The aim of this study was to better define, by immunohistochemistry, the molecular markers of
renal stem/progenitor cells localized in the different niches of ten human preterm kidneys with
gestational age ranging from 11 up to 25 weeks. Our data evidence the existence of multiple
stem/progenitor pools in different zones of the human developing kidney that are characterized by
different phenotypes: capsular stem cells were EMA (MUC1)+, MDM2+, Vimentin+ and Wnt1+;
progenitors of the sub-capsular nephrogenic zone were MDM2+ and Wnt1+; cap mesenchymal
cells were EMA (MUC1)+, CD15+, vimentin+, Wt1+, CD10+, Bcl2+, Wnt1+ and PAX2+;
interstitial progenitor cells were Vimentin+, Wt1+ and α1Anti-tripsin +. Our data evidence the
existence of multiple stem/progenitor cell pools in the fetal and neonatal human kidney. Progenitors
of these different pools are characterized by a peculiar phenotype, indicating a different
differentiation stage of these renal progenitors. A better knowledge of the molecular markers
expressed by renal stem/progenitors might represent a relevant datum for researchers involved in
renal regenerative medicine
