title: Effects of bisphosphonate on matrix metalloproteinase enzymes in human periodontal ligament cells.
abstract: BACKGROUND
  The host response is a critical component in the pathogenesis of periodontitis. In fact, the clinical benefits associated with regulating the host response have been demonstrated in studies using several different classes of drugs. Biophosphates are one host-modulating class of drugs that has demonstrated this ability. These drugs are clinically effective at reducing bone resorption and have shown the ability to inhibit host degradative enzymes, specifically the matrix metalloproteinases (MMPs). Therefore, the purpose of this study was to investigate the regulatory effects of a bisphosphonate, tiludronate, on MMP levels and activity in human periodontal cells.
  
  
  METHODS
  MMP-1 and MMP-3 were assessed in cultured human periodontal ligament cells treated with a bisphosphonate, tiludronate. Reverse transcription-polymerase chain reaction was used to identify mRNA levels for both enzymes, and also for tissue inhibitors (TIMP-1). Enzyme immunoassay (EIA) and immunocytochemistry were used to assess MMP proteins in these cell cultures. Enzyme activity was assessed using FITC-conjugated substrates and quantitated using spectrophotofluorometry.
  
  
  RESULTS
  Tiludronate significantly inhibited both MMP-1 and MMP-3 activity in a concentration-dependent manner. A maximal reduction in activity of 35% was achieved for each of the enzymes at a 10(-4) M concentration. Tiludronate did not have a significant effect on the mRNA levels for MMP-1, MMP-3, or TIMP-1. Similarly, there were no effects noted for either MMP-1 or MMP-3 on the protein level.
  
  
  CONCLUSIONS
  This study demonstrates an inhibitory effect of tiludronate on the activity of both MMP-1 and MMP-3. These effects appear to occur without altering either mRNA or protein levels for these enzymes, supporting a possible mechanism of action that involves the ability of bisphosphonates to chelate cations from the MMPs. Furthermore, these results support the continued investigation of these drugs as potential therapeutic agents in periodontal disease.
authors.affiliation: Department of Periodontology, Nippon Dental University, School of Dentistry at Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Nakaya
authors.forename: G
authors.initials: G
authors.lastname: Osawa
authors.forename: N
authors.initials: N
authors.lastname: Iwasaki
authors.forename: D L
authors.initials: DL
authors.lastname: Cochran
authors.forename: K
authors.initials: K
authors.lastname: Kamoi
authors.forename: T W
authors.initials: TW
authors.lastname: Oates
mesh_terms: D000704:Analysis of Variance; D002478:Cells, Cultured; D004164:Diphosphonates / Q000737:chemistry / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007150:Immunohistochemistry; D061965:Matrix Metalloproteinase Inhibitors; D015394:Molecular Structure; D010513:Periodontal Ligament / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology*; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000819:agonists; D015854:Up-Regulation
chemical_list: D004164:Diphosphonates; D061965:Matrix Metalloproteinase Inhibitors; D012333:RNA, Messenger; D019715:Tissue Inhibitor of Metalloproteinase-1; C058651:tiludronic acid