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 静脉注射脂肪乳剂(ILE)是重要的治疗方法。虽然是为肠外营养而设计的，但他们 被发现是局部麻醉剂全身毒性的解毒剂(最后)。随着血管内流量的上升 局麻药(LAS)的浓度，它典型地抑制电压门控钠通道(NAV)， 中枢神经系统(CNS)中毒的症状进展到癫痫发作，并可能随之而来的心脏骤停。最后的 是一项重大的临床挑战，而将ILES确定为治疗方法是一项突破，它已经利用 更安全的拉斯维加斯。尽管有这种重要的作用，但ILE最后治疗的分子机制还不完全。 明白了。此外，很少有研究考察Intralipid®，即乳剂 在医学指南中推荐的由来自大豆油的长链甘油三酯组成的产品是最好的 选择。对ILES效应最简单的模型是它们形成血管内隔室以 分配LAS并降低效应点浓度，但浓度在水溶液中的下降程度 阶段是有争议的。一个在心脏模型中有强有力证据的相互竞争的假说认为，ILE是一种燃料 通过甘油三酯的β氧化，克服LAS引起的线粒体功能障碍。这一机制 已经被驳回以解释中枢神经系统功能障碍的逆转，因为神经元依赖于 葡萄糖代谢。此外，在证据有限的情况下，LAS的神经毒性被归因于 优先阻断抑制性神经元，但在中枢神经系统的重要作用不能用这一假说解释。我的 初步的体外数据显示，神经元可以使用Intralipid®来维持突触功能 其他燃料，支持ILES的新陈代谢假说。 这项研究计划将检验ILES通过克服LA诱导的神经毒性而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ILES的成分。在这样做的过程中，我将全面调查血脂对燃料的适应性 突触功能。在目标1中，我将利用我在培养神经元表达的光学成像方面的开发专业知识 基因编码的生物传感器，用于比较血脂维持突触小泡循环和 在没有葡萄糖的情况下产生三磷酸腺苷。脂类将作为长链和中链TGS的乳剂进行测试 以及不同长度和饱和度的游离脂肪酸。在目标2中，新陈代谢优化的乳剂将是 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，优化的 乳剂将在小鼠身上与Intralipid®进行比较，通过宽视野钙成像来量化对癫痫发作的影响， 局部场电位和代谢活动的自体荧光黄素成像。我五年的研究和职业生涯 提案充分利用了我优秀的导师和机构环境。我将获取发布记录 以及被认可为麻醉神经药理学全国领导者所需的专业知识，并为 独立调查，由R01提供资金。