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.

项目摘要/摘要大量研究表明了镰状细胞疾病（SCD）诱导血管病和血管结构的增加是复杂且多因素的。在此修订后的更新应用中，我们假设 SCD诱导血管病是SCD增加血管的机制的第一步之一阻塞。我们的研究表明，SCD诱导了由MPO引发的破坏性循环，并通过高移动性组Box-1（HMGB1），以及改变肺部生理学的其他炎症成分损害血管功能并增加血管结构。以前，我们报道了L-乙酰基乙酰二甲基半胱氨酸酰胺（KYC）抑制MPO，改善了血管功能和减少SCD小鼠过度血管结构引起的肝损伤。新研究表明KYC不仅减少了镰状RBC（SRBC）的拥塞，但也增加了SCD小鼠肺中圆形SRBC的数量。机械研究表明，KYC不仅是MPO有毒氧化剂产生的抑制剂，而是独特的利用MPO过氧化物酶活性将转化为新型抗炎剂的三肽底物灭活HMGB1并激活负责抗氧化剂防御酶的细胞途径在肺中的表达。由于KYC在我们假设的破坏性循环中抑制多种炎症成分时，甚至激活介导抗氧化基因表达的成分，使用机械研究确定哪些成分会增加SCD中的血管病和血管结构，需要抑制剂。虽然系统药物可能对治疗多因素疾病有用，但它们不能用于直接确定因果机制。在此修订的应用程序中，我们假设SCD引起了破坏性循环，由至少三个主要组成部分介导。我们的工作假设是SCD引起的破坏性周期由MPO，HMGB1和一种新颖的基因组成，共同诱导血管病和增加血管结构。通过治疗镰状小鼠，镰刀MPO敲除（KO）小鼠，嵌合镰刀莫昔芬 - 可诱导的HMGB1 KO小鼠和另一只具有高选择性机械抑制剂的嵌合镰状KO小鼠我们将能够单独和/或单独和/或IN确定MPO，HMGB1和第三个基因产物的程度以及在多大程度上组合诱导血管病并增加血管结构。为了评估血管病，我们将量化肺动脉松弛，肺渗透性，SRBC血管结构的差异和易感性镇上缺氧 - 抗氧化损伤（HRI）诱导的每种小鼠血管结构纯合子镰刀HB（SS）WT SS MPO KO小鼠和嵌合SS新型基因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型疗法并减少SRBC血管结构。