title: Kinetics of RANKL, RANK and OPG expressions in experimentally induced rat periapical lesions.
abstract: OBJECTIVE
  The object of this study was to elucidate the kinetics of receptor activator of NFkB ligand (RANKL), RANK, osteoprotegerin (OPG), and cytokine expressions in experimentally induced rat periapical lesions.
  
  
  METHODS
  The mRNA expressions of RANKL, RANK, OPG, and cytokines in experimentally induced rat periapical lesions were evaluated by real-time PCR. The lesions were induced in male Wistar rats (n = 48, 5 weeks of age) by unsealed pulp exposure of the lower first molars.
  
  
  RESULTS
  Expression of RANKL was up-regulated at the beginning of lesion expansion, and expression ratio of RANKL against OPG, a competitor of RANKL, peaked at 2 and 3 weeks. Expression of inflammatory cytokines, such as TNF-alpha, IL-1alpha, and IL-1beta also increased at this stage, suggesting contribution of synergic effects of RANKL and proinflammatory cytokine signaling to lesion expansion. Most of RANKL+ cells were fibroblastic, but few of them were T cells.
  
  
  CONCLUSIONS
  Expression of RANKL and proinflammatory cytokines was correlated with periapical lesion expansion.
authors.affiliation: Graduate School of Tokyo Medical and Dental University, Tokyo, Japan. kawashima.n.endo@tmd.ac.jp
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Kawashima
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Suzuki
authors.forename: Guangyan
authors.initials: G
authors.lastname: Yang
authors.forename: Chie
authors.initials: C
authors.lastname: Ohi
authors.forename: Shigeru
authors.initials: S
authors.lastname: Okuhara
authors.forename: Hiromi
authors.initials: H
authors.lastname: Nakano-Kawanishi
authors.forename: Hideaki
authors.initials: H
authors.lastname: Suda
mesh_terms: D000135:Acid Phosphatase / Q000378:metabolism; D000818:Animals; D016207:Cytokines / Q000096:biosynthesis*; D007124:Immunoenzyme Techniques; D016753:Interleukin-10 / Q000096:biosynthesis; D053582:Interleukin-1alpha / Q000096:biosynthesis; D053583:Interleukin-1beta / Q000096:biosynthesis; D007527:Isoenzymes / Q000378:metabolism; D007700:Kinetics; D008297:Male; D053244:Osteoprotegerin / Q000096:biosynthesis*; D010485:Periapical Periodontitis / Q000378:metabolism* / Q000473:pathology; D053245:RANK Ligand / Q000096:biosynthesis*; D051381:Rats; D017208:Rats, Wistar; D053246:Receptor Activator of Nuclear Factor-kappa B / Q000096:biosynthesis*; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000071681:Tartrate-Resistant Acid Phosphatase; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: D016207:Cytokines; D053582:Interleukin-1alpha; D053583:Interleukin-1beta; D007527:Isoenzymes; D053244:Osteoprotegerin; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; D016693:Receptors, Antigen, T-Cell, alpha-beta; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase