Ca2+ and secretory dynamics in salivary acinar cells

Ca2 和唾液腺泡细胞的分泌动态

• 批准号: 8664242
• 负责人: David I Yule
• 金额: $ 48.4万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-15 至 2017-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8664242
• 关键词: Acinar Cell; Acinus organ component; Acute; Address; Affect; Agonist; Animal Model; Area; Attenuated; Autoimmune Diseases; Automobile Driving; B-Lymphocytes; Biological Models; Biopsy; Calcium; Cell membrane; Cells; Characteristics; Clinical; Complex; Coupling; Cyclic AMP; Data; Defect; Digestion; Disease; Electric Capacitance; Event; Exocytosis; Exposure to; Eye; Female; Fluids and Secretions; Generations; Gland; Goals; Health; Hydration status; IL14 gene; Image; Infiltration; Ion Channel; Ion Transport; Knock-in Mouse; Knowledge; Lacrimal gland structure; Light; Liquid substance; Literature; Lobule; Lubrication; Lymphocyte; Maintenance; Measurement; Mechanics; Modeling; Molecular; Monitor; Mus; Nutrient; Oral cavity; Oral health; Oral mucous membrane structure; Parotid Gland; Pathway interactions; Patients; Pattern; Phase; Physiology; Potassium Channel; Production; Protein Secretion; Proteins; Quality of life; Refractory; Research Design; Rodent; Saliva; Salivary; Salivary Glands; Second Messenger Systems; Signal Pathway; Signal Transduction; Signal Transduction Pathway; Sjogren' s Syndrome; Speed; Stimulus; Submandibular gland; Surface; Syndrome; Testing; Time; Tissues; Upper digestive tract structure; Xerophthalmia; Xerostomia; antimicrobial; autoimmune exocrinopathy; base; cytokine; design; experience; eye dryness; flash photolysis; fluid flow; human tissue; mouse model; multi-photon; neural stimulation; research study; response; salivary acinar cell; second messenger; therapy design

DESCRIPTION (provided by applicant): Saliva is vital for oral health. It is essential for the hydration of the oral mucosa; it provides lubrication, begins nutrient digestion and imparts antimicrobial and mechanical protection for the mouth and upper gastrointestinal tract. Reduced flow of saliva results in "dry mouth" (xerostomia) and greatly impacts the quality of life of sufferers. A major cause of salivary gland hypofunction is Sjogrens syndrome (SS), a relatively common autoimmune exocrinopathy affecting the salivary and lacrimal glands. SS results in progressively worsening dry mouth and dry eye (xerophthalmia) as significant glandular tissue is ultimately destroyed following lymphocyte infiltration. Significantly, in established animal models of SS, such as the IL14a B cell "knock-in" mouse, or the C57BL/6.NOD-Aec1Aec2 mouse, signaling events and fluid flow are markedly decreased prior to any evidence of destruction of glandular tissue. Moreover, morphologically intact tissue is often retained in SS patients, but paradoxically, is apparently refractory to stimulation. Given this information, this project will tst the hypothesis that defects in stimulus-secretion coupling are responsible for decreased saliva formation early in the disease and in remaining functional tissue as the disease progresses. The proposal will utilize mouse models of SS to probe the underlying defects in pathways leading to fluid and protein secretion from salivary and lacrimal glands as the disease develops. Important findings in mouse models will be validated by performing similar experiments in labial gland biopsies from SS patients. In specific aim 1, experiments will be performed to ascertain why intracellular Ca2+ signaling, the primary stimulus for fluid secretion is compromised in SS mouse models. Experiments will determine whether the production of second-messengers is compromised in SS. Multi-photon imaging in gland lobules together with high-speed wide-field imaging, combined with focal flash photolysis in isolated acini, will question if the machinery responsible for Ca2+ release, Ca2+ influx or Ca2+ clearance is altered in SS. In specific aim 2, experiments will be performed to elucidate why the exocytosis of protein is attenuated in SS models and if the function of ion channels necessary for fluid secretion is altered. Multi-photon imaging of fluid phase markers together with capacitance measurements of cell membrane surface area will be used to monitor exocytosis. We will determine whether signaling, or the exocytotic machinery in SS is disrupted. Finally, we will evaluate if the function of Ca2+- activated Cl- and K+ channels are altered in SS. These studies are designed to provide fundamental information regarding the functional changes occurring in stimulus-secretion coupling in SS. The ultimate goal of this project is to use this knowledge to rationale design and test strategies for the rescue and maintenance of secretion based on exploiting the physiology of remaining functional secretory tissue in SS.

描述（由申请人提供）：唾液对口腔健康至关重要。它对口腔粘膜的水合作用至关重要;它提供润滑，开始营养消化，并为口腔和上消化道提供抗菌和机械保护。唾液流量减少导致“口干”（口腔干燥症），并极大地影响患者的生活质量。唾液腺功能减退的主要原因是干燥综合征（SS），一种影响唾液腺和泪腺的相对常见的自身免疫性外分泌病。SS导致口干和干眼症（干眼症）进行性恶化，因为淋巴细胞浸润后，显著的腺组织最终被破坏。值得注意的是，在已建立的动物模型中， SS的小鼠，如IL 14 a B细胞“敲入”小鼠或C57 BL/6. NOD-Aec 1 Aec 2小鼠，在任何腺体组织破坏的证据之前，信号传导事件和流体流动显著减少。此外，形态完整的组织往往保留在SS患者，但矛盾的是，显然是难治性的刺激。鉴于这些信息，本项目将验证这一假设，即刺激-分泌偶联的缺陷是导致疾病早期唾液形成减少和疾病进展时剩余功能组织中唾液形成减少的原因。该提案将利用SS的小鼠模型来探测疾病发展时导致唾液腺和泪腺分泌液体和蛋白质的途径中的潜在缺陷。小鼠模型中的重要发现将通过在SS患者的唇腺活检中进行类似实验来验证。在具体目标1中，将进行实验以确定为什么细胞内Ca 2+信号传导（体液分泌的主要刺激）在SS小鼠模型中受损。实验将确定第二信使的产生是否在SS中受到损害。多光子成像在腺小叶连同高速宽场成像，结合焦点闪光光解在孤立的腺泡，将问题，如果机械负责Ca 2+释放，Ca 2+内流或Ca 2+清除改变SS。在具体目标2中，将进行实验以阐明为什么在SS模型中蛋白质的胞吐作用减弱，以及液体分泌所必需的离子通道的功能是否改变。将使用流体相标记物的多光子成像以及细胞膜表面积的电容测量来监测胞吐作用。我们将确定是否信号，或胞吐机制在SS中断。最后，我们将评估钙激活的Cl-和K+通道的功能是否在SS中改变。这些研究旨在提供有关SS中刺激-分泌偶联中发生的功能变化的基本信息。本项目的最终目标是利用这些知识的基本原理设计和测试策略的救援和维护的分泌的基础上利用剩余的功能分泌组织的生理SS。