Pregnane X receptor (PXR)-activating gut bacterial metabolites

孕烷 X 受体 (PXR) 激活肠道细菌代谢物

• 批准号: 10452237
• 负责人: Hyunyoung Jeong
• 金额: $ 20.02万
• 依托单位: PURDUE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-08 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10452237
• 关键词: Affect; Biological; Biological Assay; Biological Process; CYP3A4 gene; Cecum; Cells; Chemicals; Collection; Culture Media; DNA sequencing; Data; Disease; Drug Regulations; Enzymes; Follow-Up Studies; Fractionation; Fusobacterium nucleatum; Future; Gene Cluster; Gene Expression; Genes; Genetic Determinism; Germ-Free; Goals; Health; HepG2; Homeostasis; Homologous Gene; Human; Human body; Intestines; Investigation; Knowledge; Libraries; Ligands; Liver; Maintenance; Mass Spectrum Analysis; Mediating; Messenger RNA; Methods; Microbe; Molecular; Mus; Pharmaceutical Preparations; Physiology; Production; Protons; Receptor Activation; Regulation; Reporter; Reporting; Research; Resolution; Role; Structural Genes; Structure; Transactivation; bacterial genetics; base; gut bacteria; gut homeostasis; gut microbes; gut microbiota; host-microbe interactions; immune function; microbial; mutant; novel; overexpression; pregnane X receptor; promoter; recruit; screening; small molecule; tool; transcription factor; Affect; Biological; Biological Assay; Biological Process; CYP3A4 gene; Cecum; Cells; Chemicals; Collection; Culture Media; DNA sequencing; Data; Disease; Drug Regulations; Enzymes; Follow-Up Studies; Fractionation; Fusobacterium nucleatum; Future; Gene Cluster; Gene Expression; Genes; Genetic Determinism; Germ-Free; Goals; Health; HepG2; Homeostasis; Homologous Gene; Human; Human body; Intestines; Investigation; Knowledge; Libraries; Ligands; Liver; Maintenance; Mass Spectrum Analysis; Mediating; Messenger RNA; Methods; Microbe; Molecular; Mus; Pharmaceutical Preparations; Physiology; Production; Protons; Receptor Activation; Regulation; Reporter; Reporting; Research; Resolution; Role; Structural Genes; Structure; Transactivation; bacterial genetics; base; gut bacteria; gut homeostasis; gut microbes; gut microbiota; host-microbe interactions; immune function; microbial; mutant; novel; overexpression; pregnane X receptor; promoter; recruit; screening; small molecule; tool; transcription factor

The gut microbiota modulates human health and disease often via the production of small molecule metabolites; however, the identities of the majority of gut microbial metabolites and their biological actions remain largely unknown. Pregnane X receptor (PXR) is a ligand-activated transcription factor that is activated by structurally diverse chemicals. PXR regulates the expression of genes encoding drug-metabolizing enzymes including cytochrome P450 3A4 (CYP3A4). Additionally, PXR in the intestine and liver has been implicated in the maintenance of gut barrier and immune functions as well as energy homeostasis. Accumulating evidence suggests that the gut microbiota produces PXR ligands. To date, few bacterial metabolites have been reported as mouse or human PXR ligands, and systematic efforts to identify PXR- activating, gut microbial metabolites have been lacking. This lack of knowledge constitutes a substantial gap in defining how the gut microbiota alters human health and disease especially via PXR. The long-term goal of our research is to identify and characterize factors mediating gut microbes-host interactions. The overall objective of this application is to identify gut bacterial metabolites activating PXR, a ligand-activated transcription factor with pleiotropic biological functions including the regulation of drug-metabolizing enzymes and the maintenance of gut homeostasis. Our central hypothesis is that gut bacteria produce metabolites that activate PXR. Our hypothesis is based on the following preliminary results: (1) In HepG2 cells overexpressing human PXR (HepG2/hPXR), the organic extracts of mouse cecum contents significantly induced hPXR transactivation of PXR target gene (i.e., CYP3A4) promoter, indicating the presence of hPXR activators among gut microbial products. (2) A screening of 10 common human gut bacteria led to identification of Fusobacterium nucleatum as a producer of hPXR activator(s); in HepG2/hPXR cells, the organic extracts of F. nucleatum culture supernatants significantly induced hPXR transactivation of the CYP3A4 promoter. (3) We increased the yield of the active metabolite from F. nucleatum by changing the growth media and obtained a proton NMR and high- resolution mass spectrometry results of an active metabolite-enriched fraction. The results suggest that PXR- activating metabolite(s) of F. nucleatum are likely novel compounds. Together, our data indicate that gut bacteria produce as-yet-unknown metabolite(s) that activate PXR. Based our findings, we propose to (1) identify gut bacteria-derived metabolites that promote hPXR transactivation of CYP3A4 expression and (2) define genetic determinants for the production of hPXR activator(s) in F. nucleatum. Successful completion of these studies will set the stage for future investigation, providing much-needed tool sets to investigate underlying molecular mechanisms for how the gut microbiota modulates PXR activity. Together, these efforts will enhance our understanding of how the gut microbiota controls host physiology.

