Objective: To identify the role of p38 MAPK- NF-kB signaling pathway in TNF-α induced IL-8 production in human hepatocellular carcinoma cells.
Methods: The concentrations of IL-8 from MHCC-97H cells were measured by an enzyme-linked immunosorbent assay (ELISA). The phosphorylation of p38 MAPK was analyzed by Western blot and immunofluorescence. NF-kB p65 protein nuclear translocation was determined by non-radioactive NF-kB p50 / p65 transcription factor activity kit and immunofluorescence.
Results: The IL-8 production from MHCC-97H cells challenged with TNFa significantly increased in a time-dependent (F = 144.04, P < 0.01) and dose-dependent (F = 364.14, P < 0.01) manners, as compared with those without TNFa challenge. TNFa up-regulated the phosphorylation levels of p38 MAPK and increased the translocation of NF-kB p65 protein into the nucleus, also proved by immunofluorescence staining. p38 MAPK inhibitor (SB203580) could significantly inhibit IL-8 production in a dose-dependent manners (F = 65.47, P < 0.01), and partially inhibited NF-kB p65 nuclear translocation in a dose-dependent manner (F=141.20, P < 0.05).
Conclusion: TNF-α could increase the production of IL-8 in MHCC-97H cells and p38 MAPK- NF-kB pathways seem to play a central role in the regulation of IL-8 production.