Mechanisms of Inflammation in Sickle Cell Disease

镰状细胞病的炎症机制

基本信息

批准号：
10380784
负责人：
Kirkwood Arthur Pritchard
金额：
$ 55.04万
依托单位：
MEDICAL COLLEGE OF WISCONSIN
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-04-01 至 2025-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10380784
关键词：
Acute Amides Anti-Inflammatory Agents Antioxidants Binding Biological Availability Blood Vessels Cells Cessation of life Chronic Clinical Complex Congestive Consumption Data Disease Endothelial Cells Enzymes Gene Expression Genes Goals HMGB1 Protein Hemoglobin Hemoglobin SS Hemolytic Anemia Homozygote Hypoxia Impairment Infiltration Inflammation Inflammatory Injury Knock-out Knockout Mice Lung Lung diseases Mediating Mediator of activation protein Molecular Mouse Strains Mus Myeloid Cells Necrosis Nervous System Trauma Nitric Oxide Outcome Oxidants Oxidative Stress Oxides Oxidoreductase Pathway interactions Pattern Permeability Peroxidases Persons Pharmacologic Substance Pharmacology Physiology Predisposition Production Protein S Pulmonary artery structure Relaxation Reporting Research Role S-Nitrosoglutathione S-Nitrosothiols SKIL gene Sickle Cell Sickle Cell Anemia Sickle Hemoglobin Stroke System Tamoxifen Tertiary Protein Structure Testing Vascular Diseases Vasodilation base design experimental study gene product improved inhibitor knockout gene liver injury mimetics multimodality neutrophil novel novel therapeutics organ injury recruit sickling suicide inhibitor vaso-occlusive crisis

项目摘要

Project Summary/Abstract Numerous studies show the mechanisms by which sickle cell disease (SCD) induces vasculopathy and increases vasocongestion are complex and multifactorial. In this revised, renewal application, we hypothesize that SCD induces vasculopathy as one of the first steps in the mechanism by which SCD increases vaso- occlusion. Our studies show that SCD induces a destructive cycle that is initiated by MPO and propagated by high mobility group box-1 (HMGB1), and one other inflammatory component that alters pulmonary physiology, impairs vascular function, and increases vasocongestion. Previously, we reported L-acetyl-lysyltyrosylcysteine amide (KYC) inhibits MPO, improves vascular function and reduces liver injury induced by excessive vasocongestion in SCD mice. New studies suggest that KYC not only reduces sickle RBC (sRBC) congestion but also increases the number of round sRBC in the lungs of SCD mice. Mechanistic studies reveal that KYC isn't just an inhibitor of MPO toxic oxidant production, but rather, is a unique tripeptide substrate that exploits MPO peroxidase activity to be converted into a novel anti-inflammatory agent that inactivates HMGB1 and activates the cellular pathways that are responsible for antioxidant defense enzyme expression in the lung. As KYC inhibits multiple inflammatory components in our hypothesized destructive cycle, and even activates a component that mediates antioxidant gene expression, new studies using mechanistic inhibitors are required for determine which components increase vasculopathy and vasocongestion in SCD. While a systems pharmaceutical agent may be useful for treating multifactorial diseases, they cannot be used to identify causal mechanisms directly. In this revised application, we hypothesize that SCD induces a destructive cycle, mediated by at least three major components. Our working hypothesis is SCD induces a destructive cycle that is composed of MPO, HMGB1 and a novel, dysregulate gene and together induce vasculopathy and increase vasocongestion. By treating sickle mice, sickle MPO knockout (ko) mice, chimeric sickle Tamoxifen- inducible HMGB1 ko mice and another chimeric sickle ko mice with highly selective mechanistic inhibitors we will be able to determine if and the extent to which MPO, HMGB1 and the third gene product, alone and/or in combination induces vasculopathy and increases vasocongestion. To assess vasculopathy, we will quantify differences in pulmonary artery relaxation, pulmonary permeability, sRBC vasocongestion, and susceptibility of each mouse strain to sRBC vasocongestion induced by hypoxia-reoxygenation injury (HRI) in Townes homozygote sickle Hb (SS) wt SS Mpo ko mice, and chimeric SS novel gene ko mice. Our long-term goals are to confirm the identities of each component and develop novel therapies aimed at improving vascular function and reducing sRBC vasocongestion.

项目概要/摘要大量研究表明镰状细胞病 (SCD) 诱发血管病变的机制血管充血的增加是复杂且多因素的。在这个修订后的续展申请中，我们假设 SCD 诱发血管病变是 SCD 增加血管病变机制的第一步闭塞。我们的研究表明，SCD 会引发一个由 MPO 引发并通过 MPO 传播的破坏性循环。高迁移率族盒-1 (HMGB1) 和另一种改变肺部生理学的炎症成分，损害血管功能，增加血管充血。此前，我们报道了 L-乙酰基-赖氨酰酪氨酰半胱氨酸酰胺 (KYC) 抑制 MPO、改善血管功能和减少 SCD 小鼠因过度血管充血引起的肝损伤。新研究表明 KYC 不仅减少镰状红细胞 (sRBC) 充血，但也增加 SCD 小鼠肺部圆形 sRBC 的数量。机理研究表明，KYC 不仅是 MPO 有毒氧化剂产生的抑制剂，而且是一种独特的利用 MPO 过氧化物酶活性转化为新型抗炎剂的三肽底物使 HMGB1 失活并激活负责抗氧化防御酶的细胞途径表达于肺。由于 KYC 抑制了我们假设的破坏性循环中的多种炎症成分，甚至激活介导抗氧化基因表达的成分，使用机制的新研究需要抑制剂来确定哪些成分会增加 SCD 中的血管病变和血管充血。虽然系统药剂可用于治疗多因素疾病，但它们不能用于治疗多因素疾病。直接识别因果机制。在这个修改后的应用中，我们假设 SCD 会引起破坏性的循环，由至少三个主要成分介导。我们的工作假设是 SCD 会引发破坏性循环它由 MPO、HMGB1 和一种新的失调基因组成，共同诱发血管病变和增加血管充血。通过治疗镰状小鼠、镰状 MPO 敲除 (ko) 小鼠、嵌合镰状他莫昔芬- 诱导型 HMGB1 ko 小鼠和另一种具有高度选择性机制抑制剂的嵌合镰状 ko 小鼠将能够确定 MPO、HMGB1 和第三基因产物是否单独和/或在何种程度上组合会诱发血管病变并增加血管充血。为了评估血管病变，我们将量化肺动脉舒张、肺通透性、sRBC 血管充血和敏感性的差异汤斯缺氧复氧损伤 (HRI) 引起的 sRBC 血管充血的各小鼠品系纯合子镰状Hb (SS) wt SS Mpo ko 小鼠和嵌合SS 新基因ko 小鼠。我们的长期目标是确认每个成分的身份并开发旨在改善血管功能的新疗法并减少 sRBC 血管充血。