Direct reprogramming of human mesenchymal stem cells into functional renal cells using cell-free extracts

We investigated here the reprogramming of human bone marrow mesenchymal stem cells (MSC) using cell-free extracts from renal proximal tubular epithelial cells (HK2). Reprogramming of MSC is evidenced by a dramatic change in the cell structure with the formation of microvilli, the expression of specific markers and the acquisition of functional properties characteristic of the proximal tubular epithelial cells. To better characterize the MSC treated with HK2 extracts, we next isolated clones using a limiting dilution approach. Five out of 50 clones, showing the most epithelial-like morphology, were subjected to further analysis by qRT-PCR to examine their mesenchymal and epithelial marker profile. The difference in the expression of these markers reflects an heterogeneity in the reprogramming efficiency. Cells from clone 17 (CL17) were the most similar to the HK2 cells. RNA sequencing of CL17, MSC and HK2 cells was performed in order to evaluate the global effect of MSC reprogramming with cell extracts. RNA sequencing confirmed a switch of the reprogrammed cells toward a proximal tubular epithelial genotype along the EGF receptor pathway. CL 17 cells were analyzed in comparison with MSC and HK2 cells. Analysis was performed in duplicates.