Figure 5

Effects of Se deficiency on WNV-induced apoptosis and cell death. Vero cells grown in control, Se-, and Se+ media were infected with WNV at MOI 1 for 2 hr at day 7 post-induction of Se deficiency. After adsorbtion, the cells were washed and maintained in control M199 medium, Se- and Se+ media. (A) Caspase 3/7 activity was analyzed using fluorogenic substrate at day 2 after infection in WNV-infected and mock-infected cells. The data are expressed as percentage increase of caspase activity in infected cells grown in control, Se-, and Se+ media as compared to corresponding mock-infected cells. *p < 0.05 and **p < 0.05 as compared to cells grown in control and Se- media, respectively. (B) loss of mitochondrial membrane potential is represented as ratio of fluorescence at 590 and 535 nm measured by JC-1 staining at 48 and 72 hr after infection, and expressed as percentage decline in infected cells grown in control, Se-, and Se+ media as compared to corresponding mock-infected cells. *p < 0.05 and **p < 0.05 as compared to cells grown in control and Se- media, respectively. (C) Cell viability of infected and mock-infected Vero cells at day 2 after infection was assessed by cell proliferation assay and percentage cell viability of WNV-infected control, Se- and Se+ cells was calculated by comparing to their respective mock-infected cells. *p < 0.05 as compared to WNV-infected Vero cells grown in control media. (D) WNV-infected Vero cells grown in control, Se-, and Se+ media were analyzed for LDH levels at day 2 after infection and expressed as fold-change over levels present in mock-infected cells. *p < 0.05 and **p < 0.05 as compared to cells grown in control and Se- media, respectively. All the data are presented as mean ± SD of at least two independent infections performed in triplicate.