Fig. 6.

Metformin ameliorated chondrocytes senescence and OA through microRNA-34a/SIRT1 pathway. After treated with 1 mM metformin for 48 h, chondrocytes were transfected with 100 nM miR-34a negative control and miR-34a mimics for 48 h, respectively. NC group was treated with culture medium as blank control. Metformin treatment significantly inhibited P16 (b) expression in Metformin group compared with NC group. Furthermore, metformin promoted expression level of Collagen II (f) and Aggrecan (c) while downregulated expression level of MMP-13 (e) and IL-6 (d). Transfection of microRNA-34a mimic after metformin treatment reversed this favorable effect by increasing expression level of P16, IL-6 and MMP-13 while decreasing expression level of Collagen II and Aggrecan (a). All experiments were repeated three times. *P < 0.05. **P < 0.01