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.

美国有超过 300 万成年人患有炎症性肠病 (IBD)，其中包括克罗恩病疾病（CD）和溃疡性结肠炎（UC）的特点是肠道菌群失调、上皮受损。屏障功能、慢性肠道炎症和粘膜细胞因子增加。受一系列细胞间连接的调节，这些连接包括紧密连接 (TJ)、粘附连接和桥粒的破坏允许管腔内容物进入免疫学。特殊区室，从而导致肠道菌群失调引起的 IBD 发病机制。粘膜炎症扰乱细胞间连接和上皮稳态特性，从而导致然而，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、上皮稳态和受损上皮的恢复因此，该提案的总体目标是确定肠道炎症期间的屏障。特定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，并防止上皮屏障受损和损伤。我们的初步数据。确定共生的均匀拟杆菌主要分解代谢精氨酸以产生多胺亚精胺，促进健康屏障，相比之下，失调的变形菌种大肠杆菌占主导地位。分解代谢赖氨酸合成多胺尸胺，这会损害肠道通透性。根据我们的初步数据，我们发现调节多种细胞过程的脂肪胺。微生物多胺通过激活 TRPV 和调节 TJ SUMOylation（一种肠道上皮屏障中密蛋白和 ZO 蛋白的翻译后修饰可以激活多胺。调节细胞功能的瞬时受体电位受体 (TRPV) 在目标 1 中，我们将剖析共生多胺激活的TRPV1和失调的尸胺引发的TRPV3介导的TJ调节在目标 2 中，我们将阐明微生物多胺驱动的 TJ 蛋白 SUMO 化。最后，在目标 3 中，我们将确定小分子和管腔的影响。代谢物，抑制肠道菌群失调的尸胺合成酶，从而抑制细菌和抑制该项目在概念和技术上都具有创新性。使用Trpv1和Trpv3基因敲除小鼠和新型病原体特异性抗菌剂的研究。肠道细菌产生的多胺对上皮 TRPV 和 TJ SUMO 化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清晰的见解共生体氨基酸分解代谢的调节并产生新的想法和利用原理验证共生细菌代谢物开发 IBD 和其他胃肠道疾病的治疗方法， NIDDK 研究优先。