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Norrin Signaling in the Retina: Regulation of the Blood-Retina Barrier

视网膜中的诺里蛋白信号传导：血视网膜屏障的调节

基本信息

批准号：
10020983
负责人：
Harald Junge
金额：
$ 45.14万
依托单位：
UNIVERSITY OF MINNESOTA
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-04-01 至 2024-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10020983
关键词：
Address Age related macular degeneration Aging Agonist Attenuated Basic Science Biological Assay Biological Models Biology Blood Vessels Blood-Retinal Barrier Cells Chronic Classical Complement Pathway Complement Complement Activation Data Defect Diabetic Retinopathy Disease Disease model Drug Delivery Systems Edema Electroretinography Endothelial Cells Engineering Extravasation Familial exudative vitreoretinopathy Fluorescein Angiography Functional disorder Genetic Goals Health Histopathology Hypoxia Immunoglobulin G Immunoglobulins Impairment In Vitro Ionizing radiation Knowledge Maintenance Mediating Metabolic stress Modality Modeling Mus Pathologic Pathology Pathway interactions Perfusion Pericytes Phenotype Proteins Regulation Retina Retinal Diseases Retinoblastoma Retinopathy of Prematurity Role Signal Pathway Signal Transduction Stains Stress TP53 gene Testing Therapeutic Therapeutic Intervention Time Uveitis Vascular Endothelial Growth Factors Vascular Permeabilities angiogenesis antiangiogenesis therapy antibody engineering base beta catenin chemotherapy complement pathway field study genetic approach human disease in vivo inhibiting antibody inhibitor/antagonist insight mouse genetics mouse model neovascularization novel sensor side effect transcriptome sequencing

项目摘要

Our overall objective is to understand the role of norrin/frizzled4 signaling as regulator of the blood-retina barrier (BRB) in human disease, using mice as model system. Impairment of the BRB causes edema and is associated with diabetic retinopathy, age-related macular degeneration, retinopathy of prematurity, familial exudative vitreoretinopathy (FEVR), and uveitis. BRB induction and maintenance are controlled by the critical b-catenin-dependent (canonical) norrin/frizzled4 signaling pathway. Disrupted norrin/frizzled4 signaling causes FEVR. How the impairment of norrin/frizzled4 signaling causes pathological changes, how the pathway is regulated under stress, and if activation of norrin/frizzled4 signaling is a valid therapeutic approach to restore BRB dysfunction, are all not understood. These knowledge gaps need to be addressed to exploit the enormous basic research progress on norrin/frizzled4 signaling for therapeutic intervention. Aim1: We showed that endothelial cell-specific inactivation of norrin signaling in developed mice provides a new model to study pathological consequences of BRB breakdown. The new model does not display compound pathologies observed in existing models of BRB disruption characterized by pericyte defects, perfusion defects, and hypoxia, allowing us to study pathological consequences of BRB defects per se. Endothelial cell-specific disruption of norrin/frizzled4 signaling in developed mice causes immunoglobulin extravasation, complement activation, cystoid edema, and reduced b-wave in electroretinography (ERG). We will use mouse genetics to test the role of the classical complement pathway in mediating long-term pathological consequences of BRB breakdown in an otherwise intact vasculature. Fluorescein angiography and ERG will be performed at multiple time points, and histopathology at the 1-year end-point. Successful completion of this aim will determine roles of the classical complement pathway in retinal disease beyond the known roles in age-related macular degeneration. Aim2: Preliminary data show that increased levels of a stress sensor protein in endothelial cells strongly inhibit canonical signaling and negatively regulate BRB function. We will use conditional mouse genetics to activate the stress sensor in endothelial cells, determine BRB function, and test for genetic interactions with increased or reduced levels of b-catenin signaling. Cell-based assays will be performed to determine the mechanistic basis of this powerful regulation. Successful completion of this aim will provide novel insights into the regulation of the BRB under stress. These mechanisms may be exploited for modulating the BRB, e.g., in the context of restoring the barrier in disease, or for drug delivery. Aim3: Current efforts to target norrin/frizzled4 signaling for therapeutic intervention have focused on anti-angiogenesis approaches in proliferative retinopathies. We will determine if the activation of b-catenin in endothelial cells restores BRB function in a transient hypoxia disease model. Successful completion of this aim is expected to provide a model to test agonists of the pathway for their ability to restore a dysfunctional BRB (aim3).

我们的总体目标是了解norrin/ zzzzled4信号在血液视网膜中的调节作用