title: Pigment epithelium-derived factor inhibits retinal microvascular dysfunction induced by 12/15-lipoxygenase-derived eicosanoids.
abstract: We recently demonstrated that 12/15-lipoxygenase (LOX) derived metabolites, hydroxyeicosatetraenoic acids (HETEs), contribute to diabetic retinopathy (DR) via NADPH oxidase (NOX) and disruption of the balance in retinal levels of the vascular endothelial growth factor (VEGF) and pigment epithelium-derived factor (PEDF). Here, we test whether PEDF ameliorates retinal vascular injury induced by HETEs and the underlying mechanisms. Furthermore, we pursue the causal relationship between LOX-NOX system and regulation of PEDF expression during DR. For these purposes, we used an experimental eye model in which normal mice were injected intravitreally with 12-HETE with/without PEDF. Thereafter, fluorescein angiography (FA) was used to evaluate the vascular leakage, followed by optical coherence tomography (OCT) to assess the presence of angiogenesis. FA and OCT reported an increased vascular leakage and pre-retinal neovascularization, respectively, in response to 12-HETE that were not observed in the PEDF-treated group. Moreover, PEDF significantly attenuated the increased levels of vascular cell and intercellular adhesion molecules, VCAM-1 and ICAM-1, elicited by 12-HETE injection. Accordingly, the direct relationship between HETEs and PEDF has been explored through in-vitro studies using Müller cells (rMCs) and human retinal endothelial cells (HRECs). The results showed that 12- and 15-HETEs triggered the secretion of TNF-α and IL-6, as well as activation of NFκB in rMCs and significantly increased permeability and reduced zonula occludens protein-1 (ZO-1) immunoreactivity in HRECs. All these effects were prevented in PEDF-treated cells. Furthermore, interest in PEDF regulation during DR has been expanded to include NOX system. Retinal PEDF was significantly restored in diabetic mice treated with NOX inhibitor, apocynin, or lacking NOX2 up to 80% of the control level. Collectively, our findings suggest that interfering with LOX-NOX signaling opens up a new direction for treating DR by restoring endogenous PEDF that carries out multilevel vascular protective functions.
authors.affiliation: Oral Biology and Anatomy, College of Dental Medicine, Georgia Regents University (GRU), Augusta, GA, USA; Culver Vision Discovery Institute, Medical College of Georgia (MCG), GRU, Augusta, GA, USA; Department of Biochemistry, Faculty of Pharmacy, Mansoura University, Egypt.
authors.forename: Ahmed S
authors.initials: AS
authors.lastname: Ibrahim
authors.affiliation: Oral Biology and Anatomy, College of Dental Medicine, Georgia Regents University (GRU), Augusta, GA, USA; Culver Vision Discovery Institute, Medical College of Georgia (MCG), GRU, Augusta, GA, USA; Cellular Biology and Anatomy, MCG, GRU, Augusta, GA, USA.
authors.forename: Amany M
authors.initials: AM
authors.lastname: Tawfik
authors.affiliation: Oral Biology and Anatomy, College of Dental Medicine, Georgia Regents University (GRU), Augusta, GA, USA; Culver Vision Discovery Institute, Medical College of Georgia (MCG), GRU, Augusta, GA, USA.
authors.forename: Khaled A
authors.initials: KA
authors.lastname: Hussein
authors.affiliation: Oral Biology and Anatomy, College of Dental Medicine, Georgia Regents University (GRU), Augusta, GA, USA.
authors.forename: Sally
authors.initials: S
authors.lastname: Elshafey
authors.affiliation: Culver Vision Discovery Institute, Medical College of Georgia (MCG), GRU, Augusta, GA, USA; Cellular Biology and Anatomy, MCG, GRU, Augusta, GA, USA.
authors.forename: Shanu
authors.initials: S
authors.lastname: Markand
authors.affiliation: Biomedical Science Program, Faculty of Science, Qatar University, Doha, Qatar.
authors.forename: Nasser
authors.initials: N
authors.lastname: Rizk
authors.affiliation: Ophthalmology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Elia J
authors.initials: EJ
authors.lastname: Duh
authors.affiliation: Culver Vision Discovery Institute, Medical College of Georgia (MCG), GRU, Augusta, GA, USA; Cellular Biology and Anatomy, MCG, GRU, Augusta, GA, USA; Ophthalmology, MCG, GRU, Augusta, GA, USA.
authors.forename: Sylvia B
authors.initials: SB
authors.lastname: Smith
authors.affiliation: Oral Biology and Anatomy, College of Dental Medicine, Georgia Regents University (GRU), Augusta, GA, USA; Culver Vision Discovery Institute, Medical College of Georgia (MCG), GRU, Augusta, GA, USA; Cellular Biology and Anatomy, MCG, GRU, Augusta, GA, USA; Ophthalmology, MCG, GRU, Augusta, GA, USA. Electronic address: malshabrawey@gru.edu.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Al-Shabrawey
mesh_terms: D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D000098:Acetophenones / Q000494:pharmacology; D000818:Animals; D001092:Arachidonate 12-Lipoxygenase / Q000235:genetics / Q000378:metabolism; D001093:Arachidonate 15-Lipoxygenase / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D003921:Diabetes Mellitus, Experimental / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D003930:Diabetic Retinopathy / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D063928:Ependymoglial Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D005136:Eye Proteins / Q000494:pharmacology*; D005786:Gene Expression Regulation; D006801:Humans; D006893:Hydroxyeicosatetraenoic Acids / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism; D058449:Intravitreal Injections; D008562:Membrane Glycoproteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism; D009414:Nerve Growth Factors / Q000494:pharmacology*; D012160:Retina / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D015861:Retinal Neovascularization / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D015843:Serpins / Q000494:pharmacology*; D015398:Signal Transduction; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism; D019010:Vascular Cell Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism; D062826:Zonula Occludens-1 Protein / Q000235:genetics / Q000378:metabolism; D000099174:Pigment Epithelium-Derived Factor
chemical_list: D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; D000098:Acetophenones; D001092:Arachidonate 12-Lipoxygenase; D001093:Arachidonate 15-Lipoxygenase; D005136:Eye Proteins; D006893:Hydroxyeicosatetraenoic Acids; D018799:Intercellular Adhesion Molecule-1; D015850:Interleukin-6; D008562:Membrane Glycoproteins; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases; D016328:NF-kappa B; D009414:Nerve Growth Factors; D015843:Serpins; D014409:Tumor Necrosis Factor-alpha; D019010:Vascular Cell Adhesion Molecule-1; D062826:Zonula Occludens-1 Protein; D000099174:Pigment Epithelium-Derived Factor; C475064:12-15-lipoxygenase; C508600:IL6 protein, human; C569042:TJP1 protein, human; C025984:15-hydroxy-5,8,11,13-eicosatetraenoic acid; C056165:acetovanillone; C488842:Cybb protein, mouse
keywords: 12/15 HETEs; 12/15-Lipoxygenase; Diabetic retinopathy; PEDF; Retinal inflammation; Retinal vascular leakage