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.

项目概要 静脉脂肪乳剂（ILE）是重要的治疗方法。虽然它们是为肠外营养而设计的， 被发现是局部麻醉全身毒性（LAST）的解毒剂。随着血管内 局部麻醉剂 (LA) 的浓度，典型地抑制电压门控钠通道 (Nav)， 中枢神经系统 (CNS) 毒性症状进展为癫痫发作，可能会导致心脏骤停。最后的 是一项重大的临床挑战，而将 ILE 确定为治疗方法是一项突破，它已利用 洛杉矶更安全。尽管具有这一重要作用，但 ILE 治疗 LAST 的分子机制尚不完全清楚。 明白了。此外，很少有研究检验 Intralipid®（乳液）是否 医学指南推荐，由大豆油中的长链甘油三酯组成，是最好的 选择。 ILE 影响的最简单模型是它们形成血管内隔室 分配 LA 并降低效应位点浓度，但浓度在水溶液中下降的程度 阶段有争议。心脏模型中具有强有力证据的一个相互竞争的假设提出 ILE 可作为燃料 通过甘油三酯（TG）的β-氧化，克服LA引起的线粒体功能障碍。这个机制 由于神经元依赖的教条信念，解释中枢神经系统功能障碍的逆转已被驳回 葡萄糖代谢。此外，由于证据有限，LA 引起的神经毒性被归因于 优先阻断抑制性神经元，但这一假设无法解释中枢神经系统的重要影响。我的 初步体外数据表明，神经元可以在缺乏脂质的情况下使用 Intralipid® 来维持突触功能。 其他燃料，支持中枢神经系统中 LAST 的 ILE 代谢假说。 本研究计划将检验 ILE 通过克服 LA 诱导的神经毒性来逆转神经毒性的假设 线粒体功能障碍。该实验计划将系统地研究神经元的能力 代谢 ILE 的成分。在此过程中，我将全面研究脂质作为燃料的适用性 突触功能。在目标 1 中，我将利用我在表达培养神经元的光学成像方面的专业知识 基因编码生物传感器通过维持突触小泡回收的能力来比较脂质 当缺乏葡萄糖时产生 ATP。脂质将作为长链和中链 TG 的乳液进行测试 以及不同长度和饱和度的游离脂肪酸。在目标 2 中，代谢优化的乳液将是 在培养中与 Intralipid® 相比，其逆转 LA 诱导的突触功能障碍的能力。在目标 3 中，优化后的 乳液将与小鼠体内的 Intralipid® 进行比较，通过宽场钙成像量化对癫痫发作的影响， 局部场电位和代谢活动的自发荧光黄素成像。我的五年研究和职业生涯 提案利用了我优秀的导师和制度环境。我将获取出版记录 和被认可为麻醉神经药理学国家领导者所需的专业知识，并为 R01 资助下的独立调查。