Control of Inflammatory Acidity in Mucosal Inflammation

粘膜炎症中炎症酸度的控制

• 批准号: 10255086
• 负责人: Ian Michael Cartwright
• 金额: --
• 依托单位: VA EASTERN COLORADO HEALTH CARE SYSTEM
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-10-01 至 2026-09-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10255086
• 关键词: Acidity; Acidosis; Acids; Acute; Affect; American; Anxiety; Bacteria; Bicarbonates; Biological Assay; Biological Response Modifier Therapy; Buffers; Cell physiology; Cells; Chemicals; Chronic; Colitis; Colonic inflammation; Crohn' s disease; Data; Development; Disease; Disease Outcome; Epithelial Cells; Escherichia coli; Exposure to; Family; Funding; Gastrointestinal tract structure; Gene Expression Regulation; Generations; Genetic; Genetic Transcription; Germ-Free; Glycolysis; Goals; Home; Hospitalization; Hypochlorous Acid; Ileitis; Immune response; Immunology; In Vitro; Incidence; Indoles; Infiltration; Inflammation; Inflammatory; Inflammatory Bowel Diseases; Inflammatory Response; Intestines; Knowledge; Lactic acid; Malignant Neoplasms; Mental Depression; Mentorship; Modeling; Modification; Molds; Monitor; Mucositis; Mucous Membrane; Mus; Pathogenesis; Pathology; Patients; Peroxidases; Pharmacology; Phenotype; Post-Traumatic Stress Disorders; Production; Regulation; Reporting; Research Personnel; Resolution; Role; SECTM1 gene; SLC26A3 gene; Severity of illness; Signal Transduction; Site; Source; Surface; TNF gene; Testing; Time; Tissues; Training; Ulcerative Colitis; Veterans; Work; base; career development; chemically induced colitis; commensal bacteria; cytokine; design; economic impact; effective therapy; experience; extracellular; gastrointestinal; genetic approach; genetic signature; gut inflammation; hospitalization rates; host-microbe interactions; in vivo; inhibitor; intestinal epithelium; intestinal homeostasis; knock-down; member; metabolomics; microbial; microbial host; microbiota; microbiota metabolites; migration; military veteran; mouse model; murine colitis; neutrophil; novel; novel therapeutics; pH Homeostasis; psychosocial; response; symposium; transcriptome sequencing; wound healing

Within the gastrointestinal (GI) tract the primary function of the mucosal surface is to provide a selective barrier to the outside. It is widely understood that the GI tract exists in a state of low-grade inflammation, as a result of constant processing of luminal antigenic material. The GI tract is home to trillions of commensal bacteria which contribute significantly to GI homeostasis, but can also initiate and drive the progression of mucosal diseases. Acute intestinal inflammation involves early accumulation of neutrophils (PMN) followed by either resolution or progression to chronic inflammation. Without efficient PMN clearance at sites of infiltration, PMN can accumulate and contribute to chronic inflammatory conditions, including inflammatory bowel disease. The ongoing studies outline in this proposal have revealed that PMN transepithelial migration (TEM) results in a significant decrease in extracellular pH, deemed inflammatory acidification. Extensions of these studies have shown that this acidic microenvironment impacts barrier function and gene transcription in intestinal epithelial cells (IEC). Guided by an unbiased RNAseq of IEC exposed to low pH in vitro and tissue metabolomics in vivo, we identified a gene signature that includes induction of both TNF and members of the DUSP and NR4A families. We also identified a role of IEC GPR31 in sensing extracellular pH and the loss of microbial-derived indoles during active inflammation. Extending these studies, we observed significant improvement in IEC barrier function under acidic conditions in T84 cells which had GPR31 knocked down. Additionally, we observed that indole treatment significantly decreased inflammatory acidification following PMN TEM and in K12 E. coli acidic conditions induce the production of indole. Based on these observations, we hypothesize that inflammatory acidification promotes inflammatory signaling in IEC and that the microbiota-derived indoles have a significant role in promoting pH homeostasis at sites of inflammation. In vitro functional assays will define the impact of extracellular acidosis and pH sensing on PMN TEM, IEC barrier function, and IEC adaptation to chronic extracellular acidosis. These studies will be extended to examine the influence of microbial/host interactions on IEC responses to extracellular acidification. Finally, utilizing in vivo murine colitis and ileitis models we will profile inflammatory acidification. We will extend these studies to investigate the impact of the microbiota and microbiota-derived metabolites on inflammation-associated acidosis. The career development and training plan outlined in this application is designed to guide and promote my transition to independence as a VA funded researcher. The proposed combination of didactic courses, professional conferences, and mentorship committee have been designed to strengthen my knowledge of mucosal immunology and mucosal inflammation. Technically, I will gain experience in the generation of murine intestinal enteroids, genetic modification of enteroids, both chemically induced and spontaneous murine models of ileitis and colitis, and expand my knowledge of microbial/host response and technical experience in manipulating the microbiota. Upon completion of this proposal I will be well prepared to establish myself as an expert in pH regulation and inflammation-associated acidification. Furthermore, it is our hope that the studies outline in this proposal will lay the groundwork for the identification of novel therapeutic avenues in IBD, directly benefiting the veteran population.

