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Role of lacrimal gland myoepithelial cells in dry eye disease

泪腺肌上皮细胞在干眼病中的作用

基本信息

批准号：
10553199
负责人：
DRISS ZOUKHRI
金额：
$ 48.38万
依托单位：
TUFTS UNIVERSITY BOSTON
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-02-01 至 2025-01-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10553199
关键词：
Acinar Cell Acinus organ component Actins Age Animal Model Atrophic Autoimmune Candidate Disease Gene Catabolism Cell Separation Cell physiology Cells Chronic Contractile Proteins Contracts Coupling Data Denervation Disease Down-Regulation Dry Eye Syndromes Ductal Epithelial Cell Efferent Neurons G-Protein-Coupled Receptors GTP-Binding Proteins Gene Expression Genes Gland Goals Health Human Impairment In Vitro Inflammation Inflammatory Interleukin-1 Knock-out Knowledge Lacrimal gland structure Lead MAPK8 gene MMP2 gene Mammary gland Mediating Metalloproteases Microfilaments Molecular Mus Muscle Muscle Proteins Muscle denervation procedure Muscular Atrophy Myoepithelial cell N-terminal Neuropeptides Output Oxytocin Oxytocin Receptor Pathogenesis Pathway interactions Phosphotransferases Process Production Proteins Proteomics RNA Receptor Cell Receptor Signaling Reporting Role Second Messenger Systems Signal Transduction Signal Transduction Pathway Sjogren&apos s Syndrome Smooth Muscle Smooth Muscle Myocytes Sorting Stress System Techniques Tissues Translating Ubiquitin aqueous calponin cell type cytokine mammary milk production milk secretion multicatalytic endopeptidase complex muscular system neural neurotransmitter release new therapeutic target novel protein expression receptor receptor expression response sex transcriptome sequencing

项目摘要

Chronic inflammation of the lacrimal gland (LG), as occurs in Sjögren’s syndrome, is the leading cause of aqueous- deficient dry eye disease (DED). The mechanisms leading to insufficient LG secretion are still not completely understood. The LG is composed of acinar, myoepithelial, and ductal cells, with acini and myoepithelial cells (MEC) forming the secretory units. MECs express several muscle proteins, such as alpha smooth muscle actin (SMA) and calponin, and are therefore able to contract. MECs are best studied in the mammary gland where their contraction is shown to be crucial for milk production and contraction is mainly controlled by the neuropeptide oxytocin. Despite their potential critical role in LG secretion, very little is known about MEC contraction in this tissue, nor is the impact of chronic inflammation of the LG on these cells. One of goals of the current proposal is to fill this gap in knowledge. Our preliminary studies show that murine and human LG MECs express the oxytocin receptor (OXTR) and contract in response to oxytocin stimulation. Furthermore, we show that MECs in chronically inflamed LG are atrophied, with down-regulation of contractile proteins SMA and calponin and the OXTR and MECs from these glands do not contract in response to oxytocin stimulation. We previously reported that interleukin-1 (IL-1) inhibits neurotransmitter release from LG efferent nerves leading to DED. We also reported activation of the stress activated c-Jun N-terminal kinase (JNK) and metalloproteinases 2 (MMP2) in chronically inflamed LGs and that inhibition of either pathway restored LG secretion and tears output in animal models of DED. Numerous studies showed that denervation of muscle tissues leads to tissue atrophy and degradation of muscle contractile proteins via the ubiquitin/proteasome pathways. Based on these findings, we hypothesize that in chronic DED, proinflammatory cytokines inhibit neurotransmitter release from LG efferent nerves creating a denervated-like tissue and that they trigger degradation of the OXTR and MEC myofilament proteins. This degradation translates into a loss of contractibility of MECs thus further exacerbating the effect of the loss of neural input on the secretory units of the LG. We further hypothesize that the JNK, MMP2, and ubiquitin/proteasome pathways mediate the effects of proinflammatory cytokines on MEC functions. We will use both in vitro (sorted MEC cells) as well as animal models of DED to investigate how proinflammatory cytokines interfere with oxytocin-induced contraction of LG MECs. We will use unbiased RNA-seq and quantitative global proteomics techniques to identify novel pathways that are altered in MECs in chronically inflamed LGs. At the completion of these studies, we will have established a role for the MEC, an important and yet understudied cell in the LG, and the oxytocin signaling system in the pathogenesis of aqueous-deficient DED and identified potential novel therapeutic targets.

泪腺慢性炎症(LG)，如Sjögren综合征所发生的，是房水的主要原因虚型干眼病(DED)。导致LG分泌不足的机制仍不完全清楚。 LG由腺泡细胞、肌上皮细胞和导管细胞组成，腺泡细胞和肌上皮细胞(MEC)构成分泌单位。MECs表达几种肌肉蛋白，如α-平滑肌肌动蛋白(SMA)和钙蛋白，因此能够收缩。最好的研究是在乳腺，在那里它们的收缩被证明是乳汁产生的关键，而收缩主要由神经肽催产素控制。尽管它们在LG分泌中可能起到关键作用，但人们对这些组织中MEC的收缩知之甚少，也不知道LG的慢性炎症对这些细胞的影响。当前提案的目标之一就是填补这一知识空白。我们的初步研究表明，小鼠和人类LG MEC表达催产素受体(OXTR)，并对催产素刺激做出反应。此外，我们发现，慢性炎症LG的MEC萎缩，收缩蛋白SMA和Calponin下调，这些腺体的OXTR和MECs不会因催产素刺激而收缩。我们先前报道，白介素1(IL-1)抑制LG传出神经的神经递质释放，导致DED。我们还报道了应激激活的c-jun氨基末端激酶(JNK)和金属蛋白酶2(MMP2)在慢性炎症LGs中的激活，在DED动物模型中抑制这两个途径中的任何一个都可以恢复LG的分泌和泪液输出。大量研究表明，肌肉组织的失神经通过泛素/蛋白酶体途径导致组织萎缩和肌肉收缩蛋白的降解。基于这些发现，我们假设在慢性DED中，促炎细胞因子抑制LG传出神经释放神经递质，产生失神经样组织，并触发OXTR和MEC肌丝蛋白的降解。这种退化转化为微血管内皮细胞收缩能力的丧失，从而进一步加剧了神经输入丧失对LG分泌单位的影响。我们进一步假设，JNK、MMP2和泛素/蛋白酶体通路介导了促炎细胞因子对MEC功能的影响。我们将使用体外(分离的MEC细胞)和DED的动物模型来研究促炎细胞因子如何干扰催产素诱导的LG MEC的收缩。我们将使用无偏见的RNA-SEQ和定量全球蛋白质组学技术来识别慢性炎症LG中微血管内皮细胞改变的新途径。在这些研究完成后，我们将为LG中一个重要但尚未得到充分研究的细胞MEC和催产素信号系统在缺水DED发病机制中发挥作用，并确定潜在的新治疗靶点。