title: Corneal wound healing, a newly identified function of CAP37, is mediated by protein kinase C delta (PKCδ).
abstract: OBJECTIVE
  The neutrophil-derived granular protein, CAP37, an innate immune system molecule, has antibiotic and immunomodulatory effects on host cells, including corneal epithelial cells. We previously showed that CAP37 modulates corneal epithelial cell migration, adhesion, and proliferation, and that protein kinase C delta (PKCδ) mediates CAP37-induced chemotaxis of these cells. The objective of this study was to investigate the hypothesis that CAP37 facilitates corneal wound healing through the PKC signaling pathway.
  
  
  METHODS
  The standard "scratch" assay performed on monolayers of corneal epithelial cells was used to measure the in vitro effect of CAP37 on wound closure. In vivo wound healing in response to CAP37 was measured using a mouse corneal epithelium abrasion model. In vitro and in vivo wound closure were monitored over 48 hours. The PKCδ was visualized during wound closure in cell monolayers and corneal epithelium by immunohistochemistry. The importance of PKCδ in CAP37-induced corneal wound healing was assessed by siRNA.
  
  
  RESULTS
  We found that CAP37 accelerated wound closure in vitro and in vivo. Maximal closure occurred with concentrations of CAP37 between 250 and 500 ng/mL. Topical applications on mouse cornea led to re-epithelialization of the cornea by 24 hours. Immunohistochemistry of in vitro and in vivo wounds revealed a local increase of PKCδ along the wound edge in CAP37-treated cell monolayers and corneas, compared to untreated controls. CAP37-induced corneal wound healing was significantly reduced in vivo upon treatment with PKCδ siRNA.
  
  
  CONCLUSIONS
  These findings support the hypothesis that CAP37 facilitates corneal wound healing through the activation of PKCδ.
authors.affiliation: Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States.
authors.forename: Gina L
authors.initials: GL
authors.lastname: Griffith
authors.affiliation: Department of Pharmaceutical Sciences, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States.
authors.forename: Anne
authors.initials: A
authors.lastname: Kasus-Jacobi
authors.affiliation: Department of Surgery, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States.
authors.forename: Megan R
authors.initials: MR
authors.lastname: Lerner
authors.affiliation: Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States.
authors.forename: H Anne
authors.initials: HA
authors.lastname: Pereira
mesh_terms: D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000378:metabolism*; D001798:Blood Proteins / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism*; D002478:Cells, Cultured; D003315:Cornea / Q000378:metabolism* / Q000473:pathology; D065306:Corneal Injuries; D004195:Disease Models, Animal; D005131:Eye Injuries / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D007113:Immunity, Innate; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D051745:Protein Kinase C-delta / Q000378:metabolism*; D015398:Signal Transduction; D014945:Wound Healing
chemical_list: C062991:AZU1 protein, human; D023181:Antimicrobial Cationic Peptides; D001798:Blood Proteins; D002352:Carrier Proteins; D051745:Protein Kinase C-delta
keywords: antimicrobial proteins; corneal epithelium; corneal wound healing; protein kinase C