Insights into the role of bone marrow-derived stem cells in renal repair.

Acute kidney injury (AKI) is a frequent clinical problem with a high mortality rate, generally caused by ischemic insults. Nevertheless, the kidney has a remarkably high capacity to regenerate after ischemic injury. Tubular cells can restore renal function by proliferation and dedifferentiation into a mesenchymal cell type, but also stem cells residing in bone marrow may contribute. We compiled a protocol from several published methods to study the contribution of bone marrow-derived cells to renal regeneration. Bone marrow was isolated from donor FVB mice and labeled with enhanced green fluorescent protein (eGFP) through adenovirus transduction. After cell sorting, eGFP-labeled cells were transplanted in sublethally irradiated recipient FVB mice. Four weeks after transplantation, we provoked AKI in mice by inducing unilateral ischemic-reperfusion injury for 30 min. Seven days after the injury, eGFP-positive bone marrow-derived cells were clearly detectable in ischemic kidney tissue, and they contribute to the regeneration of approximately 10% of proximal tubular mass. In this review the advantages and shortcomings of our procedure are critically discussed and compared with other methods described.