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 (LG) 的慢性炎症（如干燥综合征中所发生的情况）是导致房水的主要原因。缺乏性干眼症 (DED) 导致 LG 分泌不足的机制尚不完全清楚。 LG 由腺泡、肌上皮和导管细胞组成，腺泡和肌上皮细胞 (MEC) 形成分泌单位，MEC 表达多种肌肉蛋白，例如 α 平滑肌肌动蛋白 (SMA) 和钙调蛋白，因此能够收缩。 MEC 在乳腺中得到了最好的研究，它们的收缩对于产奶至关重要，尽管它们具有潜在的关键作用，但收缩主要由神经肽催产素控制。在 LG 分泌中，人们对这种组织中的 MEC 收缩知之甚少，目前提案的目标之一就是填补小鼠的这一知识空白。人类 LG MEC 表达催产素受体 (OXTR) 并响应催产素刺激而收缩。此外，我们发现慢性发炎的 LG 中的 MEC 会萎缩，收缩蛋白 SMA 和 SMA 下调。我们之前报道过，白细胞介素-1 (IL-1) 会抑制 LG 传出神经释放神经递质，从而导致 DED。 -Jun N 末端激酶 (JNK) 和金属蛋白酶 2 (MMP2) 在慢性发炎的 LG 中，抑制任一途径可恢复 LG 分泌和眼泪大量研究表明，肌肉组织的去神经支配通过泛素/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，我们发现在慢性 DED 中，促炎细胞因子抑制神经递质的释放。 LG 传出神经产生去神经样组织，并引发 OXTR 和 MEC 肌丝蛋白的降解，这种降解转化为肌丝收缩性的丧失。因此，MEC 进一步加剧了神经输入损失对 LG 分泌单位的影响。我们进一步阻碍了 JNK、MMP2 和泛素/蛋白酶体途径介导促炎细胞因子对 MEC 功能的影响。（分类的 MEC 细胞）以及 DED 动物模型，以研究促炎细胞因子如何干扰催产素诱导的 LG MEC 收缩。 RNA-seq 和定量全局蛋白质组学技术可识别慢性炎症 LG 中 MEC 改变的新途径。完成这些研究后，我们将确定 MEC（LG 中重要但尚未得到充分研究的细胞）的作用。催产素信号系统在缺水性 DED 发病机制中的作用，并确定了潜在的新治疗靶点。