Metabolic impact of Intralipid on synaptic function as a mechanism of resuscitation in local anesthetic systemic toxicity

脂肪乳对突触功能的代谢影响作为局麻药全身毒性复苏的机制

• 批准号: 10572885
• 负责人: Daniel Charles Cook
• 金额: $ 19.5万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-02-01 至 2028-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10572885
• 关键词: Action Potentials; Adenosine Triphosphate; Agreement; Anesthetics; Antidotes; Belief; Biosensor; Brain; Bypass; Calcium; Cardiac; Cardiotoxicity; Cardiovascular system; Carnitine; Central Nervous System; Cephalic; Clinical; Convulsants; Data; Dose; Effectiveness; Emulsions; Environment; Fat emulsion; Flavins; Formulation; Functional disorder; Funding; Glucose; Glycolysis; Glycolysis Inhibition; Guidelines; Heart Arrest; Hypoglycemia; ICAM3 gene; Image; Impairment; In Vitro; Institution; Intravenous Fat Emulsions; Investigation; Ischemia; Length; Lidocaine; Life; Lipids; Local Anesthetics; Measurement; Measures; Mediating; Medical; Medicine; Medium chain triglycerides; Mentors; Metabolic; Metabolic stress; Metabolism; Mitochondrial Proteins; Modeling; Molecular; Molecular Target; Mus; Muscle; Nerve; Neurobiology; Neurologic; Neurons; Neuropharmacology; Nonesterified Fatty Acids; Optical reporter; Overdose; Oxidative Phosphorylation; Parenteral Nutrition; Pathway interactions; Perfusion; Pharmaceutical Preparations; Phase; Phenotype; Phospholipids; Prevention; Production; Publications; Pyruvate; Recommendation; Recycling; Research; Research Proposals; Resuscitation; Role; Seizures; Site; Sodium Channel; Soybean Oil; Symptoms; Synapses; Synaptic Vesicles; Syndrome; Testing; Therapeutic; Toxic effect; Triglycerides; aqueous; career; clinical application; comparative efficacy; deprivation; design; excitatory neuron; falls; glucose metabolism; improved; in vivo; inhibitory neuron; knock-down; lipid transport; lipoprotein lipase; metabolic imaging; mitochondrial dysfunction; neurotoxic; neurotoxicity; neurotransmission; optical imaging; oxidation; pharmacologic; prevent; small hairpin RNA; synaptic function; systemic toxicity; voltage

Project Summary Intravenous lipid emulsions (ILEs) are important therapies. Though designed for parenteral nutrition, they were discovered to be an antidote for local anesthetic systemic toxicity (LAST). With rising intravascular concentrations of local anesthetics (LAs), which canonically inhibit voltage-gated sodium channels (Nav), symptoms of central nervous system (CNS) toxicity progress to seizures, and cardiac arrest may ensue. LAST is a major clinical challenge, and the identification of ILEs as treatment was a breakthrough that has made use of LAs safer. Despite this important role, the molecular mechanisms by which ILEs treat LAST are not fully understood. Furthermore, there is a paucity of studies examining whether Intralipid®, the emulsion recommended in medical guidelines that is composed of long-chain triglycerides from soybean oil, is the best choice. The most simplistic model for the effects of ILEs is that they form an intravascular compartment to partition LAs and lower the effect-site concentration, but the degree to which concentrations fall in the aqueous phase is debated. A competing hypothesis with strong evidence in cardiac models proposes ILEs serve as a fuel via β-oxidation of triglycerides (TGs), overcoming mitochondrial dysfunction caused by LAs. This mechanism has been dismissed to explain reversal of CNS dysfunction because of the dogmatic belief that neurons rely on glucose metabolism. Additionally, neurotoxicity due to LAs has been attributed, with limited evidence, to preferential block of inhibitory neurons, but important effects in the CNS are unexplained by this hypothesis. My preliminary in vitro data shows that neurons can use Intralipid® to sustain synaptic function in the absence of other fuels, supporting the metabolic hypothesis of ILEs for LAST in the CNS. This research proposal will test the hypothesis that ILEs reverse neurotoxicity by overcoming LA-induced mitochondrial dysfunction. The experimental plan will systematically investigate the capacity for neurons to metabolize components of ILEs. In doing so, I will comprehensively investigate the suitability of lipids to fuel synaptic function. In Aim 1, I will use my developing expertise in optical imaging of cultured neurons expressing genetically-encoded biosensors to compare lipids by their ability to sustain synaptic vesicle recycling and produce ATP when deprived of glucose. Lipids will be tested as emulsions of both long- and medium-chain TGs and free fatty acids of different lengths and saturation. In Aim 2, a metabolically optimized emulsion will be compared in culture to Intralipid® in its ability to reverse LA-induced synaptic dysfunction. In Aim 3, the optimized emulsion will be compared to Intralipid® in mice, quantifying effects on seizures with widefield calcium imaging, local field potentials, and autofluorescence flavin imaging of metabolic activity. My five-year research and career proposals capitalize on my excellent mentors and institutional environment. I will acquire the publication record and expertise necessary for recognition as a national leader in anesthetic neuropharmacology and prepare for independent investigation with R01 funding.

