminal deoxynucleotidyl transferase assay (TUNEL method) and Western blot, respectively.Result: In comparison with the ADR+N.S group, the ADR+G-CSF group showed significant increase in percent of fractional shortening (56.16±3.61% versus 36.68±1.25%, p<0.05), ejection fraction(EF)(81.9±3.48% vs 67.9±3.47%,P<0.05),left ventricular systolic pressure(l 18.38±5.53 mm Hg versus 85.25±7.50 mm Hg, PO.05), the maximum rate of LV systolic pressure rise (+dp/dt) (7751.8±674.39 mm Hg/s versus 6439±592.52 mm Hg/s, PO.05) and LV systotic pressure descend(-dp/dp) (5387.2±531.42 mm Hg/s versus 4415±280.29 mm Hg/s, PO.05). Left ventricular end-diastolic pressure (LVEDP) in ADR+G-CSF was reduced significantly compared with ADR+N.S group...