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The role of Sirtuin 5 in acute kidney injury

Sirtuin 5在急性肾损伤中的作用

基本信息

批准号：
10176477
负责人：
Sunder Sims-Lucas
金额：
$ 44.89万
依托单位：
UNIVERSITY OF PITTSBURGH AT PITTSBURGH
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-07-01 至 2025-04-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10176477
关键词：
Acute Acute Renal Failure with Renal Papillary Necrosis Affect Age Animal Model Apoptosis Automobile Driving Cells Cellular Metabolic Process Chemicals Chronic Chronic Kidney Failure Cisplatin Clinical Coupled Data Disease model Dose Enzymes Epithelial Cells Exhibits Functional disorder Goals Histologic Human Human Cell Line In Vitro Infusion procedures Injury Injury to Kidney Kidney Knock-out Knockout Mice Life Expectancy Link Liver Long-Chain-Acyl-CoA Dehydrogenase Lysine Measures Metabolic Mitochondria Modeling Morbidity - disease rate Mus Organelles Oxidative Stress Pathogenesis Pathology Pathway interactions Patients Peptides Pharmacology Proteins Proteomics Reactive Oxygen Species Renal function Reperfusion Injury Reperfusion Therapy Resistance Risk Role Sirtuins Site Small Interfering RNA Testing Therapeutic Tissues Tubular formation Up-Regulation Western Blotting acyl-CoA oxidase base effective therapy enzyme activity fatty acid oxidation genetic manipulation in vivo in vivo Model knock-down metabolomics mitochondrial metabolism mortality nephrotoxicity novel novel therapeutics oxidative damage peroxisome prevent renal ischemia repaired response therapeutic target

项目摘要

ABSTRACT Acute kidney injury (AKI) occurs in nearly 1 of 5 hospitalized patients and is associated with increased morbidity and mortality across all ages. Many AKI patients will recover kidney function post-injury but then progress to chronic kidney disease (CKD). The mechanisms are poorly understood and there are currently no effective therapies to prevent, limit, or reverse the tissue damage. There is a critical need to identify mechanisms involved in the pathogenesis of AKI. Our long-term goal is to elucidate these mechanisms and leverage them for new therapies to limit AKI and prevent the transition to CKD. Proximal tubule epithelial cells (PTEC), a major site of damage during AKI, are very metabolically active and rich in mitochondria. Mitochondrial metabolism causes increased reactive oxygen species (ROS) which has been implicated in both ischemia-reperfusion injury (IRI) and cisplatin-induced nephrotoxicity. Modulating mitochondrial function during AKI is an attractive, but thus far unachievable, strategy. Our central hypothesis is that loss of the mitochondrial sirtuin lysine deacylase Sirt5 leads to shifts in PTEC metabolism that protects against AKI. This is supported by preliminary data showing protection against both IRI and cisplatin-induced AKI in global Sirt5 knockout (Sirt5-/-, Sirt5+/-) mice in vivo and in vitro as well as in primary human PTEC with siRNA knockdown of Sirt5. Further data support our proposed mechanism of protection in which Sirt5-/- PTEC exhibit a form of metabolic adaptation characterized by a shift of fatty acid oxidation (FAO) from mitochondria to peroxisomes. Peroxisomes have previously been linked to renoprotection in other animal models, most likely due to their ability to eliminate ROS. In Sirt5-/- kidneys, peroxisomes are more resistant to damage during AKI. Our central hypothesis will be tested with two aims. Aim 1 will define the specific site of Sirt5 action during kidney injury with a particular focus on PTEC. While aim 2 will drill down on the renoprotective role of metabolic FAO inhibition coupled with stimulation of peroxisomal fatty acid oxidation during kidney injury. Both aims will utilize a rigorous, mechanistic approach that combines in vitro and in vivo models. In vivo studies in mice will use both global Sirt5-/- PTEC-specific knockout of Sirt5 as well as global and PTEC-specific knockout of LCAD-/- (key mitochondrial FAO enzyme). In vitro studies will use isolated primary mouse and human PTEC as well as genetically manipulated mouse and human cell lines. Human AKI will be modeled in mice by unilateral ischemia-reperfusion injury and single high dose treatment with the nephrotoxin cisplatin. We have also optimized a CKD model using a unilateral ischemia-reperfusion injury model. This project will significantly advance the field by opening up new therapeutic avenues where Sirt5 can be pharmacologically inhibited or its renoprotective mechanism can be harnessed in the context of AKI to protect against injury and block the progression to chronic kidney disease.

摘要近五分之一的住院患者发生急性肾损伤（阿基），并与发病率增加相关和死亡率之间的关系。许多阿基患者会在损伤后恢复肾功能，但随后进展为慢性肾病（CKD）。人们对这些机制知之甚少，目前没有有效的预防、限制或逆转组织损伤的治疗。迫切需要查明所涉机制阿基的发病机制。我们的长期目标是阐明这些机制，并利用它们进行新的研究。限制阿基和防止向CKD转变的治疗。近端小管上皮细胞（PTEC），是一个主要的网站，阿基期间的损伤，代谢非常活跃，富含线粒体。线粒体代谢导致增加的活性氧（ROS）与缺血-再灌注损伤（IRI）和顺铂诱导的肾毒性。在阿基期间调节线粒体功能是一个有吸引力的，但到目前为止，无法实现的战略。我们的中心假设是线粒体sirtuin赖氨酸脱酰酶Sirt 5的缺失导致PTEC代谢发生变化，从而防止阿基。初步数据显示，在体内对整体Sirt 5敲除（Sirt 5-/-，Sirt 5 +/-）小鼠中的IRI和顺铂诱导的阿基的保护，在体外以及在具有Sirt 5 siRNA敲低的原代人PTEC中。进一步的数据支持我们的建议。保护机制，其中Sirt 5-/- PTEC表现出一种代谢适应形式，其特征在于从线粒体到过氧化物酶体的脂肪酸氧化（FAO）。过氧化物酶体以前被认为与在其他动物模型中的肾保护作用，最有可能是由于其消除ROS的能力。在Sirt 5-/-肾中，过氧化物酶体对阿基期间的损伤更有抵抗力。我们的中心假设将以两个目标进行检验。目的 1将定义在肾损伤期间Sirt 5作用的具体位点，特别关注PTEC。虽然aim 2将深入研究代谢性FAO抑制与过氧化物酶体脂肪酸刺激相结合的肾保护作用肾损伤时的酸氧化。这两个目标都将利用一种严格的、机械的方法，和体内模型。小鼠体内研究也将使用Sirt 5的整体Sirt 5-/-PTEC特异性敲除作为LCAD-/-（关键线粒体FAO酶）的全局和PTEC特异性敲除。体外研究将使用分离的原代小鼠和人PTEC以及遗传操作的小鼠和人细胞系。人阿基将通过单侧缺血-再灌注损伤和单次高剂量治疗在小鼠中建模，肾毒素顺铂。我们还使用单侧缺血再灌注损伤优化了CKD模型模型该项目将通过开辟新的治疗途径来显着推进该领域，其中Sirt 5可以或其肾保护机制可在阿基的背景下利用，以保护防止损伤并阻止慢性肾脏疾病的进展。