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Principal Investigator: Jian-Xing Jay Ma
Organization: UNIVERSITY OF OKLAHOMA HLTH SCIENCES CTR
Fiscal Year: 2019
Award: $333,000
Funding agency: National Eye Institute
DESCRIPTION (provided by applicant): Choroidal neovascularization (CNV) in AMD is a leading cause of vision loss. Oxidative stress and inflammation in the retina and RPE are believed to play important pathogenic roles in CNV. The canonical Wnt pathway is known to mediate inflammation, angiogenesis and fibrosis. Our previous studies have shown that very low-density lipoprotein receptor (VLDLR) knockout (KO) results in Wnt pathway over-activation, retinal inflammation and sub-retinal neovascularization (NV). Our recent study demonstrated that the Wnt pathway is also over-activated in the laser-induced CNV model, and blockade of Wnt signaling attenuated NV in Vldlr-/- mice and the laser-induced CNV. This project will extend our ongoing studies and use Wnt signaling reporter mice to further verify the activation of Wnt signaling in the retina and RPE of Vldlr-/- mice and laser-induced CNV model. We will also knockout ß-catenin, an essential effector of Wnt signaling, in the RPE to determine if interruption of Wnt signaling attenuates NV in these models. These studies will establish the pathogenic role of aberrant regulation of Wnt signaling in CNV and reveal a novel therapeutic target. There are two major alternative splicing variants of VLDLR, VLDLR1 and VLDLR2. Our preliminary data showed that the retina expresses exclusively VLDLR2 which has higher ectodomain shedding into the extracellular space than VLDLR1. VLDLR2 is known to have lower affinity to VLDL, and its function in the retina is unclear. We will test the hypothesis that
soluble VLDLR ectodomain (sVLDLRN) shed into the extracellular space and circulation may function as a soluble inhibitor of Wnt signaling and modulates Wnt signaling through dimerization with LRP6, an essential co-receptor in the Wnt pathway. The inhibitory effects of sVLDLRN and its deletion peptide fragments on Wnt signaling and on CNV will be evaluated in vitro and in vivo. This project will investigate if VLDLR2 has more potent inhibition of Wnt signaling, compared to VLDLR1, due to its higher ectodomain shedding. These studies will reveal a new function of VLDLR2 in the retina. This project will establish the receptor ectodomain shedding and receptor:receptor dimerization as a new mechanism for modulation of the Wnt pathway. The proposed studies will also explore a novel pathogenic mechanism for CNV in AMD models and reveal a new therapeutic target. Identification of the peptide fragment of VLDLR with anti-angiogenic activity in this project has potential to develop a therapeutic drug for CNV.
Terms: <Affinity><Age related macular degeneration><Age-Related Maculopathy><Alternate Splicing><Alternative RNA Splicing><Alternative Splicing><Angiogenesis Antagonists><Angiogenesis Blockers><Angiogenesis Inhibitors><Angiogenetic Antagonists><Angiogenetic Inhibitors><Angiogenic Antagonists><Angiogenic Inhibitors><Angiostatic Agents><Anti-Angiogenetic Agents><Anti-Angiogenic Agents><Anti-Angiogenic Drugs><Antiangiogenesis Agents><Antiangiogenic Agents><Antiangiogenic Drugs><Assay><Attenuated><Beta Cadherin-Associated Protein><Beta-1 Catenin><Bioassay><Biologic Assays><Biological Assay><Blindness><Blood Circulation><Bloodstream><Brain><Brain Nervous System><CUL-2><Cell Body><Cell Growth in Number><Cell Locomotion><Cell Migration><Cell Migration Assay><Cell Movement><Cell Multiplication><Cell Proliferation><Cells><Cellular Migration><Cellular Motility><Cellular Proliferation><Choroid Neovascularization><Choroidal Neovascularization><Circulation><Data><Differential Display><Dimerization><Disease><Disorder><Drug or chemical Tissue Distribution><Drugs><Encephalon><Endothelial Cells><Extracellular Space><Fibrosis><Gene Transcription><Genetic Transcription><Goals><In Vitro><Inflammation><Intercellular Space><Interruption><KO mice><Knock-out><Knock-out Mice><Knockout><Knockout Mice><Laser Electromagnetic><Laser Radiation><Lasers><Length><Mediating><Medication><Mice><Mice Mammals><Migration Assay><Modeling><Motility><Murine><Mus><Myocardium><Neovascularization Inhibitors><Nuclear Translocation><Null Mouse><Oxidative Stress><PRO2286><Pathogenicity><Pathway interactions><Patients><Peptide Fragments><Peptides><Pharmaceutic Preparations><Pharmaceutical Preparations><Phosphorylation><Play><Prebeta-Lipoproteins><Protein Dimerization><Protein Phosphorylation><RNA Expression><Receptor Protein><Regulation><Reporter><Retina><Retinal><Role><Skeletal Muscle><Staining method><Stains><Testing><Therapeutic><Tissue Distribution><Transcription><VLDL><VLDL Lipoproteins><VLDL receptor><Variant><Variation><Very low density lipoprotein><Voluntary Muscle><WNT Signaling Pathway><WNT signaling><age related macular dystrophy><aged population><aging population><angiogenesis><antiangiogenic><base><beta catenin><beta-D-Galactosidase><beta-D-Galactoside galactohydrolase><beta-Galactosidase><cardiac muscle><cell motility><cell type><differential display technique><dimer><drug/agent><fat metabolism><heart muscle><in vivo><inhibitor><inhibitor/antagonist><knockout gene><lac Z Protein><lipid metabolism><mRNA Differential Displays><nano particle><nano-sized particle><nanoparticle><nanosized particle><neovascularization><neutralizing antibody><new drug target><new druggable target><new pharmacotherapy target><new therapeutic target><new therapy target><novel><novel drug target><novel druggable target><novel pharmacotherapy target><novel therapeutic target><novel therapy target><pathway><population aging><prevent><preventing><promoter><promotor><public health relevance><receptor><senile macular disease><social role><targeted drug therapy><targeted drug treatments><targeted therapeutic><targeted therapeutic agents><targeted therapy><targeted treatment><very low density lipoprotein receptors><vision loss><visual loss><β-D-Galactosidase><β-D-Galactoside galactohydrolase><β-Galactosidase><β-catenin>