Figure 5.

Oxidative stress is involved in ZnO NPs-induced autophagy of mouse Leydig TM3 cells. Mouse Leydig TM3 cells were treated with 0–4 μg/mL ZnO NPs for 24 h (A) or treated with 4 μg/mL ZnO NPs for 24 h in absence or presence of 5 mM NAC (C); then, the protein levels of LC 3, Atg 5, and Beclin 1 were quantified by Western blot. (B,D) The relative protein levels of LC 3, Atg 5, and Beclin 1 were quantified by densitometry. (E) The cells were treated with ddH₂O, bars: 1 μm, (a), 4 μg/mL ZnO NPs (b), or 5 mM N-acetyl-L-cysteine (NAC) plus 4 μg/mL ZnO NPs for 24 h (d). Then, autophagic vacuoles in the cells were visualized by transmission electron microscopy (TEM), with starvation-treated cells as a positive control (c). The autophagic vacuoles are indicated by white arrows. The experiment was done in triplicate and repeated three times. Data were analyzed by one-way ANOVA. * p < 0.05.