Inhibition of apoptosis restores oxidative stress-promoted PCV2 replication. PK15 cells were infected with PCV2 at MOI of 1, cells were pretreated with 3-MA or pretreated with 3-MA and Z-VAD (10 µM), then cultured with H2O2. A–E The expression of ATG5, LC3-II, cleaved caspase-3 and cap protein were detected by Western blotting. F, G The number of infected cells was detected by immunofluorescence assay. H Real-time PCR was used to detect the PCV2 viral DNA copies. I, J Morphology of apoptotic cell nuclei was detected by staining Hoechst 33258. The data represent the mean ± SEM (n = 3, each). Significance represent as *P < 0.05 and **P < 0.01.