title: 8(S)-hydroxyeicosatetraenoic acid is the lipoxygenase metabolite of arachidonic acid that regulates epithelial cell migration in the rat cornea.
abstract: BACKGROUND
  We previously found that the inhibition of lipoxygenases resulted in delayed epithelial wound closure in organ-cultured rat corneas. The present study was undertaken to determine the lipoxygenase enzyme and metabolite(s) responsible for regulating reepithelialization and their mechanism of action.
  
  
  METHODS
  The effects of esculetin--an established lipoxygenase inhibitor--on endogenous hydroxyeicosatetraenoic acids (HETEs) production, epithelial wound closure, filamentous-actin (F-actin) cytoskeleton, and mitotic rate were investigated using a cell-culture assay and an organ-culture assay of rat corneal epithelium.
  
  
  RESULTS
  Lipoxygenase inhibition by esculetin, which resulted in the disruption of F-actin organization and a decrease in the mitotic rate, delayed wound closure in both cell- and organ-culture assays. Normal corneoscleral rims metabolized [3H]arachidonic acid to 12-HETE (major metabolite), 8-HETE, and 9-HETE. HETE synthesis was inhibited by esculetin in a dose-dependent fashion. Chiral-phase analysis revealed that they contained only (S)-enantiomers, which indicated that they were lipoxygenase metabolites. The inhibitory effects of esculetin on F-actin organization and epithelial wound closure in an organ-culture assay were totally reversed by exogenously added 8(S)-HETE, whereas 12- and 9-HETE had no effect. However, none of the HETEs reversed the decreased mitotic rate or achieved complete wound closure in the cell-culture assay.
  
  
  CONCLUSIONS
  These results suggest that 8(S)-HETE is the key metabolite of arachidonic acid that regulates corneal epithelial cell migration during wound healing. The metabolite responsible for cell proliferation remains to be determined.
authors.affiliation: Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan. yamadam@mc.med.keio.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Yamada
authors.forename: A D
authors.initials: AD
authors.lastname: Proia
mesh_terms: D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid / Q000378:metabolism; D000199:Actins / Q000378:metabolism; D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism*; D002465:Cell Movement / Q000502:physiology*; D002478:Cells, Cultured; D003315:Cornea / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006893:Hydroxyeicosatetraenoic Acids / Q000378:metabolism* / Q000494:pharmacology; D008084:Lipoxygenase / Q000378:metabolism*; D016859:Lipoxygenase Inhibitors / Q000494:pharmacology; D008940:Mitotic Index; D009924:Organ Culture Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley; D014468:Umbelliferones / Q000494:pharmacology; D014945:Wound Healing / Q000502:physiology
chemical_list: D000199:Actins; D006893:Hydroxyeicosatetraenoic Acids; D016859:Lipoxygenase Inhibitors; D014468:Umbelliferones; D016718:Arachidonic Acid; D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; C047628:8-hydroxyeicosatetraenoic acid; D008084:Lipoxygenase; C007628:esculetin