Role of TLR4 and the microbiome in colitis associated neoplasia

TLR4 和微生物组在结肠炎相关肿瘤中的作用

• 批准号: 10361471
• 负责人: Maria Teresa Abreu
• 金额: $ 34.54万
• 依托单位: UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2023-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10361471
• 关键词: Animal Model; Bacteria; Bioinformatics; Biological Process; Biopsy; Cell Death; Cell Proliferation; Cells; Characteristics; Chronic; Clinical; Colectomy; Colon; Colon Carcinoma; Colonic Neoplasms; Colonic inflammation; DNA Damage; Data; Defect; Diagnosis; Dimensions; Dysplasia; Enzymes; Epithelial; Epithelial Cells; Future; Gene Expression; Gene Expression Profile; Genes; Germ-Free; Gnotobiotic; Grant; Growth; Human; Hydrogen Peroxide; ITGAM gene; Immune; Immune signaling; Immune system; Inflammation; Inflammatory; Inflammatory Bowel Diseases; Innate Immune Response; Intestines; Knockout Mice; Lamina Propria; Ligands; Link; Lipopolysaccharides; Malignant Neoplasms; Mediating; Methods; Molecular; Mucous Membrane; Mus; Mutation; Myelogenous; Myeloid-derived suppressor cells; NADP; NADPH Oxidase; Neoplasm Metastasis; Neoplasms; Oxidases; Oxidation-Reduction; Oxidative Stress; Patients; Phagocytes; Population; Positioning Attribute; Predisposition; Prevention; Process; Production; Proliferating; Proteobacteria; RNA; Reactive Oxygen Species; Resources; Risk; Role; S100A8 gene; Shapes; Signal Transduction; Signaling Molecule; Specimen; TLR4 gene; Testing; Therapeutic; Tissues; Transgenic Organisms; Transplantation; Tumor Stem Cells; Ulcerative Colitis; United States National Institutes of Health; Up-Regulation; Work; base; cancer stem cell; cancer survival; carcinogenicity; chemokine; colitis associated cancer; colitis-associated neoplasia; colon cancer risk; cytokine; dysbiosis; gut bacteria; immune activation; insight; intestinal epithelium; large bowel Crohn' s disease; metagenomic sequencing; microbial; microbial signature; microbiome; microbiota; mouse model; overexpression; prevent; recruit; response; stem cells; transcriptome sequencing; tumor; tumor microenvironment; tumor progression; tumorigenesis; tumorigenic

ABSTRACT We seek to understand the progression from inflammation to neoplasia in patients with inflammatory bowel disease (IBD). Often patients are diagnosed with dysplasia and undergo colectomies even though they will never develop cancer. The focus of our studies has been the link between intestinal bacteria and innate immune signaling leading to colitis-associated neoplasia. Toll-like receptor 4 (TLR4) recognizes LPS and other endogenous ligands present in the inflamed colon. Our group has shown that TLR4 is overexpressed in inflamed and dysplastic tissues of ulcerative colitis (UC) patients. Using transgenic and knock-out mice, we have shown that intestinal epithelial expression of TLR4 engenders a colitogenic microbiome capable of transmitting inflammation. Mice with constitutively active TLR4 in epithelial cells show dramatically increased epithelial proliferation and increased colonic tumors (AOM-DSS). Our preliminary data demonstrate that cancer stem cells from these tumors have a very distinct transcriptional profile compared to tumors in WT mice. We also show that TLR4-driven tumors have enhanced recruitment of tumor supporting myeloid-derived suppressor cells (MDSCs). TLR4-driven tumors have dramatic upregulation of NADPH oxidases and enhanced production of H2O2. H2O2 and other reactive oxygen species have several biological functions, including control of cell proliferation and microbial populations. In the current proposal, we hypothesize that dysregulation of TLR4 induces redox signaling, promoting stem cell activation and leading to selection of a tumorigenic microbiome. We further hypothesize that the dysbiotic microbiome activates MDSCs to promote CAC. This is pursued in the following specific aims: 1) Analyze the role of TLR4-mediated redox signaling on cancer stem cell activation in CAC. We will use our diverse animal models for TLR4 and the NADPH dual oxidase 2 (Duox2) to define how redox signaling participates in activation and survival of cancer stem cells during TLR4- driven tumorigenesis. 2) Interrogate the inter-relationship of TLR4-mediated redox signaling on mucosal dysbiosis and the consequences of dysbiosis in tumorigenesis. We will use our animal models and metagenomic sequencing to investigate how redox signaling through Duox2 participates in TLR4-mediated dysbiosis, and will use mucosa-associated microbial transplants to test the tumorigenic effects of this microbiota in germ-free mice. 3) Dissect the role of TLR4 in shaping the response of MDSCs to the resident microbiome during tumorigenesis. We will use dual RNA sequencing of bacterial and host RNA from tumor-associated MDSCs and MDSCs from UC patients to determine the interplay between the resident microbiota and tumor-promoting gene expression in MDSCs. We will also functionally characterize the pro- tumorigenic responses of MDSCs upon TLR4 stimulation including cytokine, chemokine, and H2O2 production. The work proposed herein will provide the mechanistic justification for subsequent human studies to target TLR4 or downstream signaling molecules as a means to halt progression from UC/inflammation to dysplasia and dysplasia to cancer.

