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: 10580744
• 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/10580744
• 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 Death Induction; Cell Therapy; Cells; Cessation of life; Chemotherapy and/or radiation; Clinical; Colitis; Colon; Colon Injury; Colonic inflammation; 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; Hemolysis Induction; Hemopexin; Hemorrhage; Iatrogenesis; Immune; In Vitro; Infiltration; Inflammation; Inflammation Mediators; Inflammatory; Injury; Intestinal permeability; Intestines; Iron; Ischemia; Ischemic Bowel Disease; Lead; Link; Macrophage; Measures; Mediating; Methods; Modeling; Molecular; Morbidity - disease rate; Mus; Myelogenous; Myeloid Cells; NF-kappa B; Normal tissue morphology; Pathologic; Patients; Pattern; Phosphorylation; Physiological; Population; Production; Proliferating; Proliferation Marker; RNA; 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; chromatin immunoprecipitation; complement C2a; design; dietary heme; effective therapy; extracellular; gastrointestinal; genotoxicity; gut inflammation; gut microbiota; healing; heme a; heme oxygenase-1; human tissue; indexing; inflammatory marker; intestinal barrier; irradiation; microbiome analysis; mouse model; novel; phenylhydrazine; promoter; protective effect; reconstitution; response; tissue injury; transcriptome sequencing; translational potential; 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.

项目概要 胃肠综合征（GIS）仍然是一个重要的临床问题，没有有效的治疗方法。放射治疗 化疗会导致出血和细胞死亡，导致血红蛋白和/或游离血红素释放。 越来越多的数据表明，游离血红素可刺激活性氧 (ROS) 的产生并发挥作用 通过与 Toll 样受体 4 结合作为促炎危险相关分子模式 (DAMP) （TLR4）。 在这项研究中，我们将重点了解游离血红素如何通过基因调控来调节炎症 GIS 模型中肠道的骨髓或上皮细胞中。我们的数据表明有大量 患者结肠活检中浸润血红素加氧酶-1 (HO-1) 阳性巨噬细胞 (Mø) 放疗与未照射对照的比较，或在缺血肠道中与匹配的正常组织的比较。 此外，我们发现骨髓细胞特异性删除 HO-1 会导致上皮细胞增殖异常 照射后肠道内 DNA 损伤（磷酸化组蛋白 H2AX (H2AXg)）增加。我们 建议通过血红素清除剂、血红素结合蛋白 (Hx) 和/或 HO-1（或 生物制品）可能是 GIS 患者潜在的治疗选择。我们的新初步数据显示 Hx-/- 小鼠响应苯肼诱导的结肠损伤和炎症水平升高 溶血。我们还证明血红素通过与 G-四链体 (G4) 结合影响基因表达 基因组 DNA 的二级结构，是基因组稳定性、转录和复制的关键调节因子。 我们最先进的实验方法将使我们能够剖析游离血红素在骨髓和 结肠上皮细胞在治疗过程中引起的炎症和组织损伤。此外，我们将评估 肠道微生物群对 HO-1/Hx 对 GIS 保护作用的影响。具体来说，在本提案中，我们 打算： 1. 表征游离血红素在体外结肠上皮细胞和骨髓细胞中的作用。 2. 确定骨髓细胞表达的 HO-1 和血红素调节的肠道微生物群多样性在 GIS 模型。 3. 评估重组 Hx 在 GIS 模型中的治疗潜力。 4. 表征活检中 HO-1、Hx、DNA 损伤和增殖标记物以及 G4 的染色 来自 GIS 患者并将免疫染色与临床参数相关联。 总之，本研究将寻求游离血红素作为一种新的作用和机制的定义。 在组织损伤和肠道炎症（如在患者中观察到的）中调节基因表达的关键参与者 患有 GIS 和/或结肠炎。这项研究不仅将对血红素生物学领域产生重大影响，而且还将 有助于为 GIS 患者制定急需的治疗策略。