Figure 2. Up-regulation of Wnt signaling and down-regulation of Klotho in the joint after injury. ACLT surgery was used to induce OA in adult male C57/6J mice. Expression of Klotho, Phos-GSK3β (S9), GSK3β, MMP2, MMP9, Wnt1, Wnt4, Wnt7a and β-catenin (cytoplasm/nucleus) in the mouse cartilage tissue. (A) Expression change of Klotho, Phos-GSK3β (S9), GSK3β, MMP2, MMP9, Wnt1, Wnt4, Wnt7a, and (B) β-catenin in the cytoplasm and nucleus by Western Blot after modeling. (C) Protein levels of Klotho, Phos-GSK3β (S9), GSK3β, MMP2, MMP9, Wnt1, Wnt4, Wnt7a and β-catenin were detected by western blotting. Protein/β-actin and Protein/Lamin A were used to demonstrate the protein fold changes. (D) Klotho mRNA expression was assessed in the cartilage at 12 weeks after ACLT or control. (F) The expression of matrix-degrading enzyme genes, MMP-2 (E), MMP-9 (F) were evaluated by Real-Time PCR. (G–J) The expression of Klotho protein and β-catenin protein in the control group and OA group were compared by immunohistochemistry,. Scale bar, 50 mm. Data are the mean ±SD, n=8 mice. *P < 0.05, **P < 0.01.