Fig. 2: Low dietary-Na⁺ ameliorates kidney pathology in Nedd4-2^Ksp1.3 mice.

a Outline of salt-feeding experiments. b Representative H&E images show decreased injury in Nedd4-2^Ksp1.3 mice after low-Na⁺ diet in P40 kidneys. Red lines denote areas of damage. Scale bar: 1 mm, inset 100 μm. c Picrosirius red staining shows a decrease in fibrosis after the low-Na⁺ diet. Scale bar: 100 μm. d KIM-1 staining reveals some regions of kidney injury in Nedd4-2^Ksp1.3 kidneys under standard-Na⁺ diet, but no detectable regions after low-Na⁺ diet. Scale bar: 250 μm. e qPCR for markers of kidney injury, vimentin and KIM-1 show a significant reduction in Nedd4-2^Ksp1.3 kidneys after the low-Na⁺ diet. Vimentin levels are comparable to control kidneys on a low-Na⁺ diet (n = 6–7 mice per genotype). Data are shown as fold change from control on standard (Std.) diet, mean ± SEM with significance calculated by a Student’s t test (two tailed). f Serum levels of Na⁺ remain unchanged, however, the low-Na⁺ diet causes a decrease in urea in both control and Nedd4-2^Ksp1.3 mice. Aldosterone is increased in the Nedd4-2^Ksp1.3 mice after the low-Na⁺ diet. Data are presented as one point per mouse, mean ± SEM with significance calculated by a Mann–Whitney test. *P < 0.05, **P < 0.01, *P < 0.005.