The role of Sirtuin 5 in acute kidney injury

Sirtuin 5在急性肾损伤中的作用

• 批准号: 10003896
• 负责人: Sunder Sims-Lucas
• 金额: $ 9.39万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-10 至 2020-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10003896
• 关键词: Acute; Acute Renal Failure with Renal Papillary Necrosis; Age; Animal Model; Apoptosis; Automobile Driving; Cell Line; Cellular Metabolic Process; Chronic; Chronic Kidney Failure; Cisplatin; Clinical; Clustered Regularly Interspaced Short Palindromic Repeats; Combined Modality Therapy; Data; Development; Dose; Enzymes; Epithelial Cells; Exhibits; Fibrosis; Goals; Human; Human Cell Line; In Vitro; Injury; Injury to Kidney; Kidney; Knock-out; Knockout Mice; Life Expectancy; Link; Long-Chain-Acyl-CoA Dehydrogenase; Lysine; Measures; Mediating; Metabolic; Mitochondria; Mitochondrial Proteins; Modeling; Molecular Target; Morbidity - disease rate; Mus; Oxidative Stress; Pathogenesis; Pathology; Patients; Pharmacology; Play; Post-Translational Protein Processing; Reactive Oxygen Species; Renal function; Reperfusion Injury; Resistance; Role; Sirtuins; Site; Small Interfering RNA; Testing; Therapeutic; Time; Tissues; acyl-CoA dehydrogenase; acyl-CoA oxidase; base; cell type; effective therapy; fatty acid oxidation; in vivo; in vivo Model; inhibitor/antagonist; injury and repair; interstitial; kidney cell; knock-down; mitochondrial metabolism; mortality; nephrotoxicity; novel; novel therapeutics; peroxisome; preconditioning; prevent; targeted treatment; 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 protect against AKI. This is supported by preliminary data showing protection against both IRI and cisplatin-induced AKI in global Sirt5 knockout (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 preconditioning 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, peroxisome number is increased at baseline and the peroxisomes are more resistant to damage during AKI. Our central hypothesis will be tested with three 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 role of peroxisomal fatty acid oxidation during kidney injury. Finally, aim 3 will mechanistically define the molecular targets of Sirt5 during kidney injury. All of the three 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-/- and inducible, PTEC-specific knockout of Sirt5 as well as global 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. In both models of injury, the role of Sirt5 in mediating the progression from acute to chronic kidney disease will be studied. This project will significantly advance the field by opening up new therapeutic avenues where Sirt5 can be pharmacologically inhibited in the context of AKI to protect against injury and block the progression to chronic kidney disease.

抽象的 近五分之一的住院患者发生急性肾损伤 (AKI)，并且与发病率增加相关 以及各个年龄段的死亡率。许多 AKI 患者在受伤后会恢复肾功能，但随后会进展为 慢性肾脏病（CKD）。人们对其机制知之甚少，目前尚无有效的方法 预防、限制或逆转组织损伤的疗法。迫切需要确定所涉及的机制 AKI 的发病机制。我们的长期目标是阐明这些机制并利用它们开发新的 限制 AKI 并防止转变为 CKD 的疗法。近端小管上皮细胞（PTEC）是 AKI 期间的损伤，代谢非常活跃并且富含线粒体。线粒体代谢的原因 活性氧（ROS）增加，与缺血再灌注损伤（IRI）有关 和顺铂引起的肾毒性。在 AKI 期间调节线粒体功能是一种很有吸引力的方法，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 的缺失 导致 PTEC 代谢发生变化，从而预防 AKI。初步数据表明这一点 在体内和体外对整体 Sirt5 敲除 (Sirt5-/-) 小鼠中的 IRI 和顺铂诱导的 AKI 提供保护 以及在原代人 PTEC 中通过 siRNA 敲低 Sirt5。进一步的数据支持我们的建议 Sirt5-/- PTEC 表现出一种代谢预处理形式的保护机制，其特征在于 脂肪酸氧化（FAO）从线粒体转移到过氧化物酶体。过氧化物酶体先前已被连接 对其他动物模型的肾脏保护作用，很可能是由于它们消除 ROS 的能力。在 Sirt5-/- 肾脏中， 过氧化物酶体数量在基线时增加，并且过氧化物酶体在 AKI 期间更能抵抗损伤。我们的 中心假设将通过三个目标进行检验。目标 1 将定义 Sirt5 在肾脏过程中作用的具体位点 损伤，特别关注 PTEC。目标 2 将深入研究过氧化物酶体脂肪酸氧化的作用 肾损伤期间。最后，目标 3 将从机制上定义 Sirt5 在肾损伤过程中的分子靶点。 所有三个目标都将采用严格的机械方法，结合体外和体内模型。在 小鼠体内研究将使用 Sirt5-/- 和 Sirt5 的诱导型、PTEC 特异性敲除以及全局 LCAD-/-（FAO 关键线粒体酶）。体外研究将使用分离的原代小鼠和人类 PTEC 作为 以及基因操纵的小鼠和人类细胞系。人类 AKI 将在小鼠中通过单侧建模 缺血再灌注损伤和肾毒素顺铂单次高剂量治疗。在这两种损伤模型中， 将研究 Sirt5 在介导从急性肾病到慢性肾病进展中的作用。这个项目 将通过开辟新的治疗途径来显着推进该领域的发展，Sirt5可以在药理上发挥作用 在 AKI 背景下受到抑制，以防止损伤并阻止慢性肾脏病的进展。