title: Estrogen modulates cytokine expression in human periodontal ligament cells.
abstract: Although systemic bone loss accompanying estrogen deficiency has been proposed as a risk factor for periodontal disease in post-menopausal women, the mechanisms involved remain unclear. The objective of this study was to elucidate the potential bone-sparing effect of estrogen (17beta-estradiol, E(2)) via modulation of inflammatory cytokine production in human periodontal ligament (hPDL) cells. E. coli lipopolysaccharide (LPS) increased the production of pro-inflammatory cytokines TNF-alpha, IL-1beta, IL-6, and receptor activator of NF- B ligand (RANKL) by hPDL cells at both mRNA and protein levels. E(2) treatment reversed the stimulatory effects of LPS on pro-inflammatory cytokine expression by hPDL cells. Moreover, E(2) up-regulated osteoprotegerin (OPG) expression and therefore attenuated the reduction of the OPG vs. RANKL ratio. Our results suggested that estrogen may play a significant role in modulating periodontal tissue responses to LPS, and may exert its bone-sparing effects on periodontal tissues via altering the expression of inflammatory cytokines in hPDL cells.
authors.affiliation: Department of Orthodontics, School of Stomatology, the Fourth Military Medical University, Xi'an, 710032, China.
authors.forename: L
authors.initials: L
authors.lastname: Shu
authors.forename: S-M
authors.initials: SM
authors.lastname: Guan
authors.forename: S-M
authors.initials: SM
authors.lastname: Fu
authors.forename: T
authors.initials: T
authors.lastname: Guo
authors.forename: M
authors.initials: M
authors.lastname: Cao
authors.forename: Y
authors.initials: Y
authors.lastname: Ding
mesh_terms: D000293:Adolescent; D050071:Bone Density Conservation Agents / Q000494:pharmacology*; D001862:Bone Resorption / Q000503:physiopathology; D002478:Cells, Cultured; D016207:Cytokines / Q000187:drug effects*; D004926:Escherichia coli; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000032:analysis; D053583:Interleukin-1beta / Q000187:drug effects; D015850:Interleukin-6 / Q000032:analysis; D008070:Lipopolysaccharides / Q000494:pharmacology; D053244:Osteoprotegerin / Q000187:drug effects; D010513:Periodontal Ligament / Q000187:drug effects* / Q000276:immunology; D053245:RANK Ligand / Q000187:drug effects; D014409:Tumor Necrosis Factor-alpha / Q000187:drug effects; D015854:Up-Regulation
chemical_list: D050071:Bone Density Conservation Agents; D016207:Cytokines; D018836:Inflammation Mediators; D053583:Interleukin-1beta; D015850:Interleukin-6; D008070:Lipopolysaccharides; D053244:Osteoprotegerin; D053245:RANK Ligand; D014409:Tumor Necrosis Factor-alpha; D004958:Estradiol