Changes of ubiquitin C-terminal hydrolase L1 following ischemic injury in mouse kidney

The kidney has shown the capacity to regenerate and repair after ischemic injury. However, the adult renal stem/progenitor cells are still not identified or characterized. It has been recently suggested that the renal papilla is a niche for adult renal stem cells. Here, we describe the characterization of ubiquitin C-terminal hydrolase L1 (UCH-L1) positive cells in the intact mouse kidney and their dynamics after ischemic injury. Previously, UCHL1 expression was identified in normal/pathologic kidney of human and rats, and suggesting that UCH-L1 functions in the regulation of the cell cycle and proliferation and in nephrogenesis. In this study, UCH-L1 was selectively expressed in the renal papilla, which was exclusively showed numerous BrdU-positive cells in the intact mouse kidney. In addition, UCH-L1/BrdU-positive cells were increased in the medulla and cortex after renal ischemic injury and both positive cells were colocalized. These results suggest that a function of UCH-L1 may be in repairing cells during mouse renal regeneration after ischemic injury.