title: IL-1β-induced matrix metalloproteinase-3 regulates cell proliferation in rat dental pulp cells.
abstract: OBJECTIVE
  We previously reported that matrix metalloproteinase-3(MMP-3) accelerates wound healing following dental pulp injury. In this study, we tested the hypothesis that induction of MMP-3 activity by interleukin-1β would promote proliferation and apoptosis of dental pulp cells.
  
  
  METHODS
  Dental pulp cells were isolated from rat incisors and subjected to interleukin-1β. Matrix metalloproteinase-3 mRNA and protein expression were assessed using reverse transcription-polymerase chain reaction and Western blotting, respectively. Matrix metalloproteinase-3 activity was measured using fluorescence. Dental pulp cell proliferation and apoptosis were determined using enzyme-linked immunosorbent assays (ELISA) for BrdU and DNA fragmentation, respectively. siRNA was used to reduce MMP-3 transcripts in these cells.
  
  
  RESULTS
  Treatment with interleukin-1β increased MMP-3 mRNA and protein levels as well as its activity in dental pulp cells. Cell proliferation was also markedly increased, with no changes in apoptosis observed. Treatment with siRNA against MMP-3 potently suppressed this interleukin-1β-induced increase in MMP-3 expression and activity, and also suppressed cell proliferation but unexpectedly increased apoptosis in these cells (P < 0.05). This siRNA-mediated increase in apoptosis could be reversed with exogenous MMP-3 stimulation (P < 0.05).
  
  
  CONCLUSIONS
  Interleukin-1β induces MMP-3-regulated cell proliferation and suppresses apoptosis in dental pulp cells.
authors: Department of Endodontics, School of Dentistry, Aichi Gakuin University, Nagoya, Japan.
authors: N
authors: N
authors: Ozeki
authors: H
authors: H
authors: Yamaguchi
authors: T
authors: T
authors: Hiyama
authors: R
authors: R
authors: Kawai
authors: K
authors: K
authors: Nakata
authors: M
authors: M
authors: Mogi
authors: H
authors: H
authors: Nakamura
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D015153:Blotting, Western; D049109:Cell Proliferation / Q000187:drug effects / Q000502:physiology*; D003782:Dental Pulp / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D053583:Interleukin-1beta / Q000494:pharmacology*; D019278:Matrix Metalloproteinase 3 / Q000502:physiology*; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D053583:Interleukin-1beta; D019278:Matrix Metalloproteinase 3
keywords: IL-1β; cytokines; dental pulp cells; inflammation; matrix metalloproteinases