title: Cannabinoid-induced chemotaxis in bovine corneal epithelial cells.
abstract: OBJECTIVE
  Cannabinoid CB1 receptors are found in abundance in the vertebrate eye, with most tissue types expressing this receptor. However, the function of CB1 receptors in corneal epithelial cells (CECs) is poorly understood. Interestingly, the corneas of CB1 knockout mice heal more slowly after injury via a mechanism proposed to involve protein kinase B (Akt) activation, chemokinesis, and cell proliferation. The current study examined the role of cannabinoids in CEC migration in greater detail.
  
  
  METHODS
  We determined the role of CB1 receptors in corneal healing. We examined the consequences of their activation on migration and proliferation in bovine CECs (bCECs). We additionally examined the mRNA profile of cannabinoid-related genes and CB1 protein expression as well as CB1 signaling in bovine CECs.
  
  
  RESULTS
  We now report that activation of CB1 with physiologically relevant concentrations of the synthetic agonist WIN55212-2 (WIN) induces bCEC migration via chemotaxis, an effect fully blocked by the CB1 receptor antagonist SR141716. The endogenous agonist 2-arachidonoylglycerol (2-AG) also enhances migration. Separately, mRNA for most cannabinoid-related proteins are present in bovine corneal epithelium and cultured bCECs. Notably absent are CB2 receptors and the 2-AG synthesizing enzyme diglycerol lipase-α (DAGLα). The signaling profile of CB1 activation is complex, with inactivation of mitogen-activated protein kinase (MAPK). Lastly, CB1 activation does not induce bCEC proliferation, but may instead antagonize EGF-induced proliferation.
  
  
  CONCLUSIONS
  In summary, we find that CB1-based signaling machinery is present in bovine cornea and that activation of this system induces chemotaxis.
authors.affiliation: The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences Indiana University, Bloomington, Indiana, United States.
authors.forename: Natalia
authors.initials: N
authors.lastname: Murataeva
authors.affiliation: School of Optometry, Indiana University, Bloomington, Indiana, United States.
authors.forename: Shimin
authors.initials: S
authors.lastname: Li
authors.affiliation: The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences Indiana University, Bloomington, Indiana, United States.
authors.forename: Olivia
authors.initials: O
authors.lastname: Oehler
authors.affiliation: The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences Indiana University, Bloomington, Indiana, United States.
authors.forename: Sally
authors.initials: S
authors.lastname: Miller
authors.affiliation: The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences Indiana University, Bloomington, Indiana, United States.
authors.forename: Amey
authors.initials: A
authors.lastname: Dhopeshwarkar
authors.affiliation: Department of Psychology, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Sherry Shu-Jung
authors.initials: SS
authors.lastname: Hu
authors.affiliation: School of Optometry, Indiana University, Bloomington, Indiana, United States.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Bonanno
authors.affiliation: The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences Indiana University, Bloomington, Indiana, United States.
authors.forename: Heather
authors.initials: H
authors.lastname: Bradshaw
authors.affiliation: The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences Indiana University, Bloomington, Indiana, United States.
authors.forename: Ken
authors.initials: K
authors.lastname: Mackie
authors.affiliation: Frank H. Netter MD School of Medicine, Quinnipiac University, North Haven, Connecticut, United States.
authors.forename: Douglas
authors.initials: D
authors.lastname: McHugh
authors.affiliation: The Gill Center for Biomolecular Science and the Department of Psychological and Brain Sciences Indiana University, Bloomington, Indiana, United States.
authors.forename: Alex
authors.initials: A
authors.lastname: Straiker
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D048588:Benzoxazines / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002186:Cannabinoids / Q000378:metabolism / Q000494:pharmacology*; D002417:Cattle; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D002633:Chemotaxis / Q000187:drug effects / Q000502:physiology*; D004847:Epithelial Cells / Q000187:drug effects / Q000502:physiology*; D019573:Epithelium, Corneal / Q000166:cytology* / Q000187:drug effects; D009025:Morpholines / Q000494:pharmacology; D009281:Naphthalenes / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis; D043884:Receptor, Cannabinoid, CB1 / Q000037:antagonists & inhibitors / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology; D014945:Wound Healing
chemical_list: D048588:Benzoxazines; D002121:Calcium Channel Blockers; D002186:Cannabinoids; D009025:Morpholines; D009281:Naphthalenes; D012333:RNA, Messenger; D043884:Receptor, Cannabinoid, CB1; C070417:(3R)-((2,3-dihydro-5-methyl-3-((4-morpholinyl)methyl)pyrrolo-(1,2,3-de)-1,4-benzoxazin-6-yl)(1-naphthalenyl))methanone