Decoding regulation of glucose homeostasis and metabolic responses to mitochondrial stress by AMPK

AMPK 解码葡萄糖稳态和线粒体应激代谢反应的调节

• 批准号: 10327604
• 负责人: Elijah Trefts
• 金额: $ 6.76万
• 依托单位: SALK INSTITUTE FOR BIOLOGICAL STUDIES
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-12-01 至 2023-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10327604
• 关键词: 5' -AMP-activated protein kinase; Acute; Address; Aging; Automobile Driving; Biological; Biology; Body mass index; Caloric Restriction; Carbon; Cardiovascular Diseases; Catalytic Domain; Cell Respiration; Cell model; Cells; Cellular Metabolic Process; Chronic; Confocal Microscopy; DNA Sequence Alteration; DNA polymerase gamma; Data; Defect; Development; Disease; Dissection; Epidemic; Event; Exercise; Fasting; Future; Gene Expression; Genes; Gluconeogenesis; Glucose; Glucose Intolerance; Glycogen; Goals; Hepatocyte; Homeostasis; Hormones; Hyperglycemia; Hypoglycemia; Image; Impairment; Individual; Insulin Resistance; Knock-out; Link; Longevity; Mediating; Metabolic; Metabolic Diseases; Metabolic dysfunction; Metabolism; Metformin; Mitochondria; Modeling; Modernization; Molecular; Mus; Muscle Fibers; Non-Insulin-Dependent Diabetes Mellitus; Organ; Organ Culture Techniques; Overnutrition; Pathologic; Pathology; Pharmacology; Phosphotransferases; Physiological; Physiology; Premature aging syndrome; Production; Program Development; Protein Kinase; Quality Control; Regulation; Research; Research Design; Risk Factors; Role; Signal Pathway; Signal Transduction; Stress; Symptoms; System; Testing; Therapeutic; Therapeutic Intervention; Tissues; Training; Work; amino acid metabolism; blood glucose regulation; career; cell injury; cell type; fasting glucose; fasting plasma glucose; flexibility; genetic manipulation; glucose metabolism; glucose production; glucose tolerance; glucose uptake; improved; in utero; in vivo; insight; metabolic profile; mitochondrial dysfunction; mitochondrial metabolism; mortality; mortality risk; mouse model; novel; preservation; response; stress activated protein kinase; therapeutic development; therapeutically effective; therapy development

Project Summary/Abstract High fasting plasma glucose and body mass index ranked 3rd and 4th, respectively, as global mortality risk factors in 2017. Metabolic dysfunction links these factors with modern disease epidemics such as Type 2 diabetes (T2D). Many current therapies and therapeutic development programs focus on symptoms rather than underlying metabolic dysfunction common among these diseases. A primary goal of this work is to define mechanisms driving maladaptive metabolism to develop more effective therapeutic strategies with potential for multi-disease applicability. Mitochondrial impairments (e.g. inefficient oxidative metabolism and insufficient mitochondrial quality control) are hypothesized as major pathologic components in these diseases. Therefore, understanding mechanisms of mitochondrial regulation in conjunction with defective metabolism in diseases is a means towards improving disease treatments going forward. AMP-activated protein kinase (AMPK) is a central regulator of cell metabolism and multiple aspects of mitochondrial biology. Deficient AMPK signaling often overlaps the pathological profile of mitochondrial impairments in disease. However, understanding whole-body effects of deficient AMPK signaling as a multi-faceted driver of metabolic dysfunction and disease has been hampered by lack of viable mammalian models. Organ-specific loss of AMPK mouse models have been critical for dissection of metabolic implications of AMPK for individual cell types in vivo, but do not address multi-organ defects in AMPK signaling that has been associated with insulin resistance and T2D. Additionally, developmental whole- body knockout of AMPKα1 and AMPKα2 catalytic subunits (AMPK-DKO) causes in utero lethality in mice. To address these issues, the first mouse model for inducible, whole-body AMPK-DKO (iAMPK-DKO) has been generated. This model circumvents lethality of developmental AMPK-DKO and recapitulates disease-relevant multi-organ defects in AMPK signaling. Preliminary data from this model demonstrate deficient glucose homeostasis that is relevant to the study of T2D including postabsorptive hyperglycemia and glucose intolerance as well as a seemingly paradoxical fasting induced hypoglycemia. Additionally, combining iAMPK-DKO with genetically induced chronic mitochondrial stress in mice results in unique metabolic profiles, which are likely relevant to glucose control. The PI for this project has extensive expertise with decoding in vivo metabolic physiology. Combining this expertise with assessment of organ-specific mitochondrial function in acutely isolated primary models, culture of organ-specific primary cells, molecular manipulation of gene expression, and confocal microscopy of cellular systems will enable testing of this proposal’s central hypothesis: AMPK preserves mitochondrial metabolism to maintain normal physiologic glucose homeostasis and enables metabolic flexibility to preserve glucose homeostasis during chronic mitochondrial stress. Testing this hypothesis offers insight in to the role of AMPK in glucoregulatory physiology and begins to decode the mechanisms by which AMPK supports glucose homeostasis in normal physiology and pathologic mitochondrial stress.

