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 5
Characterization of renal papillary cell clones. (A) As the example shows, many cells coexpressed mesenchymal proteins such as α-smooth muscle actin (left) as well as epithelial proteins such as ZO-1 (right). (B) In standard control conditions in the absence of sera, all cells were spindle-shaped and stained strongly for α-smooth muscle actin (Control; left) but when LIF was added to the media, two phenotypes were apparent (+ LIF; right): the majority of cells grew in a monolayer and were negative for α-smooth muscle actin (nuclei stained with 10 nM Sytox green), but a few cells grew on top of the monolayer of cells, were spindle-shaped, and expressed α-smooth muscle actin. (C) In standard control culture conditions, a small number of cells expressed the intermediate filament nestin. Occasional cells also expressed the neuronal marker class III β-tubulin (III-β-tubulin) and some cells even acquired the morphological characteristics of neurons. Scale bars: A, 20 μm; B and C, 50 μm.