title: Anandamide rescues retinal barrier properties in Müller glia through nitric oxide regulation.
abstract: The blood retinal barrier (BRB) can mitigate deleterious immune response. Dysfunction at the BRB can affect disease progression. Under inflammatory conditions Müller glia produce increased pro-inflammatory factors, like nitric oxide (NO). In this study we describe molecular events at the Müller glia during inflammation which could affect inner BRB properties. Griess assay and 4,5-diaminofluorescein diacetate (DAF-2DA) time-lapse fluorescence were used to measure NO production. Western blot was used to analyze the expression of inducible nitric oxide synthase (iNOS) and mitogen-activated protein kinases (MAPK) components. Lucifer Yellow was used to measure permeability. Griess assay and DAF-2DA time-lapse fluorescence images revealed that lipopolysaccharide (LPS) induced inflammation and increased NO production. In parallel, changes were observed in tight junction proteins, zona occludens 1 (ZO-1), connexin 43 (Cx43), and permeability. This was mediated through activation of iNOS and mitogen-activated protein kinase phosphatase-1 (MKP-1), implicated in immune response. Endocannabinoids can exert a protective and anti-inflammatory effect. Exogenous arachidonoyl ethanolamide (AEA) inhibited NO generation and also abolished LPS-induced increase in permeability. Our work suggests that subtle changes in Müller glia function, which act as part of the BRB, could contribute to retinal health. AEA which can reduce inflammatory cytotoxicity has potential as treatment in several ocular manifestations where the integrity of the BRB is crucial.
authors.affiliation: L&T Department of Ocular Pathology, Vision Research Foundation, Sankara Nethralaya, 41 College Road, Chennai 600006, India; CeNTAB, School of Chemical and Biotechnology, SASTRA University, Tanjore, India.
authors.forename: G
authors.initials: G
authors.lastname: Krishnan
authors.affiliation: L&T Department of Ocular Pathology, Vision Research Foundation, Sankara Nethralaya, 41 College Road, Chennai 600006, India. Electronic address: chatterjee.nivedita@gmail.com.
authors.forename: N
authors.initials: N
authors.lastname: Chatterjee
mesh_terms: D000818:Animals; D001095:Arachidonic Acids / Q000494:pharmacology*; D001813:Blood-Retinal Barrier / Q000187:drug effects* / Q000276:immunology; D002417:Cattle; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D063388:Endocannabinoids / Q000494:pharmacology*; D008070:Lipopolysaccharides; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology; D016328:NF-kappa B / Q000378:metabolism; D009457:Neuroglia / Q000187:drug effects* / Q000276:immunology; D018696:Neuroprotective Agents / Q000494:pharmacology*; D009569:Nitric Oxide / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D053284:Polyunsaturated Alkamides / Q000494:pharmacology*; D012160:Retina / Q000187:drug effects / Q000276:immunology
chemical_list: D001095:Arachidonic Acids; D063388:Endocannabinoids; D008070:Lipopolysaccharides; D016328:NF-kappa B; D018696:Neuroprotective Agents; D053284:Polyunsaturated Alkamides; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II; C078814:anandamide
keywords: AEA; Müller glia; NO; blood retinal barrier; retina