Apoptosis signal-regulating kinase 1 is mediated in TNF-α-induced CCL2 expression in human synovial fibroblasts

J Cell Biochem. 2012 Nov;113(11):3509-19. doi: 10.1002/jcb.24227.

Abstract

Tumor necrosis factor-α (TNF-α), a pro-inflammatory cytokine with a critical role in osteoarthritis (OA), was primarily produced by monocytes/macrophages and plays a crucial role in the inflammatory response. Here, we investigated the intracellular signaling pathways involved in TNF-α-induced monocyte chemoattractant protein 1 (MCP-1)/CCL2 expression in human synovial fibroblast cells. Stimulation of synovial fibroblasts (OASF) with TNF-α induced concentration- and time-dependent increases in CCL2 expression. TNF-α-mediated CCL2 production was attenuated by TNFR1 monoclonal antibody (Ab). Pretreatment with an apoptosis signal-regulating kinase 1 (ASK1) inhibitor (thioredoxin), JNK inhibitor (SP600125), p38 inhibitor (SB203580), or AP-1 inhibitor (curcumin or tanshinone IIA) also blocked the potentiating action of TNF-α. Stimulation of cells with TNF-α enhanced ASK1, JNK, and p38 activation. Treatment of OASF with TNF-α also increased the accumulation of phosphorylated c-Jun in the nucleus, AP-1-luciferase activity, and c-Jun binding to the AP-1 element on the CCL2 promoter. TNF-α-mediated AP-1-luciferase activity and c-Jun binding to the AP-1 element were inhibited by TNFR1 Ab, thioredoxin, SP600125, and SB203580. Our results suggest that the interaction between TNF-α and TNFR1 increases CCL2 expression in human synovial fibroblasts via the ASK1, JNK/p38, c-Jun, and AP-1 signaling pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anthracenes / pharmacology
  • Antibodies / pharmacology
  • Bursa, Synovial / drug effects
  • Bursa, Synovial / metabolism*
  • Bursa, Synovial / pathology
  • Chemokine CCL2 / genetics
  • Chemokine CCL2 / metabolism*
  • Curcumin / pharmacology
  • Dose-Response Relationship, Drug
  • Fibroblasts / drug effects
  • Fibroblasts / metabolism*
  • Fibroblasts / pathology
  • Gene Expression Regulation / drug effects
  • Genes, Reporter
  • Humans
  • Imidazoles / pharmacology
  • Luciferases
  • MAP Kinase Kinase 4 / antagonists & inhibitors
  • MAP Kinase Kinase 4 / genetics
  • MAP Kinase Kinase Kinase 5 / antagonists & inhibitors
  • MAP Kinase Kinase Kinase 5 / genetics
  • MAP Kinase Kinase Kinase 5 / metabolism*
  • Osteoarthritis / metabolism
  • Osteoarthritis / pathology
  • Primary Cell Culture
  • Pyridines / pharmacology
  • Receptors, Tumor Necrosis Factor, Type I / antagonists & inhibitors
  • Receptors, Tumor Necrosis Factor, Type I / genetics
  • Signal Transduction / drug effects
  • Signal Transduction / genetics
  • Thioredoxins / pharmacology
  • Transcription Factor AP-1 / antagonists & inhibitors
  • Transcription Factor AP-1 / genetics
  • Tumor Necrosis Factor-alpha / pharmacology*
  • p38 Mitogen-Activated Protein Kinases / antagonists & inhibitors
  • p38 Mitogen-Activated Protein Kinases / genetics

Substances

  • Anthracenes
  • Antibodies
  • CCL2 protein, human
  • Chemokine CCL2
  • Imidazoles
  • Pyridines
  • Receptors, Tumor Necrosis Factor, Type I
  • Transcription Factor AP-1
  • Tumor Necrosis Factor-alpha
  • pyrazolanthrone
  • Thioredoxins
  • Luciferases
  • p38 Mitogen-Activated Protein Kinases
  • MAP Kinase Kinase Kinase 5
  • MAP3K5 protein, human
  • MAP Kinase Kinase 4
  • Curcumin
  • SB 203580