No abstract

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.

The use of stem cells has been proposed as an alternative treatment for certain neurodegenerative disorders. It has also been suggested that pre-differentiated stem cells might provide a better therapeutic option than differentiated or undifferentiated stem cells. The aim of this preliminary study was to determine if immature dopamine neurons cells are capable to engraft into a Parkinson´s Disease rat model. Stem cells from rat bone marrow, undifferentiated or pre-differentiated into dopamine precursor cells were implanted into brains of rats Parkinson Disease model. Histological brain analysis and rat rotational behavior were analyzed 1 and 2 weeks after transplantation. Immuno-histochemical analysis of brains showed positive engraftment of transplanted and survived at last for 3 weeks after transplantation. Rotational behavior showed a significantly decreased (P