Characterizing the role of the heme catabolism in tissue damage and inflammation.

表征血红素分解代谢在组织损伤和炎症中的作用。

• 批准号: 10219490
• 负责人: Barbara Wegiel
• 金额: $ 52.36万
• 依托单位: BETH ISRAEL DEACONESS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-03-29 至 2025-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10219490
• 关键词: 16S ribosomal RNA sequencing; Abnormal Epithelial Cell; Affect; Antibiotics; Bacteria; Biliverdine; Binding; Biological; Biological Products; Biology; Biopsy; Body Weight; Catabolism; Cell Death; Cell Therapy; Cells; Cessation of life; Chemotherapy-Oncologic Procedure; Chromatin; Clinical; Colitis; Colon; Cytolysis; DNA; DNA Damage; DNA Markers; DNA Sequence; Data; Deferoxamine; Disease; Doxorubicin; Enzymes; Epithelial Cell Proliferation; Epithelial Cells; Equilibrium; Erythrocytes; Excision; Feces; G-Quartets; Gastrointestinal Hemorrhage; Gastrointestinal Injury; Gene Expression; Gene Expression Regulation; Genes; Genetic Transcription; Genome Stability; Genomic DNA; Genotoxic Stress; H2AFX gene; Heme; Hemoglobin; Hemolysis; Hemopexin; Hemorrhage; Iatrogenesis; Immune; In Vitro; Inflammation; Inflammation Mediators; Inflammatory; Injury; Intestinal permeability; Intestines; Iron; Ischemia; Lead; Link; Measures; Mediating; Methods; Modeling; Molecular; Morbidity - disease rate; Mus; Myelogenous; Myeloid Cells; Normal tissue morphology; Pathologic; Patients; Pattern; Physiological; Population; Production; Proliferation Marker; RNA; RNA analysis; Radiation; Radiation therapy; Reactive Oxygen Species; Recombinants; RiboTag; Role; Scheme; Stains; Stimulus; Structure; Survival Rate; Symptoms; Syndrome; TLR4 gene; Therapeutic; Tissues; Toxic effect; Work; anti-cancer; biological adaptation to stress; c-myc Genes; cancer radiation therapy; chemotherapy; complement C2a; design; dietary heme; effective therapy; extracellular; gastrointestinal; genotoxicity; gut microbiota; healing; heme a; heme oxygenase-1; human tissue; indexing; inflammatory disease of the intestine; inflammatory marker; intestinal barrier; irradiation; macrophage; microbiome analysis; mouse model; novel; phenylhydrazine; promoter; protective effect; reconstitution; response; tissue injury; transcriptome sequencing; treatment strategy

Project Summary Gastrointestinal syndrome (GIS) remains a significant clinical problem with no effective treatment. Radiotherapy and chemotherapy lead to bleeding and cell death resulting in release of hemoglobin and/or free heme. Accumulating data suggest that free heme stimulates the production of reactive oxygen species (ROS) and acts as a pro-inflammatory danger-associated molecular pattern (DAMP) through its binding to Toll-Like Receptor 4 (TLR4). In this study, we will focus on understanding how free heme regulates inflammation through gene regulation in myeloid or epithelial cells in the gut in the GIS models. Our data indicate there are high numbers of infiltrating heme oxygenase-1 (HO-1)-positive macrophages (Mø) in colonic biopsies from patients after radiotherapy versus non-irradiated controls or in the ischemic intestine compared to matched normal tissues. Further, we showed that myeloid cell-specific deletion of HO-1 resulted in abnormal epithelial cell proliferation and increased DNA damage (phosphorylated histone H2AX (H2AXg)) in the intestine upon irradiation. We propose that removal of free heme by the heme scavenger, hemopexin (Hx), and/or by the activity of HO-1 (or biological products) may be potential therapeutic option for patients with GIS. Our new preliminary data showed heightened levels of colonic damage and inflammation in Hx-/- mice in response to phenylhydrazine-induced hemolysis. We also demonstrated that heme affects gene expression through binding to G-quadruplex (G4) secondary structures in genomic DNA, which are key regulators of genomic stability, transcription and replication. Our state-of-the-art experimental approaches will allow us to dissect functions of free heme in myeloid and colonic epithelial cells during treatment-induced inflammation and tissue damage. Moreover, we will assess the impact of the gut microbiota in the protective effects of HO-1/Hx against GIS. Specifically, in this proposal we intend to: 1. Characterize the role of free heme in colonic epithelial and myeloid cells in vitro. 2. Determine the role of myeloid cell-expressed HO-1 and heme-regulated gut microbiota diversity in the GIS models. 3. Assess the therapeutic potential of recombinant Hx in the GIS models. 4. Characterize the staining of HO-1, Hx, DNA damage and proliferation markers and G4 in biopsies from patients with GIS and correlate immunostaining with clinical parameters. In summary, this study will pursue the definition of a novel role and mechanisms by which free heme acts as a key player in regulating gene expression upon tissues injury and gut inflammation such as observed in patients with GIS and/or colitis. This study will not only have high impact on the field of heme biology but will also contribute to developing much needed treatment strategies for GIS patients.

项目摘要 胃肠道综合征（GIS）仍然是一个重大的临床问题，没有有效的治疗。放疗 化学疗法导致出血和细胞死亡，导致血红蛋白和/或游离血红素的释放。 累积数据表明，游离血红素刺激活性氧（ROS）的产生，并作用 作为促炎性危险相关的分子模式（潮湿），其结合与Toll样受体4 （TLR4）。 在这项研究中，我们将专注于理解自由血红素如何通过基因调节调节感染 在GIS模型中的肠道中的髓样细胞或上皮细胞中。我们的数据表明有很高的数量 浸润性血红素加氧酶-1（HO-1） - 阳性巨噬细胞（Mø）在患者的结肠活检中 与匹配的正常组织相比，放射疗法与非辐照的对照或缺血性肠道。 此外，我们表明HO-1的髓样细胞特异性缺失导致异常上皮细胞增殖 并增加了辐照后肠道中的DNA损伤（磷酸化的组蛋白H2AX（H2AXG））。我们 提议由血红素清除剂，血红素（HX）和/或HO-1的活动（或/或 生物制品）可能是GIS患者的潜在治疗选择。我们显示的新初步数据 HX - / - 小鼠的结肠损伤和感染水平升高，响应于苯羟酰亚拉嗪诱导的 溶血。我们还证明了血红素通过与G-四链体的结合（G4）影响基因表达（G4） 基因组DNA中的二级结构，这是基因组稳定性，转录和复制的关键调节剂。 我们最先进的实验方法将使我们能够剖析髓样中的自由血红素的功能，并且 治疗诱导的注射和组织损伤期间的结肠上皮细胞。此外，我们将评估 肠道菌群对HO-1/HX对GIS的受保护作用的影响。具体来说，在这个建议中我们 打算： 1。表征游离血红素在体外中结肠上皮细胞和髓样细胞中的作用。 2。确定髓样细胞表达的HO-1和血红素调节的肠道菌群多样性在 GIS模型。 3。评估GIS模型中重组HX的治疗潜力。 4。表征HO-1，HX，DNA损伤和增殖标记的染色以及活检中的G4 来自GIS患者并将免疫染色与临床参数相关。 总而言之，这项研究将追求一种新型作用和机制的定义 控制组织损伤和肠道注射基因表达的关键人物，例如患者观察到的 与GIS和/或结肠炎。这项研究不仅会对血红素生物学领域产生很大影响，而且还将 为GIS患者制定急需的治疗策略做出贡献。