Purpose of review: To review the current knowledge of the contribution of mesenchymal stem cells (MSCs) during renal repair and the factors and mechanisms underlying these effects.
Recent findings: Although many studies using MSCs as therapeutic agents have been published in recent years, our understanding is incomplete how migration, growth, and differentiation of adult MSCs are governed by interactions with resident renal cells, growth factors, and cytokines. Different laboratories have shown that extrarenal stem cells contribute to renal regeneration: MSCs migrate into injured renal tissue, are integrated into the tubular system, and differentiate into epithelial cells. Nevertheless, a couple of studies could not verify these results in all, but despite this they have shown a beneficial effect of administered MSCs on renal regeneration. It is well established that renal tubular epithelial cells secrete growth factors and cytokines. These factors participate in renal repair as paracrine regulators or chemoattractants to induce migration of extrarenal stem cells, whereas only limited data are available about the interactions between all key players during renal repair mechanisms.
Summary: Although different studies demonstrate the effectiveness of MSC therapy, there are still open questions defining the mechanism of action during homing and differentiation and the long-term safety on the way to a therapeutic option.