title: Menadione-Induced DNA Damage Leads to Mitochondrial Dysfunction and Fragmentation During Rosette Formation in Fuchs Endothelial Corneal Dystrophy.
abstract: Fuchs endothelial corneal dystrophy (FECD), a leading cause of age-related corneal edema requiring transplantation, is characterized by rosette formation of corneal endothelium with ensuing apoptosis. We sought to determine whether excess of mitochondrial reactive oxygen species leads to chronic accumulation of oxidative DNA damage and mitochondrial dysfunction, instigating cell death.
  
  
  
  We modeled the pathognomonic rosette formation of postmitotic corneal cells by increasing endogenous cellular oxidative stress with menadione (MN) and performed a temporal analysis of its effect in normal (HCEnC, HCECi) and FECD (FECDi) cells and ex vivo specimens. FECDi and FECD ex vivo specimens exhibited extensive mtDNA and nDNA damage as detected by quantitative PCR. Exposure to MN triggered an increase in mitochondrial superoxide levels and led to mtDNA and nDNA damage, while DNA amplification was restored with NAC pretreatment. Furthermore, MN exposure led to a decrease in ΔΨm and adenosine triphosphate levels in normal cells, while FECDi exhibited mitochondrial dysfunction at baseline. Mitochondrial fragmentation and cytochrome c release were detected in FECD tissue and after MN treatment of HCEnCs. Furthermore, cleavage of caspase-9 and caspase-3 followed MN-induced cytochrome c release in HCEnCs.
  
  
  
  This study provides the first line of evidence that accumulation of oxidative DNA damage leads to rosette formation, loss of functionally intact mitochondria via fragmentation, and subsequent cell death during postmitotic cell degeneration of ocular tissue.
  
  
  
  MN induced rosette formation, along with mtDNA and nDNA damage, mitochondrial dysfunction, and fragmentation, leading to activation of the intrinsic apoptosis via caspase cleavage and cytochrome c release. Antioxid. Redox Signal. 24, 1072-1083.
authors.affiliation: 1 Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary (MEEI), Harvard Medical School , Boston, Massachusetts.
authors.forename: Adna
authors.initials: A
authors.lastname: Halilovic
authors.affiliation: 1 Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary (MEEI), Harvard Medical School , Boston, Massachusetts.
authors.forename: Thore
authors.initials: T
authors.lastname: Schmedt
authors.affiliation: 1 Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary (MEEI), Harvard Medical School , Boston, Massachusetts.
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Benischke
authors.affiliation: 1 Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary (MEEI), Harvard Medical School , Boston, Massachusetts.
authors.forename: Cecily
authors.initials: C
authors.lastname: Hamill
authors.affiliation: 1 Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary (MEEI), Harvard Medical School , Boston, Massachusetts.
authors.forename: Yuming
authors.initials: Y
authors.lastname: Chen
authors.affiliation: 2 Department of Pharmacology and Physiology, New Jersey Medical School Rutgers, Rutgers University , New Jersey.
authors.forename: Janine Hertzog
authors.initials: JH
authors.lastname: Santos
authors.affiliation: 1 Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary (MEEI), Harvard Medical School , Boston, Massachusetts.
authors.forename: Ula V
authors.initials: UV
authors.lastname: Jurkunas
mesh_terms: D017209:Apoptosis; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D002478:Cells, Cultured; D045304:Cytochromes c / Q000378:metabolism; D004249:DNA Damage; D004272:DNA, Mitochondrial / Q000235:genetics; D005642:Fuchs' Endothelial Dystrophy / Q000473:pathology*; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects* / Q000473:pathology; D018384:Oxidative Stress; D012397:Rosette Formation; D024483:Vitamin K 3 / Q000633:toxicity*
chemical_list: D004272:DNA, Mitochondrial; D024483:Vitamin K 3; D045304:Cytochromes c; C505407:CASP3 protein, human; C506433:CASP9 protein, human; D053148:Caspase 3; D053453:Caspase 9