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）是高能量的肾细胞。他们的能量需求涵盖主要来自线粒体脂肪酸氧化。如果没有足够的ATP满足高能量需求产生，管状上皮细胞会凋亡和萎缩。线粒体脂肪酸的出轨因此，代谢是管状细胞死亡中的主要基础候选机制。最近已经在2型糖尿病小鼠和人类中发现的糖尿病肾脏表现出增加的脂肪酸代谢和氧化，但这与ATP的产生不符。肾脏皮质积聚典型的线粒体超负荷的氧化代谢产物不完全氧化。我们的中心假设是这种不完全的脂肪酸氧化会导致小管的近端凋亡通过至关重要的途径线粒体功能。我们引人注目的初步数据表明，细胞中的线粒体超负荷会导致能量缺陷，并且氧化剂产生。在我们的新鼠标模型中，不完全的脂肪酸氧化和线粒体超负荷引起肾脏疾病。这是通过PTC特异性缺失的肉碱 - 乙酰转移酶（CRAT）来实现的。这酶从线粒体中将多余的脂肪酸产物穿梭；因此，缺乏crat模型线粒体超负荷。我们的目标是定义由于线粒体超负荷。三个相互连接但独立的目标将使用最先进的分子和氧化还原生物学的艺术方法。在AIM 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缺陷，然后对管状细胞有害。 AIM 2将测试假设不完全的脂肪酸氧化会导致过量的Mitchondrial ROS产生和凋亡。前两个目标将使用功能丧失方法（单独或仅在结合肥胖和2型糖尿病），从这些原发性PTC中分离出来的机械研究模型和晚期生物物理测量（细胞外通量分析仪，电子自旋共振光谱法）。在AIM 3中，我们将测试是否通过增强出境来减轻线粒体过载不完全氧化的产品提供预防。我们将使用体外和体内功能获得实验（克拉特过表达和重新表达）作为救援实验。实验策略旨在确定线粒体脂肪酸氧化在管状损伤中的作用，破译基础生化机制，并解决此类途径是否可以为管状细胞保存提供基础在肥胖和2型糖尿病的背景下出现凋亡之前。规定这些机制是管状细胞凋亡的先驱，靶向线粒体脂肪酸超负荷可能是突出的新领域可以预防，而不是治疗管状萎缩和慢性肾脏疾病。

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）

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

DOI：
10.1016/j.redox.2022.102520
发表时间：
2022-12
期刊：
REDOX BIOLOGY
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

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

DOI：
10.1152/ajprenal.00031.2020
发表时间：
2020-03
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：
Allison N. Mccrimmon;Mark Domondon;Regina F. Sultanova;D. Ilatovskaya;K. Stadler