Could the coculture of skeletal myoblasts and mesenchymal stem cells be a solution for postinfarction myocardial scar?

Currently two lines of research have been proposed for treatment of heart failure in an attempt to address its main cause: skeletal myoblast (SM) transplants, which increase the contractile muscular mass, and mesenchymal stem cell (MSC) transplants, which increase neoangiogenesis. The objective of this study was to establish methods whereby cocultures of SM and MSC proliferate and expand, making possible the interaction of these cell types prior to their transplantation to the myocardium. Seeking to support the survival of these cells after myocardial transplantation and achieve subsequent functional improvement, SM and MSC from 10 rats were isolated and cultivated in DMEM medium supplemented with 15% fetal calf serum, 1% ATB, and growth factors. Following plating in variable proportions of satellite cells/mononuclear cells namely 2:1, 1:1, 1:2, morphological observations were made regarding cell survival, adhesion to substrate, and confluence. After 48 hours nonadherent cells were aspirated from the flasks, leaving the adherent cells, SM, and MSC. The better level of cell proliferation was observed with the proportion 2:1 cocultivated at a concentration of 5 x 10(5)/mL for 14 days. The results were satisfactory; the cell production was up to 10(8), increasing the chances of transplant success after myocardial infarction. Transplants with this model are ongoing.

Aneural culture of rat myoblasts for myocardial transplant.

Due to the peculiar characteristics of skeletal muscle, myoblast transplants have emerged as a therapy for cardiomyopathy, particularly after myocardial infarction. The objectives of this study were to define the mean time of cultivation necessary to obtain a cellular concentration of 10(6) to expand the mass for transplant, and to identify the proliferation phase of myoblasts. Ten myoblast cultures were performed using newborn Wistar rats. The isolation method used enzymatic dissociation in culture medium (HAM-F12 and 199) supplement with basic-fibroblast growth factor (b-FGF) and insulin growth factor (IGF-I). The mean cultivation time to obtain the desired concentration of 10(6) was 7 days, with expansion of up to 10(8)/g. When b-FGF was used, the cellular yield was approximately 10(7), with IGF-I the cellular yield was approximately 10(8), independent of the medium. We concluded that IGF-I is the better option for mass cellular expansion of myoblasts for application in myocardial transplants.