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.

阿片受体家族的第四个成员--NOP受体一直是研究的对象 自1993年发现以来，关于药理学、解剖学和由激动剂引起的行为， 对手。尽管进行了大量的研究工作，但缺乏合适的受体抗体阻止了 适当的解释许多研究有关的细节受体的位置，内化， 二聚化。为了检验与NOP受体功能有关的假设，Brigitte Kieffer博士和 我的同事们已经产生了携带与NOP偶联的绿色荧光蛋白（eGFP）的基因敲入小鼠 受体的类似的GFP标记的Delta受体和mCherry标记的mu受体敲入小鼠已被证明非常 有助于理解δ和μ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，NOP受体在所有与疼痛相关的组织中的数量都非常高。 大脑区域，包括PAG，RVM，MHb，丘脑等。然而，NOP受体与其他受体不同， 阿片受体家族的成员，因为当施用NOP受体激动剂时， 同时当鞘内施用时具有抗伤害感受活性。此外，NOP受体激动剂 在慢性疼痛状态下似乎更有效，而不是更无效。这是令人惊讶的，因为 DRG和前扣带皮层（ACC）中的NOP受体mRNA减少， 脊髓神经结扎小鼠脊髓板层。使用NOP-eGFP（+/+）小鼠，免疫组织化学实验 将进行更好地了解电路和细胞定位在大脑，脊髓和DRG 这导致了N/OFQ和其他NOP受体激动剂的这些不寻常的特性。这些将是相互关联的 通过对特定大脑区域进行显微注射后的行为实验， 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中的位置以及确定疼痛形式（热， 冷，触摸）减弱全身性管理的NOP激动剂和拮抗剂，并确定如何这些 参数在慢性神经性和炎性疼痛期间改变。Specific Aim 2将检查脊髓 NOP-eGFP表达以及表征脊髓向脑和外周的投射。 这些结果将与鞘内注射后NOP激动剂对不同疼痛模式的影响进行比较。 在假手术和神经病小鼠中施用。具体目标3将检查神经性疼痛引起的变化 脑中NOP-eGFP受体水平，特别强调参与感觉的区域（PAG）， 疼痛的情感成分（ACC）。将NOP受体激动剂和拮抗剂直接注射到这些细胞中， 大脑区域将被用来更好地理解NOP受体相关的电路， 触觉和情感上的疼痛。这些实验将清楚地确定NOP的作用 受体在急性和慢性热和触觉疼痛，异常性疼痛和痛觉过敏。