Mucosal modulation by LGG and R. gnavus specific tryptophan metabolites

LGG 和 R. gnavus 特异性色氨酸代谢物对粘膜的调节

基本信息

批准号：
9788244
负责人：
RONALDO PARAOAN FERRARIS
金额：
$ 38.75万
依托单位：
RUTGERS THE STATE UNIV OF NJ NEWARK
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-09-20 至 2022-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9788244
关键词：
16S ribosomal RNA sequencing ARNT gene Ablation Acute Address Affect Affinity Agonist Animal Model Anti-inflammatory Aryl Hydrocarbon Receptor Bacteria Binding Biological Biological Assay Cell Compartmentation Cell Nucleus Cell physiology Colitis Collaborations Data Diet Disease Elements Engineering Epithelial Epithelial Cells Essential Amino Acids Excision Gene Expression Genes Genetic Germ-Free Gnotobiotic Health Homeostasis Immune Impairment Inflammatory disease of the intestine Innate Immune Response Intervention Intestinal Mucosa Intestines Knock-out Knockout Mice Lactobacillus Lactobacillus casei rhamnosus Lamina Propria Ligands Link Literature Mammals Mediating Mucolytics Mucosal Immune Responses Mucous Membrane Mus Nature Organoids Pathway interactions Perfusion Physiology Play Predisposition Probiotics Property Protein Biosynthesis Public Health Receptor Activation Receptor Signaling Recording of previous events Role Signal Pathway Signal Transduction Source Structure System Testing Tight Junctions Tryptamines Tryptophan Work aryl hydrocarbon receptor ligand bacterial genetics beta catenin cytokine dietary manipulation dimer dysbiosis experience high risk host-microbe interactions innovation metabolomics microbial microbial community microbiota mouse model mutant pathobiont promoter receptor structure function screening stem cell division transcriptome sequencing

项目摘要

PROJECT SUMMARY: The dietary benefits of tryptophan have been classically linked to its property as an essential amino acid required by mammals for protein synthesis, but recent work in the past decade has revealed its equally essential role as an important source of metabolites for the microbial community to generate signals, mainly via the Aryl Hydrocarbon Receptor (AHR), to affect a plethora of cellular functions. AHR signaling pathway is highly promiscuous not only responding to diverse ligands with resembling structures, but also crosstalk with and is modulated by numerous cellular signaling pathways. Distinct agonists can result in ligand selective differences in AHR structure and function, ultimately leading to agonist-selective gene expression and biological effects. In the gut, AHR activation by bacterial tryptophan catabolites influences mucosal homeostasis and microbiota composition. Although bacterial tryptophan metabolites and AHR axis may contribute to microbial sensing and tolerance, it is unclear if probiotics and pathobionts produce distinct tryptophan metabolites thereby eliciting bacterial species- and agonist-specific host mucosal modulating effects. Both Lactobacillus and Ruminoccocus spp catabolize tryptophan to a variety of tryptamine and indolic products that bind at low to high affinities to the AHR. The identities and specific biological effects of tryptophan metabolites produced by the probiotic Lactobacillus rhamnosus GG (LGG) and the pathobiont R. gnavus are currently unknown. Preliminary RNA-Seq analysis of mouse intestinal mucosa perfused with live LGG revealed a robust induction of AHR signaling activity as well as anti-inflammatory cytokines. Bacterial 16s rRNA sequencing and untargeted fecal metabolomics screening of a newly engineered Lyz1 knockout mouse model revealed a dysbiosis featured by expansion of mucolytic bacterial species (e.g., R. gnavus), accompanied by a pronounced elevation of tryptophan metabolites and a changed epithelial cell composition. The hypothesis is that the probiotic LGG and the pathobiont R. gnavus metabolize dietary tryptophan into distinct agonists that elicit differential mucosal modulating effects via the host AHR signaling. Aim I will use mono-colonization of germ-free mice, dietary tryptophan depletion, unbiased metabolomics profiling, and isogenic mutant bacteria deficient in tryptophan-metabolizing to identify LGG and R. gnavus specific tryptophan metabolites and their differential mucosal modulating effects. Aim 2 will employ organoid culture, intraluminal perfusion of AHR agonists, and genetic ablation of host AHR signaling to determine the direct effects of bacterial species-specific tryptophan metabolites and AHR signaling on Lyz1-deficient mouse mucosal homeostasis and colitis susceptibility. This MPI project uses rigorous approaches, including gnotobiotics, bacterial genetics, dietary manipulation, and unbiased metabolomics, etc. to address an important mechanism involving diet-microbe-host interaction that may underlie the biological natures of probiotics and pathobionts. The two PIs have a history of productive collaboration, and have demonstrated experiences in studying intestinal physiology. This project employing innovative animal models is significant for public health and disease intervention.

项目摘要：色氨酸的饮食益处经典地与其特性联系在一起，作为必需的氨基酸通过哺乳动物进行蛋白质合成，但在过去十年中最近的工作揭示了其同样重要的作用微生物群落生成信号的代谢产物的重要来源，主要通过芳基碳氢化合物受体（AHR），以影响大量细胞功能。 AHR信号通路高度高混杂的不仅与结构相似的不同配体做出反应，而且还与由许多细胞信号通路调节。不同的激动剂会导致配体选择性差异在AHR结构和功能中，最终导致了激动剂选择性基因表达和生物学作用。在细菌色氨酸分解代谢物的肠道激活会影响粘膜稳态和微生物群作品。尽管细菌色氨酸代谢产物和AHR轴可能有助于微生物感应和耐受性，尚不清楚益生菌和病原体是否产生不同的色氨酸代谢产物，从而引起细菌种类和激动剂特异性宿主粘膜调节作用。乳酸杆菌和蔬菜菌 SPP将色氨酸分解为各种色氨酸和吲哚胺的产品，它们以低至高亲和力结合到高亲和力啊。益生菌产生的色氨酸代谢产物的身份和特定生物学作用目前尚不清楚rhamnosus lamnosus gg（LGG）和Pathobiont R. gnavus。初步RNA-Seq 用实时LGG灌注的小鼠肠粘膜分析显示AHR信号传导活性的强烈诱导以及抗炎细胞因子。细菌16S rRNA测序和未靶向的粪便代谢组学筛选新设计的LYZ1敲除鼠标模型显示出一种营养不良的膨胀。粘液溶解细菌种（例如，gnavus），伴随着色氨酸代谢物的明显升高以及改变的上皮细胞组成。假设是益生菌LGG和Pathobiont R. gnavus 将饮食色氨酸代谢成不同的激动剂，这些激动剂会通过宿主引起差异粘膜调节作用 AHR信号。目的我将使用无细菌小鼠的单色殖民化，饮食色氨酸耗竭，无偏见代谢组学分析和异源性突变细菌缺乏色氨酸量代谢，以鉴定LGG和R。特异性色氨酸代谢产物及其差异粘膜调节作用。 AIM 2将使用器官培养，AHR激动剂的腔内灌注以及宿主AHR信号的遗传消融以确定细菌特异性色氨酸代谢产物和AHR信号对LYZ1缺陷小鼠的直接影响粘膜稳态和结肠炎的敏感性。该MPI项目使用严格的方法，包括 gnotobiotics，细菌遗传学，饮食操纵和无偏的代谢组学等，以解决重要的涉及饮食 - 微生物宿主相互作用的机制，可能是益生菌和 Pathobionts。这两个PI有生产性合作的历史，并展示了研究肠道生理学。这个采用创新动物模型的项目对公共卫生非常重要和疾病干预。