Kidney side population reveals multilineage potential and renal functional capacity but also cellular heterogeneity

Abstract

Side population (SP) cells in the adult kidney are proposed to represent a progenitor population. However, the size, origin, phenotype, and potential of the kidney SP has been controversial. In this study, the SP fraction of embryonic and adult kidneys represented 0.1 to 0.2% of the total viable cell population. The immunophenotype and the expression profile of kidney SP cells was distinct from that of bone marrow SP cells, suggesting that they are a resident nonhematopoietic cell population. Affymetrix expression profiling implicated a role for Notch signaling in kidney SP cells and was used to identify markers of kidney SP. Localization by in situ hybridization confirmed a primarily proxim..