项目总结/摘要 高空腹血糖和高体重指数分别为全球死亡危险因素的第3位和第4位 2017年代谢功能障碍将这些因素与2型糖尿病等现代疾病流行联系起来 （T2D）。许多当前的疗法和治疗开发计划关注的是症状而不是潜在的问题 这些疾病中常见的代谢功能障碍。这项工作的一个主要目标是确定机制 推动适应不良的代谢，以开发更有效的治疗策略，具有治疗多种疾病的潜力 适用性线粒体损伤（例如，氧化代谢效率低下和线粒体功能不足） 质量控制）被假设为这些疾病的主要病理成分。因此了解 线粒体调节机制与疾病中代谢缺陷的结合是一种手段， 改善疾病的治疗。AMP活化蛋白激酶（AMPK）是细胞增殖的中枢调节因子， 代谢和线粒体生物学的多个方面。AMPK信号传导缺陷通常与 疾病中线粒体损伤的病理学特征。然而，了解全身的影响， 缺乏AMPK信号传导作为代谢功能障碍和疾病的多方面驱动因素， 缺乏可行的哺乳动物模型。AMPK小鼠模型的器官特异性丧失对于解剖至关重要 AMPK对体内单个细胞类型的代谢影响，但不能解决体内多器官缺陷。 AMPK信号传导与胰岛素抵抗和T2D相关。此外，整体发展- AMPK α 1和AMPK α 2催化亚基的体敲除（AMPK-DKO）导致小鼠子宫内致死。到 为了解决这些问题，第一个可诱导的全身AMPK-DKO（iAMPK-DKO）小鼠模型已经在 生成的.该模型避免了发育AMPK-DKO的致死性，并概括了疾病相关的 AMPK信号传导的多器官缺陷。该模型的初步数据表明葡萄糖缺乏 与T2D研究相关的稳态，包括吸收后高血糖和葡萄糖耐受不良 以及看似矛盾的禁食引起的低血糖。此外，将iAMPK-DKO与 遗传诱导的小鼠慢性线粒体应激导致独特的代谢谱，这可能是 与血糖控制有关。本项目的PI具有解码体内代谢的广泛专业知识 physiology.将这一专业知识与急性孤立性胰腺炎中器官特异性线粒体功能的评估相结合， 原代模型、器官特异性原代细胞的培养、基因表达的分子操作和共聚焦显微镜 细胞系统的显微镜将使测试这一建议的中心假设：AMPK保存 线粒体代谢以维持正常的生理葡萄糖稳态，并使代谢 在慢性线粒体应激期间保持葡萄糖稳态的灵活性。验证这个假设 提供了对AMPK在糖调节生理学中作用的深入了解，并开始解码机制， AMPK支持正常生理和病理线粒体应激中的葡萄糖稳态。