Mitochondrial overload and proximal tubular cell atrophy

线粒体过载和近端肾小管细胞萎缩

基本信息

批准号：
10159897
负责人：
Krisztian Stadler
金额：
$ 43.96万
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：
2018
资助国家：
美国
起止时间：
2018-06-05 至 2024-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10159897
关键词：
Ablation Acetylcarnitine Acyl Coenzyme A Address Affect Apoptosis Apoptotic Appearance Area Atrophic Biochemical Biology Carnitine O-Acetyltransferase Cell Death Cells Characteristics Chronic Kidney Failure Citric Acid Cycle Complication Critical Pathways Data Development Diabetic mouse Diet Disease Disease Progression Electron Spin Resonance Spectroscopy Enzymes Epithelial Epithelial Cells Exhibits Fatty Acids Fibrosis Future Genetic Engineering Goals Human Impairment In Vitro Injury Intervention Kidney Kidney Diseases Kidney Failure Knockout Mice Knowledge Lead Link Metabolic Metabolism Mitochondria Modeling Molecular Molecular Profiling Mus Non-Insulin-Dependent Diabetes Mellitus Obesity Outcome Oxidants Oxidation-Reduction Oxides Pathway interactions Phenotype Prevention Production Protons Quality of life Reactive Oxygen Species Research Respiration Role Route Structure Testing Tissues Transferase Tubular formation Type 2 diabetic Urine acylcarnitine biophysical properties biophysical techniques catalase cell injury db/db mouse design diabetic end stage disease experimental study extracellular fatty acid metabolism fatty acid oxidation gain of function genetic approach glomerular filtration in vivo kidney cell kidney cortex lipid metabolism loss of function mouse model mutant outcome prediction overexpression oxidant stress oxidation peroxiredoxin 2 preservation prevent

项目摘要

Proximal tubular epithelial cells (PTC) are highly energy demanding kidney cells. Their energy need is covered mostly from mitochondrial fatty acid oxidation. If the high energy demand is not met with sufficient ATP production, tubular epithelial cells undergo apoptosis and atrophy. Derailments in mitochondrial fatty acid metabolism are therefore the main underlying candidate mechanisms in tubular cell death. It has recently been discovered in type 2 diabetic mice and humans that the diabetic kidney exhibits increased fatty acid metabolism and oxidation, but this is not matched with ATP production. The kidney cortex accumulates incompletely oxidized metabolic products which is typical of mitochondrial overload. Our central hypothesis is that this incomplete fatty acid oxidation causes proximal tubule apoptosis through pathways critical to mitochondrial function. Our compelling set of preliminary data show that mitochondrial overload in cells causes energy deficit and oxidant production. In our new mouse model, incomplete fatty acid oxidation and mitochondrial overload causes kidney disease. This was achieved by PTC-specific deletion of carnitine-acetyltransferase (CrAT). The enzyme shuttles excess fatty acid products out of the mitochondria; therefore, lack of CrAT models mitochondrial overload. Our goal is to define the mechanisms that are forerunners of tubular apoptosis due to mitochondrial overload. Three interconnected but independent aims will test our hypothesis using state-of-the- art approaches of both molecular and redox biology. In Aim 1, we will test the prediction that incomplete fatty acid oxidation causes mitochondrial energy deficit, which is then detrimental to tubular cells. Aim 2 will test the hypothesis that incomplete fatty acid oxidation leads to excess mitchondrial ROS production and apoptosis. The first two aims will use loss-of-function approaches (PTC-specific CrAT knockout mice alone or in combination with obesity and type 2 diabetes), mechanistic studies from primary PTCs isolated from these models and advanced biophysical measurements (extracellular flux analyzer, electron spin resonance spectroscopy). In Aim 3, we will test whether alleviating mitochondrial overload by enhancing the efflux of incompletely oxidized products offers prevention. We will use in vitro and in vivo gain-of-function experiments (CrAT overexpression and re-expression) as rescue experiments. The experimental strategy is designed to establish the role of incomplete mitochondrial fatty acid oxidation in tubular injury, decipher the underlying biochemical mechanisms and address whether such pathways can offer the basis for tubular cell preservation well before the appearance of apoptosis, in the context of obesity and type 2 diabetes. Provided that these mechanisms are forerunners of tubular cell apoptosis, targeting mitochondrial fatty acid overload can be a prominent new area to prevent, rather than treat tubular atrophy and chronic kidney disease.

