title: Effects of estrogen on interleukin-6 production in rheumatoid fibroblast-like synoviocytes.
abstract: OBJECTIVE
  In view of the importance of estrogen and IL-6 in the pathogenesis of rheumatoid arthritis (RA), the effects of 17 beta-estradiol (E2) on interleukin (IL)-6 production in cultured rheumatoid fibroblast-like synoviocytes were investigated.
  
  
  METHODS
  Cultured fibroblast-like synoviocytes obtained from RA joints were treated with the vehicle (control), as well as 10(-8) and 10(-6) M of E2, with or without IL-1 beta stimulation. After 72 hours of culture, the levels of IL-6 in supernatants were measured by ELISA.
  
  
  RESULTS
  Treatment with 10(-8) and 10(-6) M of E2 had no effect on the constitutive production of IL-6 in cultured fibroblast-like synoviocytes. However, E2 increased IL-1 beta-induced IL-6 production in a dose-dependent manner, with a mean 12.5% increase with 10(-8) M of E2 (p = 0.048) and 33.4% with 10(-6) M (p < 0.0001) versus the control.
  
  
  CONCLUSIONS
  Estrogen up-regulates IL-1 beta-induced IL-6 production in cultured fibroblast-like synoviocytes, possibly contributing to the enhancement of rheumatoid inflammation in synovial tissues.
authors.affiliation: Department of Orthopedic Surgery, Shiga University of Medical Science, Seta, Otsu, Shiga, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kawasaki
authors.forename: T
authors.initials: T
authors.lastname: Ushiyama
authors.forename: K
authors.initials: K
authors.lastname: Inoue
authors.forename: S
authors.initials: S
authors.lastname: Hukuda
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001172:Arthritis, Rheumatoid / Q000378:metabolism* / Q000473:pathology; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D005347:Fibroblasts / Q000378:metabolism*; D006801:Humans; D015850:Interleukin-6 / Q000096:biosynthesis*; D008297:Male; D008875:Middle Aged; D013583:Synovial Membrane / Q000378:metabolism* / Q000473:pathology
chemical_list: D015850:Interleukin-6; D004958:Estradiol