title: Retinoic acid suppresses interleukin-6 production in human endometrial cells.
abstract: OBJECTIVE
  To determine whether retinoic acid (RA) can regulate the expression of interleukin (IL)-6 in human endometrial cells in a manner that might be beneficial to women with endometriosis.
  
  
  METHODS
  In vitro study.
  
  
  METHODS
  Academic medical center.
  
  
  METHODS
  Patients with endometriosis and controls.
  
  
  METHODS
  Endometrial cell cultures were treated with RA.
  
  
  METHODS
  Interleukin-6 protein secretion, messenger RNA expression, and IL-6-promoter activity.
  
  
  RESULTS
  Using a human endometrial cell line (EM42), as well as primary stromal and epithelial endometrial cells, we demonstrated that RA suppresses IL-6 protein and messenger RNA expression in a time- and dose-dependent fashion, showing maximal effects at pharmacologically achievable blood serum concentrations (micromoles per liter). Retinoic acid specifically inhibited the activity of IL-6-promoter reporter constructs that were transiently transfected into EM42 cells. Mutational analysis of reporter constructs indicated that RA suppression of IL-6 expression was mediated, at least in part, through the nuclear factor IL-6 binding site located in the IL-6 promoter.
  
  
  CONCLUSIONS
  Retinoids may play a fundamental role in altering the pathophysiology of endometriosis related to aberrant production of IL-6.
authors.affiliation: Division of Research, Department of Gynecology and Obstetrics, Emory University School of Medicine, Atlanta, Georgia, USA.
authors.forename: S
authors.initials: S
authors.lastname: Sawatsri
authors.forename: N
authors.initials: N
authors.lastname: Desai
authors.forename: J A
authors.initials: JA
authors.lastname: Rock
authors.forename: N
authors.initials: N
authors.lastname: Sidell
mesh_terms: D002478:Cells, Cultured; D004717:Endometrium / Q000187:drug effects / Q000378:metabolism*; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000096:biosynthesis*; D010641:Phenotype; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000378:metabolism; D018168:Receptors, Retinoic Acid / Q000096:biosynthesis / Q000235:genetics; D000072482:Retinoic Acid Receptor alpha; D014212:Tretinoin / Q000494:pharmacology*; D000097768:Retinoic Acid Receptor gamma
chemical_list: D015850:Interleukin-6; D012333:RNA, Messenger; D018168:Receptors, Retinoic Acid; D000072482:Retinoic Acid Receptor alpha; D014212:Tretinoin; D000097768:Retinoic Acid Receptor gamma; C000607071:RARA protein, human; C082925:retinoic acid receptor beta