The Role of Hypobromous Acid in Renal Disease

次溴酸在肾脏疾病中的作用

基本信息

批准号：
9902413
负责人：
Gautam Bhave
金额：
$ 35.55万
依托单位：
VANDERBILT UNIVERSITY MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-05-01 至 2023-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9902413
关键词：
Address Adult Affect Angiotensin II Animals Apoptosis Aristolochic Acids Attention Basement membrane Biochemical Biochemistry Bromine Cell Surface Receptors Cells Chemicals Chronic Kidney Failure Cicatrix Collagen Type IV Complex Cultured Cells Data Development Dialysis procedure Disease Drosophila genus End stage renal failure Epithelial Cells Equilibrium Exhibits Extracellular Matrix Extracellular Matrix Proteins Fibroblasts Fibrosis Generations Health Heme Hydrogen Peroxide Inflammation Inflammatory Infusion procedures Injury Injury to Kidney Kidney Kidney Diseases Knockout Mice Knowledge Lead Lipids Location Mass Spectrum Analysis Mechanical Stress Mechanics Mediating Modeling Mus Nephrectomy Nucleic Acids Oxidants Pathogenicity Pathway interactions Patients Peroxidases Phenotype Phosphotransferases Physiology Post-Translational Protein Processing Production Proteins Reactive Oxygen Species Role Signal Transduction Site Stretching Superoxides Testing Tissues Tubular formation Ureteral obstruction Work base cell behavior cell injury complex IV crosslink disorder prevention glomerular basement membrane hypobromous acid improved interstitial kidney cell kidney fibrosis loss of function mouse model novel overexpression oxidative damage perlecan peroxidasin pressure targeted treatment tissue injury

项目摘要

The excessive generation of reactive oxygen species (ROS) significantly contributes to maladaptive renal inflammation and fibrosis. While most attention has been directed towards superoxide, hydrogen peroxide (H2O2), and other ROS, our recent work has focused on hypobromous acid (HOBr) as an important ROS. Animal heme peroxidases produce HOBr using H2O2 and Br- as substrates. HOBr, a chemical cousin of bleach (HOCl), is a powerful oxidant capable of damaging proteins, lipids, and nucleic acids and typically promotes tissue injury. We recently discovered that an extracellular matrix (ECM) protein known as peroxidasin (Pxdn) also generates HOBr. Pxdn uses HOBr as an anabolic, reactive intermediate to form novel sulfilimine (S=N) cross- links in collagen IV, a prominent constituent of basement membranes (BM), such as glomerular BM (GBM). In Drosophila, we found that loss of Pxdn and sulfilimine cross-links compromised basement membrane and tissue integrity leading to larval lethality. However, Pxdn knock-out (KO) mice are viable but demonstrate reduced sulfilimine cross-links and BM strength. Based on this phenotype, we expected that unilateral ureteral obstruction (UUO) and increased intratubular pressures would lead to greater tubular BM stretch and mechanical stress on tubular cells in Pxdn KO mice. Consequently, Pxdn KO mice would exhibit increased renal inflammation and fibrosis. Paradoxically, Pxdn KO mice demonstrated less renal inflammation and fibrosis with diminished HOBr mediated oxidative damage. Based on these data, we hypothesize that Pxdn normally uses HOBr to cross-link collagen IV and support tissue integrity, but when dysregulated, Pxdn generates excessive HOBr leading to oxidative damage and tissue injury. To test this hypothesis, in Aim 1, we will determine whether Pxdn loss of function protects against renal injury that varies in extent of inflammation and localization contrasting glomerular and tubulointerstitial disease. Aim 2 will examine how HOBr alters renal cell behavior to promote tubulointerstitial fibrosis and inflammation, including the use of mass spectrometry to identify HOBr mediated oxidative modifications of proteins. In Aim 3, we will mechanistically address how Pxdn uses HOBr to cross-link collagen IV yet avoid collateral damage to other biomolecules. Taken together, this proposal aims to define a novel role for HOBr in renal inflammation and fibrosis. These studies hope to rationalize a strategy to target HOBr to treat chronic kidney disease.

活性氧（ROS）的过度产生显着导致不良适应性肾脏炎症和纤维化。虽然大多数关注已针对超氧化物，但氢过氧化物（H2O2）和其他ROS，我们最近的工作集中于低含量（HOBR）作为重要的罗斯。动物血红素过氧化物酶使用H2O2和BR-作为底物产生HOBR。霍布，一个化学表亲漂白剂（HOCL）是一种强大的氧化剂，能够损坏蛋白质，脂质和核酸，通常促进组织损伤。我们最近发现，也称为过氧化物素（PXDN）的细胞外基质（ECM）蛋白生成霍布。 PXDN使用HOBR作为合成代谢的，反应性中间体形成新型硫胺（S = N）横交胶原蛋白IV的链接是地下膜（BM）的突出成分，例如肾小球BM（GBM）。在果蝇，我们发现PXDN和亚硫胺交联的损失损害了地下膜和组织完整性导致幼虫致死性。但是，PXDN敲除（KO）小鼠是可行的，但证明了硫胺交联和BM强度降低。基于此表型，我们期望单侧输尿管障碍物（UUO）和增加的细胞内压力会导致更大的管状BM拉伸，并且 PXDN KO小鼠中管细胞的机械应力。因此，PXDN KO小鼠会显示出增加肾脏炎症和纤维化。矛盾的是，PXDN KO小鼠表现出较少的肾脏炎症和 HOBR介导的氧化损伤减少的纤维化。基于这些数据，我们假设PXDN 通常使用HOBR交联胶原蛋白IV并支持组织完整性，但是当失调时，PXDN 产生过多的HOBR导致氧化损伤和组织损伤。为了检验这一假设，在AIM 1中，我们将确定PXDN功能丧失是否可以防止肾脏在炎症和定位程度上有所不同的伤害与肾小球和肾小管间质疾病对比。 AIM 2将研究HOBR如何改变肾细胞行为以促进肾小管间隙纤维化和炎症，包括使用质谱法来鉴定HOBR介导的蛋白质氧化修饰。在AIM 3中，我们将机械地解决PXDN如何使用HOBR交联胶原蛋白IV，但避免了附带损害其他生物分子。综上和纤维化。这些研究希望将靶向霍布尔以治疗慢性肾脏疾病的策略合理化。