title: Role of phospholipase A₂ (PLA₂) inhibitors in attenuating apoptosis of the corneal epithelial cells and mitigation of Acanthamoeba keratitis.
abstract: The aim of this study is to determine if the mannose-induced protein (MIP-133) from Acanthamoeba castellanii trophozoites induces apoptosis of corneal epithelial cells through a cytosolic phospholipase A2α (cPLA2α)-mediated pathway. The efficacy of cPLA2α inhibitors to provide protection against Acanthamoeba keratitis was examined in vivo. Chinese hamster corneal epithelial (HCORN) cells were incubated with or without MIP-133. MIP-133 induces significant increase in cPLA2α and macrophage inflammatory protein-2 (MIP-2/CXCL2) levels from corneal cells. Moreover, cPLA2α inhibitors, MAFP (Methyl-arachidonyl fluorophosphonate) and AACOCF3 (Arachidonyl trifluoromethyl ketone), significantly reduce cPLA2α and CXCL2 from these cells (P < 0.05). Additionally, cPLA2α inhibitors significantly inhibit MIP-133-induced apoptosis in HCORN cells (P < 0.05). Subconjunctival injection of purified MIP-133 in Chinese hamster eyes induced cytopathic effects resulting in corneal ulceration. Animals infected with A. castellanii-laden contact lenses and treated with AACOCF3 and CAY10650, showed significantly less severe keratitis as compared with control animals. Collectively, the results indicate that cPLA2α is involved in MIP-133 induced apoptosis of corneal epithelial cells, polymorphonuclear neutrophil infiltration, and production of CXCL2. Moreover, cPLA2α inhibitors can be used as a therapeutic target in Acanthamoeba keratitis.
authors.affiliation: Department of Cell Biology and Anatomy, University of North Texas Health Science Center, North Texas Eye Research Institute, 3500 Camp Bowie Blvd., Fort Worth, TX 76107, USA.
authors.forename: Trivendra
authors.initials: T
authors.lastname: Tripathi
authors.forename: Mahshid
authors.initials: M
authors.lastname: Abdi
authors.forename: Hassan
authors.initials: H
authors.lastname: Alizadeh
mesh_terms: D015823:Acanthamoeba Keratitis / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D048248:Acanthamoeba castellanii / Q000187:drug effects; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001095:Arachidonic Acids / Q000378:metabolism / Q000494:pharmacology; D015153:Blotting, Western; D002478:Cells, Cultured; D054426:Chemokine CXCL2 / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D003228:Conjunctiva / Q000187:drug effects / Q000378:metabolism; D006224:Cricetinae; D003412:Cricetulus; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D004797:Enzyme-Linked Immunosorbent Assay; D019573:Epithelium, Corneal / Q000473:pathology*; D008358:Mannose / Q000378:metabolism; D063065:Organophosphonates / Q000494:pharmacology; D054510:Phospholipases A2, Cytosolic / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D015800:Protozoan Proteins / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015854:Up-Regulation
chemical_list: D001095:Arachidonic Acids; D054426:Chemokine CXCL2; D004791:Enzyme Inhibitors; D063065:Organophosphonates; D015800:Protozoan Proteins; D012333:RNA, Messenger; C534367:mannose-induced cytopathic protein 133, Acanthamoeba; C104810:methyl arachidonylfluorophosphonate; C081565:arachidonyltrifluoromethane; D054510:Phospholipases A2, Cytosolic; D008358:Mannose
keywords: Acanthamoeba; Chinese hamster; corneal epithelial cells; cytosolic phospholipase A(2α); keratitis; macrophage inflammatory protein-2; mannose-induced protein