FIGURE 3.

Inflammatory response and activation of the WNT/β-catenin pathway in vitro chondrocytes stimulated by IL-1β and siBMAL1. (A) Levels of TNF-α, IL-6, and PGE2 in ECS. Results are expressed as mean ± SEM; n = 3–4. (B) Protein expression changes of β-catenin and p-β-catenin, and mRNA levels of β-catenin in chondrocytes in each group. All experiments were performed in triplicate, and the results are expressed as the mean ± SEM. (C) Protein expression changes of GSK-3β and p-GSK-3β, and mRNA levels of GSK-3β in chondrocytes in each group. All experiments were performed in triplicate, and the results are expressed as the mean ± SEM. (D) Nuclear translocation of β-catenin in chondrocytes stimulated with IL-1β and transfected with siBMAL1. β-catenin was highly expressed in the cytoplasm of control chondrocytes, yet mostly transferred into the nucleus after IL-1β stimulation. A considerable number of β-catenin protein were also transferred to the nucleus in KD-BMAL1 chondrocytes. Mag, 400×. Scale bar, 100 μm. (E) Expression changes of β-catenin in tibial plateau cartilage of rats in each group. Mag, 200×. Scale bar, 50 μm. Results are expressed as mean ± SD; n = 4. *p < 0.05, **p < 0.01, ***p < 0.001, and ****p < 0.0001.