Figure 4.

Progressive kidney injury in kidney-specific Nedd4-2 KO mice. (a) Representative hematoxylin–eosin (H&E) images show enlarged tubules (black asterisk), thinning of lining epithelium (open arrowhead), cellular debris within tubules (black arrows) and mesenchyme infiltration (black arrowhead) in P40 Nedd4-2^Ksp1.3 mice. (b) Picrosirius red staining demonstrates fibrosis in Nedd4-2^Ksp1.3kidneys (red). (c) Immunostaining shows increased expression of vimentin, SMA and Kim-1. (d) Increased gene expression for markers of kidney injury at P40, including collagen (encoded by Col1a1), vimentin (Vim), SMA (Acta2) and Kim-1, determined by qRT-PCR. Only Kim-1 levels were significantly altered at P20. Data are normalized to tbp levels and represent mean±s.e.m. for four mice per genotype. (e) Immune cell infiltration demonstrated by staining for CD3 (T-lymphocyte marker; and quantitated in (f)). (g and h) Immunostaining and quantitation of cleaved caspase-3-expressing cells shows apoptotic cells within tubules (white asterisk) and lining epithelia (white arrows) of Nedd4-2^Ksp1.3kidneys at P40. (f and h) n=4 per genotype. *P<0.05, **P<0.01, ***P<0.005 and ****P<0.001. Scale bars: (a)=50 μm, inset=1 mm; (b)=100 μm; (c) vimentin and SMA=100 μm, Kim-1=50 μm; (e and g)=50 μm. fov, Field of view; NS=not significant (P>0.05)