IL-17A stimulates osteoclast formation by inducing autophagy. (A) The mRNA expression of autophagy-related genes was determined using real-time quantitative polymerase chain reaction with IL-17A treatment after 48 h (mean ± standard deviation). (B) The expression of LC3 protein during IL-17A-mediated osteoclastogenesis was detected using western blot analysis. (C) Densitometric analysis of LC3-II expression. (D) Assessment of autophagy activity by transmission electron microscopy. Typical observations depict autophagosomes. (E) The quantitation of the number of autophagosomes (mean ± standard deviation). *P<0.05, **P<0.01, ***P<0.001 compared to the control group. IL-17A, interleukin IL-17A; LC3, microtubule-associated protein 1 light chain 3; con, control group.