Figure 1. Inhibition of IFNγ-JAK-STAT-1 signaling decreases Con A-induced nitric oxide production in mouse splenocytes.

(A) Splenocytes from placebo- and estrogen-treated mice were stimulated with Con A or left unstimulated (media) for 48 hours. The nitric oxide level in culture supernatants was measured by Griess assays. The graph shows the means ± SEM (n≥6). (B) Splenocytes were pretreated with AG490, ethanol (vehicle), or left untreated for 1 hour, then stimulated with Con A for 48 hours. The nitric oxide levels in supernatants from Con A plus AG490 or vehicle treated cells are shown as the percentage of the level in paired Con A only stimulated cells. The graph shows means ± SEM (n≥5). (C) Splenocytes were transfected with negative siRNA or STAT-1 siRNA. Twenty-four hours after transfection, the cells were stimulated with Con A for 24 hours and then collected for Western blot analysis of the expression of iNOS, STAT-1, and β-actin (loading control). Representative data are shown from at least three independent experiments. (D) Twenty-four hours after siRNA transfection, the splenocytes were stimulated with Con A for 48hrs and the nitric oxide levels in culture supernatants were determined by Griess assays. The graph shows the means ± SEM (n=5 each). The nitric oxide level in STAT-1 siRNA transfected cells was compared to paired negative siRNA transfected cells, which was regarded as 100%. *, **, and *** denote p<0.05, p<0.01, and p<0.001, respectively.