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：
9495212
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/9495212
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 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 loss of function mouse model novel overexpression oxidative damage perlecan peroxidasin pressure targeted treatment

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）的过度产生会显着导致适应不良肾脏炎症和纤维化。虽然大多数注意力都集中在超氧化物、氢过氧化物 (H2O2) 和其他 ROS，我们最近的工作重点是次溴酸 (HOBr) 作为一种重要的活性氧。动物血红素过氧化物酶使用 H2O2 和 Br- 作为底物产生 HOBr。 HOBr，化学表亲漂白剂 (HOCl) 是一种强氧化剂，能够破坏蛋白质、脂质和核酸，通常促进组织损伤。我们最近发现一种称为过氧化物酶 (Pxdn) 的细胞外基质 (ECM) 蛋白也生成HOBr。 Pxdn 使用 HOBr 作为合成代谢反应中间体来形成新型硫亚胺 (S=N) 交叉- IV 型胶原蛋白是基底膜 (BM) 的重要组成部分，例如肾小球 BM (GBM)。在在果蝇中，我们发现 Pxdn 和硫亚胺交联的丧失会损害基底膜和组织完整性导致幼虫死亡。然而，Pxdn 敲除 (KO) 小鼠是可行的，但证明降低硫亚胺交联和 BM 强度。基于这种表型，我们预计单侧输尿管梗阻 (UUO) 和肾小管内压力增加会导致肾小管 BM 更大的拉伸和 Pxdn KO 小鼠肾小管细胞的机械应力。因此，Pxdn KO 小鼠会表现出增加的肾脏炎症和纤维化。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导致纤维化。根据这些数据，我们假设 Pxdn 通常使用 HOBr 交联 IV 型胶原蛋白并支持组织完整性，但当失调时，Pxdn 产生过量的HOBr，导致氧化损伤和组织损伤。为了检验这一假设，在目标 1 中，我们将确定 Pxdn 功能丧失是否可以预防肾病与肾小球和肾小管间质疾病相比，炎症程度和定位不同的损伤。目标 2 将研究 HOBr 如何改变肾细胞行为以促进肾小管间质纤维化和炎症，包括使用质谱法来识别 HOBr 介导的蛋白质氧化修饰。在目标 3 中，我们将机械地解决 Pxdn 如何使用 HOBr 交联 IV 型胶原蛋白，同时避免对其他生物分子。总而言之，该提案旨在确定 HOBr 在肾脏炎症中的新作用和纤维化。这些研究希望合理化靶向 HOBr 治疗慢性肾脏疾病的策略。