Lacritin Regulated Ocular Surface Homeostasis

泪泌素调节眼表稳态

基本信息

批准号：
9060945
负责人：
Gordon William Laurie
金额：
$ 45.81万
依托单位：
UNIVERSITY OF VIRGINIA
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：
2014-05-01 至 2018-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9060945
关键词：
Adrenergic Agents Adrenergic Receptor Amino Acids Autoimmune Process Autophagocytosis Binding Biological Assay Boxing California Cations Cell Culture Techniques Cell surface Cells Cellular Stress Cornea Coupling Dose Electrophysiology (science)Enzymes Epithelial Cells Eye Eye diseases FOXO3A gene Goals Health Heparan Sulfate Proteoglycan Homeostasis Hour Human Inflammation Inflammatory Lacrimal gland structure Longevity Mediator of activation protein Metabolic Metabolism Mitochondria Molecular Molecular Chaperones Monitor Mus Oryctolagus cuniculus Oxidative Phosphorylation Pennsylvania Peptide Hydrolases Philadelphia Play Quality Control Rattus Reporting Ribosomes Role San Francisco Sensory Signal Pathway Stress Testing Therapeutic Time Tissues Transglutaminases Translations Universities Up-Regulation Validation Virginia Work afferent nerve aqueous corneal epithelium crosslink cytokine density eye dryness mouse model mutant neurophysiology ocular surface receptor relating to nervous system response syndecan synthetic peptide

项目摘要

DESCRIPTION (provided by applicant): 'Lacritin' is an ocular specific prosecretory and prosurvival factor in human tears. Selective lacritin deficiency has been reported in human dry eye tears. Here we test the hypothesis that lacritin is a key regulator of corneal sensory nerve activity for basal tearing, and of ocular surface metabolism for survival against stress. Important implications of this hypothesis are that deficiency of active lacritin may initiate dry eye disease and that topical lacritin may be therapeutic. We recently reported on treating mice suffering from aqueous deficient dry eye disease. Autoimmune regulator (Aire)-deficient [Aire-/-] mice dosed with lacritin displayed enhanced tear flow and ocular surface health. Lacritin also reduced lacrimal gland inflammation. On normal rabbit eyes, we found that a single lacritin dose was effective for hours. Our new electrophysiological studies in rats reveal that topical lacritin enhances the basal tear stimulatory 'dry response' of corneal sensory nerves. The dry response is regulated by TRPM8 cation channels that exquisitely sense slight corneal cooling as a consequence of the natural tendency of the eye to dessicate. Truncating 25 amino acids from lacritin's C- terminus ('C-25') abrogated dry response stimulation and tearing, implying that the capacity for cell targeting resides within this domain. We recently found that the domain generated synthetically as KQFIENGSEFAQKLLKKFS ('N-94/C-6') is as potent as lacritin, and interacts specifically with the cell surface heparan sulfate proteoglycan 'syndecan-1', and with the adrenergic ¿2C receptor. This discovery suggests a neural regulatory mechanism since adrenergic ¿2C and/or ¿2A receptors modulate TRPM8 activity. We just reported how lacritin restores ocular surface function in corneal epithelial cells stressed with inflammatory cytokines. Through a signaling pathway dependent of the longevity factor 'Forkhead Box 03' (FOXO3) and on the little known 'ATG101', lacritin stimulates mitochondrial oxidative phosphorylation and autophagy. Autophagy is a common quality control mechanism in cells. Binding partners of ATG101 suggest mechanisms by which lacritin accelerates autophagy and restores mitochondrial function (respectively through autophagy mediator ATG13, and mitochondrial ETFA). Our working hypothesis is that lacritin is essential for normal tearing, and ocular surface and glandular health. Our immediate goal is to elucidate unifying mechanisms of lacritin stimulated tearing and ocular surface health. Our specific aims are to (1) stabilize N-94/C-6 or smaller synthetic form of lacritin, (2) characterize how topical lacritin promotes basal tearing, and (3) resolve how lacritin restores ocular surface health. University of Virginia Charlottesville Virginia James Madison University Harrisonburg Virginia University of California, San Francisco San Francisco California Thomas Jefferson University Philadelphia Pennsylvania

描述（由适用提供）：“流质蛋白”是人眼泪中的眼部特定起诉和生存因素。已经报道了人眼泪中有选择性的长蛋白缺乏症。在这里，我们检验了一个假设，即乳葡萄蛋白是角膜感觉神经活性的关键调节剂，用于基本撕裂和眼表面代谢，以抗压力。重要的该假设的意义是活性卓蛋白的缺乏可能启动干眼病，而局部曲息蛋白可能具有治疗性。我们最近报道了治疗患有缺乏干眼病的小鼠。自身免疫调节剂（AIRE） - 缺陷型[AIRE - / - ]用圆锥蛋白的小鼠表现出增强的茶水和眼表面健康。流质蛋白还减少了泪腺注射。在正常的兔子眼中，我们发现单一的酸性剂量有效了几个小时。我们在大鼠中的新电生理研究表明，局部曲息蛋白增强了角膜感觉神经的基本撕裂刺激剂的“干燥反应”。干燥的反应受TRPM8阳离子通道调节，由于眼睛自然倾向于镶嵌，因此完全感觉到角膜冷却。截断了来自乳蛋白素C末端（“ C-25”）的25种氨基酸促进了干燥反应刺激和撕裂，这意味着该结构域内细胞靶向住宅的能力。我们最近发现，域在合成中生成的结构域作为KQfiengsefaqkllkkfs（'n-94/c-6'）与曲息蛋白一样潜在，并且与细胞表面硫酸乙酰肝素蛋白聚糖蛋白聚糖'syndecan-1'和肾上腺素疫苗受体特别相互作用。该发现提出了一种神经调节机制，因为肾上腺素2C和/或2a接收器调节TRPM8活性。我们刚刚报道了流质素如何恢复与炎性细胞因子胁迫的角膜上皮细胞中的眼表功能。通过寿命因子“ Forkhead Box 03”（FOXO3）和鲜为人知的“ ATG101”的信号传导途径，透明蛋白刺激线粒体氧化磷酸化和自噬。自噬是细胞中常见的质量控制机制。 ATG101的结合伴侣提出了基准素加速自噬并恢复线粒体功能的机制（分别通过自噬介质ATG13和线粒体ETFA）。我们的工作假设是，透质蛋白对于正常的撕裂，眼表面和腺体健康至关重要。我们的近期目标是阐明刺激泪液和眼表面健康的统一机制。我们的具体目的是（1）稳定N-94/C-6或较小的曲息蛋白合成形式，（2）表征局部曲息蛋白如何促进碱性撕裂，以及（3）解决曲盘素如何恢复眼部表面健康。弗吉尼亚大学夏洛茨维尔大学弗吉尼亚州詹姆斯·麦迪逊大学哈里森堡加利福尼亚大学，旧金山旧金山加利福尼亚州托马斯·杰斐逊大学费城宾夕法尼亚州