Figure 4

Podocin-Cre Bmp4 tgm exhibited glomerular injury. (A) Representative light microscopy, immunohistochemistry and electron microscopy images of glomeruli. The left panel shows a non-induced mouse (CAG-Bmp4 cont), and the right panel shows a Podocin-Cre induced Bmp4 tgm (CAG-B4xPod-Cre). Extracellular matrix deposition was determined by PAS staining. PAS staining was increased in CAG-B4xPod-Cre mice (b). The Col4-expressing area was increased in CAG-B4xPod-Cre mice (f). Compared to the CAG-Bmp4 cont mice, the WT1- (h) and nephrin-positive areas (j) were reduced in CAG-B4xPod-Cre mice. The number of phospho-Smad1 (pSmad1)-positive cells was increased in CAG-B4xPod-Cre mice compared with CAG-Bmp4 cont mice (l). The GBM thickness was increased in CAG-B4xPod-Cre mice compared with CAG-Bmp4 cont mice (m and n). (B) A bar graph summarizes the histological scores of PAM staining. CAG-B4xPod-Cre mice exhibited mesangial matrix expansion compared with CAG-Bmp4 cont mice. (C) The number of WT1-positive cells was obtained by immunostaining. Fewer WT1-positive cells were observed in CAG-B4xPod-Cre mice than in CAG-Bmp4 cont mice. (D) The nephrin-positive area was determined by measuring the immunostaining. The nephrin-positive area was decreased in CAG-B4xPod-Cre mice compared with CAG-Bmp4 cont mice. (E) Images of BMP4 and nephrin immunohistochemical staining in glomeruli. In CAG-B4xPod-Cre mice, BMP4 expression was increased in the glomerulus compared with that in CAG-Bmp4 cont mice. The BMP4-expressing areas are shown in green, and the nephrin area is shown in red. Yellow indicates the area of BMP4 and nephrin overlap (arrowhead). (F) Podocin levels were determined by western blotting. Podocin levels were decreased in CAG-B4xPod-Cre mice compared with those in CAG-Bmp4 cont mice. G) Glomerular PAS staining in each mouse from 10 weeks to 40 weeks of age. PAS staining was increased in CAG-B4xPod-Cre mice aged more than 30 weeks (g and h). ^*P < 0.01, (t-test).