项目摘要 静脉脂质乳液（ILES）是重要的疗法。虽然是为肠胃外营养设计的 被发现是局部麻醉系统毒性的解毒剂（最后）。血管内增加 局部麻醉剂（LAS）的浓度，该麻醉量可以抑制电压门控通道（NAV）， 中枢神经系统（CNS）毒性毒性的症状可能导致心脏骤停。最后的 是一个主要的临床挑战，将ILE作为治疗的识别是一种突破 拉斯更安全。尽管有这种重要作用，但iles处理的分子机制并非完全 理解齿。此外，研究了IntaLipid®是否乳液的研究很少 在医疗指南中建议，由大豆油组成的长链甘油三酸酯是最好的 ILES影响的最简单模型是它们形成了血管内室 分区LAS并降低效应位点的浓度，但浓度落在水中的程度 阶段是有争议的。在心脏模型中具有强大证据的竞争假设，提案Iles是燃料 通过甘油三酸酯（TGS）的β氧化，克服了由LAS引起的线粒体功能障碍。这种机制 被驳回以解释CNS功能障碍的逆转，因为教条主义的信念是神经元依靠 葡萄糖代谢。另外，由于LA引起的神经毒性，有限的证据归因于 通过这一假设，抑制性神经元的优先块抑制性神经元，但中枢神经系统的重要作用是出乎意料的。我的 初步的体外数据表明，神经元可以在不存在的情况下使用Intalipid®维持突触功能 其他燃料，支持CNS中最后一个Iles代谢假设。 该研究建议将检验以下假设，即通过克服LA诱导的，纤维反向神经毒性逆转神经毒性 线粒体功能障碍。实验计划将系统地研究神经元的能力 代谢Iles的成分。这样，我将全面研究脂质对加油的适用性 突触功能。在AIM 1中，我将使用我正在发展的专业知识来表达培养的神经元的光学成像 一般编码的生物传感器可以通过维持突触囊泡回收的能力来比较脂质 当剥夺葡萄糖时会产生ATP。脂质将被测试为长和中链TG的乳液 以及不同长度和饱和的游离脂肪酸。在AIM 2中，代谢优化的乳液将是 在培养物与Intralipid®逆转LA诱导的突触功能障碍的能力上进行了比较。在AIM 3中，优化 将乳液与小鼠中的intalipid®进行比较，从而量化对具有广阔钙成像的癫痫发作的作用， 局部场电位和代谢活性的自荧光黄素成像。我的五年研究和职业 提案利用了我的出色导师和机构环境。我将获得出版记录 以及承认是麻醉神经药理领域国家领导者所必需的专业知识并为 R01资金的独立投资。