Figure 6. Gαi signaling is required for LTB₄/BLT1-induced JAK2/STAT1 phosphorylation and MyD88 expression.

(A) WT macrophages were pretreated for 24 hours with or without the Gαi inhibitor PTX (600 ng/ml), followed by 30 minutes of treatment with or without LTB₄. pSTAT1 (Tyr701), pJAK2 (Tyr1007/1008), total JAK2, and actin were determined by immunoblotting. Densitometric analysis of pSTAT1 and pJAK2 protein levels in WT macrophages is also shown, expressed relative to untreated WT cells; data are mean ± SEM from 3 individual experiments. *P < 0.05 versus untreated WT; ^#P < 0.001 versus LTB₄ alone. (B) WT and 5-LO^–/– macrophages were pretreated with PTX (600 ng/ml) for 24 hours and incubated with or without LTB₄ for another 24 hours, after which RNA was isolated for Myd88 mRNA determination by real-time RT-PCR. Data are mean ± SEM from 3 individual experiments, each performed in triplicate. *P < 0.05 versus untreated WT; ^#P < 0.05 versus LTB₄ alone.