FIG 3.

Knockdown of PARP1 inhibits PRV infection. (A) PK15 cells were transfected with NC, siPARP1-1, and siPARP1-2 for 48 h. The PARP1 mRNA level was assessed by qRT-PCR analysis. (B) PK15 cells were transfected with NC, siPARP1-1, and siPARP1-2 for 48 h. PAR, PARP1, and actin were assessed by immunoblotting analysis. (C) PK15 cells were transfected with NC, siPARP1-1, and siPARP1-2 for 48 h. The cell cycle was assessed with Hoechst 33342 staining in flow cytometry. (D) PK15 cells were transfected with NC, siPARP1-1, and siPARP1-2 for 48 h. Apoptosis was assessed with annexin V-FITC and PI staining in flow cytometry (left). Quantification of the percentage of cell death is shown on the right. (E) PK15 cells were transfected with NC, siPARP1-1, and siPARP1-2 for 24 h and infected with PRV-GFP (MOI = 0.01) for 36 h. Viral replication was analyzed by fluorescence microscopy (left), and GFP-positive cells were analyzed by flow cytometry (right). Bar, 100 μm. (F) PK15 cells were transfected with NC, siPARP1-1, and siPARP1-2 for 24 h and infected with PRV-QXX (MOI = 0.1) for 24 h. PRV gE, PAR, PARP1, and actin were assessed by immunoblotting analysis. (G) PK15 cells were transfected with NC, siPARP1-1, and siPARP1-2 for 24 h and infected with PRV-QXX (MOI = 0.01 and 0.1) for 24. PRV titers were assessed by TCID₅₀ assay. (H) PK15 cells were transfected with NC, siPARP1-1, and siPARP1-2 for 24 h. Cells were infected with PRV-QXX (MOI = 0.01 and 0.1) and simultaneously treated with DMSO or olaparib (10 μM) for 24 h. PRV titers were assessed by TCID₅₀ assay. Data are means and SD based on three independent experiments. ***, P < 0.001, determined by two-tailed Student's t test (A, E, and G) or one-way ANOVA (H).