Functional Regulation of the Lacrimal Duct System

泪道系统的功能调节

• 批准号: 7535492
• 负责人: CHUANQING DING
• 金额: $ 40.75万
• 依托单位: UNIVERSITY OF SOUTHERN CALIFORNIA
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7535492
• 关键词: Acinar Cell; Acinus organ component; Address; American; Animal Model; Attention; Autoimmune Process; Biology; Caring; Cell Volumes; Cell physiology; Cells; Characteristics; Complex; Coupled; Data; Development; Diestrus; Dry Eye Syndromes; Duct (organ) structure; Ductal; Ductal Epithelial Cell; Electrolytes; Epithelial; Epithelial Cells; Exhibits; Eye; Female; Flow-It; Fluorescence Microscopy; Functional disorder; GTP-Binding Proteins; Goals; Human; Image; Immunohistochemistry; Impairment; In Situ Hybridization; Ions; Knowledge; Lacrimal gland structure; Lasers; Lead; Liquid substance; Lymphocyte; Mediating; Methods; Microdissection; Modeling; Monitor; Muscarinic Acetylcholine Receptor; Muscarinic Acetylcholine Receptor M3; Ophthalmology; Oryctolagus cuniculus; Patients; Phenotype; Physiological; Pilocarpine; Pregnancy; Production; Receptor Signaling; Regulation; Research; Research Personnel; Risk; Role; Scanning; Syndrome; System; Techniques; Testing; Time; Vision research; Visit; Water; absorption; effective therapy; eye dryness; innovation; insight; lacrimal; laser capture microdissection; multi-photon; ocular surface; programs; treatment strategy; water channel

DESCRIPTION (provided by applicant): Dry eye afflicts millions of Americans, and it is the leading cause of visits to eye care clinicians. Dry eye often results from insufficient tear formation from the lacrimal gland. Lacrimal fluid is initially formed in acini and then modified during passage through the duct system. However, little is known about the ducts and their function. It has been assumed that the decreased lacrimal production in dry eye is caused primarily by decreased acinar secretion. However, our preliminary data suggest that a competing hypothesis also must be considered, i.e., lacrimal hyposecretion may result from inappropriate or excessive reabsorption of fluid in the ducts. In this proposal, the investigators will use normal rabbits and two rabbit models, pregnancy and induced autoimmune dacryoadenitis [IAD], both of which exhibit decreased basal lacrimal secretion and pathological features of lacrimal insufficiency, to address three aims: #1 Determine whether the volume and composition of lacrimal fluid is modified in isolated duct segments and deduce the functional capabilities of duct epithelial cells in normal control rabbits. #2 Determine whether transepithelial ion and fluid transport functions of isolated duct segments are altered in pregnancy and IAD. #3 Identify cellular mechanisms underlying decreased lacrimal fluid production in pregnancy and IAD. These studies will employ a broad repertoire of innovative techniques. Microdissection and microperfusion methods will be used to determine ionic and volumetric changes in fluids perfused through specific duct segments under basal and pilocarpine-stimulated conditions, and to assess the potential influence of periductal lymphocytes on these functions. Ex vivo real time imaging using multi-photon excitation laser scanning fluorescence microscopy will be used to assess changes in cytosolic Ca2+ associated with M3 muscarinic acetylcholine receptor (M3AChR) signaling; changes in cell volume associated with activation of K+ and Cl- efflux mechanisms and regulatory activation of Na+ and Cl- influx mechanisms; and changes in cytosolic electrolyte contents associated with activation or inhibition of ion transporters hypothesized to mediate transepithelial absorption or secretion. Laser capture microdissection, real time RT- PCR, immunohistochemistry and in situ hybridization will be used to determine whether expression of aquaporins, M3AChR, G proteins coupled to M3AChR (i.e., Gq and G11), and various ion transporters associated with epithelial electrolyte and fluid absorption and secretion is altered in duct cells in the two models. Therefore, these studies will define the functional roles of specific duct segments within the lacrimal gland in production of lacrimal fluid. This research is highly relevant to the Program Goals of the National Plan for Eye and Vision Research, and knowledge gained from these studies has considerable potential to enhance the development of more effective treatment strategies.Dry eye is the most prevalent problem in ophthalmology which afflicts millions of Americans, and is the leading cause of visits to eye care clinicians. The proposed studies take advantage of two excellent animal models to study the biology of the lacrimal gland duct system, which has heretofore received little attention. Gaining an understanding of the lacrimal duct system is critical to enhancing our ability to develop more effective treatment strategies ultimately benefiting millions of dry eye patients.

描述（由申请人提供）：干眼症困扰着数百万美国人，它是访问眼科护理临床医生的主要原因。干眼症通常由泪腺泪液形成不足引起。泪液最初在腺泡中形成，然后在通过导管系统的过程中改变。然而，人们对这些管道及其功能知之甚少。据推测，干眼症中泪液产生的减少主要是由腺泡分泌减少引起的。然而，我们的初步数据表明，还必须考虑一个竞争性假设，即，泪腺分泌不足可能是由于导管中液体的不适当或过度重吸收造成的。在该提案中，研究者将使用正常家兔和两种家兔模型，妊娠和诱导性自身免疫性泪腺炎[IAD]，这两种模型均表现出基础泪液分泌减少和泪液功能不全的病理特征，以解决三个目标：#1确定离体导管中泪液的体积和成分是否发生改变，并推断正常对照导管上皮细胞的功能能力家兔#2确定在妊娠和IAD中，离体导管段的跨上皮离子和液体运输功能是否改变。#3确定怀孕和IAD中泪液产生减少的细胞机制。这些研究将采用广泛的创新技术。显微解剖和微灌注方法将用于确定在基础和毛果芸香碱刺激条件下通过特定导管段灌注的液体的离子和体积变化，并评估导管周围淋巴细胞对这些功能的潜在影响。使用多光子激发激光扫描荧光显微镜的离体真实的时间成像将用于评估与M3毒蕈碱乙酰胆碱受体（M3 AChR）信号传导相关的细胞溶质Ca 2+的变化;与K+和Cl-流出机制的激活以及Na+和Cl-流入机制的调节激活相关的细胞体积的变化;以及与离子转运蛋白的激活或抑制相关的细胞溶质电解质含量的变化，假设离子转运蛋白介导跨上皮吸收或分泌。激光捕获显微切割、真实的时间RT-PCR、免疫组织化学和原位杂交将用于确定水通道蛋白、M3 AChR、与M3 AChR偶联的G蛋白（即，Gq和G11），以及与上皮细胞电解质和液体吸收和分泌相关的各种离子转运蛋白在两种模型中的导管细胞中发生改变。因此，这些研究将明确泪腺内特定导管段在产生泪液中的功能作用。这项研究与国家眼科和视力研究计划的计划目标高度相关，从这些研究中获得的知识具有相当大的潜力，可以促进更有效的治疗策略的发展。干眼症是眼科最普遍的问题，困扰着数百万美国人，也是眼科护理临床医生就诊的主要原因。建议的研究利用两个优秀的动物模型来研究泪腺导管系统的生物学，迄今为止很少受到关注。了解泪道系统对于提高我们开发更有效的治疗策略的能力至关重要，最终使数百万干眼症患者受益。