Résumé :
|
Several basic and clinical studies have generated large enthusiasm for the potential of cell therapy of cardiac diseases. However, many questions remain unanswered concerning the mechanisms of action of grafted stem cells and the clinical outcome of cell therapy. The use of appropriate animal models is an essential step toward a better understanding of basic features of stem cells and generation of data necessary prior to clinical transfer. Studies on small animals, in particular mice and rats, have supplied crucial informations on the fundamental aspects of stem cell biology. In particular, the possibility to generate a large panel of experimental models represents the major advantage gained from using wild type and genetically modified mice. Among the major advances generated by studies on mice and rats, we can mention i) the identification of resident cardiac precursor or stem cells, ii) the demonstration that bone-marrow derived cells can be mobilized and participate to cardiac repair, iii) the existence of the homing of precursor/stem cells towards injured heart and iv) the characterization of the molecular processes involved cardiac repair. It is evident that studies on mice and rats are absolutely necessary for the improvement of our knowledge on stem cells. However, large animals seem to be more appropriate for prediction of beneficial and side effects of cardiac cell therapy prior to the clinical translation. Extensive investigations in dogs; pigs, sheep or monkeys should be performed to define the ideal stem cells for transplantation, the doses and route of administration, the fate of grafted cells and the beneficial/side effect ratio of cell therapy. These studies will supply strong basis for the transfer of cell therapy to the clinic with the best chances to improve the therapeutical approach of cardiac diseases and the safety of patients.
|