Fig. 4
C2S NPs stimulate autophagy in BMSCs (a) TEM observations of BMSCs following treatment with 50 μg/mL C2S NPs for 24 h. Distinct autophagic vacuoles (black arrows) were denoted in the enlarged images (lower) from the dash line squares. b–d BMSCs were treated with C2S NPs (0, 10, 50, 100 µg/mL) for 3, 6, and 12 h. FITC-labeled LC3 was observed under a fluorescence microscope. e The fluorescence intensity ratio was analyzed using ImageJ software (below). f total protein levels of Beclin, P62, and LC3(LC3II/LC3I) detected by western blot analysis, treating the cells as in (d). g Densitometry data were normalized to GAPDH. The relative optical density was analyzed using ImageJ software. Values are expressed as the mean ± SEM, n = 3. *p < 0.05, **p < 0.01, ***p < 0.001 compared with the control group