在胃肠道 (GI) 内，粘膜表面的主要功能是提供选择性屏障 众所周知，胃肠道由于以下原因而处于低度炎症状态。 胃肠道是数万亿共生细菌的家园。 显着促进胃肠道稳态，但也可以引发和驱动粘膜疾病的进展。 急性肠道炎症涉及中性粒细胞 (PMN) 的早期积累，随后消退或 如果浸润部位没有有效的 PMN 清除，PMN 就会进展为慢性炎症。 积累并导致慢性炎症，包括炎症性肠病。 该提案中正在进行的研究概述表明，PMN 跨上皮迁移（TEM）导致 细胞外 pH 值显着降低，被认为是炎症酸化。 研究表明，这种酸性微环境会影响肠上皮的屏障功能和基因转录 细胞 (IEC) 的指导下，暴露于体外低 pH 值和体内组织代谢组学的 IEC 的无偏 RNAseq， 我们确定了一个基因特征，其中包括 TNFα 以及 DUSP 和 NR4A 成员的诱导 我们还确定了 IEC GPR31 在感知细胞外 pH 值和微生物来源的损失中的作用。 扩展这些研究，我们观察到 IEC 的显着改善。 GPR31 敲低的 T84 细胞在酸性条件下的屏障功能。 观察到吲哚治疗显着降低了 PMN TEM 后的炎症酸化，并且在 K12 大肠杆菌酸性条件诱导吲哚的产生 基于这些观察，我们陷入了困境。 炎症酸化促进 IEC 中的炎症信号传导，并且微生物群衍生的吲哚 体外功能测定对促进炎症部位的 pH 稳态具有重要作用。 定义细胞外酸中毒和 pH 传感对 PMN TEM、IEC 屏障功能和 IEC 的影响 这些研究将扩展到检查慢性细胞外酸中毒的影响。 微生物/宿主相互作用对细胞外酸化的 IEC 反应的影响最后利用，体内小鼠结肠炎。 和回肠炎模型，我们将分析炎症酸化。 微生物群和微生物群衍生的代谢物对炎症相关酸中毒的影响。 本申请中概述的发展和培训计划旨在指导和促进我向 独立作为 VA 资助的研究人员 建议结合教学课程、专业。 会议和指导委员会的目的是加强我对粘膜的了解 从技术上讲，我将获得小鼠肠道生成的经验。 肠类，肠类的基因改造，化学诱导和自发性回肠炎小鼠模型 和结肠炎，并扩展我对微生物/宿主反应的知识以及操纵微生物/宿主反应的技术经验 完成这项提案后，我将做好充分准备，成为 pH 方面的专家。 此外，我们希望本文中的研究能够概述。 该提案将为确定 IBD 的新治疗途径奠定基础，直接受益 退伍军人人口。