[Ca2+]i and Secretory Dynamics in Parotid Acinar Cells

[Ca2]i 和腮腺腺泡细胞的分泌动态

• 批准号: 7795243
• 负责人: David I Yule
• 金额: $ 37.96万
• 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 2012-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7795243
• 关键词: Acetylcholine; Acinar Cell; Acinus organ component; Address; Adenosine Triphosphate; Animal Model; Automobile Driving; Calcium; Characteristics; Chemosensitization; Complex; Confocal Microscopy; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Data; Digestion; Electric Stimulation; Event; Exocytosis; Fluids and Secretions; Funding; Gland; Goals; Hydration status; Imaging Techniques; Inositol; Ion Channel; Lead; Liquid substance; Lubrication; Major salivary gland structure; Mechanics; Mediating; Mediator of activation protein; Microscopy; Molecular; Muscarinic Acetylcholine Receptor; Muscarinics; Nutrient; Optics; Oral cavity; Oral health; Oral mucous membrane structure; P2X-receptor; Parotid Gland; Pathway interactions; Pharmacology; Physiological; Physiology; Preparation; Process; Production; Property; Protein Secretion; Proteins; Purinoceptor; Quality of life; Receptor Activation; Regulation; Research Design; Saliva; Salivary; Salivary Glands; Series; Signal Transduction; Slice; Techniques; Therapeutic; Therapeutic Intervention; Tissues; Transgenic Animals; Upper digestive tract structure; Xerostomia; antimicrobial; base; design; digital imaging; in vivo; neural stimulation; novel; receptor; research study; saliva secretion; salivary acinar cell; treatment strategy

DESCRIPTION (provided by applicant): A key event in the secretagogue stimulation of both the fluid and protein component of saliva is an increase in the cytosolic free calcium concentration [Ca2+].i This increase in [Ca2+]i has specific temporal and spatial characteristics which are important for appropriately activating effectors pivotal for the secretion of saliva. Acetylcholine and the majority of other secretagogues act in a metabotropic manner stimulating the production of inositol 1,4,5-trisphosphate (InsP3) and the release of intracellular Ca2+. In salivary acinar cells, Ca2+ signals can also be generated by an alternative, largely independent ionotropic process following adenosine triphosphate (ATP) activation of the P2X class of Ca2+ permeable ion channels. The latter mechanism would be predicted to result in Ca2+ signals and effector activation with distinct spatial and temporal characteristics. Using contempory optical techniques, such as digital imaging, total internal reflection microscopy and confocal microscopy combined with transgenic animal models and specific pharmacology we will expand on findings generated in isolated salivary gland acini to define Ca2+ signaling events stimulated through both metabotropic and in particular through the P2X4 purinergic receptor (P2X4R) in an organotypic parotid gland slice preparation (aim 1). Ca2+ signals as a result of P2X4R activation are profoundly enhanced following protein kinase A (PKA) activation. Since fluid secretion is also enhanced when PKA is activated this may be the physiologically relevant situation. In specific aim 2 we propose to define the molecular mechanism underlying this event. In specific aim 3 a primary goal will also be to assess whether ionotropic purinergic signaling through P2X4 receptors (P2X4R), either alone, or following specific pharmacological manipulation is an effective activator of the fluid and exocytotic secretion mechanism. These studies are designed to advance our understanding of the complex series of regulated molecular events which result in fluid secretion and may ultimately lead to the design of therapeutic strategies for the treatment of xerostomia based on exploiting the physiology of remaining functional acinar tissue. 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 (xerostomia) greatly impacts the quality of life of sufferers. A key event in the secretagogue stimulation of both the fluid and protein component of saliva is an increase in the cytosolic free calcium concentration [Ca2+].i These studies are designed to advance our understanding of the complex series of regulated molecular events which result in the increase in [Ca2+]i and hence fluid secretion. Ultimately these data are designed to lead to the design of therapeutic strategies for the treatment of xerostomia based on exploiting the physiology of remaining functional acinar tissue.

描述（由申请人提供）：促分泌剂刺激唾液液体和蛋白质成分的一个关键事件是胞质游离钙浓度[Ca2+]的增加。[Ca2+]i的增加具有特定的时间和空间特征，这对于适当激活唾液分泌的关键效应物是重要的。乙酰胆碱和大多数其他促分泌物以代谢方式刺激肌醇1,4,5-三磷酸（InsP3）的产生和细胞内Ca2+的释放。在唾液腺泡细胞中，Ca2+信号也可以通过三磷酸腺苷（ATP）激活P2X类Ca2+渗透离子通道后的另一种独立的嗜离子过程产生。后一种机制将导致具有不同时空特征的Ca2+信号和效应激活。利用现代光学技术，如数字成像、全内反射显微镜和共聚焦显微镜，结合转基因动物模型和特定药理学，我们将扩展在分离的唾液腺腺腺腺腺中产生的发现，以定义通过代谢，特别是通过器官型腮腺切片制备中的P2X4嘌呤能受体（P2X4R）刺激的Ca2+信号事件（目的1）。Ca2+信号作为P2X4R激活的结果，在蛋白激酶a （PKA）激活后显著增强。当PKA被激活时，液体分泌也会增强，这可能是生理上相关的情况。在具体目标2中，我们建议定义这一事件背后的分子机制。在特定目标3中，主要目标还将是评估通过P2X4受体（P2X4R）的嗜离子嘌呤能信号，无论是单独的，还是经过特定的药理学操作，是否是液体和胞外分泌机制的有效激活剂。这些研究的目的是促进我们对导致液体分泌的复杂系列调控分子事件的理解，并可能最终导致基于开发剩余功能性腺泡组织生理学的治疗口干病的治疗策略的设计。唾液对口腔健康至关重要。它对口腔黏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。唾液流动减少（口干症）极大地影响患者的生活质量。唾液的液体和蛋白质成分的促分泌刺激的一个关键事件是细胞质游离钙浓度[Ca2+]的增加。这些研究旨在促进我们对一系列复杂的调控分子事件的理解，这些事件导致[Ca2+]i增加，从而导致液体分泌。最终，这些数据的目的是导致设计治疗策略的口干病的基础上，利用生理剩余的功能性腺泡组织。