肠道菌群经常通过小分子的产生调节人类健康和疾病 代谢物；但是，大多数肠道微生物代谢产物及其生物学作用的身份 在很大程度上未知。妊娠X受体（PXR）是一种被激活的配体激活转录因子 通过结构上多样化的化学物质。 PXR调节编码药物代谢的基因的表达 包括细胞色素P450 3A4（CYP3A4）的酶。此外，肠和肝脏中的PXR已经 与维持肠道障碍和免疫功能以及能量稳态有关。 积累的证据表明肠道菌群产生PXR配体。迄今为止，细菌很少 已报道了代谢物为小鼠或人PXR配体，并进行了系统的努力，以鉴定PXR- 激活，肠道微生物代谢产物缺乏。缺乏知识构成了很大的差距 定义肠道菌群如何改变人类健康和疾病，尤其是通过PXR改变。我们的长期目标 研究是为了识别和表征介导肠道微生物 - 宿主相互作用的因素。总体目标 该应用的是识别肠道细菌代谢物激活PXR，这是一种配体激活的转录因子 具有多效性生物学功能，包括调节药物代谢酶和 维持肠稳态。我们的中心假设是肠道细菌产生活化的代谢产物 pxr。我们的假设基于以下初步结果：（1）在过表达人的HEPG2细胞中 PXR（HEPG2/HPXR），小鼠盲含量的有机提取物显着诱导HPXR反式激活 PXR靶基因（即CYP3A4）的启动子的启动子的存在，表明HPXR激活剂在肠道微生物中存在 产品。 （2）对10种常见的人肠道细菌进行筛查，导致核细菌的核细菌鉴定 作为HPXR激活剂的生产商；在HEPG2/HPXR细胞中，核培养的有机提取物 上清液显着诱导CYP3A4启动子的HPXR反式激活。 （3）我们提高了产量 通过改变生长培养基并获得质子NMR和高 - 高 - 富含代谢物富集的分辨率质谱结果。结果表明PXR- F. nutleatum的活化代谢产物可能是新型化合物。一起，我们的数据表明肠道 细菌会产生激活PXR的尚未尚未代谢的代谢产物。基于我们的发现，我们建议（1） 鉴定肠道细菌衍生的代谢产物，这些代谢物促进了CYP3A4表达的HPXR反式激活和（2） 定义用于F.核中HPXR激活剂的产生的遗传决定因素。成功完成 这些研究将为未来的研究奠定基础，提供急需的工具集以调查 肠道菌群如何调节PXR活性的基本分子机制。在一起，这些努力 将增强我们对肠道微生物群如何控制宿主生理的理解。