Induction of interleukin-1 beta production in human dermal fibroblasts by interleukin-1 alpha and tumor necrosis factor-alpha. Involvement of protein kinase-dependent and adenylate cyclase-dependent regulatory pathways.
It has previously been demonstrated that interleukin-1 (IL-1) is expressed in a variety of fibroblast cell lines. In this study, we investigated the mechanisms involved in the regulation of IL-1 beta production by cultured human dermal fibroblasts. We have shown that IL-1 beta is constitutively expressed as a cell-associated form, with no soluble form detectable in control cell or in stimulated cell supernatants. IL-1 alpha and tumor necrosis factor-alpha (TNF-alpha) exerted a dose-dependent stimulation on the production of the cell-associated IL-1 beta, as estimated using a specific enzyme linked immunosorbent assay (ELISA). As expected, this effect was accompanied by a huge release of prostaglandin E2 (PGE2) and a transient rise in intracellular cyclic AMP. Furthermore, IL-1 beta production was elevated to a lesser extent by the addition of increasing concentrations of the protein kinase C activator phorbol myristate acetate or by low concentration (0.001 microgram/ml) of PGE2. In contrast, higher concentrations (0.1 and 1 micrograms/ml) of PGE2, as well as exogenous dibutyryl-cyclic AMP, were clearly inhibitory. H7, an inhibitor of protein kinases also reduced the stimulatory effect of IL-1 alpha and TNF-alpha. Together with the results obtained with phorbol myristate acetate, these data suggest that protein kinase C may play a role in the upregulation of IL-1 beta expression in normal skin fibroblasts. The addition of indomethacin not only suppressed prostaglandin synthesis, but also dramatically reduced cyclic AMP formation, probably because the PGE2-induced stimulation of adenylate cyclase was abolished. This resulted in a strong potentiation of the stimulatory effect of IL-1 alpha and TNF-alpha, supporting the role of both the cyclooxygenase and adenylate cyclase pathways in the endogenous downregulation of IL-1 beta induction by the two cytokines studied.
Mauviel
A
A
Laboratoire de Biochimie du Tissu Conjonctif, C.H.U. Côte de Nacre, Caen, France.
Temime
N
N
Charron
D
D
Loyau
G
G
Pujol
J P
JP
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D000262:Adenylyl Cyclases / Q000378:metabolism*; D003994:Bucladesine / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007231:Infant, Newborn; D007375:Interleukin-1 / Q000096:biosynthesis* / Q000494:pharmacology*; D007546:Isoquinolines / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases / Q000378:metabolism*; D012867:Skin / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D007375:Interleukin-1; D007546:Isoquinolines; D010879:Piperazines; D047428:Protein Kinase Inhibitors; D014409:Tumor Necrosis Factor-alpha; D003994:Bucladesine; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D000242:Cyclic AMP; D011494:Protein Kinases; D000262:Adenylyl Cyclases; D013755:Tetradecanoylphorbol Acetate