Abstract
The histological features of rheumatoid arthritis (RA) consist of overgrowth of synovial cells. Several growth factors that cause synovial hyperplasia have been identified in RA synovium. The basic-fibroblast growth factor (b-FGF), representing one of these growth factors, may play an important role in the pathogenesis of RA. We examined the b-FGF-mediated intracellular signal pathway involved in synovial cell growth. b-FGF-induced synovial cell growth was inhibited by protein tyrosine kinase (PTK) inhibitors, herbimycin A and genistein, but not by H7 that inhibits protein kinase C (PKC). Stimulation of synovial cells with b-FGF resulted in tyrosine phosphorylation of cellular proteins and MAP kinase activation. Our results also demonstrated that b-FGF-mediated activation of MAP kinase was inhibited by herbimycin A indicating that protein tyrosine kinase may be involved in the activation of MAP kinase in human synovial cells. However, inhibition of b-FGF-mediated MAP kinase activation by PKC downregulation did not occur.
MeSH terms
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1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine
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Arthritis, Rheumatoid / enzymology*
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Arthritis, Rheumatoid / pathology
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Benzoquinones
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Calcium-Calmodulin-Dependent Protein Kinases / metabolism
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Cell Cycle / drug effects
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Cell Cycle / physiology*
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Cell Division* / drug effects
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Cells, Cultured
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Fibroblast Growth Factor 2 / pharmacology*
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Fibroblasts / enzymology
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Genistein
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Humans
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Hyperplasia
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Isoflavones / pharmacology
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Isoquinolines / pharmacology
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Kinetics
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Lactams, Macrocyclic
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Piperazines / pharmacology
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Protein Kinase C / antagonists & inhibitors
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Protein Kinases / metabolism*
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Protein-Tyrosine Kinases / antagonists & inhibitors
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Quinones / pharmacology
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Rifabutin / analogs & derivatives
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Signal Transduction / drug effects
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Signal Transduction / physiology
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Synovial Membrane / enzymology*
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Synovial Membrane / pathology*
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Thymidine / metabolism
Substances
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Benzoquinones
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Isoflavones
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Isoquinolines
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Lactams, Macrocyclic
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Piperazines
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Quinones
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Fibroblast Growth Factor 2
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Rifabutin
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herbimycin
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1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine
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Genistein
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Protein Kinases
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Protein-Tyrosine Kinases
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Protein Kinase C
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Calcium-Calmodulin-Dependent Protein Kinases
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Thymidine