近端肾小管上皮细胞（PTC）是高能量需求的肾细胞。他们的能源需求得到满足主要来自线粒体脂肪酸氧化。如果没有足够的 ATP 来满足高能量需求产生后，肾小管上皮细胞发生凋亡和萎缩。线粒体脂肪酸脱轨因此，代谢是肾小管细胞死亡的主要潜在候选机制。最近已经是在 2 型糖尿病小鼠和人类中发现，糖尿病肾脏的脂肪酸含量增加代谢和氧化，但这与 ATP 的产生不匹配。肾皮质蓄积不完全氧化的代谢产物，这是线粒体超载的典型特征。我们的中心假设是这种不完全的脂肪酸氧化通过对细胞至关重要的途径导致近端小管细胞凋亡线粒体功能。我们令人信服的一组初步数据表明，细胞中的线粒体超载会导致能量不足和氧化剂的产生。在我们的新小鼠模型中，脂肪酸氧化不完全和线粒体过载导致肾脏疾病。这是通过 PTC 特异性删除肉碱乙酰转移酶 (CrAT) 来实现的。这酶将多余的脂肪酸产物运送出线粒体；因此，缺乏 CrAT 模型线粒体超载。我们的目标是确定肾小管细胞凋亡的先导机制线粒体超载。三个相互关联但独立的目标将使用最新情况来检验我们的假设分子生物学和氧化还原生物学的艺术方法。在目标 1 中，我们将测试不完全脂肪的预测酸氧化会导致线粒体能量不足，从而对肾小管细胞有害。目标 2 将测试假设不完全脂肪酸氧化导致线粒体过量产生 ROS 和细胞凋亡。前两个目标将使用功能丧失方法（单独或联合使用 PTC 特异性 CrAT 敲除小鼠）与肥胖和 2 型糖尿病相结合），从这些中分离出的原发性 PTC 的机制研究模型和先进的生物物理测量（细胞外通量分析仪、电子自旋共振光谱）。在目标 3 中，我们将测试是否可以通过增强线粒体外流来减轻线粒体超载。不完全氧化的产品可提供预防作用。我们将使用体外和体内功能获得实验（CrAT 过度表达和重新表达）作为救援实验。实验策略旨在建立不完全线粒体脂肪酸氧化在肾小管损伤中的作用，破译潜在的机制生化机制并解决这些途径是否可以为肾小管细胞保存提供基础在肥胖和 2 型糖尿病的背景下，早在细胞凋亡出现之前。前提是这些机制是肾小管细胞凋亡的先行者，针对线粒体脂肪酸超载可以是预防而不是治疗肾小管萎缩和慢性肾脏疾病的突出新领域。

项目成果

期刊论文数量（3）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Comprehensive assessment of mitochondrial respiratory function in freshly isolated nephron segments.

综合评估新鲜分离的肾单位片段的线粒体呼吸功能。

DOI：
10.1152/ajprenal.00031.2020
发表时间：
2020-03-30
期刊：
American journal of physiology. Renal physiology
影响因子：
0
作者：
Allison N. Mccrimmon;Mark Domondon;Regina F. Sultanova;D. Ilatovskaya;K. Stadler
通讯作者：
K. Stadler

Renal Glomerular Mitochondria Function in Salt-Sensitive Hypertension.

肾小球线粒体在盐敏感性高血压中的功能。

DOI：
发表时间：
2019
期刊：
影响因子：
0
作者：
Domondon, Mark;Polina, Iuliia;Nikiforova, Anna B;Sultanova, Regina F;Kruger, Claudia;Vasileva, Valeriia Y;Fomin, Mikhail V;Beeson, Gyda C;Nieminen, Anna;Smythe, Nancy;Maldonado, Eduardo N;Stadler, Krisztian;Ilatovskaya, Daria V
通讯作者：
Ilatovskaya, Daria V

Redox phospholipidomics analysis reveals specific oxidized phospholipids and regions in the diabetic mouse kidney.

氧化还原磷脂组学分析揭示了糖尿病小鼠肾脏中特定的氧化磷脂和区域。

DOI：
发表时间：
2022-12
期刊：
影响因子：
11.4
作者：
McCrimmon, Allison;Corbin, Sydney;Shrestha, Bindesh;Roman, Gregory;Dhungana, Suraj;Stadler, Krisztian
通讯作者：
Stadler, Krisztian