Stem cell therapy for cardiac infarct regeneration has been widely used in clinical research. Despite the fact that important advances in this field have been reached, the observed recovery does not demonstrate new cardiac muscle formation. Benefits have been observed due to an improvement in neovascularisation. The main objective of this study was to determine if predifferentiated stem cells into cells of myocardic lineage are capable of engraftment in animal models with induced cardiac infarct and are capable of truly differentiating into myocardiocytes. Bone marrow rat stem cells were predifferentiated with 5-AZ. After 4 weeks, pre-differentiated stem cells express muscarinic 1, 2 and β adrenergic 2 receptors. Also, proteins such as sarcomeric α-actin, cardiac myosin heavy chain, desmin and vimentin were detected by immunocytochemistry. Cells were transplanted intracardialy in an ischemic cardiac rat model. Pre-differentiated or non differentiated cells were transplanted after 4 weeks post infarct induction. Histopathology of the hearts was made 2 weeks after cell transplantation. Typical granulated tissue, scare formation and neovascularisation were observed in both groups. However, in those hearts from rats inoculated with pre-differentiated cells many appeared atypical and were α-actin sarcomeric positive. These events suggest that pre-differentiated cells conserve some muscle characteristic traits in situ that at least last for two weeks after transplantation.

No abstract