Effects of estrogen on interleukin-6 production in rheumatoid fibroblast-like synoviocytes

Objective In view of the importance of estrogen and IL-6 in the pathogenesis of rheum atoid 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 w ithout 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 in creased 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 central. Conclusion Estrogen up-regulates IL-1<beta>-induced IL-6 production in cultured fibrob last-like synoviocytes, possibly contributing to the enhancement of rheumat oid inflammation in synovial tissues.