Fig. 5.

Metformin increased chondrocytes colony formation in vitro. After treated with 1 mM metformin for 48 h, chondrocytes were transfected with 100 nM miR-34a negative control (b), miR-34a mimics (c) or siRNA-SIRT1 (d) for 48 h, respectively. NC group (a) was treated with culture medium as blank control. Cell colony was observed and counted. (e) Chondrocytes treated with metformin in Metformin group formed increased cell colonies compared with NC group, while transfection of miR-34a mimic or siRNA for SIRT1 following metformin treatment inhibited cell colony formation in Met + miR-34a group and Met + si-SIRT1 group. All experiments were repeated three times. *P < 0.05. **P < 0.01