LPS Cooperates with Poly-L-Arginine to Promote IL-6 and IL-8 Release via the JNK Signaling Pathway in NCI-H292 Cells

Figure 3

The JNK pathway inhibitor SP600125 alters the release of IL-6 and IL-8 by NCI-H292 cells. NCI-H292 cells were stimulated with 5 μg/mL PLA, 5 μg/mL LPS, or 5 μg/mL PLA + 5 μg/mL LPS for 60 min after preincubation with SP600125. The expressions of p-JNK and JNK were measured using western blotting. β-actin was used as an internal control. Production of IL-6 and IL-8 was measured by ELISA. ((a) and (b)) The expression level of phosphorylated JNK in NCI-H292 exposed to PLA, LPS, or PLA+LPS was inhibited effectively by the inhibitor SP600125. ((c) and (d)) PLA+LPS stimulated significantly more IL-6 and IL-8 production than either PLA or LPS treatment alone. The synergistic effects of PLA+LPS on the release of IL-6 and IL-8 could be blocked by SP600125. Significant differences are shown as follows: compared with the control group, , ; compared with the PLA+LPS group, ; PLA compared with PLA+SP600125, LPS compared with LPS+SP600125, and PLA+LPS compared with PLA+LPS+SP600125, .

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