Epithelial Beta-catenin Signaling Improves Chronic Renal Injury

上皮β-连环蛋白信号传导改善慢性肾损伤

基本信息

批准号：
10266013
负责人：
Leslie S Gewin
金额：
--
依托单位：
VETERANS HEALTH ADMINISTRATION
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：
2018-07-01 至 2022-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10266013
关键词：
Affect American Angiotensins Animal Model Animal Testing Antioxidants Apoptosis Aristolochic Acids Atrophic Binding Cell Culture Techniques Cell Cycle Cell Cycle Arrest Cell Cycle Inhibition Cell Cycle Progression Cell Death Cell Nucleus Cell Proliferation Cells Chronic Chronic Kidney Failure Clinical Data DNA Repair Data Diabetes Mellitus Disease Progression Doxycycline Economic Burden Epithelial Epithelial Cell Proliferation Epithelial Cells Etiology FOXO1A gene Fibrosis Funding Future G1 Arrest Gene Expression Profile General Population Genetic Genetic Transcription Growth Factor Homeostasis Hypertension Impairment In Vitro Inflammation Injury Injury to Kidney Kidney Kidney Diseases Knockout Mice Knowledge Lead Ligands Measures Mediating Mediator of activation protein Morbidity - disease rate Mus Mutation Nuclear Oxidative Stress Pathway interactions Play Prevalence Production Proteins Public Health Renal function Reporter Role Signal Transduction Stress TCF Transcription Factor Testing Transforming Growth Factors Tubular formation Veterans base beta catenin biological adaptation to stress cell injury conditional knockout cytokine epithelial injury genetic approach improved inhibitor/antagonist injured innovation mortality mouse model mutant novel novel therapeutics pre-clinical preservation prevent programs protective effect response response to injury tempol transcription factor transcriptome sequencing

项目摘要

Chronic kidney disease (CKD) is a growing public health problem that affects more than 10% of Veterans, increases morbidity and mortality, and imposes a huge economic burden. Persistent renal tubular injury is an important component of tubulointerstitial fibrosis (TIF), the common feature of progressive CKD of any etiology. Growth factors such as transforming growth factor- (TGF-) and Wnt/-catenin are important determinants of how tubular epithelia respond to injury. Various inhibitors of the Wnt/-catenin pathway have had mixed effects on chronic renal injury. We used a genetic approach to augment -catenin signaling in the proximal tubule, and this resulted in marked improvement in CKD progression after renal injury. Wnt/-catenin signaling mediates very different actions in injury versus homeostasis. Our preliminary data suggest that -catenin binding to the transcription factor FoxO may be an important mediator of the altered -catenin-dependent responses in injury. This proposal tests the hypothesis that epithelial -catenin signaling protects against CKD progression by protective effects on inflammation, oxidative stress, and cell cycle progression in a manner partly dependent on FoxO. The first aim investigates how epithelial -catenin signaling alters epithelial survival through effects on inflammation, cell cycle, and antioxidant production using murine models of injury. We will use genetically modified mice that have a mutation in -catenin that prevents its degradation, and this mutant -catenin is either specifically expressed in the proximal tubule or present throughout the tubule in a doxycycline-inducible manner. We will induce chronic kidney injury by either angiotensin/uninephrectomy or aristolochic acid. We anticipate that mice with increased epithelial -catenin activity have reduced inflammation, altered cell cycle progression, reduced oxidative stress, and increased epithelial survival after injury. We have identified a number of potential -catenin targets that may mediate these effects based on our preliminary data. We will measure expression of these targets in the injured animal models and test how they affect cell death using cell culture techniques. The second aim explores the role of FoxO in mediating -catenin's protective effect after chronic kidney injury. We will determine how injury (i.e. oxidative stress) alters the way -catenin signals to promote FoxO- mediated responses using a special reporter mouse. We will also cross our mouse containing the active - catenin in the proximal tubule with our mouse lacking FoxO in the same epithelial segment. If the benefit of - catenin activity is mediated through FoxO, then this double conditional knockout mouse should lose the protective effect (i.e. more epithelial cell death) conferred by augmented -catenin activity. Furthermore, we will define how FoxO targets change epithelial responses to stress using cell culture techniques. This proposal uses innovative genetic approaches to determine the role of -catenin and FoxO interactions in epithelial injury. We will investigate several novel targets of these protein interactions identified by sequencing the transcriptome (preliminary data). These studies will provide valuable pre-clinical data for these targets which may lead to future therapies for CKD. In addition, these studies will further our knowledge of Wnt/-catenin signaling and the role of FoxO in CKD.

慢性肾脏疾病（CKD）是一个日益增长的公共卫生问题，影响了超过10％的退伍军人，增加发病率和死亡率，不可能带来巨大的经济负担。持续的肾结结核损伤是小节间质纤维化（TIF）的重要组成部分，这是任何病因的进行性CKD的共同特征。诸如转化生长因子-（TGF-）和Wnt/-catenin之类的生长因子是重要的决定剂管状上皮如何应对损伤。 Wnt/-catenin途径的各种抑制剂具有混合作用关于慢性肾脏损伤。我们使用遗传学方法来增强近端管中的-catenin信号传导，并这导致肾脏损伤后CKD进展明显改善。 Wnt/-catenin信号传导培养基在伤害与体内平衡方面的行动截然不同。我们的初步数据表明-catenin与转录因子FOXO可能是损伤中-catenin依赖性反应改变的重要介体。该提案检验了以下假设：上皮-catenin信号传导可预防CKD的进展保护对炎症，氧化应激和细胞周期进展的影响，部分取决于福克斯。第一个目的研究上皮-catenin信号如何通过对使用鼠损伤模型的炎症，细胞周期和抗氧化剂产生。我们将一般使用在-catenin中具有突变的改良小鼠，可防止其降解，而这种突变的-catenin是在近端管中特异性表达，或在整个管中以多西环诱导方式。我们将通过血管紧张素/单次切除术或aristolochicac诱导慢性肾脏损伤。我们预计上皮-catenin活性增加的小鼠的注射降低，细胞周期改变损伤后进展，氧化应激减少和上皮存活增加。我们已经确定了潜在的-catenin靶标可能会根据我们的初步数据介导这些效果。我们将测量这些靶标在受伤的动物模型中的表达，并测试它们如何使用细胞影响细胞死亡文化技术。第二个目的探讨了福克斯在介导-catenin的保护作用后的作用受伤。我们将确定损伤（即氧化应激）如何改变-catenin信号的方式来促进foxo- 使用特殊的记者鼠标介导的响应。我们还将跨越包含活性-的小鼠在近端小管中的Catenin，我们的小鼠在同一上皮段中缺乏FOXO。如果有利于- Catenin活动是通过Foxo介导的，然后这种双重条件敲除鼠标应失去保护作用（即更多的上皮细胞死亡）由增强的-catenin活性赋予。此外，我们会的定义FOXO目标如何改变使用细胞培养技术对压力的上皮反应。该建议使用创新的遗传方法来确定-catenin和foxo的作用上皮损伤的相互作用。我们将研究这些蛋白质相互作用的几个新靶标通过对转录组进行测序（初步数据）。这些研究将为临床前数据提供宝贵的临时数据这些目标可能会导致CKD的未来疗法。此外，这些研究将进一步我们的知识 Wnt/-catenin信号传导和FOXO在CKD中的作用。