Ex vivo expanded bone marrow stromal cells survival in ischemic myocardium and its impact on myocardial remodeling

Objective:To investigate the survival of ex vivo expanded bone marrow stromal cells(MSCs) in ischemic myocardium and its therapeutic potential for myocardial remodeling.Method:The MSCs obtained from adult rabbit leg were isolated by density-gradient centrifugation, the second generatons were harvested and labled with 4,6-diamidino-2-phenylindole(DAPI).Myocardial infarction(MI) was induced by ligating the left anterior descending coronary artery. The 2×106 MSCs labled by DAPI 8 rabbits were injected drectly into ischemic myocardium in 8 rabbits(MSCs group) 3 days after MI, 6 other rabbits(control group)received culture media. The echocardiography was performed just before and 1 week,4weeks after MSCs being implanted.The myocardium samples were harvesded at 4weeks after MSCs implantation to examin the scope of ischemic myocardium and the area of infarction.The implanted MSCs labled DAPI were investigated by fluorescence microscope. The scar degree of two group was campared by Masson's stainning. Result:The implanted MSCs were survial in ischemic area and incorporated into local myocardium confirmed by fluorescence microscope;Echocardiograpy displayed ventricular dimensions changes that were significantly smaller in MSCs group than that in the control group in 4 weeks [ΔEDV ( 0.27±0.11)ml vs (0.46±0.14) ml,P 0.05; ΔESV (0.17 ±0.13) ml vs (0.32±0.11) ml,P 0.05];the regional wall motion was better preserved in the MSCs group; the average ischemic scope and infarction area were significantly smaller in MSCs group than that in the control group in 4 weeks(14.70±0.04)%vs( 19.6± 0.09)%, P 0.05; (4.43±1.0)%vs(13.72±0.92)%,P 0.05);moreover,the extent of left ventricular scarring was siginificantly less in MSCs group than that in controls. Conclousion:The MSCs expanded ex vivo can be survival and incorporation into ischemic area ,and they can also reduce the myocardium remodeling.