Identification of cells and signaling mechanisms underlying opioid analgesia and side effects

鉴定阿片类镇痛和副作用背后的细胞和信号机制

• 批准号: 10165682
• 负责人: Gregory Scherrer
• 金额: $ 34.99万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-01 至 2023-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10165682
• 关键词: Absence of pain sensation; Acute; Affect; Affective; Analgesics; Behavioral Assay; Binding; Blood - brain barrier anatomy; Bromides; Cells; Chronic; Complement; Complex; Complex Regional Pain Syndromes; Constipation; Data; Development; Dissociation; Dose; Drug Compounding; Electrophysiology (science); Epidemic; FDA approved; Future; Gene Expression; Genetic Transcription; Hyperalgesia; Hypersensitivity; Individual; Knockout Mice; Lead; Long-Term Potentiation; Measures; Microglia; Mission; Modeling; Molecular; Molecular Target; Morphine; Mus; Mutant Strains Mice; National Institute of Drug Abuse; National Institute of General Medical Sciences; Neuronal Plasticity; Neurons; Nociception; Nociceptors; Opioid; Opioid Analgesics; Opioid Antagonist; Opioid agonist; Overdose; Pain; Pain management; Peripheral; Pharmaceutical Preparations; Pharmacology; Population; Process; Public Health; Publishing; Quality of life; Receptor Cell; Receptor Signaling; Reflex action; Reporting; Research; Rest; Signal Pathway; Signal Transduction; Slice; Spinal; Spinal Cord; Spinal Ganglia; Synapses; TLR4 gene; Translating; United States National Institutes of Health; Ventilatory Depression; Virus; Wild Type Mouse; addiction; beta-arrestin; chronic pain; clinical practice; conditional knockout; dosage; experimental study; genetic approach; inflammatory pain; innovation; morphine tolerance; mortality; mouse genetics; mouse model; mu opioid receptors; neurophysiology; neurotransmission; neurotransmitter release; new therapeutic target; novel; opiate tolerance; opioid abuse; opioid mortality; optogenetics; overdose death; pain patient; pain relief; painful neuropathy; prescription opioid abuse; presynaptic; programs; receptor; receptor expression; receptor function; recruit; relating to nervous system; side effect; spontaneous pain; therapeutic development; tool; transcriptome sequencing

Opioids are used extensively to relieve pain but also produce detrimental effects, including opioid-induced hyperalgesia (OIH) and analgesic tolerance. OIH and tolerance reduce opioid efficacy and drive dose escalation, which worsens other deleterious effects such as respiratory depression, and transition to addiction. These effects dramatically impact the quality of life of pain patients. Until now it has not been possible to dissociate the analgesic from the OIH and tolerance effects, because the receptors and cells on which opioids act to cause OIH and tolerance have not been identified. In contrast to the current model of opioids acting on CNS microglia to initiate antinociceptive tolerance and OIH, we found in RNA-sequencing experiments that the mu opioid receptor (MOR) is not expressed by microglia, and that OIH is lost, but microglia activation intact, in MOR global knockout mice. Furthermore, we generated new mutant mice that lack MOR only in dorsal root ganglion (DRG) nociceptors, but have intact MOR function in the CNS, and found that these mice show intact morphine antinociception, but no OIH or tolerance. These preliminary studies open the possibility of dissociating opioid analgesia from side effects, and lead to the following hypothesis: MORs in CNS underlie opioid analgesia, while MOR signaling and maladaptive neuroplasticity in DRG is responsible for OIH and tolerance. In Aim 1, we will use mouse genetics and viruses to delete MOR only in DRG of mice with chronic pain and treated with opioids, and submit these mice to behavioral assays to measure opioid analgesia, analgesic tolerance, and OIH, including with measures of pain affect and spontaneous pain. We will also block peripheral MORs with FDA- approved peripherally restricted antagonist methylnaltrexone bromide. We predict that deleting or blocking MOR in DRG will reduce morphine tolerance and OIH without impacting analgesia. In Aim 2, we will resolve the maladaptive synaptic mechanisms that underlie OIH and tolerance. Opioids induce pronociceptive long-term potentiation (LTP) at the synapse between DRG and spinal neurons. We will combine optogenetics and electrophysiological analysis to determine whether activation of presynaptic MORs in DRG initiates maladaptive LTP. In Aim 3, we will use RNA-sequencing on individual DRG nociceptors and PZM21, a novel Gi-biased MOR agonist, to determine the MOR effectors present in identified nociceptors, the relevance to tolerance/OIH of Gi versus beta-arrestin signaling in DRG neurons, and how opioids alter the expression of the genes controlling DRG neuron excitability and neurotransmission. This research will transform our understanding of the mechanisms of action of opioids by identifying MOR in DRG as the target of opioids for OIH and tolerance. This research also has the potential to transform clinical practice, as MNB, or other drugs acting on targets identified by RNA-sequencing, might be used to treat pain at lower opioid dosage. In the future, the approach established here may help uncover the mechanisms underlying other opioid side effects, such as respiratory depression and addiction, to identify innovative strategies to limit transition to addiction and death by overdose from opioid abuse.

