OBJECTIVEDiabetic cardiomyopathy (DCM), an important cause of heart failure, is characterized by microvascular pathologies and interstitial fibrosis. Bone marrow mesenchymal stem cells (MSCs) are pluripotent, which can differentiate into cardiomyocytes and vascular endothelial cells. They also secrete angiogenic and antiapoptotic factors. However, little information is available about the effect of MSCs transplantation on diabetic heart.

METHODSMSCs were isolated from bone marrow of isogenic adult rats and cultured ex vivo. Eight weeks post streptozotocin injection, saline or exogenous MSCs labelled with 4'6-Diamidino-2-Phenylindole (DAPI) were injected into the femoral vein of diabetic rats and examined 4 weeks later by echocardiography, histopathologic analysis, reverse transcription polymerase chain reaction analysis for matrix metalloproteinase (MMP)-2, MMP-9 and tissue inhibitor of matrix metalloproteinase (TIMP)-1, zymography analysis for activities of MMP-2 and Western blot analysis for troponin T.

RESULTSLeft ventricular posterior wall thickness and myocardial arteriolar density as well as the TIMP-1 mRNA and MMP-2 activity were significantly decreased in DCM group (P < 0.01 versus control group respectively), these changes were significantly attenuated by MSCs transplantation (P < 0.05 versus DCM). MSCs transplantation also significantly reduced fibrosis and downregulated MMP-9 mRNA in diabetic myocardium.

CONCLUSIONIntravenous MSCs transplantation could attenuate LV remodeling in DCM rats.