title: Evidence that estrogen receptor beta enhances MMP-13 promoter activity in HIG-82 cells and that this enhancement can be influenced by ligands and involves specific promoter sites.
abstract: Degradation of articular cartilage is characteristic of osteoarthritis, and matrix metalloproteinase-13 (MMP-13) has been implicated in this condition. Estrogen receptors (ERs) are present in connective tissues, indicating these tissues' potential responsiveness to estrogen. We based this study on the hypothesis that estrogen receptor beta (ERbeta) can modulate MMP-13 promoter activity. Transfection of cells with ERbeta constructs led to the induction of the endogenous MMP-13 gene, as evidenced by increased mRNA levels. The results also indicated that MMP-13 promoter construct activity in the HIG-82 cell line significantly increased when ERbeta was present, and that estrogen downregulated this response in a dose-dependent manner. ERbeta was shown to enhance MMP-13 expression somewhat more strongly than ERalpha, and the impact of a number of selective ER modulators (tamoxifen, raloxifene, and ICI 182,780) on ERbeta enhancement of promoter activity was found to be significantly less than that of estrogen. Furthermore, transcription regulatory sites in the MMP-13 promoter, specifically AP-1 and PEA-3, were shown to act in conjunction to mediate ERbeta effects. Thus, ERbeta likely influences MMP-13 promoter expression in normal and disease processes.
authors.affiliation: McCaig Centre for Joint Injury and Arthritis Research, Faculty of Medicine, University of Calgary, 3330 Hospital Dr. N.W, Calgary, AB T2N 4N1, Canada.
authors.forename: Ting
authors.initials: T
authors.lastname: Lu
authors.forename: Yamini
authors.initials: Y
authors.lastname: Achari
authors.forename: Jerome B
authors.initials: JB
authors.lastname: Rattner
authors.forename: David A
authors.initials: DA
authors.lastname: Hart
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D017931:DNA Primers / Q000235:genetics; D004958:Estradiol / Q000378:metabolism / Q000494:pharmacology; D047628:Estrogen Receptor alpha / Q000378:metabolism; D047629:Estrogen Receptor beta / Q000235:genetics / Q000378:metabolism*; D008024:Ligands; D053509:Matrix Metalloproteinase 13 / Q000235:genetics*; D010003:Osteoarthritis / Q000209:etiology / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011817:Rabbits; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013583:Synovial Membrane / Q000166:cytology / Q000378:metabolism; D014162:Transfection
chemical_list: D017931:DNA Primers; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D008024:Ligands; D012333:RNA, Messenger; D011994:Recombinant Proteins; D004958:Estradiol; D053509:Matrix Metalloproteinase 13