title: Increased secretion of tissue inhibitors of metalloproteinases 1 and 2 (TIMPs -1 and -2) in fibroblasts are early indicators of oral sub-mucous fibrosis and ageing.
abstract: Oral submucous fibrosis (OSMF) is associated with paan chewing, altered collagen metabolism, inflammation and the upregulation of numerous cytokines. OSMF fibroblasts accumulate senescent cells at an increased rate because of increased reactive oxygen species production and DNA double-strand breaks (DDBs), generated intrinsically by damaged mitochondria. This results in a reduced replicative lifespan. However, it is still unclear which other changes are intrinsic to the fibroblasts and associated with OSMF rather than the paan chewing habit or the OSMF environment. Both the oral epithelium and the mesenchyme have elevated levels of TGF-β(1) in OSMF in vivo. However, in cultured fibroblasts, secreted levels of TGF-β(1,) other cytokines and the matrix metalloproteinases 1 and 2 showed no association with OSMF. In contrast, the tissue inhibitors of metalloproteinases, TIMP-1 and TIMP-2, were increased in 10/11 OSMF fibroblast cultures relative to normal and non-diseased paan user controls. OSMF fibroblast collagen levels were normal. TIMP levels correlated with replicative lifespan of the cultures but not with the presence of senescent cells, as senescent cell depletion in OSMF fibroblast cultures did not result in a reduction in either TIMP-1 or TIMP-2. However, the introduction of unrepairable DDBs into normal oral fibroblasts by ionizing radiation increased TIMP-1 and TIMP-2 secretion by two-fold and seven-fold, respectively, within 5 days, replicating early senescence and the elevation seen in OSMF cultures. Therefore, increased fibroblast TIMP-1/2 levels could be early disease-specific markers of OSMF onset, DDBs and ageing and may have clinical significance, as OSMF can be reversed in its early stages.
authors.affiliation: Centre for Clinical and Diagnostic Oral Sciences, Institute of Dentistry, Barts & The London School of Medicine and Dentistry, Queen Mary University of London, London, UK.
authors.forename: Gayani N
authors.initials: GN
authors.lastname: Pitiyage
authors.forename: Kue P
authors.initials: KP
authors.lastname: Lim
authors.forename: Emilios
authors.initials: E
authors.lastname: Gemenitzidis
authors.forename: Muy-Teck
authors.initials: MT
authors.lastname: Teh
authors.forename: Ahmad
authors.initials: A
authors.lastname: Waseem
authors.forename: Stephen S
authors.initials: SS
authors.lastname: Prime
authors.forename: Wanninayake M
authors.initials: WM
authors.lastname: Tilakaratne
authors.forename: Farida
authors.initials: F
authors.lastname: Fortune
authors.forename: E K
authors.initials: EK
authors.lastname: Parkinson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D016022:Case-Control Studies; D018929:Cell Culture Techniques; D016922:Cellular Senescence; D024042:Collagen Type I / Q000032:analysis; D017077:Culture Media, Conditioned; D004249:DNA Damage; D004848:Epithelium / Q000473:pathology; D005347:Fibroblasts / Q000201:enzymology* / Q000528:radiation effects; D006801:Humans; D020781:Matrix Metalloproteinase 1 / Q000032:analysis; D020778:Matrix Metalloproteinase 2 / Q000032:analysis; D019278:Matrix Metalloproteinase 3 / Q000032:analysis; D020780:Matrix Metalloproteinase 9 / Q000032:analysis; D008648:Mesoderm / Q000473:pathology; D008875:Middle Aged; D009914:Oral Submucous Fibrosis / Q000201:enzymology* / Q000473:pathology; D011480:Protease Inhibitors / Q000032:analysis / Q000378:metabolism*; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000032:analysis / Q000378:metabolism*; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000032:analysis / Q000378:metabolism*; D053773:Transforming Growth Factor beta1 / Q000032:analysis; D055815:Young Adult
chemical_list: D015415:Biomarkers; D024042:Collagen Type I; D017077:Culture Media, Conditioned; D011480:Protease Inhibitors; C560822:TIMP1 protein, human; C560823:TIMP2 protein, human; D019715:Tissue Inhibitor of Metalloproteinase-1; D053773:Transforming Growth Factor beta1; D019716:Tissue Inhibitor of Metalloproteinase-2; C511768:MMP3 protein, human; D019278:Matrix Metalloproteinase 3; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; C522360:MMP1 protein, human; D020781:Matrix Metalloproteinase 1