The role of Sirtuin 5 in acute kidney injury

Sirtuin 5在急性肾损伤中的作用

• 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
• 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

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.

抽象的 急性肾脏损伤（AKI）发生在5例住院患者中的近1例，与发病率增加有关 和所有年龄段的死亡率。许多AKI患者会在伤害后恢复肾脏功能，但随后恢复 慢性肾脏病（CKD）。这些机制知之甚少，目前没有有效 预防，限制或逆转组织损伤的疗法。识别涉及机制的迫切需要 在AKI的发病机理中。我们的长期目标是阐明这些机制并利用它们为新的 限制AKI并防止过渡到CKD的疗法。近端小管上皮细胞（PTEC），一个主要部位 在AKI期间的损害，非常代谢活跃，并在线粒体中富含。线粒体代谢原因 活性氧（ROS）增加，与两种缺血 - 再灌注损伤有关（IRI） 和顺铂诱导的肾毒性。在AKI期间调节线粒体功能是一个吸引人的，但到目前为止 无法实现的策略。我们的中心假设是线粒体Sirtuin赖氨酸脱酰酶Sirt5的丧失 导致PTEC代谢的转变，可预防AKI。这是由显示的初步数据支持 在全球SIRT5敲除（SIRT5 - / - ，SIRT5 +/-）小鼠中，防止IRI和Cisplatin诱导的AKI在体内和 在体外和原代人PTEC中，Sirnna敲低SIRT5。进一步的数据支持我们提议的 SIRT5 - / - PTEC表现出一种以移位为特征的代谢适应形式的保护机制 从线粒体到过氧化物酶体的脂肪酸氧化（FAO）。过氧化物酶体以前已与 在其他动物模型中，肾脏保护的能力很可能是由于它们消除ROS的能力。在sirt5 - / - 肾脏中， 过氧化物酶体在AKI期间更具耐受性。我们的中心假设将以两个目标进行检验。目的 1将在肾脏损伤期间定义SIRT5动作的特定部位，特别关注PTEC。而AIM 2将 在代谢粮农组织抑制作用的重新保护作用以及过氧化物酶体脂肪的刺激 肾损伤期间的酸氧化。两种目标都将利用一种严格的机械方法，将体外结合在一起 和体内模型。小鼠的体内研究也将使用全球SIRT5 - / - PTEC特定的SIRT5敲除 作为LCAD的全局和PTEC特异性敲除 - / - （密钥线粒体FAO酶）。体外研究将使用 孤立的原代小鼠和人PTEC以及遗传操纵的小鼠和人类细胞系。 人AKI将通过单侧缺血 - 再灌注损伤和单剂量治疗在小鼠中建模 肾毒素顺铂。我们还使用单侧缺血 - 灌注损伤优化了CKD模型 模型。该项目将通过开放新的治疗途径，从而大大推动整个领域 可以在药理上抑制或在AKI的背景下利用其重新保护机制 反对受伤并阻止慢性肾脏疾病的进展。