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.

1999至2018年间，超过44.6万人死于阿片类药物后呼吸极其缓慢和浅 服药过量。这一数字每年以更快的速度增长，2019年有近5万人死于服药过量。 阿片类药物可能是最有效的止痛剂，因此，尽管存在担忧，它们仍将作为一种主要治疗方法。 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)。 最近我们证明了阿片类药物抑制呼吸主要是通过作用于µ-阿片受体 (MOR)在产生呼吸节律的同一部位表达神经元，即Prebötzinger复合体 (PrebötC)。在这个提案中，一个中心目标是定义关键的PrebötC神经类型和MOR信号通路(S) 这导致了OIRD。这两个目标的结果都将对临床和治疗产生直接影响。在这里，我们假设 阿片类药物通过阻断140个MOR+兴奋性PrebötC神经元的突触小泡释放而导致OIRD。 此外，我们预计，尽管这些神经元不到PrebötC的10%，但它们是专用于 创造一般的呼吸节奏，类似于心脏起搏细胞。如果是这样，这将是第一次 神经元被认为具有如此重要的用途。这是该提案的第二个核心目标。为了测试这些 三个假设，我们设计了一种复杂的交叉遗传方法来选择性地删除MOR 在成年小鼠中，兴奋性或抑制性PrebötC神经元或附近的上呼吸道运动神经元 比较OIRD是否发生了变化以及变化了多少。接下来，我们将使用一个敏感的体外系统来统一测试 各初级MOR信号通路在抑制PrebötC节律性中的必要性。最后，我们将使用 测量急性异位静息PrebötC后呼吸变化的交叉遗传学方法 MOR+兴奋性神经元。 OIRD细胞和分子机制的确定将为未来的研究建立一个框架 开发新的药理方法来阻断或挽救它。此外，这项提案旨在确定是否 MOR+兴奋性神经元是呼吸的起搏器。如果是这样的话，我们可能已经确定了一些最 大脑中的重要神经元。