Fig. 4

Activated RASF promote TREM-1expression in monocytes through the COX-2/PGE₂ pathway. a TLR2, TLR3, TLR4, TLR7, TLR8, and TLR9 levels in RASF (n = 5) were detected by qPCR. b After stimulation with 1 μg/mL LPS, 10 μg/mL PGN, 25 μg/mL poly(I:C), 10 μg/mL CpG respectively, RASF (n = 5) were co-cultured with allogeneic normal monocytes for 24 h. The monocytes were harvested for flow cytometry analysis of the TREM-1 expression. After stimulation with DMSO, PGN, poly I:C and LPS respectively, c the mRNA level of COX-2 in RASF (n = 5) was detected by qPCR, and d the secretion of PGE₂ in RASF (n = 5) was measured using ELISA. RASF expressing control siRNA or COX-2 siRNA were stimulated with e poly I:C or f LPS and then co-cultured with CD14⁺ monocytes for 24 h. TREM-1 expression in CD14⁺ monocytes was detected by flow cytometry. *P < 0.05, by ANOVA followed by Bonferroni’s post hoc test (a, e, and f) and two-tailed Student’s t test (b, c, and d)