MIXED NOP/MU COMPOUNDS AND THE INVOLVEMENT OF THEIR RECEPTORS IN ANALGESIA

混合 NOP/MU 化合物及其受体在镇痛中的作用

• 批准号: 9552765
• 负责人: LAWRENCE R TOLL
• 金额: $ 45.33万
• 依托单位: FLORIDA ATLANTIC UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2022-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9552765
• 关键词: Absence of pain sensation; Acute; Acute Pain; Affective; Afferent Neurons; Agonist; Analgesics; Anatomy; Animals; Anterior; Attenuated; Back; Behavior; Behavioral; Brain; Brain region; C-terminal; Cells; Chimeric Proteins; Chronic; Coupled; Crystallization; Development; Dimerization; Down-Regulation; Drug abuse; Emotional; Family; Fc Receptor; Gender; Grant; Green Fluorescent Proteins; Histocytochemistry; Hyperalgesia; Injections; Investigation; Knock-in Mouse; Laboratories; Ligands; Location; Mechanics; Mediating; Messenger RNA; Methods; Microinjections; Modality; Mus; Neurons; Neuropathy; Nociception; Opioid; Opioid Analgesics; Opioid Receptor; Pain; Pathway interactions; Peripheral; Pharmaceutical Preparations; Pharmacology; Property; Receptor Activation; Receptor Down-Regulation; Research; Role; Sensory; Skin; Spinal; Spinal Cord; Spinal Ganglia; Spinal nerve structure; Structure; System; Tactile; Testing; Thalamic structure; Touch sensation; allodynia; animal pain; brain pathway; chronic neuropathic pain; chronic pain; chronic painful condition; cingulate cortex; delta receptors; enhanced green fluorescent protein; experimental study; inflammatory pain; member; mu opioid receptors; mu receptors; neural circuit; novel; pain processing; painful neuropathy; postsynaptic; prevent; protein expression; protein kinase C gamma; receptor; receptor function; response; sensory system; small molecule; somatosensory; tool

The NOP receptor, the fourth member of the opioid receptor family, has been the target of investigation since its discovery in 1993, with respect to pharmacology, anatomy, and behaviors elicited by agonists and antagonists. Despite considerable research efforts, the lack of suitable receptor antibodies has prevented the appropriate interpretation of many studies pertaining to the details of receptor location, internalization, and dimerization. In order to test hypotheses pertaining to NOP receptor function, Dr. Brigitte Kieffer and colleagues have generated knock-in mice that carry green fluorescent protein (eGFP) coupled to the NOP receptor. Similar GFP-tagged delta receptor and mCherry-tagged mu receptor knock-in mice have proven very useful in understanding the relationship among anatomy, cellular localization, and function of delta and mu opioid receptors. Like the mu receptor, NOP receptors are found in very high numbers in all of the pain-related brain regions, including PAG, RVM, MHb, thalamus, etc. However, NOP receptors are unlike the other members of the opiate receptor family in that NOP receptor agonists block opiate analgesia when administered i.c.v. while having antinociceptive activity when administered intrathecally. In addition, NOP receptor agonists appear to be more effective rather than less effective in chronic pain states. This is surprising since NOP receptor mRNA decreases in DRG and anterior cingulate cortex (ACC) and NOP receptors decrease in certain spinal cord laminae in spinal nerve ligated mice. Using NOP-eGFP(+/+) mice, immunohistochemical experiments will be carried out to better understand the circuitry and the cellular localization in brain, spinal cord, and DRG that leads to these unusual properties of N/OFQ and other NOP receptor agonists. These will be correlated with behavioral experiments subsequent to microinjections into specific brain regions to understand how NOP receptor activation modulates the sensory as well as the affective component of pain. Specific Aim 1 will carefully examine the location of NOP-eGFP receptors in DRG as well as determine the pain modalities (heat, cold, touch) attenuated by systemic administration of NOP agonists and antagonists and determine how these parameters change during chronic neuropathic and inflammatory pain. Specific Aim 2 will examine spinal cord NOP-eGFP expression as well as characterize spinal projections both to the brain and to the periphery. These results will be compared with the effects of NOP agonists on different pain modalities after intrathecal administration in sham and neuropathic mice. Specific Aim 3 will examine neuropathic pain-induced changes in NOP-eGFP receptor levels in brain with particular emphasis on regions involved in the sensory (PAG) and affective (ACC) components of pain. Direct injections of NOP receptor agonists and antagonists into these brain regions will be used to better understand the NOP receptor-related circuitry that modulates thermal, tactile, and emotional pain through these brain regions. These experiments will clearly identify the role of NOP receptors in acute and chronic thermal and tactile pain, allodynia and hyperalgesia.

NOP受体是阿片受体家族的第四个成员，一直是研究的目标 自1993年发现以来，关于药理学，解剖学和行为，激动剂和行为。 对手。尽管研究了大量研究，但缺乏合适的受体抗体已经阻止了 适当解释与受体位置，内在化和的细节有关的许多研究 二聚化。为了测试与NOP受体功能有关的假设，Brigitte Kieffer博士和 同事产生了敲入小鼠，载有绿色荧光蛋白（EGFP），耦合到NOP 受体。类似的GFP标记的三角洲受体和麦克里标记的MU受体敲入小鼠已经证明非常 有助于理解三角洲和MU的解剖学，细胞定位和功能之间的关系 阿片受体。像MU受体一样，所有与疼痛有关的NOP受体的数量很高 大脑区域，包括PAG，RVM，MHB，Thalamus等。但是，NOP受体与其他受体不同 鸦片受体家族的成员在施用NOP受体激动剂时阻止鸦片镇痛 I.C.V.胸前给药时具有抗伤害性活性。此外，NOP受体激动剂 在慢性疼痛状态中似乎更有效而不是有效。这是令人惊讶的，因为 受体mRNA在DRG和前扣带回皮层（ACC）中降低，而NOP受体在某些方面降低 脊髓神经结扎的小鼠中的脊髓层层。使用NOP-EGFP（+/+）小鼠，免疫组织化学实验 将进行以更好地了解大脑，脊髓和DRG中的电路和细胞定位 这导致了N/OFQ和其他NOP受体激动剂的这些异常特性。这些将是相关的 通过对特定大脑区域进行微注射后的行为实验，以了解如何nop 受体激活调节疼痛的感觉和情感成分。具体目标1将 仔细检查NOP-EGFP受体在DRG中的位置，并确定疼痛方式（热， 寒冷，触摸）由全身施用NOP激动剂和拮抗剂减弱，并确定这些如何 慢性神经性疼痛和炎症性疼痛期间的参数变化。特定目标2将检查脊髓 NOP-EGFP表达以及表征对大脑和周围的脊柱投影。 这些结果将与NOP激动剂对鞘内后不同疼痛方式的影响进行比较 在假和神经性小鼠中给药。特定目标3将检查神经性疼痛引起的变化 在大脑的NOP-EGFP受体水平中，特别强调了涉及的区域（PAG）和 情感（ACC）疼痛的成分。将NOP受体激动剂和拮抗剂直接注射到这些 大脑区域将用于更好地了解调节热热的NOP受体相关电路 触觉和通过这些大脑区域的情绪疼痛。这些实验将清楚地确定NOP的作用 急性和慢性热和触觉疼痛的受体，异常性和痛觉过敏。