Tumor necrosis factor alpha (TNF-alpha)-induced RANTES chemokine expression via activation of NF-kappaB and p38 MAP kinase: roles of TNF-alpha in alcoholic liver diseases.

BACKGROUND/AIMS: Increased concentration of plasma tumor necrosis factor alpha (TNF-alpha) correlates with the clinical course of alcoholic liver diseases. In addition, hepatic RANTES which migrates CD4 T lymphocytes to liver is increased in patients with alcoholic hepatitis. We investigated that roles of TNF-alpha on RANTES expression in hepatocytes.
METHODS: HLE cells were treated with TNF-alpha in the presence, or absence of several inhibitors. Enzyme-linked immunoassay and reverse transcriptase-polymerase chain reaction were performed for the measurement of protein production and mRNA of RANTES, respectively. Moreover, DNA-binding activity of NF-kappaB was investigated using electrophoretic mobility shift assay. To examine effects of TNF-alpha on RANTES gene expression, luciferase assay was performed.
RESULTS: TNF-alpha clearly up-regulated RANTES expression in a time-dependent fashion and induced DNA-binding activity of NF-kappaB. Moreover, TNF-alpha-induced RANTES expression was completely inhibited by SB203580, but not calphostin C and wortmannin. Luciferase assay showed that TNF-alpha increased RANTES gene expression and mutation of NF-kappaB binding sites in the RANTES promoter ablated TNF-alpha inducibility.
CONCLUSIONS: We showed that RANTES was transcriptionally induced in human hepatoma cells by treatment with TNF-alpha via activation of NF-kappaB and p38 MAP kinase, presumably suggesting that TNF-alpha-induced expression of RANTES plays important roles in cell-mediated liver injury in alcoholic liver diseases.