Increased senescence and altered ECM remodelling in oral submucous fibrosis

Background: Oral submucous fibrosis (OSMF) is a pre-neoplastic condition, causally linked to areca nut consumption, the pathogenesis of which is poorly understood. TGF-β and disturbances in the balance between MMPs and TIMPs have been implicated in increased collagen deposition and fibrosis but no p...

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Main Author: Pitiyage, Gayani
Published: Queen Mary, University of London 2010
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Online Access:https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.516699
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spelling ndltd-bl.uk-oai-ethos.bl.uk-5166992019-02-27T03:25:25ZIncreased senescence and altered ECM remodelling in oral submucous fibrosisPitiyage, Gayani2010Background: Oral submucous fibrosis (OSMF) is a pre-neoplastic condition, causally linked to areca nut consumption, the pathogenesis of which is poorly understood. TGF-β and disturbances in the balance between MMPs and TIMPs have been implicated in increased collagen deposition and fibrosis but no previous study has addressed the role of mesenchymal senescence in OSMF. Materials & Methods: Senescence and its secretome, DNA damage, oxidative damage, ROS production and mitochondrial damage were studied in OSMF in vivo and in vitro using ELISA, immunofluorescence, western blot and FACS techniques. Results: Senescent cells increased in all OSMF samples (1.9±0.3; p=0.004) peaking when dysplasia was present in the OSMF epithelium. There was increased oxidative damage (6.7±1.8; p=0.004); elevated DSBs (10.4±1.1; p=0.004) and P16ink4a accumulation (4.2±1.7; p=0.004). The results were similar in vitro. The OSMF fibroblasts demonstrated a reduced replicative lifespan (MPD-22±7.2; p=0.0001), despite having normal telomere lengths and in vivo growth rates. However, the OSMF fibroblasts showed increased ROS production and increased mitochondrial density and hyperpolarization, suggesting mitochondrial damage. The antioxidant, N-tert-Butyl-α- phenylnitrone (PBN) reduced the frequency of senescent fibroblasts and their associated markers in both OSMF and the control cultures. The mild uncoupling of mitochondrial oxidative phosphorylation from ROS generation with dinitrophenol (DNP) gave similar results. Cytokine profiles from cells obtained from OSMF showed a significant elevation of TIMP-1 (2217.4±406.5; p=0.003) and TIMP-2 (1763.2+/-363.7 pg/ml; p=0.004) production as compared to normal. The levels of MMP-1 (7.0±2.2 ng/ml; p=0.30), MMP-2 (157.8±91.3 ng/ml; p=0.75) and TGF-β1 (389.5±250.6 ng/ml; p=0.22) were not different to the normal and non-diseased controls (ND) collagen production was not elevated in OSMF in vitro (20.6±4.4 μg/ml; p=0.22). 3 Conclusion: Senescence, DNA damage, oxidative damage and P16inka accumulation are associated with neoplastic progression of OSMF. Elevated TIMP levels did not result in increased collagen secretion but may be an early marker of fibroblast aging and senescence.616.994DentistryQueen Mary, University of Londonhttps://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.516699http://qmro.qmul.ac.uk/xmlui/handle/123456789/611Electronic Thesis or Dissertation
collection NDLTD
sources NDLTD
topic 616.994
Dentistry
spellingShingle 616.994
Dentistry
Pitiyage, Gayani
Increased senescence and altered ECM remodelling in oral submucous fibrosis
description Background: Oral submucous fibrosis (OSMF) is a pre-neoplastic condition, causally linked to areca nut consumption, the pathogenesis of which is poorly understood. TGF-β and disturbances in the balance between MMPs and TIMPs have been implicated in increased collagen deposition and fibrosis but no previous study has addressed the role of mesenchymal senescence in OSMF. Materials & Methods: Senescence and its secretome, DNA damage, oxidative damage, ROS production and mitochondrial damage were studied in OSMF in vivo and in vitro using ELISA, immunofluorescence, western blot and FACS techniques. Results: Senescent cells increased in all OSMF samples (1.9±0.3; p=0.004) peaking when dysplasia was present in the OSMF epithelium. There was increased oxidative damage (6.7±1.8; p=0.004); elevated DSBs (10.4±1.1; p=0.004) and P16ink4a accumulation (4.2±1.7; p=0.004). The results were similar in vitro. The OSMF fibroblasts demonstrated a reduced replicative lifespan (MPD-22±7.2; p=0.0001), despite having normal telomere lengths and in vivo growth rates. However, the OSMF fibroblasts showed increased ROS production and increased mitochondrial density and hyperpolarization, suggesting mitochondrial damage. The antioxidant, N-tert-Butyl-α- phenylnitrone (PBN) reduced the frequency of senescent fibroblasts and their associated markers in both OSMF and the control cultures. The mild uncoupling of mitochondrial oxidative phosphorylation from ROS generation with dinitrophenol (DNP) gave similar results. Cytokine profiles from cells obtained from OSMF showed a significant elevation of TIMP-1 (2217.4±406.5; p=0.003) and TIMP-2 (1763.2+/-363.7 pg/ml; p=0.004) production as compared to normal. The levels of MMP-1 (7.0±2.2 ng/ml; p=0.30), MMP-2 (157.8±91.3 ng/ml; p=0.75) and TGF-β1 (389.5±250.6 ng/ml; p=0.22) were not different to the normal and non-diseased controls (ND) collagen production was not elevated in OSMF in vitro (20.6±4.4 μg/ml; p=0.22). 3 Conclusion: Senescence, DNA damage, oxidative damage and P16inka accumulation are associated with neoplastic progression of OSMF. Elevated TIMP levels did not result in increased collagen secretion but may be an early marker of fibroblast aging and senescence.
author Pitiyage, Gayani
author_facet Pitiyage, Gayani
author_sort Pitiyage, Gayani
title Increased senescence and altered ECM remodelling in oral submucous fibrosis
title_short Increased senescence and altered ECM remodelling in oral submucous fibrosis
title_full Increased senescence and altered ECM remodelling in oral submucous fibrosis
title_fullStr Increased senescence and altered ECM remodelling in oral submucous fibrosis
title_full_unstemmed Increased senescence and altered ECM remodelling in oral submucous fibrosis
title_sort increased senescence and altered ecm remodelling in oral submucous fibrosis
publisher Queen Mary, University of London
publishDate 2010
url https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.516699
work_keys_str_mv AT pitiyagegayani increasedsenescenceandalteredecmremodellinginoralsubmucousfibrosis
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