Cardiac and renal cell therapies: similarities and differences.

Patients with terminal cardiac or renal disease have few therapeutic options besides organ transplantation. Optimally, cell therapies would be used both in acute and chronic stages of such diseases. In the injured myocardium, the main therapeutic goal is reestablishment of adequate perfusion and cardiac output. This can be achieved by stem cell (SC) infusions, and currently several clinical trials have provided promising results. Considering the heart's low intrinsic capacity for regeneration and its paucity of resident cardiac SCs, we believe that induction of angiogenesis must be the primary goal, thereby promoting activation of resident SCs as well as mobilization of perivascular mesenchymal SCs that can mediate myocardial regeneration. Renal tissue, in contrast to the myocardium, has a high intrinsic capacity to respond to injuries and thus repair itself. Infusion of bone marrow (BM) cells or of their sub-populations protects the injured renal tissue and elicits immediate activation and proliferation of resident cells, which are able to undertake repair and regeneration of structures of both mesenchymal and epithelial origin. Experimental evidence indicates that infused cells function essentially through paracrine pathways, decreasing inflammation and fibrosis. In both severe cardiac and renal disorders, cell therapies appear to be a promising therapeutic option.