title: Matrix metalloproteinases and their inhibitors in oral lichen planus.
abstract: BACKGROUND
  Oral lichen planus (OLP) is characterized by a sub-epithelial lymphocytic infiltrate, basement membrane (BM) disruption, intra-epithelial T-cell migration and apoptosis of basal keratinocytes. BM damage and T-cell migration in OLP may be mediated by matrix metalloproteinases (MMPs).
  
  
  METHODS
  We examined the distribution, activation and cellular sources of MMPs and their inhibitors (TIMPs) in OLP using immunohistochemistry, ELISA, RT-PCR and zymography.
  
  
  RESULTS
  MMP-2 and -3 were present in the epithelium while MMP-9 was associated with the inflammatory infiltrate. MMP-9 and TIMP-1 secretion by OLP lesional T cells was greater than OLP patient (p < 0.01) and healthy control subject (p < 0.001) peripheral blood T cells. MMP-9 and TIMP-1 mRNA levels were greater in OLP lesional T cells compared with healthy control subject peripheral blood T cells p < 0.01). Tumor necrosis factor (TNF)-alpha upregulated OLP lesional T-cell MMP-9 (not TIMP-1) mRNA and secretion (p < 0.05). The in vitro activation rate of MMP-9 from OLP lesional T cells was greater than that from OLP peripheral blood T cells (p < 0.05).
  
  
  CONCLUSIONS
  T-cell-derived MMP-9 may be involved in the pathogenesis of OLP. Relative over-expression of MMP-9 (compared with TIMP-1) may cause BM disruption and facilitate intra-epithelial T-cell migration in OLP.
authors.affiliation: Oral Biology and Pathology, School of Dentistry, The University of Queensland, Brisbane, Australia.
authors.forename: X J
authors.initials: XJ
authors.lastname: Zhou
authors.forename: P B
authors.initials: PB
authors.lastname: Sugerman
authors.forename: N W
authors.initials: NW
authors.lastname: Savage
authors.forename: L J
authors.initials: LJ
authors.lastname: Walsh
mesh_terms: D000328:Adult; D000368:Aged; D002465:Cell Movement; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D017676:Lichen Planus, Oral / Q000201:enzymology* / Q000209:etiology / Q000473:pathology; D008297:Male; D061965:Matrix Metalloproteinase Inhibitors; D020782:Matrix Metalloproteinases / Q000378:metabolism*; D008875:Middle Aged; D012313:RNA / Q000032:analysis; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000201:enzymology / Q000473:pathology / Q000502:physiology; D019714:Tissue Inhibitor of Metalloproteinases / Q000235:genetics / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D061965:Matrix Metalloproteinase Inhibitors; D012333:RNA, Messenger; D019714:Tissue Inhibitor of Metalloproteinases; D014409:Tumor Necrosis Factor-alpha; D012313:RNA; D020782:Matrix Metalloproteinases