Utilizing opioid receptor expression to identify the neurons and molecules responsible for opioid respiratory depression and basal breathing.

利用阿片受体表达来识别负责阿片类呼吸抑制和基础呼吸的神经元和分子。

• 批准号: 10701824
• 负责人: Kevin Yackle
• 金额: $ 35.8万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-15 至 2027-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10701824
• 关键词: ARRB2; Acute; Address; Adult; Analgesics; Behavior; Behavioral; Brain; Brain Stem; Breathing; Cardiac pacemaker; Cessation of life; Clinical; Compensation; Data; Future; GTP-Binding Proteins; Generations; Genetic; Goals; In Vitro; Measures; Mediating; Mediator; Medicine; Modeling; Molecular; Motor Neurons; Mus; Neurons; Opioid; Opioid Receptor; Pacemakers; Pain management; Pathway interactions; Periodicity; Persons; Play; Respiratory physiology; Role; Signal Pathway; Signal Transduction; Site; Societies; Synaptic Vesicles; System; Testing; Therapeutic; Time; United States; Ventilatory Depression; Work; beta-arrestin; design; excitatory neuron; experimental study; genetic approach; in vivo; inward rectifier potassium channel; mouse genetics; neural; nodal myocyte; novel; opioid epidemic; opioid misuse; opioid mortality; opioid overdose; opioid use; optogenetics; overdose death; pandemic disease; pharmacologic; preBotzinger complex; presynaptic; prevent; receptor expression; side effect; vesicular release

Between 1999 and 2018 more than 446,000 people died from profoundly slow and shallow breathing after opioid overdose. This number grows at a faster rate each year and in 2019 there were nearly 50,000 overdose deaths. Opioids are perhaps the most effective analgesic, therefore, despite concern, they will persist as a staple therapy in medicine and within our society into the future. Thus, novel solutions to safely use opioids must be developed. But to discover these, we must first understand the key cellular and molecular mechanisms for opioid depression of breathing, known as opioid induced respiratory depression (OIRD). Recently we demonstrated that opioids depress breathing mostly through their action upon µ-opioid receptor (MOR) expressing neurons in the same site where the breathing rhythm is created, the preBötzinger Complex (preBötC). In this proposal, a central goal is to define the key preBötC neural type and MOR signaling pathway(s) that cause OIRD. Results from both aims will have direct clinical and therapeutic impact. Here, we hypothesize that opioids cause OIRD by blocking synaptic vesicle release from just 140 MOR+ excitatory preBötC neurons. Additionally, we expect that these same neurons, despite being less than 10% of preBötC, are specialized for creating the pace of breathing in general, analogous to the cardiac pacemaker cells. If so, these will be the first neurons identified with such an important purpose. This is the second central goal of the proposal. To test these three hypotheses, we have designed a sophisticated intersectional genetic approach to selectively delete MOR in adult mice from either excitatory or inhibitory preBötC neurons or nearby upper airway motor neurons to then compare if and how much OIRD changes. Next, we will use a sensitive in vitro system to uniformly test the necessity of each primary MOR signaling pathway in suppressing preBötC rhythmicity. And last, we will use an intersectional genetic approach to measure changes in breathing after acutely, ectopically silencing the preBötC MOR+ excitatory neurons. The identification of the cellular and molecular mechanisms of OIRD will establish a framework for future studies to develop novel pharmacological approaches to block or rescue it. Moreover, this proposal aims to determine if MOR+ excitatory neurons are pacemakers for breathing. If so, we will have identified, perhaps, some of the most vital neurons in the brain.

在1999年至2018年期间，超过446，000人死于阿片类药物后的缓慢和浅呼吸 服药过量这一数字每年以更快的速度增长，2019年有近50，000例过量死亡。 阿片类药物可能是最有效的止痛药，因此，尽管存在担忧，但它们仍将作为主要治疗药物 在医学和我们的社会中走向未来。因此，必须开发安全使用阿片类药物的新解决方案。 但要发现这些，我们必须首先了解阿片类药物抑制的关键细胞和分子机制 阿片类药物引起的呼吸抑制（OIRD）。 最近，我们证明阿片类药物主要通过作用于μ-阿片受体来抑制呼吸 (MOR)在产生呼吸节律的同一部位表达神经元，即前Bötzinger复合体 (preB OtC）。在这个提议中，一个中心目标是定义关键的preBötC神经类型和莫尔信号通路。 导致OIRD。这两个目标的结果都将产生直接的临床和治疗影响。我们假设 阿片类药物通过阻断140个莫尔+兴奋性preBötC神经元的突触囊泡释放而引起OIRD。 此外，我们预计，这些相同的神经元，尽管不到10%的preBötC，是专门为 产生呼吸的节奏，类似于心脏起搏细胞。如果是这样，这将是第一个 神经元具有如此重要的功能。这是该提案的第二个核心目标。测试这些 三个假设，我们设计了一个复杂的交叉遗传方法来选择性地删除莫尔 在成年小鼠中，从兴奋性或抑制性前BötC神经元或附近的上气道运动神经元， 比较OIRD是否发生变化以及变化的程度。接下来，我们将使用敏感的体外系统来统一测试 每个主要莫尔信号通路在抑制preBötC节律性中的必要性。最后，我们将使用 交叉遗传方法测量急性异位沉默preBötC后呼吸的变化 莫尔+兴奋性神经元。 OIRD的细胞和分子机制的确定将为未来的研究奠定基础 开发新的药理学方法来阻断或挽救它。此外，这项建议旨在确定， 莫尔+兴奋性神经元是呼吸的起搏器。如果是这样的话，我们将确定，也许，一些最 重要的神经元