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EFFECTIVENESS OF SKELETAL MYOBLASTS AND BONE MARROW STROMAL CELLS TRANSPLANTATION ON POST-INFARCT VENTRICULAR DYSFUNCTION.
Luiz Cesar G. Souza, MD,MS,Phd , Katherine A. Teixeira de Carvalho, MD,MS , Alexandra C. Senegaglia, BS , Carmen Lucia K. Rebelatto, BS,MS , Marcus Furuta MD , Nelson Myague MD , Marcio Scorsin MD,MS,Phd and Paulo R. Brofman, MD,MS,Phd . Curitiba Paran
, Brazil, Pontificia Universidade Catolica do Parana, 80215901, Health and Biological Science Institute .
The aim of this study is to compare the functional outcome of skeletal myoblasts (SM) and bone marrow stem cells (BMSC) on left ventricle (LV)dysfunction. Those cells were expanded in vitro for 10 days. One week after myocardial infarction, they underwent the first 2-D echocardiographic study (ES) for baseline assessment for function evaluation, left ventricle end diastolic volume (LVEDV). Two days later, they were reoperated by sternotomy and randomly assigned for intramyocardial transplantation (Tx) of SM (n=9; 5x106cells), BMSC (n=9; 3 x 106cells) and controls (n=8; 150µ/L of medium). Four weeks later, another ES was performed. Cells were identified by muscle-specific protein (embryonaire myosine), factor VIII imunostaining, hematoxylin-eosin and Gomeri trichome histopathology. Statistics were performed by Anova 2 way for repeated measures. There were no difference between groups in baseline EF or LVEDV. However, 1 month after Tx, we observed a decrease in EF in controls (26.7 ± 6.0% to 22.3 ± 7.0%, p=0.004) while EF markedly improved after myoblast Tx (23.0 ± 6.2% to 28.2 ± 9.1%, p=0.04) and remained unchanged after BMSC Tx (26.8 ± 8.4% to 24.8 ± 10.2%, p=0.37). LV volume did not differ between groups after transplantation (0.53 ± 0 to 0.64 ± 0.1 mL, 0.53 ± 0 to 0.68 ± 0 mL, and 0.58 ± 0.1 to 0.72 ± 0.2 mL, p=0.2 for SM, BMSC and controls). Elongated striated fibers characteristics of skeletal origin in SM group and neoangiogenisis in BMSC group were identified in myocardial scar .Our data suggest that myogenic differentiated cells are more effective than undifferentiated stromal cells on post infarct ventricular dysfunction.