Fig 4. Knockdown of SPHK2 but not knockdown of TNFSF12 reduces apoptosis in DENV-infected Huh7 cells.

Huh7 cells were reverse transfected with siRNA directed against TNFSF12 or SPHK2 genes for 24 hours before being infected with DENV for 48 hours. Apoptotic cells were determined by Annexin V/PI staining and flow cytometry analysis. (A) Dot plot indicates cell death; and, (B) Apoptotic cells (Annexin V+/PI-) were plotted and compared with percentage of cell population. The results are expressed as the average of three independent experiments ± SD. The asterisks indicate statistically significant differences between groups (p < 0.05) (Student’s t test).