title: Antioxidant enzymes reduce DNA damage and early activation of valvular interstitial cells in aortic valve sclerosis.
abstract: OBJECTIVE
  Accumulation of reactive oxygen species (ROS) and remodeling of the microstructure of the cusp characterize aortic valve sclerosis, the early phase of calcific aortic valve disease. These events are associated with activation of valvular interstitial cells (VICs) toward an osteogenic-like phenotype. Because ROS cause DNA damage and transcriptional activation we investigated the relationship between ROS, DNA damage response, and transdifferentiation of VICs.
  
  
  RESULTS
  Human aortic valve cusps and patient-matched VICs were collected from 39 patients both with and without calcific aortic valve disease. VICs were exposed to hydrogen peroxide (0.1-1 mmol/L) after cell transduction with extracellular superoxide dismutase/catalase adenoviruses and characterized for DNA-damage response, osteogenic transdifferentiation, and calcification. ROS induce relocalization of phosphorylated γH2AX, MRE11, and XRCC1 proteins with expression of osteogenic signaling molecule RUNX2 via AKT. We report a sustained activation of γH2AX in aortic valve sclerosis-derived VICs suggesting their impaired ability to repair DNA damage. Adenovirus superoxide dismutase/catalase transduction decreases ROS-induced DNA damage and VIC transdifferentiation in aortic valve sclerosis-derived cells. Finally, adenoviral transduction with catalase reverts ROS-mediated calcification and cellular transdifferentiation.
  
  
  CONCLUSIONS
  We conclude that the ROS-induced DNA damage response is dysfunctional in early asymptomatic stages of calcific aortic valve disease. We unveiled an association among ROS, DNA-damage response, and cellular transdifferentiation, reversible by antioxidant enzymes delivery.
authors.affiliation: Department of Surgery, Division of Cardiovascular Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19036, USA.
authors.forename: Emanuela
authors.initials: E
authors.lastname: Branchetti
authors.forename: Rachana
authors.initials: R
authors.lastname: Sainger
authors.forename: Paolo
authors.initials: P
authors.lastname: Poggio
authors.forename: Juan B
authors.initials: JB
authors.lastname: Grau
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Patterson-Fortin
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Bavaria
authors.forename: Michael
authors.initials: M
authors.lastname: Chorny
authors.forename: Eric
authors.initials: E
authors.lastname: Lai
authors.forename: Robert C
authors.initials: RC
authors.lastname: Gorman
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Levy
authors.forename: Giovanni
authors.initials: G
authors.lastname: Ferrari
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D001021:Aortic Valve / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology; D058070:Asymptomatic Diseases; D002114:Calcinosis / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D002374:Catalase / Q000235:genetics / Q000378:metabolism*; D054338:Cell Transdifferentiation; D002478:Cells, Cultured; D050659:Core Binding Factor Alpha 1 Subunit / Q000378:metabolism; D004249:DNA Damage; D004268:DNA-Binding Proteins / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D005822:Genetic Vectors; D006349:Heart Valve Diseases / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D006657:Histones / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D000076228:MRE11 Homologue Protein; D051379:Mice; D010012:Osteogenesis; D016877:Oxidants / Q000494:pharmacology; D018384:Oxidative Stress / Q000187:drug effects; D010641:Phenotype; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D012598:Sclerosis; D015398:Signal Transduction; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism*; D000072105:Superoxide Dismutase-1; D013997:Time Factors; D014161:Transduction, Genetic; D014162:Transfection; D000076105:X-ray Repair Cross Complementing Protein 1; D000099156:Superoxide Dismutase 2
chemical_list: D002374:Catalase; D050659:Core Binding Factor Alpha 1 Subunit; D004268:DNA-Binding Proteins; D006657:Histones; D006861:Hydrogen Peroxide; D000076228:MRE11 Homologue Protein; D016877:Oxidants; D051057:Proto-Oncogene Proteins c-akt; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1; D000076105:X-ray Repair Cross Complementing Protein 1; D000099156:Superoxide Dismutase 2; C468783:H2AX protein, human; C121766:MRE11 protein, human; C493709:RUNX2 protein, human; C000606290:SOD1 protein, human; C000619371:XRCC1 protein, human; C000619352:Xrcc1 protein, mouse; C441642:SOD3 protein, human; C000606291:Sod1 protein, mouse