Not a process of simple vicariousness, the differentiation of human adipose-derived mesenchymal stem cells to renal tubular epithelial cells plays an important role in acute kidney injury repairing.

The recent findings indicate that under conditions of severe tubular injuries, transplantation of mesenchymal stem cells (MSCs) may be a promising treatment in acute kidney diseases; nevertheless, the underling mechanism is still under debate. To investigate the differentiation characteristics and the role of MSCs in renal tubular injury, human adipose-derived MSCs (hAD-MSCs) were transplanted into ischemia-reperfusion (I/R) kidneys in C57BL/6 mouse model. Results showed that hAD-MSCs were able to differentiate toward renal tubular epithelium at an early stage of injuries. The differentiated donor cells replaced the vacant space left over by the dead cells, contributed to maintenance of structural integrity and proceeded to a subsequent tissue repair process. Furthermore, MSCs as supportive cells may promote repair via secreting cytokines. The differentiation and replacement of MSCs at an extremely early stage play important roles for the subsequent self-repair and -renewal of functional cells. Direct differentiation of MSCs, as an important mechanism of injured kidney repair, warrants further investigation.