The renal papilla is a niche for adult kidney stem cells
J. Clin. Invest. Juan A. Oliver, et al. 114:795 doi:10.1172/JCI20921 [Go to this article.]

Figure 2
BrdU-retaining cells in the adult kidney. (A_F) Composite views obtained by confocal microscopy with 1-μm optical sections, except where indicated otherwise (E and F). (A) Composite view 20 μm in thickness of a kidney cortex from a 3-month-old rat showing no BrdU-positive cells. g, glomerulus. (B) Composite view 10 μm in thickness of a glomerulus from a 2-month-old rat with a single BrdU-retaining cell in the glomerular tuft. (C) Composite view 20 μm in thickness of a kidney medulla from a 2-month-old rat with a single BrdU-retaining cell. (D) Composite view 20 μm in thickness of a kidney papilla from a 2-month-old rat showing numerous BrdU-positive cells. Arrows, interstitial cells; arrowheads, tubular cells. (E) Section 100 μm in thickness of a kidney papilla from a 3-month-old rat showing more fluorescent signal (i.e., BrdU) in the outer parts of the papilla. (F) Section 5 μm in thickness of the kidney papilla from a 5-month-old rat. (G) Composite view 20 μm in thickness of kidney papillary tubules from a 4-month-old rat showing that some of the BrdU-retaining cells are tubular epithelial cells expressing ZO-1 in their tight junctions. (H) Composite view 10 μm in thickness of a kidney medulla from a 3-month-old rat showing a single interstitial BrdU-retaining cell surrounded by collagen IV. (I) Composite view 20 μm in thickness of a kidney papilla from a 4-month-old rat showing BrdU-retaining cells in close association with endothelial cells. Scale bars: 50 μm.