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Mechanism of action for the epithelial-specific ER stress sensor IRE1β in regulating intestinal homeostasis and host defense

上皮特异性 ER 应激传感器 IRE1β 调节肠道稳态和宿主防御的作用机制

基本信息

批准号：
10596581
负责人：
Michael J Grey
金额：
$ 75.57万
依托单位：
BOSTON CHILDREN'S HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
1993
资助国家：
美国
起止时间：
1993-09-01 至 2025-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10596581
关键词：
Address Affect Animals Area Asthma Attenuated Binding Biochemical Biology Cell Communication Cell Differentiation process Cell Line Cell physiology Cells Cellular Stress Cholera Toxin Chronic Citrobacter rodentium Colon Data Defect Defense Mechanisms Development Disease Endoplasmic Reticulum Endosomes Environment Epithelial Cells Epithelium Event Functional disorder Gastrointestinal tract structure Germ-Free Goals Goblet Cells Grant Gut Mucosa Host Defense Human Impairment Individual Infection Inflammation Inflammatory Inflammatory Bowel Diseases Intestinal Diseases Intestines Invaded Investigation Link Mediator Membrane Microbe Modeling Molecular Mucous Membrane Mucous body substance Mus Outcome Study Output Pathogenesis Pathway interactions Phenocopy Physiology Post-Translational Protein Processing Proteins Recombinant Proteins Recovery Role Sequence Homology Shapes Signal Transduction Stress Structure Surface Taxonomy Testing Toxin Ulcerative Colitis Vibrio cholerae Work acute infection biological adaptation to stress biophysical techniques cell assembly dysbiosis endoplasmic reticulum stress extracellular gastrointestinal epithelium gut microbes gut microbiota host microbiota human disease in vivo inhibitor interest intestinal homeostasis microbial microbiota paralogous gene pathogen reconstitution response sensor therapeutic target

项目摘要

PROJECT SUMMARY Our overarching goal is to understand how the epithelial-specific ER stress sensor IRE1b (ERN2) and its ubiquitously expressed paralogue IRE1a (ERN1) contribute to intestinal homeostasis and host defense. A notable adaptation of the ER unique to epithelial cells lining mucosal surfaces, especially in the gut, is expression of the ER stress sensor IRE1b, a close paralogue of the major and most evolutionarily conserved ER stress sensor IRE1a. We recently discovered, however, that IRE1b functions distinctly from IRE1a in enzymatic activity, enabling it to act as a non-competitive inhibitor of IRE1a signaling in the ER stress response. Our new and ongoing studies demonstrate in vivo that IRE1b operates critically in goblet cell differentiation and assembly of the mucus barrier - with both activities dependent on the normal gut microbiota: gut microbes and their products stimulate IRE1b expression, and IRE1b in turn affects the assembly, taxonomy, and functional output of colonizing gut microbes. These data frame our central hypothesis that IRE1b acts as an environmentally induced mediator of innate epithelial host defense by affecting the ER stress response via IRE1a, and then goblet cell development, mucus assembly, and host epithelial-microbe interactions that shape the structure and function of the colon. In Aim 1, we will use recombinant proteins and biochemical and biophysical approaches to test how IRE1a and IRE1b may be activated by gut lumenal factors, explain how IRE1b oligomerizes with IRE1a, and elucidate what structural features and post-translational modifications modify this assembly, IRE1b signaling, and mechanisms for IRE1b activation and suppression of IRE1a function. In Aim 2, we will use wt and IRE1b-/- mice and colonoids prepared from these animals to determine how IRE1b links the gut microbiota with epithelial stress and development responses and identify core microbial pathways and metabolites that regulate IRE1b expression and perhaps function. In Aim 3, we will explain how the lack of IRE1b attenuates recovery from acute infection with C. rodentium. We found that IRE1b-/- mice have impaired assembly of the colonic mucus layer and dysbiosis - mimicking defects in the colonic mucosa seen in humans with ulcerative colitis (UC). As modeled by Citrobacter rodentium, the altered mucus layer in IRE1b-/- mice was associated with impaired recovery following normal clearance of the pathogen. We will (i) test if the dysbiotic gut microbiota, or unresolved epithelial ER stress, or both, drive the sustained inflammation following C. rodentium infection in IRE1b-/- mice; and (ii) determine if microbiota obtained from humans with UC phenocopy these effects and fail to induce IRE1b, goblet cell development, or an effective mucus barrier when reconstituted in germ-free wt IRE1b+/+ mice. ER stress is implicated in the chronic inflammatory and other intestinal diseases. The outcomes of these studies will be informative of the host-microbiota interactions that regulate epithelial development and host defense.