阿片类药物被广泛用于缓解疼痛，但也产生有害影响，包括阿片类药物诱导的疼痛。 痛觉过敏（OIH）和镇痛耐受。OIH和耐受性降低阿片类药物的疗效并推动剂量递增， 这会导致其他有害影响，如呼吸抑制和成瘾。这些影响 极大地影响了疼痛患者的生活质量。到目前为止，还无法将 镇痛从OIH和耐受性的影响，因为受体和细胞上的阿片类药物的作用，以引起 OIH和耐受性尚未确定。与目前阿片类药物作用于CNS小胶质细胞的模型相反， 为了启动抗伤害耐受和OIH，我们在RNA测序实验中发现， 小胶质细胞不表达莫尔受体，并且在莫尔的整体中，OIH丢失，但小胶质细胞活化完整 敲除小鼠此外，我们产生了仅在背根神经节（DRG）中缺乏莫尔的新突变小鼠。 伤害感受器，但在CNS中具有完整的莫尔功能，并发现这些小鼠显示完整的吗啡 抗伤害，但没有OIH或耐受性。这些初步研究开启了分离阿片类药物的可能性， 阿片类镇痛的副作用，并导致以下假设：中枢神经系统中的MORs是阿片类镇痛的基础， 莫尔信号和背根神经节中的适应不良神经可塑性是OIH和耐受的原因。在目标1中，我们 使用小鼠遗传学和病毒仅在患有慢性疼痛并用阿片类药物治疗的小鼠的DRG中删除莫尔， 并对这些小鼠进行行为测定以测量阿片类镇痛、镇痛耐受性和OIH， 包括疼痛情感和自发性疼痛的测量。我们还将用FDA阻止外周MOR- 批准的外周限制性拮抗剂甲基纳洛酮溴。我们预测，删除或阻止莫尔 将减少吗啡耐受和OIH而不影响镇痛。在目标2中，我们将解决 适应不良的突触机制，OIH和耐受性的基础。阿片类药物诱导长时程伤害感受 在DRG和脊髓神经元之间的突触处的增强（LTP）。我们将联合收割机光遗传学和 电生理分析以确定DRG中突触前MORs的激活是否引发适应不良 LTP在目标3中，我们将对单个DRG伤害感受器和PZM 21（一种新的GI偏置莫尔）使用RNA测序。 激动剂，以确定鉴定的伤害感受器中存在的莫尔效应物，与Gi的耐受性/OIH的相关性 与DRG神经元中的β-arrestin信号传导，以及阿片类药物如何改变控制DRG神经元中β-arrestin信号传导的基因表达。 DRG神经元兴奋性和神经传递。这项研究将改变我们对 通过鉴定DRG中的莫尔作为阿片类药物治疗OIH和耐受的靶点，研究阿片类药物的作用机制。这 研究还有可能改变临床实践，例如MNB或其他作用于已确定目标的药物 通过RNA测序，可以用于以较低的阿片类药物剂量治疗疼痛。今后，建立的办法 这可能有助于揭示其他阿片类药物副作用的潜在机制，如呼吸抑制， 成瘾，以确定创新战略，以限制过渡到成瘾和死亡的过量阿片类药物滥用。

项目成果

Endogenous and Exogenous Opioids in Pain.

• DOI: 10.1146/annurev-neuro-080317-061522
• 发表时间: 2018-07-08
• 期刊: Annual review of neuroscience
• 影响因子: 13.9
• 作者: Corder G;Castro DC;Bruchas MR;Scherrer G
• 通讯作者: Scherrer G

Delta opioid receptor regulation of calcitonin gene-related peptide dynamics in the trigeminal complex.

• DOI: 10.1097/j.pain.0000000000002235
• 发表时间: 2021-08-01
• 期刊: Pain
• 影响因子: 7.4
• 作者: Moye LS;Siegersma K;Dripps I;Witkowski W;Mangutov E;Wang D;Scherrer G;Pradhan AA
• 通讯作者: Pradhan AA

A Brainstem-Spinal Cord Inhibitory Circuit for Mechanical Pain Modulation by GABA and Enkephalins.

• DOI: 10.1016/j.neuron.2017.01.008
• 发表时间: 2017-02-22
• 期刊: Neuron
• 影响因子: 16.2
• 作者: François A;Low SA;Sypek EI;Christensen AJ;Sotoudeh C;Beier KT;Ramakrishnan C;Ritola KD;Sharif-Naeini R;Deisseroth K;Delp SL;Malenka RC;Luo L;Hantman AW;Scherrer G
• 通讯作者: Scherrer G