Nociceptive Role of SST and NT receptor-expressing dorsal horn neurons

表达 SST 和 NT 受体的背角神经元的伤害感受作用

• 批准号: 8803243
• 负责人: RONALD Gordon WILEY
• 金额: --
• 依托单位: VETERANS HEALTH ADMINISTRATION
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-04-01 至 2016-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8803243
• 关键词: Absence of pain sensation; Adenylate Cyclase; Adverse effects; Alcohol or Other Drugs use; Analgesics; Anatomy; Animal Model; Animals; Behavior; Behavioral; Biological Neural Networks; Brain; Brain Injuries; Caring; Cells; Cerebrum; Cholera Toxin A Subunit; Chronic; Chronic inflammatory pain; Clinical; Clinical Trials; Cordotomy; Cyclic AMP-Responsive DNA-Binding Protein; Cytotoxin; DNA; Data; Dose; Galanin; Gene Expression; Genes; Glutamates; Goals; Health; Hour; Human; Hyperalgesia; Interneurons; Intervention; Intractable Pain; Intrathecal Injections; Knockout Mice; Lesion; Long-Term Effects; Medicine; Mind; Modeling; Mus; Naloxone; Nerve; Neurologic; Neurons; Neuropathy; Neuropeptides; Neurotensin; Neurotensin Receptors; Neurotransmitter Receptor; Nociception; Nociceptive Reflex; Operative Surgical Procedures; Opiates; Opioid; Pain; Pathogenesis; Patients; Pharmaceutical Preparations; Phase; Plastics; Population; Post-Traumatic Stress Disorders; Posterior Horn Cells; Process; Protein Isoforms; Protein Kinase C; Proteins; Quality of life; Rattus; Reporting; Resistance; Role; Somatostatin; Somatostatin Receptor; Spinal Cord; Spinal Cord Part; Spinal cord posterior horn; Staining method; Stains; Substance P; