Figure 11.

Regulation of ROS levels within autophagy-impaired cells triggers the extrinsic apoptosis pathway during CSFV infection. (A) PK-15 and 3D4/2 cells were treated and cultured as described in the legend to Fig. 9A. The activities of CASP3, CASP8, and CASP9 in cell samples were assessed by the CASP activity assay as described in Materials and Methods. The data represent the mean ± SD of 3 independent experiments. One-way ANOVA test; test of homogeneity of variances, P < 0.05, Dunnett's T3 (3) was used for correction of post-hoc test. *, P < 0.05; **, P < 0.01; ^#, P > 0.05. (B) PK-15 and 3D4/2 cells were treated and cultured as described in the legend to Fig. 10A and B. The levels of cleaved-PARP and ACTB (loading control) were detected by western blot using specific antibodies. The relative expression ratios of these proteins were assessed by densitometric scanning. The data represent the mean ± SD of 3 independent experiments. One-way ANOVA test; test of homogeneity of variances, P > 0.05, LSD (L) was used for correction of post-hoc test. *, P < 0.05; **, P < 0.01; ***, P < 0.001. (C) PK-15 and 3D4/2 cells were transfected as described in the legend to Fig. 9A. At 24 and 48 h after CSFV infection, virus copy number was detected by qRT-PCR as described in Materials and Methods. The data represent the mean ± SD of 3 independent experiments. One-way ANOVA test; test of homogeneity of variances, P > 0.05, LSD (L) was used for correction of post-hoc test. **, P < 0.01; ***, P < 0.001.