Protective effect and localization by optical imaging of human renal CD133+ progenitor cells in an acute kidney injury model

Recent approaches of regenerative medicine can offer a therapeutic option for patients undergoing acute kidney injury. In particular, mesenchymal stem cells were shown to ameliorate renal function and recovery after acute damage. We here evaluated the protective effect and localization of CD133(+) renal progenitors from the human inner medulla in a model of glycerol-induced acute tubular damage and we compared the results with those obtained with bone marrow-derived mesenchymal stem cells. We found that CD133(+) progenitor cells promoted the recovery of renal function, preventing tubular cell necrosis and stimulating resident cell proliferation and survival, similar to mesenchymal stem cells. In addition, by optical imaging analysis, CD133(+) progenitor cells accumulated within the renal tissue, and a reduced entrapment in lung, spleen, and liver was observed. Mesenchymal stem cells were detectable at similar levels in the renal tissue, but a higher signal was present in extrarenal organs. Both cell types produced several cytokines/growth factors, suggesting that a combination of different mediators is involved in their biological action. These results indicate that human CD133(+) progenitor cells are renotropic and able to improve renal regeneration in acute kidney injury.