N-glycosylation and ocular surface homeostasis

N-糖基化和眼表稳态

基本信息

批准号：
9196100
负责人：
Pablo Argueso
金额：
$ 49.25万
依托单位：
SCHEPENS EYE RESEARCH INSTITUTE
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-08-01 至 2020-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9196100
关键词：
Address Affect Affinity Aging Anabolism Animal Model Apical Automobile Driving Binding Biological Process Cell Differentiation process Cell Proliferation Cell physiology Cell surface Cells Cellular Stress Clinical Treatment Cornea Critical Pathways Data Disease Epithelial Epithelial Cells Epithelium Extracellular Domain Eye Galectin 3 Genes Glycocalyx Health Hexosamines Homeostasis Human In Vitro Inflammation Inflammation Mediators Inflammatory Integrin alpha3beta1 Kinetics Laboratories Lectin Longevity Matrix Metalloproteinases Medial Golgi Mediating Metabolic Molecular Mucins Organism Pathologic Processes Pathway interactions Pharmacological Treatment Physiological Physiological Processes Polysaccharides Prevention Process Proteins Quality Control RNA interference screen Reaction Regulation Research Role Series Signal Transduction Structure Supplementation TNF gene Therapeutic Therapeutic Uses Translating abstracting age related base biological adaptation to stress conjunctiva corneal epithelium crosslink defined contribution endoplasmic reticulum stress eye dryness genome-wide glycosylation glycosyltransferase improved in vivo mouse model novel novel therapeutics ocular surface prevent receptor receptor binding research study response senescence

项目摘要

Project Summary/Abstract Disruption of barrier function at the ocular surface epithelia is associated with a wide range of disorders that includes dry eye—an age-related disease affecting millions of people worldwide and whose pharmacological treatment remains unresolved. Terminally differentiated stratified epithelial cells in cornea and conjunctiva maintain barrier function through a specialized protective structure composed of transmembrane mucins, a group of heavily glycosylated proteins characterized by extremely large extracellular domains. Galactosyl residues on mucin glycans are cross-linked on the apical glycocalyx by the multimeric protein galectin-3 to prevent cellular damage. Critical to preventing the decline in cellular function and homeostasis is the hexosamine pathway—a series of anabolic reactions that generate increased synthesis of N-glycan precursors. Activation of the hexosamine pathway leads to increased branching of N-glycans in the medial Golgi and the formation of cell-surface galectin-3 lattices that can modulate cell differentiation. Importantly, metabolic supplementation with hexosamine pathway metabolites is also known to enhance protein quality control mechanisms. Despite these critical roles, the relevance of N-glycosylation and the function of hesoxamine metabolites in ocular surface health and disease remains understudied. We hypothesize that N- glycans have a dynamic role in ocular surface epithelial cells, changing in response to inflammation and driving mucin barrier and stress responses. The long-term objective of this proposal is to determine the contribution of the N-glycan branching in promoting ocular surface health, and whether activation of the hexosamine pathway can be used for therapeutic gain in the eye. The following specific aims will address this objective: (1) to characterize mucin N-glycans in human corneal epithelial cells and their relationship to galectin-3 under normal and pro-inflammatory conditions, (2) to determine the regulatory role of N-glycans in promoting barrier function and reducing stress responses at the ocular surface, and (3) to evaluate whether activation of the hexosamine pathway promotes ocular surface homeostasis. This research will address the largely unstudied function of N-glycans in ocular surface barrier function and stress responses, and explore the potential of pharmacologically activating the hexosamine pathway for the treatment of ocular surface diseases.

项目摘要/摘要眼表上皮的屏障功能的破坏与多种疾病有关包括干眼症 - 一种与年龄相关的疾病，影响了全球数百万的人和药理学治疗仍未解决。角膜和结膜中的终末分化的分层上皮细胞通过由跨膜粘液组成的专门保护结构，A 一组重糖基化的蛋白质，其特征在于非常大的细胞外结构域。半乳糖基多聚体蛋白乳糖素3至防止细胞损伤。防止细胞功能和稳态下降至关重要的是己胺途径 - 一系列合成代谢反应，产生增加的N-聚糖合成前体。己糖胺途径的激活导致培养基中N-聚糖的分支增加高尔基体和可以调节细胞分化的细胞表面乳糖素-3晶格的形成。重要的是，众所周知，补充己糖胺途径代谢物可以提高蛋白质质量控制机制。尽管这些关键作用，但N-糖基化的相关性和眼科健康和疾病中的紫杉胺代谢产物仍然了解。我们假设n- 聚糖在眼部表面上皮细胞中具有动态作用，响应炎症和驱动而变化粘蛋白屏障和压力反应。该提案的长期目标是确定贡献 N-Glycan分支在促进眼表健康以及己糖胺的激活是否激活途径可用于眼睛的治疗。以下具体目标将解决此目标：（1）表征人角膜上皮细胞中的粘蛋白N-聚糖及其与Galectin-3的关系正常和促炎条件，（2）确定N-糖在促进障碍中的调节作用功能和减少眼表的应力反应，（3）评估是否激活己胺途径促进眼表稳态。这项研究将解决很大程度上未研究的 N-聚糖在眼表屏障功能和应力反应中的功能，并探索在药理学上激活六舒胺途径以治疗眼表疾病。