Abstract
Both insulin and IGF-1 have been implicated in control of retinal endothelial cell growth, neovascularization, and diabetic retinopathy. To precisely define the role of insulin and IGF-1 signaling in endothelium in these processes, we have used the oxygen-induced retinopathy model to study mice with a vascular endothelial cell-specific knockout of the insulin receptor (VENIRKO) or IGF-1 receptor (VENIFARKO). Following relative hypoxia, VENIRKO mice show a 57% decrease in retinal neovascularization as compared with controls. This is associated with a blunted rise in VEGF, eNOS, and endothelin-1. By contrast, VENIFARKO mice show only a 34% reduction in neovascularization and a very modest reduction in mediator generation. These data indicate that both insulin and IGF-1 signaling in endothelium play a role in retinal neovascularization through the expression of vascular mediators, with the effect of insulin being most important in this process.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Animals
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Diabetic Retinopathy / etiology
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Diabetic Retinopathy / pathology
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Diabetic Retinopathy / physiopathology
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Diabetic Retinopathy / prevention & control*
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Disease Models, Animal
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Endothelial Growth Factors / physiology
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Endothelin-1 / physiology
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Endothelium, Vascular / pathology
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Endothelium, Vascular / physiopathology
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Humans
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Hypoxia / pathology
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Hypoxia / physiopathology
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Insulin / physiology
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Intercellular Signaling Peptides and Proteins / physiology
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Lymphokines / physiology
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Mice
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Mice, Inbred C57BL
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Mice, Inbred DBA
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Mice, Knockout
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Neovascularization, Pathologic*
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Nitric Oxide Synthase / physiology
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Nitric Oxide Synthase Type II
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Nitric Oxide Synthase Type III
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Receptor, IGF Type 1 / deficiency*
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Receptor, IGF Type 1 / genetics
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Receptor, IGF Type 1 / physiology
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Receptor, Insulin / deficiency*
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Receptor, Insulin / genetics
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Receptor, Insulin / physiology
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Retinal Vessels / pathology*
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Signal Transduction
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Vascular Endothelial Growth Factor A
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Vascular Endothelial Growth Factors
Substances
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Endothelial Growth Factors
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Endothelin-1
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Insulin
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Intercellular Signaling Peptides and Proteins
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Lymphokines
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Vascular Endothelial Growth Factor A
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Vascular Endothelial Growth Factors
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NOS3 protein, human
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Nitric Oxide Synthase
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Nitric Oxide Synthase Type II
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Nitric Oxide Synthase Type III
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Nos3 protein, mouse
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Receptor, IGF Type 1
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Receptor, Insulin