摘要 我们试图了解炎症性肠病患者从炎症到肿瘤的进展 疾病（IBD）。通常患者被诊断为发育不良，并接受结肠切除术，即使他们将 永远不会患癌症。我们研究的重点一直是肠道细菌和先天性 导致结肠炎相关瘤形成的免疫信号。Toll样受体4（TLR 4）识别LPS和其他 存在于发炎结肠中的内源性配体。我们的研究小组已经表明，TLR 4在人乳腺癌细胞中过表达， 溃疡性结肠炎（UC）患者的发炎和发育不良组织。使用转基因和基因敲除小鼠，我们 已经表明TLR 4的肠上皮表达产生了能够产生大肠杆菌的微生物组 传播炎症在上皮细胞中具有组成型活性TLR 4的小鼠显示出显著增加的 上皮细胞增殖和结肠肿瘤增加（AOM-DSS）。我们的初步数据表明癌症 与WT小鼠中的肿瘤相比，来自这些肿瘤的干细胞具有非常不同的转录谱。我们 还表明TLR 4驱动的肿瘤增强了支持骨髓源性肿瘤的募集， 抑制细胞（MDSC）。TLR 4驱动的肿瘤具有显著上调的NADPH氧化酶和增强的 生产H2 O2。H2 O2和其他活性氧具有多种生物学功能，包括控制 细胞增殖和微生物数量的变化。在目前的建议中，我们假设， TLR 4诱导氧化还原信号传导，促进干细胞活化，并导致选择致瘤因子。 微生物组我们进一步假设，微生态失调的微生物组激活MDSC以促进CAC。这是 本论文的主要目的如下：1）分析TLR 4介导的氧化还原信号在肿瘤发生中的作用 CAC中的干细胞活化。我们将使用我们的TLR 4和NADPH双氧化酶2的多种动物模型， （Duox 2）来定义氧化还原信号传导如何参与TLR 4 - 1过程中癌症干细胞的活化和存活。 驱动的肿瘤发生。2)探讨TLR 4介导的氧化还原信号对粘膜细胞凋亡的影响 生态失调和肿瘤发生中生态失调的后果。我们将使用动物模型， 宏基因组测序，以研究通过Duox 2的氧化还原信号传导如何参与TLR 4介导的 生态失调，并将使用粘膜相关的微生物移植来测试这种肿瘤的影响。 无菌小鼠的微生物群。3)剖析TLR 4在塑造MDSC对IL 4的应答中的作用。 在肿瘤发生过程中的常驻微生物组。我们将使用细菌和宿主RNA的双重RNA测序 从肿瘤相关的MDSC和UC患者的MDSC，以确定居民之间的相互作用 微生物群和MDSC中的肿瘤促进基因表达。我们还将功能特性的亲- MDSC在TLR 4刺激后的致瘤反应，包括细胞因子、趋化因子和H2 O2产生。 本文提出的工作将为随后的人体研究提供机制依据，以靶向 TLR 4或下游信号分子作为阻止UC/炎症进展为异型增生的手段 发育不良发展为癌症