Description
The adult kidney has a remarkable capacity for self-renewal upon damage. Whether this regeneration is mediated by dedifferentiating surviving cells or as recently suggested by stem cells has not been unequivocally settled. The stem cell concept is however hampered by lack of consensus regarding the histological localization of and defining markers for these cells. Here, we demonstrate that aldehyde dehydrogenase (ALDH) activity may be used for isolation of cells with progenitor-like characteristics from adult human renal cortical tissue. Gene expression profiling of the isolated ALDHhigh and ALDHlow cell fractions followed by immunohistochemical interrogation of renal tissues enabled us to delineate a tentative progenitor cell population with a scattered distribution in the epithelial layer of the proximal tubules (PT). The cells differed from the surrounding cells by expression of CD133, CD24, vimentin, KRT7, KRT19, and BCL2, and were negative for PT-specific markers. Based on functional and bioinformatic analyses as well as an immunophenotypical resemblance to cells of regenerating tubules we suggest that these cells are endowed with a more robust phenotype, allowing increased resistance to acute renal injury, enabling rapid repopulation of the tubules. The rare intratubular cells also displayed marked transcriptional and immunophenotypical similarities to that of cortical adenomas and papillary renal cell carcinomas, indicating that these renal neoplasms arise through oncogenic transformation of this subset of PT cells.
Overall Design
Total RNA extracted from three pairs of ALDH-high and ALDH-low cell fractions were hybridized to Illumina humanHT-12 v3.0 Expression BeadChips (Illumina Inc) at the SCIBLU Genomics Centre at Lund University Sweden (http://www.lth.se/sciblu).
Curator
RGEDv1