[Mesenchymal stem cells for cardiac regeneration].

Since physiological regeneration of cardiac muscle is limited, scar tissue replaces damaged myocardial tissue leading to impaired cardiac function. Whether stem cell therapy can prevent this process and regenerate cardiac tissue is the issue of many research projects at present. Some studies investigate mesenchymal stem cells (MSC) from bone marrow, which are known to have the potential to differentiate into various tissues. Under certain conditions the formation of cardiomyocytes was observed in vitro and in vivo, which, however, is a controversial issue. Nevertheless many investigators found an improvement of cardiac function after transplantation of MSC into damaged heart tissue. Since only few cells survive mid-term after transplantation, the impact of real cell replacement might be limited. Instead of or besides the replacement of lost cells by transdifferentiated MSC, the secretion of paracrine factors by MSC may be important for functional improvement. Thus, MSC show promising experimental results, and may be of therapeutic value for heart disease in the future. However, there are many unanswered questions and problems, which need to be resolved before.