Figure 2. CM from leptin-conditioned MSCs promotes autophagy in OS cells. (A) Representative fluorescence images of cultured OS cells transfected with a GFP-LC3 vector and treated with CM collected from MSCs cultured in the presence (CM) or absence (Control) of leptin. Quantification of fluorescent puncta for each cell line is presented in the histogram shown on the right. *p<0.05. (B) Western blot analysis of LC3 and P62 expression in MG-63 and U-2 OS cells treated with CM from MSCs cultured in the presence (CM) or absence (Control) of leptin. (C) In the presence or absence of the autophagy inhibitor chloroquine (CQ, 10 μM), the expression of LC3 and P62 expression in MG-63 cells incubated with CM collected from leptin-conditioned MSCs was explored by western blot. (D) Effect of CQ (10 μM) on the viability of MG-63 cells exposed to cisplatin (40 μM) and CM from leptin-conditioned MSCs. **p<0.01. (E) Results of the PI/Annexin V-FITC flow cytometry assay showing the effect of CQ on apoptosis in MG-63 cells treated with cisplatin and CM from leptin-treated MSCs. **p<0.01.