Research Paper Volume 12, Issue 2 pp 1087—1103

Metformin attenuates cartilage degeneration in an experimental osteoarthritis model by regulating AMPK/mTOR

Figure 4. Metformin reduces the expression of p-S6 protein and affects the expression of other related pathway proteins. (A) Immunofluorescence detection of p-S6 in tibial cartilage at 2, 5, and 10 weeks after destabilization of the medial meniscus (DMM) surgery. (B) Quantitation of cells positively stained for p-S6. ***P < 0.001 between the two groups. (C) Immunofluorescence detection of p-AMPK in tibial cartilage at 2, 5, and 10 weeks after DMM surgery. (D) Quantitation of cells positively stained for p-AMPK. ***P < 0.001 between the two groups. And (E) the western blot analyses of the protein expression levels of selected proteins in primary chondrocytes which were induced with IL-1β (10 ng/mL) and co-cultured with metformin (1, 2, 4, and 5 mM) for 24 h, 48 h and 72 h. (NC = normal control, C = IL-1β).