Prolactin--Autocrine/paracrine factor in lacrimal gland

催乳素--泪腺自分泌/旁分泌因子

• 批准号: 6620355
• 负责人: AUSTIN K MIRCHEFF
• 金额: $ 16.25万
• 依托单位: UNIVERSITY OF SOUTHERN CALIFORNIA
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-05-01 至 2005-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6620355
• 关键词: Adenoviridae; acinar cell; antibody receptor; autocrine; cell morphology; hormone regulation /control mechanism; immunocytochemistry; laboratory rabbit; lacrimal apparatus; leukocyte activation /transformation; neutralizing antibody; paracrine; polymerase chain reaction; prolactin; receptor expression; secretion; tissue /cell culture; transfection /expression vector; transport proteins; western blottings

Dry eye is a common problem with a severe impact on the quality of life and potential vision-threatening complications. It often results from lacrimal insufficiency caused by immune-related processes, as in Sjogren's syndrome, or by hormone changes associated with aging and various physiological states. One critical hormonal influence on the lacrimal glands appears to be prolactin. Studies with human subjects, hypophysectomized rats, transgenic mice, and acinar cells in primary culture indicate that prolactin can impair lacrimal function, even at serum concentrations within the range of normal values. Moreover, the source of the prolactin that impairs lacrimal gland function may be the lacrimal glands themselves. The lacrimal glands express prolactin mRNA and protein, which may act as an autocrine or intracrine factor that in some circumstances may interfere with secretion. This project will use lacrimal acinar cells in primary culture to answer the following questions: 1. Does locally expressed prolactin act as an autocrine/intracrine factor that supports secretory functions at normal concentrations and impairs them at excessive concentrations? Neutralizing antibodies and antisense reagents will be used to minimize actions of locally expressed prolactin. Expression constructs will be used to overexpress prolactin. Acinar cell morphology, carbachol-induced protein secretion, expression of polymeric immunoglobulin receptors, and expression of ion transport proteins will be evaluated for changes related to altered prolactin expression. 2. Do altered forms of prolactin (16 kDa and phosphorylated 24 kDa) that have inhibitory effects in other cells inhibit lacrimal secretory function? The effects of overexpressed and added forms will be tested as in Specific Aim 1. 3. Does lacrimal prolactin act as a paracrine factor contributing to autoimmune activation? Antisense reagents and expression constructs will be used to suppress or enhance acinar cell prolactin expression, and the modified cells will be tested for their ability to promote proliferation of autologous lymphocytes in mixed cell reactions. This work will advance our understanding of significant mechanisms in lacrimal physiology, and it will have immediate implications for the direction of other studies now in progress. It also has the possibility of stimulating much work well beyond its present scope, including epidemiological studies aimed at identifying sub-populations of lacrimal deficiency patients with different etiologies, followed by design of appropriate, highly specific therapies.

干眼是一种常见问题，严重影响生活质量并可能出现危及视力的并发症。 它通常是由于免疫相关过程（如干燥综合征）或与衰老和各种生理状态相关的激素变化引起的泪腺功能不全所致。 对泪腺有重要影响的一种激素似乎是催乳素。 对人类受试者、垂体切除大鼠、转基因小鼠和原代培养腺泡细胞的研究表明，即使血清浓度在正常值范围内，催乳素也会损害泪腺功能。 此外，损害泪腺功能的催乳素的来源可能是泪腺本身。 泪腺表达催乳素 mRNA 和蛋白质，它们可能充当自分泌或内分泌因子，在某些情况下可能会干扰分泌。 该项目将利用原代培养的泪腺腺泡细胞来回答以下问题： 1. 局部表达的催乳素是否作为自分泌/内分泌因子在正常浓度下支持分泌功能并在浓度过高时损害分泌功能？ 中和抗体和反义试剂将用于最小化局部表达的催乳素的作用。 表达构建体将用于过表达催乳素。将评估腺泡细胞形态、卡巴胆碱诱导的蛋白质分泌、聚合免疫球蛋白受体的表达和离子转运蛋白的表达，以了解与催乳素表达改变相关的变化。 2. 对其他细胞具有抑制作用的催乳素改变形式（16 kDa 和磷酸化 24 kDa）是否会抑制泪液分泌功能？ 过表达和添加形式的影响将按照具体目标 1 进行测试。 3. 泪腺催乳素是否作为有助于自身免疫激活的旁分泌因子？ 反义试剂和表达构建体将用于抑制或增强腺泡细胞催乳素表达，并且将测试修饰的细胞在混合细胞反应中促进自体淋巴细胞增殖的能力。这项工作将增进我们对泪腺生理学重要机制的理解，并将对目前正在进行的其他研究的方向产生直接影响。 它还可能激发远远超出其目前范围的许多工作，包括旨在识别具有不同病因的泪道缺陷患者亚群的流行病学研究，然后设计适当的、高度特异性的疗法。