FIG 8.

OmpV-mediated proinflammatory signaling involves transcription factor AP-1. (A to D) A significant decrease in TNF-α and IL-6 was observed upon pretreatment with AP-1 inhibitor in OmpV-activated macrophages (A, B) and monocytes (C, D). (E, F) AP-1 is involved in OmpV-proteoliposome (PL)-mediated proinflammatory signaling. (A to F) RAW 264.7 and THP-1 cells were pretreated with AP-1 inhibitor followed by treatment with PmB and OmpV or OmpV-proteoliposome (PL). Following respective incubations, supernatants were collected and analyzed for cytokines by ELISA. Bar graphs are expressed as mean ± SEM from three independent experiments; *, P < 0.05; **, P < 0.01; ***, P < 0.001; ns, P > 0.05 versus only OmpV-treated cells or OmpV-proteoliposome (PL)-treated cells. (G) Translocation of AP-1 subunits to the nucleus was observed in OmpV-targeted cells. RAW 264.7 and THP-1 cells were treated with PmB followed by OmpV and incubated for different time points as indicated. Following incubations, nuclear fractions were extracted and probed for AP-1 subunits. PCNA and lamin were used as loading controls for nuclear lysates. Western blots are representatives of three independent experiments.