title: Interruption of Wnt signaling in Müller cells ameliorates ischemia-induced retinal neovascularization.
abstract: Retinal Müller cells are major producers of inflammatory and angiogenic cytokines which contribute to diabetic retinopathy (DR). Over-activation of the Wnt/β-catenin pathway has been shown to play an important pathogenic role in DR. However, the roles of Müller cell-derived Wnt/β-catenin signaling in retinal neovascularization (NV) and DR remain undefined. In the present study, mice with conditional β-catenin knockout (KO) in Müller cells were generated and subjected to oxygen-induced retinopathy (OIR) and streptozotocin (STZ)-induced diabetes. Wnt signaling was evaluated by measuring levels of β-catenin and expression of its target genes using immunoblotting. Retinal vascular permeability was measured using Evans blue as a tracer. Retinal NV was visualized by angiography and quantified by counting pre-retinal nuclei. Retinal pericyte loss was evaluated using retinal trypsin digestion. Electroretinography was performed to examine visual function. No abnormalities were detected in the β-catenin KO mice under normal conditions. In OIR, retinal levels of β-catenin and VEGF were significantly lower in the β-catenin KO mice than in littermate controls. The KO mice also had decreased retinal NV and vascular leakage in the OIR model. In the STZ-induced diabetic model, disruption of β-catenin in Müller cells attenuated over-expression of inflammatory cytokines and ameliorated pericyte dropout in the retina. These findings suggest that Wnt signaling activation in Müller cells contributes to retinal NV, vascular leakage and inflammation and represents a potential therapeutic target for DR.
authors.affiliation: Department of Physiology, Harold Hamm Diabetes Center, the University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America.
authors.forename: Kelu Kevin
authors.initials: KK
authors.lastname: Zhou
authors.affiliation: Department of Physiology, Harold Hamm Diabetes Center, the University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America.
authors.forename: Siribhinya
authors.initials: S
authors.lastname: Benyajati
authors.affiliation: Department of Medicine Endocrinology, Harold Hamm Diabetes Center, the University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America.
authors.forename: Yun
authors.initials: Y
authors.lastname: Le
authors.affiliation: Department of Physiology, Harold Hamm Diabetes Center, the University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America.
authors.forename: Rui
authors.initials: R
authors.lastname: Cheng
authors.affiliation: Department of Ophthalmology and Visual Sciences, the University of Texas Medical Branch, Galveston, Texas, United States of America.
authors.forename: Wenbo
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Department of Physiology, Harold Hamm Diabetes Center, the University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America.
authors.forename: Jian-xing
authors.initials: JX
authors.lastname: Ma
mesh_terms: D000818:Animals; D003930:Diabetic Retinopathy / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D063928:Ependymoglial Cells / Q000378:metabolism*; D015870:Gene Expression; D007511:Ischemia / Q000473:pathology*; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D009389:Neovascularization, Pathologic / Q000378:metabolism*; D020286:Pericytes / Q000378:metabolism / Q000473:pathology; D010641:Phenotype; D012160:Retina / Q000378:metabolism* / Q000473:pathology*; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism; D060449:Wnt Signaling Pathway; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism
chemical_list: D042461:Vascular Endothelial Growth Factor A; D051176:beta Catenin