Direct Isolation and Characterization of Human Nephron Progenitors.. Homo sapiens

Mature nephrons originate from a small population of uninduced nephrogenic progenitor cells (NPs) within the cap mesenchyme. These cells are characterized by the coexpression of SIX2 and CITED1. Many studies on mouse models as well as on human pluripotent stem cells have advanced our knowledge of NPs, but very little is known about this population in humans, since it is exhausted before birth and strategies for its direct isolation are still limited. Here we report an efficient protocol for direct isolation of human NPs without genetic manipulation or stepwise induction procedures. With the use of RNA-labeling probes, we isolated SIX2+CITED1+ cells from human fetal kidney for the first time. We confirmed their nephrogenic state by gene profiling and evaluated their nephrogenic capabilities in giving rise to mature renal cells. We also evaluated the ability to culture these cells without complete loss of SIX2 and CITED1 expression over time. In addition to defining the gene profile of human NPs, this in vitro system facilitates studies of human renal development and provides a novel tool for renal regeneration and bioengineering purposes Overall design: Single cell suspensions from 3 freshly isolated human fetal kidneys ( 17 weeks of gestation) were labelled overnight with RNA probes for SIX2 and CITED1 and sorted to obtain a 1) double positive population and2) a negative fraction. Long term goal is to investigate the transcription profile that differentiate positive versus negative selections. *************************************************************** Raw files for human/patient samples were not submitted to GEO due to concerns about submitting personally identifiable sequence data for open access. ***************************************************************