Impact of dysbiotic and symbiotic catabolism of luminal amino acids on intestinal epithelial barrier function and inflammation

管腔氨基酸的失调和共生分解代谢对肠上皮屏障功能和炎症的影响

基本信息

批准号：
10912096
负责人：
M. Ashfaqul Alam
金额：
$ 37.51万
依托单位：
UNIVERSITY OF KENTUCKY
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-09-20 至 2024-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10912096
关键词：
6-Aminocaproic Acid Adherens Junction Adult Agmatine Amines Amino Acids Anti-Bacterial Agents Arginine Attention Bacteria Bacteroides Cadaverine Carboxy-Lyases Catabolism Cell membrane Cell physiology Cells Cellular biology Chronic Colon Creativeness Crohn&apos s disease Data Desmosomes Disease Ensure Enterocytes Enzymes Epithelial Attachment Epithelial Cells Epithelium Escherichia coli Gastrointestinal Diseases Germ-Free Goals Health Homeostasis Immune Immunologics Impairment Inflammation Inflammatory Bowel Diseases Injury Intercellular Junctions Interleukin-10 Intestinal Mucosa Intestinal permeability Intestines Investigation Knockout Mice Knowledge Link Lysine Mediating Metabolic Molecular Mucositis Mucous Membrane Mus National Institute of Diabetes and Digestive and Kidney Diseases Neurons Oxidative Stress Pathogenesis Pathway interactions Perception Permeability Polyamines Post-Translational Protein Processing Process Property Proteins Proteobacteria Putrescine Regulation Research Priority Role Series Shotguns Spermidine Spermine Sumoylation Pathway TRPV1 gene Testing Therapeutic Tight Junctions Ulcerative Colitis Vanilloid commensal bacteria cytokine design dysbiosis emerging pathogen extracellular gastrointestinal epithelium gut bacteria gut inflammation gut microbes gut microbiota improved in vitro Assay innovation insight intestinal barrier intestinal epithelium mass spectrometric imaging member metabolomics microbial microbiota microbiota metabolites mutant novel novel therapeutic intervention pathobiont protein function receptor restoration small molecule small molecule inhibitor success symbiont

项目摘要

Over 3 million adults in the U.S. suffer from inflammatory bowel diseases (IBD), which encompasses Crohn’s disease (CD) and ulcerative colitis (UC). IBD is characterized by dysbiotic gut microbiota, compromised epithelial barrier function, chronic intestinal inflammation, and increased mucosal cytokines. Epithelial barrier function is regulated by a series of intercellular junctions that encompass the tight junction (TJ), adherens junction, and desmosomes. Disruption of the critical epithelial barrier allows access of luminal contents to immunologically privileged compartments, thereby contributing to IBD pathogenesis. The dysbiotic gut microbiota-induced mucosal inflammation perturbs intercellular junctions and epithelial homeostatic properties, thereby resulting in a compromised epithelial barrier. However, our knowledge of the molecular basis of commensal-stimulated intercellular junction proteins’ function, epithelial homeostasis, and restoration of the compromised epithelial barrier during intestinal inflammation is very limited. Thus, the overall goals of this proposal are to identify mechanisms by which specific commensal bacteria and bacterial metabolic products regulate functions of intercellular junction proteins, and protect from epithelial barrier compromise and injury. Our preliminary data determined that the symbiotic Bacteroides uniformis predominantly catabolizes arginine to produce polyamine spermidine, which promotes a healthy barrier. In contrast, dysbiotic Proteobacterial species E. coli predominantly catabolizes lysine to synthesize polyamine cadaverine, which impairs gut permeability. Bacterial polyamines are aliphatic amines that regulate multiple cellular processes. Based on our preliminary data, we hypothesize that microbial polyamines regulate epithelial barrier functions by activating TRPV and regulating TJ SUMOylation, a post-translational modification of claudin and ZO proteins in the gut epithelial barrier. Polyamines can activate Transient Receptor Potential Receptors (TRPVs) to regulate cellular functions. In Aim 1, we will dissect the symbiotic polyamine-activated TRPV1 and dysbiotic cadaverine-elicited TRPV3-mediated TJ regulatory processes. In Aim 2, we will elucidate microbial polyamine-driven SUMOylation of TJ proteins eventuating in the perturbed barrier function. Finally, in Aim 3, we will determine the impact of small molecules and luminal metabolites, which inhibit cadaverine synthesizing enzymes of the dysbiotic gut bacteria and thereby dampen intestinal inflammation. This project is both conceptually and technically innovative. It will employ the creative use of Trpv1 and Trpv3 knockout mice and a novel pathogen-specific antibacterial agent. The investigation of the effects of gut bacterially produced polyamines on epithelial TRPV and TJ SUMOylation approach is novel. Completion of these studies will provide clear insights into the molecular basis of intestinal epithelial barrier regulation by commensals’ amino acid catabolism and engender new ideas and proof-of-principle of exploiting commensal bacterial metabolites to develop therapeutics for IBD and other gastrointestinal diseases, a high NIDDK research priority.

美国超过300万成年人患有炎症性肠病（IBD），其中包括克罗恩疾病（CD）和溃疡性结肠炎（UC）。 IBD的特征是肠道疾病菌群，上皮损害屏障功能，慢性肠道注射和粘膜细胞因子增加。上皮屏障功能是由一系列涵盖紧密连接（TJ），粘附连接点和脱骨小体。临界上皮屏障的破坏允许在免疫学上访问腔内内容物特权隔室，从而导致IBD发病机理。不植物肠道菌群诱导的粘膜炎症渗透细胞间连接和上皮稳态特性，从而导致折衷的上皮屏障。但是，我们对共生刺激的分子基础的了解细胞间连接蛋白的功能，上皮稳态和损害上皮的恢复肠道注射过程中的障碍非常有限。这是该提议的总体目标是确定特定的共生细菌和细菌代谢产物调节功能的机制细胞间连接蛋白，并防止上皮屏障的损害和损伤。我们的初步数据确定共生细菌均匀的均匀分解精氨酸以产生多胺精子，可促进健康的障碍。相比之下，不植物蛋白细菌物种主要是大肠杆菌将赖氨酸分解为合成多胺尸体，从而损害肠道渗透性。细菌多胺是调节多个细胞过程的脂肪族胺。根据我们的初步数据，我们假设微生物多胺通过激活TRPV并控制TJ Sumoylation（A）来调节上皮屏障功能肠道上皮屏障中claudin和ZO蛋白的翻译后修饰。多胺可以激活瞬态受体电位受体（TRPV）调节细胞功能。在AIM 1中，我们将剖析共生多胺激活的TRPV1和失毒蛋白诱发的TRPV3介导的TJ调节过程。在AIM 2中，我们将阐明TJ蛋白的微生物多胺驱动的Sumoylation在扰动屏障功能。最后，在AIM 3中，我们将确定小分子和腔的影响代谢物，抑制不植物肠道肠道细菌的尸体合成酶肠炎。该项目在概念上和技术上都是创新的。它将采用创意使用TRPV1和TRPV3敲除小鼠以及一种新型病原体特异性抗菌剂。调查肠道细菌产生的多胺对上皮TRPV和TJ Sumoylation方法的影响是新颖的。这些研究的完成将为肠上皮屏障的分子基础提供明确的见解由Censals的氨基酸分解代谢进行调节，并产生新的想法和原则证明共生细菌代谢物为IBD和其他胃肠道疾病开发治疗 NIDDK研究优先。