Fig. 4.

Ouabain activates PI3K_PDK1 axis signaling that leads to an inhibition of TGEV activity. A. Ouabain anti-TGEV activity was not mediated by PI3K_Akt axis signaling. B. Ouabain anti-TGEV activity was not mediated by PI3K_mTOR axis signaling. C. Ouabain anti-TGEV activity was mediated by PI3K_PDK1axis signaling. ST cells were pretreated with the indicated test compounds for 30 min, then treated with ouabain for 1 h prior to TGEV infection at an MOI of 7 for 6 h, and the resultant cells were harvested for western analysis with the indicated antibodies. NS: no significance; * and #, P < .05; ** and ##, P < .01. #/##: was compared to TGEV infected control; */**: was compared to TGEV infection with ouabain treatment; N protein, p-Akt, and p-P70S6K, were normalized with GAPDH. p-RSK2 was normalized with regular RSK2. Results shown are represented results or averages ± SD from three independent experiments.