title: Inhibition of ataxia telangiectasia mutated (ATM) kinase suppresses herpes simplex virus type 1 (HSV-1) keratitis.
abstract: OBJECTIVE
  Herpes keratitis (HK) remains the leading cause of cornea-derived blindness in the developed world, despite the availability of effective antiviral drugs. Treatment toxicity and the emergence of drug resistance highlight the need for additional therapeutic approaches. This study examined ataxia telangiectasia mutated (ATM), an apical kinase in the host DNA damage response, as a potential new target for the treatment of HK.
  
  
  METHODS
  Small molecule inhibitor of ATM (KU-55933) was used to treat herpes simplex virus type 1 (HSV-1) infection in three experimental models: (1) in vitro--cultured human corneal epithelial cells, hTCEpi, (2) ex vivo--organotypically explanted human and rabbit corneas, and (3) in vivo--corneal infection in young C57BL/6J mice. Infection productivity was assayed by plaque assay, real-time PCR, Western blot, and disease scoring.
  
  
  RESULTS
  Robust ATM activation was detected in HSV-1-infected human corneal epithelial cells. Inhibition of ATM greatly suppressed viral replication in cultured cells and in explanted human and rabbit corneas, and reduced the severity of stromal keratitis in mice. The antiviral effect of KU-55933 in combination with acyclovir was additive, and KU-55933 suppressed replication of a drug-resistant HSV-1 strain. KU-55933 caused minimal toxicity, as monitored by clonogenic survival assay and fluorescein staining.
  
  
  CONCLUSIONS
  This study identifies ATM as a potential target for the treatment of HK. ATM inhibition by KU-55933 reduces epithelial infection and stromal disease severity without producing appreciable toxicity. These findings warrant further investigations into the DNA damage response as an area for therapeutic intervention in herpetic ocular diseases.
authors.affiliation: Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania.
authors.forename: Oleg
authors.initials: O
authors.lastname: Alekseev
authors.forename: Kelly
authors.initials: K
authors.lastname: Donovan
authors.forename: Jane
authors.initials: J
authors.lastname: Azizkhan-Clifford
mesh_terms: D000212:Acyclovir / Q000494:pharmacology; D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology; D064007:Ataxia Telangiectasia Mutated Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D015153:Blotting, Western; D002478:Cells, Cultured; D004195:Disease Models, Animal; D004338:Drug Combinations; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D019573:Epithelium, Corneal / Q000201:enzymology / Q000821:virology*; D005260:Female; D018259:Herpesvirus 1, Human / Q000502:physiology*; D006801:Humans; D007150:Immunohistochemistry; D016849:Keratitis, Herpetic / Q000201:enzymology / Q000517:prevention & control* / Q000821:virology; D051379:Mice; D008810:Mice, Inbred C57BL; D009025:Morpholines / Q000494:pharmacology*; D009924:Organ Culture Techniques; D011753:Pyrones / Q000494:pharmacology*; D011817:Rabbits; D060888:Real-Time Polymerase Chain Reaction; D010948:Viral Plaque Assay; D014779:Virus Replication / Q000502:physiology
chemical_list: C495818:2-morpholin-4-yl-6-thianthren-1-yl-pyran-4-one; D000998:Antiviral Agents; D004338:Drug Combinations; D004791:Enzyme Inhibitors; D009025:Morpholines; D011753:Pyrones; D064007:Ataxia Telangiectasia Mutated Proteins; C576325:Atm protein, mouse; D000212:Acyclovir
keywords: DNA damage response; HSV-1; ataxia telangiectasia mutated (ATM); cornea; herpes simplex keratitis