FIGURE 10.

Wnt/β-catenin signaling modulates PAI-1 expression in vivo. A–C, expression of exogenous Wnt1 gene induces renal β-catenin and PAI-1 expression after obstructive injury. Representative Western blots (A) and relative levels (fold induction over sham controls) of β-catenin (B) and PAI-1 (C) are presented. Numbers 1–3 indicate individual animals in a given group. The data are presented as the means ± S.E. of five animals (n = 5). *, p < 0.05; **, p < 0.01 versus sham controls. †, p < 0.05 versus UUO controls. D–F, immunohistochemical staining shows the localization of PAI-1 protein in different groups. Kidney sections from sham (D), UUO (E), and UUO plus Wnt1 (F) were immunostained with antibody against PAI-1. The arrows indicate positive staining. Scale bar, 50 μm. G–I, blockade of Wnt/β-catenin canonical pathway by DKK1 inhibits renal PAI-1 expression but not Smad2 phosphorylation after obstructive injury. Representative Western blots (G) and relative levels (fold induction over sham controls) of PAI-1 (H) and phospho-Smad2 (I) are presented. The data are presented as the means ± S.E. of three to five animals (n = 3–5). *, p < 0.05 versus sham controls. †, p < 0.05 versus UUO controls.