项目概要我们的首要目标是了解上皮特异性 ER 应激传感器 IRE1b (ERN2) 及其普遍表达的旁系同源物 IRE1a (ERN1) 有助于肠道稳态和宿主防御。内质网对粘膜表面（尤其是肠道）的上皮细胞所特有的一个显着适应是 ER 应激传感器 IRE1b 的表达，它是主要且进化上最保守的 ER 的密切旁系同源物压力传感器 IRE1a。然而，我们最近发现 IRE1b 在酶促作用中的功能与 IRE1a 不同。活性，使其能够作为 ER 应激反应中 IRE1a 信号传导的非竞争性抑制剂。我们的新正在进行的体内研究表明 IRE1b 在杯状细胞分化和组装中发挥着关键作用粘液屏障 - 这两项活动都依赖于正常的肠道微生物群：肠道微生物及其产品刺激 IRE1b 表达，而 IRE1b 反过来影响组装、分类和功能输出定植肠道微生物。这些数据框架了我们的中心假设，即 IRE1b 充当先天环境诱导的调节剂。通过 IRE1a 影响内质网应激反应，从而实现上皮宿主防御，然后杯状细胞发育，粘液组装以及宿主上皮微生物相互作用塑造结肠的结构和功能。在目标 1 中，我们将使用重组蛋白以及生物化学和生物物理方法来测试 IRE1a 和 IRE1b 可能被肠腔因子激活，解释 IRE1b 如何与 IRE1a 寡聚，并阐明什么结构特征和翻译后修饰会改变该组装、IRE1b 信号传导和机制用于 IRE1b 激活和 IRE1a 功能抑制。在目标 2 中，我们将使用 wt 和 IRE1b-/- 小鼠以及从这些动物制备的结肠来确定 IRE1b 如何将肠道微生物群与上皮应激和发育反应联系起来，并确定核心微生物途径以及调节 IRE1b 表达和功能的代谢物。在目标 3 中，我们将解释 IRE1b 的缺乏如何削弱啮齿类弯曲杆菌急性感染的恢复。我们发现 IRE1b-/- 小鼠的结肠粘液层组装受损并出现菌群失调 - 模仿缺陷存在于患有溃疡性结肠炎（UC）的人的结肠粘膜中。以啮齿类柠檬酸杆菌为模型， IRE1b-/-小鼠粘液层的改变与正常清除后的恢复受损有关病原。我们将 (i) 测试失调的肠道微生物群或未解决的上皮内质网应激，或两者兼而有之，是否会驱动 IRE1b-/- 小鼠感染啮齿类梭菌后出现持续炎症； (ii) 确定微生物群是否获得来自患有 UC 表型的人类，这些效应无法诱导 IRE1b、杯状细胞发育或有效的在无菌 wt IRE1b+/+ 小鼠中重建时的粘液屏障。内质网应激与慢性炎症和其他肠道疾病有关。这些研究的结果将提供调节上皮发育和宿主防御的宿主-微生物群相互作用的信息。

项目成果

期刊论文数量（40）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Cryptdin 3 forms anion selective channels in cytoplasmic membranes of human embryonic kidney cells.

DOI：
10.1152/ajpgi.00152.2001
发表时间：
2002-05
期刊：
American journal of physiology. Gastrointestinal and liver physiology
影响因子：
0
作者：
G. Yue;D. Merlin;M. Selsted;W. Lencer;J. Madara;D. Eaton
通讯作者：
G. Yue;D. Merlin;M. Selsted;W. Lencer;J. Madara;D. Eaton

The antifungal antibiotic, clotrimazole, inhibits Cl- secretion by polarized monolayers of human colonic epithelial cells.

DOI：
10.1172/jci119012
发表时间：
1996-11
期刊：
The Journal of clinical investigation
影响因子：
0
作者：
P. Rufo;Lianwei Jiang;S. Moe;C. Brugnara;Seth L. Alper;W. I. Lencer
通讯作者：
P. Rufo;Lianwei Jiang;S. Moe;C. Brugnara;Seth L. Alper;W. I. Lencer

The Cdc42 inhibitor secramine B prevents cAMP-induced K+ conductance in intestinal epithelial cells.

Cdc42 抑制剂 secramine B 可防止肠上皮细胞中 cAMP 诱导的 K 电导。

DOI：
10.1016/j.bcp.2006.03.011
发表时间：
2006
期刊：
Biochemical pharmacology
影响因子：
5.8
作者：
Pelish,HenryE;Ciesla,William;Tanaka,Nori;Reddy,Krishna;Shair,MatthewD;Kirchhausen,Tomas;Lencer,WayneI
通讯作者：
Lencer,WayneI

Intestinal goblet cells sample and deliver lumenal antigens by regulated endocytic uptake and transcytosis.

DOI：
10.7554/elife.67292
发表时间：
2021-10-22
期刊：
eLife
影响因子：
7.7
作者：
Gustafsson JK;Davis JE;Rappai T;McDonald KG;Kulkarni DH;Knoop KA;Hogan SP;Fitzpatrick JA;Lencer WI;Newberry RD
通讯作者：
Newberry RD

Role of the glycocalyx in regulating access of microparticles to apical plasma membranes of intestinal epithelial cells: implications for microbial attachment and oral vaccine targeting.