Fig. 3
p57Kip2 expression is lost during RPGN and p57Kip2 silencing decreases podocyte proliferation. a, b Western blot analysis (a) and quantification (b) of p57 on magnetic beads isolated glomeruli from unchallenged (control) or NTS-challenged (NTN) mice. Values are means ± s.e.m. (n = 5 per group). *p < 0.05 vs. control. c Immunostaining of p57 (strong brown staining) and immunofluorescent p57 (red)/WT1 (green) staining in kidney sections from normal mice (control) and NTS-challenged mice (NTN). Scale bars, 10 µm. d Quantification of p57-positive cells per glomerular section in mice described in a. e Representative photomicrographs of p57 immunostaining (strong brown staining) in kidney sections from random biopsies from individuals diagnosed with non-crescentic glomerulopathies, including minimal change disease (MCD) and membranous nephropathy (MN), and from patients with RPGN of various etiologies including stage III and IV lupus nephritis (LN) and microscopic polyangiitis (MPA). Scale bars, 50 µm. f Quantification of p57-positive cells per glomerular section in biopsies described in e. Values are means ± s.e.m. *p < 0.05 vs. non-crescentic glomerular diseases. g Representative pictures of p57 staining (red) and podocyte proliferation assay in control cells (non-transfected) or transfected with a control siRNA (siRNA-control) or a siRNA for p57 (siRNA-p57). DAPI-stained nuclei (blue). Top panel (scale bars, 50 μm); bottom panel (scale bars, 100 µm). h Quantification of podocyte proliferation assay involving decapsulated mouse glomeruli. Podocyte proliferation was assessed after 4 days. Values are means ± s.e.m. (n = 6 per group). ***p < 0.001 vs. non-transfected cells. Statistical analysis: Kruskal–Wallis one-way analysis of variance followed by Dunn’s multiple comparaison test or Mann–Whitney test to compare groups. Values are means ± s.e.m
