Ca2+ and secretory dynamics in salivary acinar cells

Ca2 和唾液腺泡细胞的分泌动态

• 批准号: 8468675
• 负责人: David I Yule
• 金额: $ 46.46万
• 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/8468675
• 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.

描述（由申请人提供）：唾液对口腔健康至关重要。这对于口服粘膜的水合至关重要。它提供润滑，开始营养消化，并为口腔和上部胃肠道提供抗菌和机械保护。唾液流量减少会导致“口干”（切除术），并极大地影响了患者的生活质量。唾液腺功能低下的主要原因是Sjogrens综合征（SS），Sjogrens综合征是一种相对常见的自身免疫性外分病，影响唾液和泪腺。 SS导致逐渐恶化的口腔和干眼症（Xerophthalmia），因为淋巴细胞浸润后最终破坏了明显的腺组织。值得注意的是，在已建立的动物模型中 SS（例如IL14A B细胞“敲入”小鼠或C57BL/6.NOD-AEC1AEC2小鼠，信号传导事件和流体流量在任何销毁腺组织的证据之前明显减少。此外，SS患者通常保留形态完整的组织，但自相矛盾的是，显然对刺激是难治性的。鉴于此信息，该项目将提出一个假设，即刺激 - 分泌耦合中的缺陷负责疾病早期唾液形成减少，并且随着疾病的进展而保持功能性组织。该提案将利用SS的小鼠模型来探测导致随着疾病发展而导致唾液和泪腺的液体和蛋白质分泌的途径的潜在缺陷。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的实验来验证。在特定的目标1中，将进行实验以确定为什么细胞内Ca2+信号传导，流体分泌的主要刺激在SS小鼠模型中受到损害。实验将确定在SS中是否妥协了第二次收入者的产生。腺体小叶中的多光子成像以及高速宽视野成像以及隔离acini中的局灶性闪光光解会质疑负责CA2+释放，CA2+膨胀或CA2+清除率的机械是否在SS中改变。在特定的目标2中，将进行实验，以阐明为什么在SS模型中减弱蛋白质的胞吐作用，以及是否改变了流体分泌所需的离子通道的功能。流体相位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。我们将确定信号传导或SS中的胞吐机械是否被破坏。最后，我们将评估Ca2+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。该项目的最终目的是利用这些知识来基于利用SS中剩余功能性分泌组织的生理学来营救和维持分泌的基本原理设计和测试策略。