Basal-Lateral/Endomembrane Traffic in Lacrimal Acini

泪腺腺泡的基底外侧/内膜交通

• 批准号: 7122431
• 负责人: AUSTIN K MIRCHEFF
• 金额: $ 39.79万
• 依托单位: UNIVERSITY OF SOUTHERN CALIFORNIA
• 依托单位国家: 美国
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-04-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7122431
• 关键词: SDS polyacrylamide gel electrophoresis; Sjogren' s syndrome; acinar cell; autoimmune disorder; basolateral membrane; biological signal transduction; carbachol; confocal scanning microscopy; cysteine endopeptidases; dynein ATPase; enzyme activity; histamine; immunoprecipitation; intracellular transport; laboratory rabbit; lacrimal apparatus; lacrimal disorder; leukocyte adhesion molecules; lysosomes; muscarinic receptor; oxytocin; prostaglandin E; receptor expression; serotonin

DESCRIPTION (provided by applicant): Sjogren's syndrome (SjS) and other immune-related diseases cause lacrimal dysfunction, impaired vision, and ocular surface inflammation in 2 to 4 million Americans. Primary lacrimal deficiency (PLD), which also may have an immune-related component, affects at least 6 million more. These concepts are unified by the hypothesis that: the milieu in the lacrimal glands reflects an immunohomeostasis involving regulatory lymphocytes, autoimmune effector lymphocytes, and secretory epithelial cells; lymphocyte and inflammatory cell mediators modulate epithelial cell functions; and the immunohomeostasis evolves in response to altered epithelial cell functions. However, little is known about the triggers that alter epithelial function to initiate the diseases, the reasons they occur more frequently in women than in men, and the molecular mechanisms that cause lacrimal dysfunction. The investigators have found that chronic stimulation of lacrimal acinar cells with the muscarinic receptor (MAChR) agonist, carbachol, causes epithelial secretory quiescence and also activates an aberrant endomembrane traffic program that blocks movement to lysosomes, potentially increasing exposure of constitutive autoantigens and initiating exposure of previously cryptic epitopes. The G proteins that classically couple to MAChR, Gq and G11, are shared by receptors for a wide variety of mediators, and their signaling is influenced by the sex hormones. Therefore, the investigators propose that: (a) physiological perturbations can initiate inappropriate Gq/G11 signaling that activates the aberrant traffic program, and (b) the local environments in SjS and PLD stimulate inappropriate Gq/G11 signaling that causes functional quiescence underlying lacrimal dysfunction. Specific Aim 1. What are the signals that activate the aberrant membrane traffic program? The central hypothesis is that MAChR remain activated and continue to activate Gq/G11. Specific Aim 2. Can chronic stimulation of other receptors also cause functional quiescence and activate the aberrant traffic program? The central hypothesis is that these changes can be elicited by agonists for receptors that utilize Gq/G11, including histamine, 5-hydroxytryptamine, PGE2, and estradiol. Specific Aim 3. What traffic effectors are responsible for the aberrant program? The central hypothesis is that chronic stimulation decreases dynein motor function but increases p150(Glued) association with kinesin II, thereby increasing kinesin-mediated traffic. Specific Aim 4. How extensively does the aberrant program alter traffic of lysosomal proteins? The investigators will use a GFP-cathepsin S fusion protein and confocal microscopy to test the hypothesis that lysosomal proteins accumulate in the endosomes.

描述（由申请人提供）：干燥综合征（SjS）和其他免疫相关疾病导致200万至400万美国人的泪液功能障碍、视力受损和眼表炎症。原发性泪液缺乏症（PLD）也可能有免疫相关的成分，影响至少600万人。这些概念是统一的假设：泪腺中的环境反映了免疫稳态，涉及调节淋巴细胞，自身免疫效应淋巴细胞和分泌上皮细胞;淋巴细胞和炎症细胞介质调节上皮细胞的功能;和免疫稳态的演变响应改变上皮细胞的功能。然而，人们对改变上皮功能以引发疾病的触发因素，女性比男性更频繁发生的原因以及导致泪腺功能障碍的分子机制知之甚少。研究人员发现，用毒蕈碱受体（MAChR）激动剂卡巴胆碱长期刺激泪腺腺泡细胞，导致上皮分泌静止，并激活异常内膜运输程序，阻止溶酶体运动，可能增加组成性自身抗原的暴露，并启动先前隐藏的表位的暴露。典型地与MAChR、Gq和G11偶联的G蛋白由多种介质的受体共享，并且它们的信号传导受性激素的影响。因此，研究者提出：（a）生理扰动可以启动不适当的Gq/G11信号传导，激活异常的交通程序，和（B）SjS和PLD的局部环境刺激不适当的Gq/G11信号传导，导致潜在的泪腺功能障碍的功能性静止。具体目标1.激活异常膜交通程序的信号是什么？的 中心假设是MAChR保持激活并继续激活Gq/G11。具体目标2。慢性刺激其他受体是否也会引起功能性静止并激活异常的交通程序？中心假设是，这些变化可以引起的受体，利用Gq/G11，包括组胺，5-羟色胺，前列腺素E2和雌二醇的激动剂。具体目标3。什么样的交通效应器是导致异常程序的原因？核心假设是慢性刺激降低动力蛋白运动功能，但增加p150（胶合）与驱动蛋白II的关联，从而增加驱动蛋白介导的交通。具体目标4。异常程序对溶酶体蛋白运输的改变程度如何？研究人员将使用GFP-组织蛋白酶S融合蛋白 和共聚焦显微镜来检验溶酶体蛋白质在核内体中积累的假设。