Intracellular signaling mechanisms underlying opioid modulation of pain

阿片类药物调节疼痛的细胞内信号机制

基本信息

批准号：
10607143
负责人：
Landon Bayless-Edwards
金额：
$ 5.52万
依托单位：
OREGON HEALTH & SCIENCE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-03-01 至 2027-02-28
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10607143
关键词：
Absence of pain sensation Acute Adenylate Cyclase Affect Affective Agonist Analgesics Anterior Behavior Behavioral Assay Brain region Cells Chronic Complex Coupled Cyclic AMP Cyclic AMP-Dependent Protein Kinases Dendrites Fluorescence Resonance Energy Transfer Fluorescent in Situ Hybridization GTP-Binding Proteins Goals Hour Hyperalgesia Image In Vitro Interneurons Label Measures Mediating Membrane Methodology Modeling Morphine Motivation Mus Nature Neurons Opioid Opioid Receptor Opioid agonist Pain Pain Measurement Pathway interactions Peptides Play Positioning Attribute Production Property Protein Dynamics Protein Kinase A Inhibitor Public Health Receptor Activation Regulation Research Resolution Rewards Role Sensory Signal Pathway Signal Transduction Site Specificity Synapses Testing Thalamic structure Work addiction antagonist behavioral study brain cell cell type cingulate cortex dermorphin design experimental study fluorescence lifetime imaging hippocampal pyramidal neuron in vivo in vivo imaging insight interest morphine administration mu opioid receptors negative affect neuronal cell body novel opioid exposure opioid use disorder pain behavior pain relief photoactivation receptor receptor expression regional difference response sensor sensory integration spatiotemporal stem two-photon

项目摘要

PROJECT SUMMARY Opioid use disorder is a public health crisis that stems from the highly addictive nature and potent analgesic properties of opioids. Opioids modulate circuitry involved in analgesia, pain-induced negative affect, motivation, reward, and addiction. They act on G-protein coupled opioid receptors, inducing multiple intracellular signaling pathways. Of these, the cyclic adenosine monophosphate (cAMP) and protein kinase A (PKA) pathway is known to be a key mechanism in analgesia, pain-related aversion, and opioid- induced hyperalgesia. Most studies examining PKA signaling in response to opioids or pain are limited by in vitro or ex vivo approaches that cannot simultaneously consider cell-type specific PKA signaling, complex circuit-level regulation, and effects of behavior on PKA dynamics. As a result, it remains unclear exactly where and when PKA is modulated in response to opioids; nor is it clear what the functional effects of these spatiotemporal PKA dynamics are on analgesia. Understanding the functional significance of opioid-induced intracellular signaling and how this signaling differs in unique cell types and brain regions will allow us to better comprehend how opioids differentially effect pain and addiction circuitry. The goals of this proposal are as follows: First, I will define the temporal dynamics of mu opioid-induced PKA signaling within the mediodorsal thalamus (MD) to anterior cingulate cortex (ACC) circuitry. This circuitry highly expresses mu opioid receptors and integrates sensory and affective pain. Then, I will determine whether there is a causal relationship between these PKA dynamics and pain relief. Finally, I will examine the cell-type specificity of these PKA dynamics. My central hypothesis is that PKA dynamics will depend on the duration of opioid exposure and will determine the extent of pain response, with specific cell types acting as key sites of PKA modulation. This hypothesis will be tested using a novel genetically encoded sensor designed for in vivo imaging of PKA activity in behaving mice. To examine regional differences in temporal PKA dynamics in response to acute and chronic opioid exposure, PKA will be imaged before, during, and after opioid administration in the MD and ACC. Imaging will be paired with pain assays to assess analgesia and hyperalgesia. To test the necessity and sufficiency of PKA dynamics in pain relief, PKA activity will be modulated by either a genetically encoded PKA inhibitor or photoactivatable adenylyl cyclase while conducting behavioral assays of pain. Finally, to examine the cell-specificity of PKA dynamics, sensor expression will be isolated to each cell type of interest in a Cre-dependent manner, and peptide agonists and antagonists of mu opioid receptors will be locally infused during PKA imaging. This study will define how PKA signaling in specific components of the MD to ACC circuitry both responds to opioids and mediates pain relief. Achieving these goals will provide insight into how intracellular signaling is spatiotemporally regulated by opioids and facilitates analgesia.

项目概要阿片类药物使用障碍是一场公共卫生危机，其根源在于其高度成瘾性和强效性。阿片类药物的镇痛特性。阿片类药物调节参与镇痛、疼痛引起的负性镇痛的电路影响、动机、奖励和成瘾。它们作用于 G 蛋白偶联阿片受体，诱导多种细胞内信号通路。其中，环磷酸腺苷 (cAMP) 和蛋白质众所周知，激酶 A (PKA) 通路是镇痛、疼痛相关厌恶和阿片类药物的关键机制。诱发痛觉过敏。大多数检查 PKA 信号对阿片类药物或疼痛反应的研究都受到以下限制：体外或离体方法不能同时考虑细胞类型特异性 PKA 信号传导，复杂的电路级调节以及行为对 PKA 动态的影响。结果目前还不清楚确切地说，PKA 是在何时何地针对阿片类药物进行调节的；也不清楚功能效果如何这些时空 PKA 动力学的一部分与镇痛有关。了解功能意义阿片类药物诱导的细胞内信号传导以及该信号传导在独特的细胞类型和大脑区域中的差异将使我们更好地理解阿片类药物如何对疼痛和成瘾回路产生不同的影响。目标该提案的内容如下：首先，我将定义 mu 阿片类药物诱导的 PKA 的时间动态内侧丘脑 (MD) 内的信号传导至前扣带皮层 (ACC) 电路。这个电路高度表达 mu 阿片受体并整合感觉和情感疼痛。然后，我会确定这些 PKA 动态与疼痛缓解之间是否存在因果关系。最后，我将检查这些 PKA 动力学的细胞类型特异性。我的中心假设是 PKA 动力学将取决于取决于阿片类药物暴露的持续时间，并将确定特定细胞类型的疼痛反应程度作为 PKA 调节的关键位点。该假设将使用一种新颖的基因编码进行测试传感器设计用于对行为小鼠的 PKA 活性进行体内成像。考察区域差异响应急性和慢性阿片类药物暴露的时间 PKA 动态，PKA 将在之前成像，在 MD 和 ACC 中使用阿片类药物期间和之后。影像学检查将与疼痛检测相结合评估镇痛和痛觉过敏。为了测试 PKA 动力学在缓解疼痛方面的必要性和充分性， PKA 活性将由基因编码的 PKA 抑制剂或光活化腺苷酸调节环化酶，同时进行疼痛行为测定。最后，检查 PKA 的细胞特异性动力学，传感器表达将以 Cre 依赖性方式与每种感兴趣的细胞类型分离，并且 mu阿片受体的肽激动剂和拮抗剂将在PKA成像期间局部输注。这研究将确定 MD 至 ACC 电路特定组件中的 PKA 信号如何响应阿片类药物并介导疼痛缓解。实现这些目标将深入了解细胞内信号传导如何受阿片类药物的时空调节并促进镇痛。