Improved differentiation of human enriched CD133+CD24+ renal progenitor cells derived from embryonic stem cell with embryonic mouse kidney-derived mesenchymal stem cells co-culture.

End-stage renal disease (ESRD) is a major global public health issue. In the past decade, regenerative medicine and cell-based therapies were recommended for treatment of devastating diseases like ESRD. Renal progenitor (RP) cells are essential players in such treatment approaches. The major practical difficulties in application of RP cells are generation of these cells and preservation of their self-renewal capacity; also, they should lack identified appropriate cell surface markers. To identify and isolate RP cells, two cell surface markers namely, CD133 and CD24 were recently used. In this study, we used these markers to facilitate selection and purification of RP cells from embryoid bodies (EBs), and assessed the impact of the use of bFGF on frequency of CD133+CD24+ expression in cells presented in EBs. Moreover, following isolation of CD133+CD24+ cells from EBs, we evaluated the effect of embryonic, neonatal and adult mouse kidney-derived mesenchymal stem cells (E-KMSC, N-KMSC and A-KMSC respectively) and fibronectin on further differentiation of the sorted cells. Hence, we cultured undifferentiated human embryonic stem cells (hESCs) in suspension state in the presence or absence of bFGF and determined maximum number of CD133+CD24+ cells in bFGF-treated EBs on day 7. Then, we tested the effect of E-KMSC co-culture and seeding on fibronectin-coated plated on differentiation of the sorted cells into renal epithelial cells. Results revealed down-regulation of several RP cells, markers in CD133+CD24+ cells. In contrast, renal epithelial marker gene expressions were up-regulated after 7 days of co-culture with E-KMSC. Furthermore, fibronectin resulted in higher expression of renal epithelial markers compared to the E-KMSC co-cultured cells. All in all, bFGF could enhance the number of RP cells expressing CD133 and CD24 markers, in human EBs. We suggest E-KMSC and fibronectin as a promising supplementary factor to further induce differentiation of RP cells into renal epithelial cells.