title: Regulation of interleukin-1beta-induced chemokine production and matrix metalloproteinase 2 activation by epigallocatechin-3-gallate in rheumatoid arthritis synovial fibroblasts.
abstract: OBJECTIVE
  To evaluate the efficacy of epigallocatechin-3-gallate (EGCG), a potent antiinflammatory molecule, in regulating interleukin-1beta (IL-1beta)-induced production of the chemokines RANTES (CCL5), monocyte chemoattractant protein 1 (MCP-1/CCL2), epithelial neutrophil-activating peptide 78 (ENA-78/CXCL5), growth-regulated oncogene alpha (GROalpha/CXCL1), and matrix metalloproteinase 2 (MMP-2) activity in rheumatoid arthritis (RA) synovial fibroblasts.
  
  
  METHODS
  Fibroblasts obtained from RA synovium were grown, and conditioned medium was obtained. Cell viability was determined by MTT assay. RANTES, MCP-1, ENA-78, and GROalpha produced in culture supernatants were measured by enzyme-linked immunosorbent assay. MMP-2 activity was analyzed by gelatin zymography. Western blotting was used to study the phosphorylation of protein kinase C (PKC) isoforms and nuclear translocation of NF-kappaB.
  
  
  RESULTS
  EGCG was nontoxic to RA synovial fibroblasts. Treatment with EGCG at 10 microM or 20 microM significantly inhibited IL-1beta-induced ENA-78, RANTES, and GROalpha, but not MCP-1 production in a concentration-dependent manner. EGCG at 50 microM caused a complete block of IL-1beta-induced production of RANTES, ENA-78, and GROalpha, and reduced production of MCP-1 by 48% (P < 0.05). Zymography showed that EGCG blocked constitutive, IL-1beta-induced, and chemokine-mediated MMP-2 activity. Evaluation of signaling events revealed that EGCG preferentially blocked the phosphorylation of PKCdelta and inhibited the activation and nuclear translocation of NF-kappaB in IL-1beta-treated RA synovial fibroblasts.
  
  
  CONCLUSIONS
  These results suggest that EGCG may be of potential therapeutic value in inhibiting joint destruction in RA.
authors.affiliation: University of Michigan Medical School, Ann Arbor, MI 48109-2200, USA. salahmed@umich.edu
authors.forename: Salahuddin
authors.initials: S
authors.lastname: Ahmed
authors.forename: Angela
authors.initials: A
authors.lastname: Pakozdi
authors.forename: Alisa E
authors.initials: AE
authors.lastname: Koch
mesh_terms: D001172:Arthritis, Rheumatoid / Q000378:metabolism* / Q000473:pathology; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D018925:Chemokines / Q000378:metabolism*; D017077:Culture Media, Conditioned / Q000737:chemistry / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D004338:Drug Combinations; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology*; D019278:Matrix Metalloproteinase 3 / Q000096:biosynthesis*; D013583:Synovial Membrane / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology
chemical_list: D018925:Chemokines; D017077:Culture Media, Conditioned; D004338:Drug Combinations; D007375:Interleukin-1; D002392:Catechin; C045651:epigallocatechin gallate; D019278:Matrix Metalloproteinase 3