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 到外面。人们普遍认为，胃肠道存在于一种低度炎症状态，这是由于 腔抗原物质的持续处理。胃肠道是数万亿肠道细菌的家园， 对胃肠道内稳态有显著贡献，但也可引发和推动粘膜疾病的进展。 急性肠道炎症涉及中性粒细胞（PMN）的早期积累，随后消退或 进展为慢性炎症。如果在浸润部位没有有效的PMN清除， 积累并导致慢性炎症性疾病，包括炎症性肠病。的 该提案中概述的正在进行的研究表明，PMN跨上皮迁移（TEM）导致 细胞外pH值显着下降，被认为是炎症酸化。这些研究的扩展有 表明这种酸性微环境影响肠上皮细胞的屏障功能和基因转录， 细胞（IEC）。在体外暴露于低pH和体内组织代谢组学的IEC的无偏RNAseq的指导下， 我们鉴定了一个基因标记，包括TNF α和DUSP及NR 4A成员的诱导。 家庭我们还确定了IEC GPR 31在感知细胞外pH值和微生物来源的蛋白质丢失中的作用。 在活动性炎症期间释放吲哚。扩展这些研究，我们观察到IEC的显著改善 GPR 31敲除的T84细胞在酸性条件下的屏障功能。另外我们 观察到吲哚治疗显著降低了PMN TEM后的炎症酸化， K12 E.大肠杆菌的酸性条件诱导吲哚的产生。基于这些观察，我们假设 炎症酸化促进IEC中的炎症信号传导， 在促进炎症部位的pH稳态方面具有重要作用。体外功能测定将 明确细胞外酸中毒和pH感知对PMN TEM、IEC屏障功能和IEC的影响 适应慢性细胞外酸中毒。这些研究将扩展到检查的影响， 微生物/宿主相互作用对IEC对胞外酸化反应的影响。最后，利用体内鼠结肠炎， 和回肠炎模型，我们将分析炎症酸化。我们将扩展这些研究， 微生物群和微生物群衍生的代谢物对炎症相关性酸中毒的影响。职业 本申请中概述的发展和培训计划旨在指导和促进我过渡到 作为一个独立的研究人员。建议结合教学课程，专业 会议和导师委员会的设计，以加强我的粘膜知识 免疫学和粘膜炎症。从技术上讲，我将获得经验，在一代鼠肠 肠样物质，肠样物质的遗传修饰，化学诱导和自发性小鼠回肠炎模型 和结肠炎，并扩大我的微生物/宿主反应的知识和技术经验，在操纵 微生物群在完成这一建议后，我将做好充分的准备，以建立自己作为一个专家在pH值 调节和炎症相关的酸化。此外，我们希望这些研究概述了这一点， 该提案将为确定IBD的新治疗途径奠定基础， 退伍军人人口。