Novel redox mechanisms of oxygenated phospholipids in chronic and diabetic kidney disease

慢性和糖尿病肾病中含氧磷脂的新氧化还原机制

基本信息

批准号：
10752954
负责人：
Krisztian Stadler
金额：
$ 29.98万
依托单位：
LSU PENNINGTON BIOMEDICAL RESEARCH CTR
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-08-15 至 2026-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10752954
关键词：
Ablation Acyl Coenzyme A Address Antioxidants Apoptosis Apoptotic Arachidonate 15-Lipoxygenase Attributes of Chemicals Biochemical Biological Biology Biophysics Cell Death Cell Death Signaling Process Cell physiology Cells Cellular Metabolic Process Chronic Chronic Kidney Failure Coenzyme A Ligases Complex Complications of Diabetes Mellitus Consumption Coupled Cytoplasm Data Dependence Diabetes Mellitus Diabetic Nephropathy Disease Distant Electron Spin Resonance Spectroscopy Epithelial Cells Equilibrium Event Foundations Free Radicals Functional disorder Future Generations Injury Injury to Kidney Intervention Iron Iron Chelation Kidney Kidney Diseases Kinetics Link Lipid Peroxidation Lipid Peroxides Lipids Lysophospholipids Mediator Membrane Metabolic Metabolism Mitochondria Modeling Molecular Molecular Profiling Monitor Mus Obesity Outcome Oxidation-Reduction Oxidative Stress Oxygen Pathogenesis Pathway interactions Peroxides Phosphatidylethanolamine Phospholipids Production Proteins Publishing Reaction Reactive Oxygen Species Role Signal Transduction Site Source Specificity Stress Structure Superoxides Testing Transgenic Model Transgenic Organisms Tubular formation Work biophysical techniques cell injury cold temperature design diabetic diet-induced obesity experimental study feeding glutathione peroxidase imaging modality in vivo kidney cell mass spectrometric imaging mitochondrial dysfunction mouse model novel oxidation oxidized lipid peroxidation pharmacologic prevent programs successful intervention transmission process

项目摘要

Oxidative stress has long been implicated in the pathogenesis of diabetic and chronic kidney disease (DKD/CKD). Most of the previous studies focused on either a singular concept of oxidative stress vs antioxidant balance, or centered on overproduction of superoxide as a major reactive oxygen species (ROS) and a primary event in DKD/CKD. However, superoxide has major kinetic and biochemical barriers that limit its impacts on biological structures. We propose a key role for less reactive, more specific and membrane diffusible molecules which are also tightly related to changes in cell metabolism – (phospho)lipid peroxides (LOOH). While the basic tenets of lipid peroxidation are established in biology, the molecular entity, modes of action and specific redox signaling ability of LOOH are more enigmatic. This is a critical gap to address because impeding a highly specific form of redox signal at the right timing in disease pathogenesis can prevent renal cell dysfunction. Our central hypothesis is that LOOH are key metabolic signals that transmit an initial redox stress in cells. Furthermore, we propose that diabetes alters the molecular signature of LOOH and that from a myriad of diverse oxidized phospholipids, there are only a few specific ones that dictate the activation of programmed cell death. We focus on proximal tubular epithelial cells (PTC) which comprise ~ 70-80 % of the cortex, where we previously discovered that dysregulation of PTC metabolism potentiates LOOH production. We have a broad array of preliminary data showing that when PTC metabolism is challenged either by lipid overload or by ablating the neutralizing mechanism for membrane peroxides via deletion of glutathione peroxidase 4 (GPx4), LOOH are overproduced and mice develop kidney injury. Using diabetic models, we show that diabetes not only potentiates the formation of LOOH, but also alters the molecular signature of LOOH species in a fashion that oxidized phosphatidylethanolamines (PE) and lysophosphatidylethanolamine (LPE) become abundant. Three aims will test the hypothesis using state-of-the-art biophysical and mass spectrometry imaging methods in combination with pharmacologic and transgenic approaches using both established and newly generated mouse models. In Aim 1, we will test the prediction that changes in PTC metabolic activity regulates the production of LOOH. Aim 2 will explore mechanisms through which diabetes potentiates the production of specific oxygenated phospholipids. In Aim 3, we will test the hypothesis, that selective oxidation of phospholipid species dictates the activation of renal cell death programs. The experimental strategy combines PTC-specific transgenic models, obese CKD and diabetic DKD models, using targeted compounds to delinate originating sources of redox stress and advanced redox phospholipidomics and biophysical approaches. Outcomes from this proposal will establish a new, more specific view of redox stress in CKD/DKD and link specific oxidized (phospho)lipids to PTC injury and demise, paving the way to highly specific anti-apoptotic or anti-ferroptotic interventions in the future.

氧化应激长期以来一直与糖尿病和慢性肾脏病的发病机制有关 (DKD/CKD) 之前的大多数研究都集中在氧化应激与氧化应激的单一概念上。抗氧化平衡，或以超氧化物作为主要活性氧 (ROS) 的过量产生为中心是 DKD/CKD 的主要事件，然而，超氧化物具有限制其发挥作用的主要动力学和生化障碍。我们提出了反应性较低、特异性更强的膜的关键作用。与细胞代谢变化也密切相关的扩散分子——（磷酸）脂质过氧化物（LOOH）虽然脂质过氧化的基本原理是在生物学中确立的，但其分子实体和模式 LOOH 的作用和特定氧化还原信号传导能力更加神秘，这是一个需要解决的关键差距。因为在疾病发病机制的正确时机阻碍高度特异性形式的氧化还原信号可以预防我们的中心假设是 LOOH 是传递初始信号的关键代谢信号。此外，我们认为糖尿病会改变 LOOH 的分子特征。在无数不同的氧化磷脂中，只有少数特定的磷脂决定了我们重点关注近端肾小管上皮细胞 (PTC)，其约占 70-80%。皮层，我们之前发现 PTC 代谢失调会增强 LOOH 的产生。我们有大量初步数据表明，当 PTC 代谢受到脂质挑战时过载或通过删除谷胱甘肽消除膜过氧化物的中和机制我们使用糖尿病模型，过氧化物酶 4 (GPx4)、LOOH 产生过多，导致小鼠出现肾损伤。表明糖尿病不仅增强了 LOOH 的形成，而且还改变了 LOOH 的分子特征 LOOH 物种以氧化磷脂酰乙醇胺 (PE) 和溶血磷脂酰乙醇胺的方式（LPE）变得丰富。三个目标将利用最先进的生物物理学和质量来检验这一假设。光谱成像方法与药理学和转基因方法相结合在目标 1 中，我们将测试 PTC 变化的预测。代谢活动调节 LOOH 的产生目标 2 将探索糖尿病的机制。增强特定含氧磷脂的产生在目标 3 中，我们将检验以下假设：磷脂种类的选择性氧化决定了肾细胞死亡程序的激活。实验策略结合了 PTC 特异性转基因模型、肥胖 CKD 和糖尿病 DKD 模型，使用确定氧化还原应激来源的靶向化合物和先进的氧化还原磷脂组学该提案的结果将建立一个新的、更具体的氧化还原观点。 CKD/DKD 中的压力并将特定的氧化（磷酸）脂质与 PTC 损伤和死亡联系起来，为未来高度特异性的抗凋亡或抗铁死亡干预措施。