Abstract: Objective To investigate the differentiation capability of kidney stem cells (KSCs) into renal tubular epithelial cells
(RTECs). Methods KSCs isolated from the renal papilla of 4-week-old SD rats were co-cultured with hypoxia-exposed RTEC
in induced medium (containing activin A, BMP-7, and retinoic acid) and renal epithelial cell growth medium (REGM)
alternately. The KSCs cultured in MSC medium served as the control. The KSC differentiation rates in both groups were
determined using flow cytometry, immunofluorescence assay and qRT-PCR. Results Flow cytometry showed a CK-18 positive
rate of 6.5% in the control KSC group and of 44.2% in the induced group. Immunofluorescence assay detected the positivity for
mature epithelial cell markers CK-18, E-cadherin, and ZO-1 in the induced cells. The results of qRT-PCR showed significantly
increased expression of E-cadherin and AQP-1 mRNAs in the induced cells compared with the control cells (P<0.01).
Conclusion Rat KSCs can be induced to differentiate into RTECs in vitro.