Figure 3. Glucosamine modulates Akt/mTOR pathway in human chondrocytes.
A. Normal human chondrocytes were untreated (DMEM 2% CS) or treated with GlcN (10 mM) for 24 h. Protein extracts were analyzed by western blotting using antibodies to p-Akt, pFOXO3, prbS6 and GAPDH. B, Bar graphs show quantification of western signals of p-Akt, pFoxO3 and prbS6 normalized by GAPDH. Values represent mean ± SD of three separate experiments for p-Akt and pFoxO3, * = P < 0.05 vs. control 24h and values represent mean ± SD of 9 separate experiments for prbS6, ** = P < 0.01 vs. control 24h. C, Comparison of p-Akt and prbS6 at 8h and 24h in chondrocytes treated with GlcN (10 mM).