Ca2+ and secretory dynamics in salivary acinar cells

Ca2 和唾液腺泡细胞的分泌动态

• 批准号: 8317840
• 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/8317840
• 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; 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. PUBLIC HEALTH RELEVANCE: Saliva and tears are fluids which are essential for maintaining a healthy mouth and eyes. Sjogrens syndrome is a common disease where the secretion of these fluids is decreased resulting in major health problems for the afflicted. This study is designed to define the reasons why outwardly healthy tissue which remains in these patients does not adequately secrete these fluids. Ultimately this information may be used to design therapies for this serious health issue.

描述（由申请人提供）：唾液对于口腔健康至关重要。它对于口腔粘膜的水合作用至关重要；它提供润滑，开始营养消化，并为口腔和上胃肠道提供抗菌和机械保护。唾液流量减少会导致“口干”（口干症），并极大地影响患者的生活质量。唾液腺功能减退的一个主要原因是干燥综合征（SS），这是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 导致口干和眼干（干眼症）逐渐恶化，因为重要的腺体组织在淋巴细胞浸润后最终被破坏。值得注意的是，在已建立的动物模型中 对于 SS，例如 IL14a B 细胞“敲入”小鼠或 C57BL/6.NOD-Aec1Aec2 小鼠，在出现任何腺组织破坏证​​据之前，信号传导事件和液体流量显着减少。此外，SS 患者通常保留形态完整的组织，但矛盾的是，这些组织显然对刺激具有抵抗力。鉴于这些信息，该项目将验证以下假设：刺激-分泌耦合的缺陷导致疾病早期唾液形成减少以及随着疾病进展剩余功能组织的唾液形成减少。该提案将利用 SS 小鼠模型来探究疾病发展过程中导致唾液和泪腺分泌液体和蛋白质的途径的潜在缺陷。小鼠模型中的重要发现将通过对 SS 患者的唇腺活检进行类似的实验来验证。在具体目标 1 中，将进行实验以确定为什么细胞内 Ca2+ 信号传导（体液分泌的主要刺激）在 SS 小鼠模型中受到损害。实验将确定 SS 中第二信使的产生是否受到损害。腺小叶中的多光子成像与高速宽视场成像，再加上孤立腺泡中的焦点闪光光解，将质疑 SS 中负责 Ca2+ 释放、Ca2+ 流入或 Ca2+ 清除的机制是否发生了改变。在具体目标 2 中，将进行实验以阐明为什么 SS 模型中蛋白质的胞吐作用减弱，以及液体分泌所需的离子通道的功能是否改变。液相标记的多光子成像以及细胞膜表面积的电容测量将用于监测胞吐作用。我们将确定 SS 中的信号传导或胞吐机制是否被破坏。最后，我们将评估 SS 中 Ca2+- 激活的 Cl- 和 K+ 通道的功能是否发生改变。这些研究旨在提供有关 SS 刺激-分泌耦合中发生的功能变化的基本信息。该项目的最终目标是利用这些知识来合理设计和测试基于 SS 中剩余功能性分泌组织的生理学的拯救和维持分泌的策略。 公共卫生相关性：唾液和眼泪是维持口腔和眼睛健康所必需的液体。干燥综合征是一种常见疾病，这些液体的分泌减少，导致患者出现严重的健康问题。这项研究旨在明确这些患者体内保留的表面健康组织不能充分分泌这些液体的原因。最终，这些信息可用于设计针对这一严重健康问题的疗法。