Determining the Biological Effects of Mitochondrial Acyl Toxicity

确定线粒体酰基毒性的生物学效应

基本信息

批准号：
10034718
负责人：
Jessica M Ellis
金额：
$ 46.39万
依托单位：
EAST CAROLINA UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-07-01 至 2025-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10034718
关键词：
Acute Agreement Animal Model Biochemical Bioenergetics Biological Biological Assay Biological Models Biology Calcium Calcium Channel Carnitine Carnitine Palmitoyltransferase I Cell physiology Cells Chronic Clinical Coenzyme A Coenzyme A Ligases Complex Confounding Factors (Epidemiology)Consumption Coupled Cytosol Data Defect Diabetes Mellitus Enzymes Equilibrium Etiology Exercise Tolerance Fatigue Functional disorder Genetic Health High Fat Diet Homeostasis Human Impairment Inner mitochondrial membrane Insulin Resistance Knockout Mice Link Literature Metabolic Metabolic Diseases Metabolic stress Metabolism Mitochondria Modeling Mus Muscle Muscle Fibers Muscle function Muscular Atrophy Obesity Obesity Epidemic Outcome Oxidative Phosphorylation Pathway interactions Phenotype Physiological Physiological Processes Pre-Clinical Model Process Production Reaction Recovery Rhabdomyolysis Role Sarcoplasmic Reticulum Skeletal Muscle Soleus Muscle Source Structure Surface Testing Therapeutic Toxic effect Work acylcarnitine deprivation exercise capacity fatty acid oxidation in vivo insight insulin sensitivity insulin signaling lipid metabolism mitochondrial dysfunction mouse model novel overexpression oxidation skeletal muscle weakness therapeutic development translocase

项目摘要

PROJECT SUMMARY During acute metabolic stress and chronic metabolic disease, such as obesity and diabetes, the accumulation of fatty acid oxidation intermediary metabolites has long been suspected of toxicity. Among these possible lipotoxic metabolites are long-chain acylcarnitines (LCACs), which purportedly interfere with critical physiological processes including insulin signaling, calcium homeostasis, and mitochondrial function. However, mechanistically linking defects in these processes to LCAC accumulation has been difficult due to a lack of LCAC-accumulating pre-clinical models. We overcame this barrier by developing a unique mouse model of LCAC accumulation by deleting the enzyme that catabolizes LCACs, carnitine palmitoyltransferase-2 specifically in skeletal muscle (Cpt2Sk-/-). Consistent with the suspected roles of LCACs effects on biology, our preliminary data demonstrate that Cpt2Sk-/- muscles have reduced force production and mitochondrial dysfunction. Our preliminary data also demonstrate large accumulation of LCACs within oxidative muscle fibers, thus are the most vulnerable to potential LCAC toxicity. While our Cpt2Sk-/- model provides consistently elevated LCACs, the physiological outcomes are confounded by energy deprivation due to mitochondrial FAO deficiency. To mitigate concerns surrounding this confounding variable, we will employ three complimentary mouse models of muscle- specific FAO deficiency: 1) Cpt2Sk-/- that accumulate LCACs across the cell; 2) carnitine acylcarnitine translocase (CactSk-/-) mice that accumulate LCACs outside of the mitochondria; and 3) acyl-CoA synthetase 1 (Acsl1Sk-/-) mice that do not accumulate LCACs at all. Here, we will use this three-model system to determine the role of LCACs on insulin signaling, calcium homeostasis, and mitochondrial function. Results will be the first to provide requisite experimental contrast to unveil direct versus indirect effects of LCACs on cell physiology.

项目摘要在急性代谢应激和慢性代谢疾病（例如肥胖和糖尿病）中，积累脂肪酸氧化的中间体代谢产物长期以来一直怀疑毒性。其中可能脂肪毒性代谢物是长链酰基肉碱（LCAC），据称会干扰关键的生理包括胰岛素信号传导，钙稳态和线粒体功能在内的过程。然而，由于缺乏 LCAC累加的临床前模型。我们通过开发独特的鼠标模型克服了这一障碍 LCAC通过删除分解LCAC，肉碱棕榈转移酶-2的酶来积累在骨骼肌（CPT2SK - / - ）中。与LCACS对生物学作用的可疑作用一致，我们的初步数据表明，CPT2SK - / - 肌肉减少了力产生和线粒体功能障碍。我们的初步数据还表明，LCAC在氧化肌纤维中的积累大量，因此是最多的。容易受到潜在LCAC毒性的影响。虽然我们的CPT2SK - / - 型号提供了一致升高的LCAC，但生理结果被线粒体粮农组织缺乏造成的能量剥夺所困扰。减轻围绕此混杂变量的担忧，我们将采用三种免费的肌肉小鼠模型 - 特定的粮农组织缺陷：1）CPT2SK - / - 在整个细胞上积聚LCAC； 2）肉碱酰基苯胺易位酶（仙人掌 - / - ）在线粒体外积聚LCAC的小鼠； 3）酰基-COA合成酶1（ACSL1SK - / - ）根本不积聚LCAC的小鼠。在这里，我们将使用此三模型系统来确定胰岛素信号传导，钙稳态和线粒体功能的LCAC。结果将是第一个提供的与LCAC对细胞生理学的直接和间接影响揭示直接对形成的必要实验对比。