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项目概要/摘要 2指导阶段：镰状细胞病（SCD），美国最常见的血红蛋白病，与 3中位年龄23岁时终末期肾衰竭的高患病率。由于缺乏针对肾脏的 4种治疗方法的平均生存期小于3年。SCD环境诱导内皮素-1（ET-1）和升高的ET-1 SCD患者中的5种水平与微量白蛋白尿相关。我最近证明，ET受体A（ETA） 6和双重ET受体A和B（ETA+B）拮抗剂阻止肾小球对白蛋白通透性的增加 7，但只有ETA受体拮抗剂防止蛋白尿。这些发现让我 8的假设，ET-1通过ETA受体激活有助于SCD小鼠的肾损伤，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，升高的ET-1和增加的ETA受体活性介导肾小管功能障碍，导致肾小管功能障碍。 11 SCD小鼠中的肾小管损伤，这与ETB活性相反。具体目标1 12期将确定ET-1和ETA受体活性的增加是否通过降低ET-1和ETA受体活性介导肾小管损伤。 13 SCD小鼠中肾小管白蛋白摄取机制以及ETB受体拮抗剂是否加剧ET-1对 14例肾小管白蛋白处理。利用新的活体成像技术，我将追踪荧光- 15标记的白蛋白，以评估载体或ET受体拮抗剂处理的SCD中的肾小管白蛋白重吸收， 16只遗传对照小鼠。我们还将确定ET-1和ET受体对近端小管的直接作用 17种白蛋白转运蛋白在离体和体内环境中。独立阶段：此阶段将侧重于 18项独立的研究，探索建立在先前培训基础上的肾铁处理机制。 19证据表明，SCD患者铁沉积增加与蛋白尿有关，两者均可能是 20通过ETA受体阻断剂减弱。尽管ET-1参与了SCD中的肾小球病变，但 21铁诱导的毒性和由此产生的肾小管损伤尚不清楚。因此， 22个独立阶段是ET-1升高导致管状铁处理功能障碍、铁超载，并且 SCD肾小管损伤23例。这将通过对培养的近端小管细胞进行体外实验进行测试， 24在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导致铁 通过ET-1的25超负荷诱导近端小管铁摄取增加和/或近端小管铁摄取减少。 26篇撤具体目标3将确定导致SCD中肾小管损伤的铁毒性机制。这 27将通过确定肾铁超负荷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将阐明 29关于参与肾小管损伤的发展和进展的新机制途径， 30慢性肾病的贡献者。