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: 10434974
• 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/10434974
• 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; Lead; 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; 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 项目总结/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 中位年龄 23 岁的终末期肾衰竭患病率很高。由于缺乏针对肾脏的 4 治疗后平均生存期少于3年。 SCD 环境诱导内皮素-1 (ET-1) 和升高的 ET-1 SCD 患者的 5 水平与微量白蛋白尿相关。我最近证明 ET 受体 A (ETA) 6 和双 ET 受体 A 和 B (ETA+B) 拮抗剂可防止肾小球对白蛋白通透性的增加 7 在 SCD 小鼠模型中，但只有 ETA 受体拮抗剂才能预防白蛋白尿。这些发现引导我 8 假设 ET-1 通过 ETA 受体激活导致 SCD 小鼠肾损伤，而 ETB 9 受体提供肾小管保护。因此，指导阶段的中心假设是在 SCD 中 10 环境中，ET-1 升高和 ETA 受体活性增加介导肾小管功能障碍，导致 11 SCD 小鼠的肾小管损伤，与 ETB 活性相反。指导对象的具体目标1 第 12 阶段将确定 ET-1 和 ETA 受体活性增加是否通过减少介导肾小管损伤 13 SCD 小鼠的肾小管白蛋白摄取机制以及 ETB 受体拮抗作用是否会加剧 ET-1 对肾小管白蛋白的影响 14  管状白蛋白处理。通过使用体内成像技术的新培训，我将跟踪荧光- 15 标记白蛋白，用于评估经载体或 ET 受体拮抗剂治疗的 SCD 和肾小管白蛋白重吸收 16 只基因对照小鼠。我们还将确定 ET-1 和 ET 受体对近曲小管的直接影响 17 离体和体内环境中的白蛋白转运蛋白。独立阶段：该阶段将重点关注 18  独立的研究路线，以之前的培训为基础，探索肾铁处理机制。 19 有证据表明，SCD 中铁沉积的增加与蛋白尿有关，两者都可能与 20 因 ETA 受体阻断而减弱。尽管 ET-1 与 SCD 中的肾小球病有关，但 21 铁引起的毒性和由此产生的肾小管损伤尚不清楚。因此，总体假设 22 独立阶段是 ET-1 升高导致管状铁处理功能障碍、铁过载和 23  SCD 中的肾小管损伤。这将通过培养的近端小管细胞的体外实验进行测试 24 SCD 小鼠体内。具体目标 2 将确定 SCD 中受损的管状铁处理是否会导致铁 25 通过 ET-1 导致近端小管铁摄取增加和/或近端小管铁减少引起的过载 26 移除。具体目标 3 将确定导致 SCD 肾小管损伤的铁毒性机制。这 27 将通过确定肾铁过载是否通过氧化应激和/或导致肾小管损伤来进行测试 28 SCD 肾病中的线粒体功能障碍。拟议研究的目标无疑将阐明 29 关于参与肾小管损伤发生和进展的新机制途径，这是一个关键的因素 30 导致慢性肾脏疾病的因素。