The Role of Endothelin-1 in Tubular Injury in Sickle Cell Disease

内皮素 1 在镰状细胞病肾小管损伤中的作用

• 批准号: 10657435
• 负责人: Malgorzata Kasztan
• 金额: $ 24.9万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10657435
• 关键词: Address; Adult; Age Years; Albumins; Albuminuria; Animal Model; Attenuated; Cells; Chronic; Chronic Kidney Failure; Data; Deposition; Development; Disease; Endothelin; Endothelin A Receptor; Endothelin-1; Excision; Free Radicals; Functional disorder; Generations; Genetic; Goals; Hematological Disease; Hemoglobinopathies; Hemolysis; High Prevalence; Imaging Techniques; Impairment; In Vitro; Injury; Injury to Kidney; Investigation; Iron; Iron Overload; Kidney; Kidney Diseases; Kidney Failure; Knockout Mice; LDL-Receptor Related Protein 2; Label; Light; Lipid Peroxidation; Mediating; Mentors; Microalbuminuria; Molecular; Mus; Oxidative Stress; Pathogenesis; Pathology; Pathway interactions; Patients; Permeability; Phase; Plasma; Prevalence; Process; Proteinuria; Receptor Activation; Regulation; Research; Role; Sickle Cell Anemia; System; Technical Expertise; Testing; Toxic effect; Training; Tubular formation; absorption; antagonist; cytotoxicity; experimental study; human model; in vivo; in vivo imaging; insight; mitochondrial dysfunction; mortality; mouse model; novel; preservation; prevent; receptor; renal damage; targeted treatment; uptake

1  Project Summary/Abstract 2  Mentored Phase: Sickle cell disease (SCD), the most common hemoglobinopathy in US, is associated with 3  high prevalence of end-stage kidney failure at the median 23 years of age. Due to the lack of kidney-targeted 4  treatment the mean survival is less than 3 years. SCD milieu induces endothelin-1 (ET-1) and elevated ET-1 5  levels in SCD patients correlate with microalbuminuria. I recently demonstrated that both ET receptor A (ETA) 6  and dual ET receptor A and B (ETA+B) antagonists prevented the increase in glomerular permeability to albumin 7  in a mouse model of SCD, but only the ETA receptor antagonist prevented albuminuria. These findings led me 8  to the hypothesis that ET-1 via ETA receptor activation contributes to renal injury in SCD mice, while the ETB 9  receptor provides tubular protection. Thus, the central hypothesis of the mentored phase is that in the SCD 10  milieu, elevated ET-1 and increased ETA receptor activity mediate tubular dysfunction leading to the 11  tubular injury in SCD mice, which is opposed by the ETB activity. The specific aim 1 of the mentored 12  phase will determine if increased ET-1 and the ETA receptor activity mediate tubular injury by decreased 13  tubular albumin uptake mechanism in SCD mice and if ETB receptor antagonism exacerbates ET-1 effects on 14  tubular albumin handling. With the use of new training in in vivo imaging techniques, I will track fluorescent- 15  labeled albumin to assess tubular albumin reabsorption in vehicle- or ET receptor antagonists treated SCD and 16  genetic control mice. We will also determine the direct effect of ET-1 and ET receptors on proximal tubule 17  albumin transporters in ex vivo and in vivo settings. Independent Phase: This phase will focus on an 18  independent line of investigation exploring mechanisms of renal iron handling that builds on previous training. 19  Evidence suggests that increased iron deposition in SCD is associated with albuminuria, both of which can be 20  attenuated by ETA receptor blockade. Although, ET-1 contributes to glomerulopathy in SCD, the relevance of 21  iron-induced toxicity and resultant tubular injury is unclear. Therefore, the overall hypothesis of the 22  independent phase is that elevated ET-1 leads to dysfunctional tubular iron handling, iron overload, and 23  tubular injury in SCD. This will be tested through in vitro experiments on cultured proximal tubules cells and 24  in vivo in SCD mice. The specific aim 2 will determine if impaired tubular iron handling in SCD leads to iron 25  overload via ET-1 induced increase in proximal tubule iron uptake and/or decrease in proximal tubule iron 26  removal. The specific aim 3 will determine mechanisms of iron toxicity that lead to tubular injury in SCD. This 27  will be tested by determining if renal iron-overload leads to tubular injury via oxidative stress and/or 28  mitochondrial dysfunction in SCD nephropathy. The goals of the proposed studies will undoubtedly shed light 29  on novel mechanistic pathways involved in the development and progression of tubular injury, a crucial 30  contributor in chronic kidney disease.

1个项目摘要/摘要 2指导阶段：镰状细胞病（SCD）是美国最常见的血红蛋白病，与 3中位数23岁的中位数末期肾衰竭的高流行。由于缺乏肾脏靶向 4处理平均生存率小于3年。 SCD环境诱导内皮素-1（ET-1）并升高ET-1 SCD患者的5个水平与微珠尿症相关。我最近证明了ET受体A（ETA） 6和双ET受体A和B（ETA+B）拮抗剂阻止了肾小球渗透性对专辑的增加 7在SCD的小鼠模型中，但只有ETA受体拮抗剂阻止了蛋白尿。这些发现引导我 8以下假设，即通过ETA受体激活ET-1有助于SCD小鼠的肾脏损伤，而ETB 9接收器提供管状保护。那就是修改阶段的中心假设是在SCD中 10 MILIEU，ET-1升高和ETA受体活性的增加介导管状功能障碍，导致 SCD小鼠的11个结节损伤，与ETB活性相反。问题的特定目的1 12期将确定ET-1增加和ETA受体活性是否通过减少来介导管状损伤 SCD小鼠中的13个块茎白蛋白摄取机制，IF ETB受体拮抗剂加剧ET-1对 14块块茎专辑处理。通过在体内成像技术中使用新训练，我将跟踪荧光 - 15张标记的专辑，以评估车辆或ET受体拮抗剂中的块茎白蛋白的重新吸附，并处理过SCD和 16只通用控制小鼠。我们还将确定ET-1和ET受体对近端小管的直接影响 Ex Vivo和体内设置中的17个白蛋白转运蛋白。独立阶段：此阶段将重点放在 18独立投资探索肾脏铁处理机制，该机制是基于先前培训的。 19个证据表明，SCD中的铁沉积增加与蛋白尿有关，这两者都可以 20被ETA接收器封锁减弱。虽然，ET-1有助于SCD中的肾小球病，但 21铁诱导的毒性和导致的管状损伤尚不清楚。因此，总体假设 22独立阶段是升高的ET-1导致功能失调的管状铁处理，铁超载和 SCD中的23块茎受伤。这将通过在培养的近端管细胞和 24体内SCD小鼠。具体目标2将确定SCD中的管状铁处理受损是否导致铁 25通过ET-1超负荷诱导的近端小管摄取和/或近端小管铁的增加 26删除。具体目标3将确定导致SCD管状损伤的铁毒性机制。这 27将通过确定是否通过氧化应激和/或 28 SCD肾病中的线粒体功能障碍。拟议研究的目标无疑会揭示 29关于涉及管状损伤发展和进展的新机械途径，这是至关重要的 30个慢性肾脏疾病的贡献者。