Structure and Function of Ocular Lacritin

眼泪素的结构和功能

• 批准号: 7879266
• 负责人: Gordon William Laurie
• 金额: $ 36.53万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-01 至 2012-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7879266
• 关键词: AQP1 gene; Acinar Cell; Address; Adverse effects; Agonist; Anti-Inflammatory Agents; Binding; Biological Assay; Blepharitis; Calcineurin; Calcineurin inhibitor; Calcium; Calcium Signaling; Carbachol; Cell Culture Techniques; Cell Proliferation; Cell physiology; Cell surface; Complex; Contact Lenses; Cornea; Crystallins; Cyclosporine; Cyclosporins; Distal; Dose; Down-Regulation; Drug Design; Drug Prescriptions; Dry Eye Syndromes; Elements; Epithelial; Epithelial Cells; Epithelium; Event; Eye; Eye diseases; Female; G Protein-Coupled Receptor Genes; G Protein-Coupled Receptor Signaling; G-Protein-Coupled Receptors; Goals; Golgi Apparatus; Heart; Human; INS 365; Insulin; Ligation; Lung; Membrane; Molecular; Monkeys; Muramidase; Mutation; Oryctolagus cuniculus; Pancreas; Pathway interactions; Patients; Peroxidases; Pharmaceutical Preparations; Phosphotransferases; Production; Proliferating; Protein Phosphatase G; Proteins; Proteoglycan; RNA Splicing; Rattus; Receptor Signaling; Research; Role; Secretory Vesicles; Serum; Signal Transduction; Small Interfering RNA; Structure; T-Lymphocyte; Therapeutic; Treatment Protocols; Up-Regulation; Variant; Work; analog; base; cell type; corneal epithelium; eye dryness; feeding; heparanase; human FRAP1 protein; lacrimal; meibomian gland; novel; ocular surface; protein protein interaction; public health relevance; receptor; small molecule; syndecan; tear proteins; AQP1 gene; Acinar Cell; Address; Adverse effects; Agonist; Anti-Inflammatory Agents; Binding; Biological Assay; Blepharitis; Calcineurin; Calcineurin inhibitor; Calcium; Calcium Signaling; Carbachol; Cell Culture Techniques; Cell Proliferation; Cell physiology; Cell surface; Complex; Contact Lenses; Cornea; Crystallins; Cyclosporine; Cyclosporins; Distal; Dose; Down-Regulation; Drug Design; Drug Prescriptions; Dry Eye Syndromes; Elements; Epithelial; Epithelial Cells; Epithelium; Event; Eye; Eye diseases; Female; G Protein-Coupled Receptor Genes; G Protein-Coupled Receptor Signaling; G-Protein-Coupled Receptors; Goals; Golgi Apparatus; Heart; Human; INS 365; Insulin; Ligation; Lung; Membrane; Molecular; Monkeys; Muramidase; Mutation; Oryctolagus cuniculus; Pancreas; Pathway interactions; Patients; Peroxidases; Pharmaceutical Preparations; Phosphotransferases; Production; Proliferating; Protein Phosphatase G; Proteins; Proteoglycan; RNA Splicing; Rattus; Receptor Signaling; Research; Role; Secretory Vesicles; Serum; Signal Transduction; Small Interfering RNA; Structure; T-Lymphocyte; Therapeutic; Treatment Protocols; Up-Regulation; Variant; Work; analog; base; cell type; corneal epithelium; eye dryness; feeding; heparanase; human FRAP1 protein; lacrimal; meibomian gland; novel; ocular surface; protein protein interaction; public health relevance; receptor; small molecule; syndecan; tear proteins

