Fig. 6: MMP-10-triggered β-catenin transactivation is dependent on EGFR signaling.
From: Matrix metalloproteinase-10 promotes kidney fibrosis by transactivating β-catenin signaling
A, B Blockade of EGFR signaling by small molecule inhibitor erlotinib abolished MMP-10-mediated β-catenin transactivation in vitro. Human proximal tubular epithelial cells (HK-2) were treated with rhMMP-10 in the absence or presence of erlotinib as indicated. Representative Western blotting (A) and quantitative data (B) showed the expression levels of p-EGFR (Tyr845), p-ERK1/2 (Thr202/Tyr204), p-GSK-3β (Ser9), and active β-catenin after various treatments. Data are presented as the mean ± SEM. ***P < 0.001 versus controls (n = 6); †††P < 0.001 versus the group with rhMMP-10 treatment alone (n = 6). C Representative micrographs showed fibronectin expression and deposition in HK-2 cells after various treatments. Scale bar, 75 µm. D, E The expression of fibronectin and α-SMA was assessed in HK-2 cells after various treatments. Representative Western blotting (D) and quantitative data (E) were presented. Data are presented as the mean ± SEM. **P < 0.01, ***P < 0.001 versus controls (n = 6); ††P < 0.01, †††P < 0.001 versus rhMMP-10 treatment alone (n = 6). F In vivo experimental design. The timing of UUO surgery, plasmid injection, and oral gavage of erlotinib at dose 40 mg/kg/d or 80 mg/kg/d is indicated, respectively. G Western blotting confirmed the expression of Flag and MMP-10 after Flag-tagged MMP-10 plasmid injection. H Representative micrographs also confirmed the expression and localization of Flag and MMP-10 in three groups as indicated. Scale bar, 50 µm. Representative Western blotting (I) and quantitative data (J) showed the expression levels of p-EGFR (Tyr845), p-ERK (Thr202/Tyr204), p-GSK-3β (Ser9), and active β-catenin in different groups. Data are presented as the mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001 versus sham controls (n = 5); †P < 0.05, ††P < 0.01, †††P < 0.001 versus UUO plus pcDNA3.1 group (n = 5); #P < 0.05, ##P < 0.01, ###P < 0.001 versus UUO plus pFlag-MMP-10 group (n = 5). K, L Representative micrographs (K) and quantitative data (L) showed immunohistochemical staining for p-EGFR (Tyr845) and β-catenin. Scale bar, 50 µm. Data are presented as the mean ± SEM. *P < 0.05, ***P < 0.001 versus sham controls (n = 5); ††P < 0.01 versus UUO plus pcDNA3.1 group (n = 5); ##P < 0.01, ###P < 0.001 versus UUO plus pFlag-MMP-10 group (n = 5).