DESCRIPTION (provided by applicant): Our competitive renewal application addresses dry eye from the perspective of the new ocular-specific tear factor 'lacritin' discovered by us. Lacritin flows onto the ocular surface from lacrimal and meibomian glands to help promote ocular surface wetting. It is also a presumed contributor to corneal renewal via its basal corneal epithelial expression. Selective downregulation of lacritin in tears is associated with blepharitis and contact lens-related dry eye, the only two dry eye syndromes proteomically examined to date. Adding lacritin to eyes of normal rabbits or dry eye female monkeys ovariectomized one to two years earlier triggers elevated and sustained tear flow. These observations are reinforced by human corneal epithelial cell culture in which lacritin stimulates MUC16 protein production more efficiently than serum and by our original observation that lacritin augments tear peroxidase release from cultured rat lacrimal acinar cells independent of the parasympathetic- (carbachol-) stimulation pathway. Also subconfluent cultures of human corneal epithelial cells proliferate in a lacritin domain- and dose-specific manner. How lacritin promotes tearing and renewal is not understood. Our lacritin structure/function and lacritin signaling studies have sketched out a heparanase-dependent mechanism for targeting cell surface proteoglycan syndecan-1. This leads to putative ligation of a G-protein coupled receptor for signaling through G1i or G1o to PLC-PKC1/PLD/mTOR and PLC- PKC1/STIM1/calcineurin/Ca2+/ NFATC1. Differential upregulation of newly identified splice variants lacritin-b or -c (suspected to be incapable of respectively binding the GPCR or syndecan-1) coincident with downregulation of native lacritin, or loss of heparanase (observed preliminarily in dry eye tears) are two potential dry eye-provoking scenarios. Our working hypothesis is that lacritin is a regulator of ocular surface wetting and renewal. Our immediate goal is to characterize the signaling receptor and understand its mechanism of action. Our first aim is to understand specific protein-protein interactions constituting the lacritin/syndecan-1/G-protein coupled receptor heterocomplex. Our second aim is to characterize how upstream lacritin signaling is generated. Our third aim asks how downstream lacritin signaling can promote wetting and renewal towards a global appreciation for lacritin's role on the ocular surface. PUBLIC HEALTH RELEVANCE. Dry eye is very common. This project will work out how a new potential therapeutic for dry eye promotes ocular surface wetting. The therapeutic is based on a natural human tear protein.

描述（由申请人提供）： 我们竞争性更新应用程序从我们发现的新的眼撕裂因子“曲息蛋白”的角度解决了干眼。流质蛋白从泪腺和巨腺腺流向眼表面，以帮助促进眼表面润湿。它也是通过其基底角膜上皮表达来造成角膜更新的推测贡献者。泪液中透眼素的选择性下调与抛脑炎和与隐形眼镜相关的干眼眼有关，迄今为止，蛋白质组织唯一检查了两种干眼综合症。在正常的兔子或干眼症的雌性猴子卵巢上添加曲息蛋白，使一到两年前的一到两年触发了升高和持续的泪水流动。这些观察结果是由人角膜上皮细胞培养增强的，在该细胞培养物中比血清更有效地刺激了MUC16蛋白的产生，并且我们最初的观察结果是，基准素增强了从培养的大鼠泪液腺泡细胞中释放出过氧化物酶，独立于副交感神经（Carbachol-）刺激途径。人角膜上皮细胞的亚共聚培养物以卓蛋白结构域和剂量特异性方式增殖。尚不理解流质蛋白如何促进撕裂和更新。我们的卓蛋白结构/功能和透眼信号研究已经勾勒出一种靶向细胞表面蛋白聚糖syndecan-1的肝素酶依赖性机制。这导致了通过G1I或G1O信号传导的G蛋白偶联受体的假定连接，直达PLC-PKC1/PLD/MTOR和PLC-PKC1/Stim1/Clincinerin/CACINERIN/CA2+/NFATC1。新鉴定的剪接变体的差异上调lacritin-b或-c（涉嫌分别无法分别结合GPCR或syndecan-1）与天然曲盘蛋白下调或乙酰肝素酶的下调相吻合，或者乙酰肝素酶的丧失（在干眼撕裂中均可观察到）是两个潜在的干眼症的情况。我们的工作假设是，酸素是眼表润湿和更新的调节剂。我们的直接目标是表征信号受体并了解其作用机理。我们的第一个目的是了解构成核蛋白/syndecan-1/g蛋白偶联受体杂音蛋白的特定蛋白质蛋白质相互作用。我们的第二个目的是表征如何生成上游透眼信号传导。我们的第三个目标询问下游透眼信号传导如何促进润湿和更新，以全球欣赏曲息蛋白在眼部表面的作用。 公共卫生相关性。干眼很常见。该项目将弄清干眼的新潜在治疗方法如何促进眼表面润湿。治疗性基于天然人泪蛋白。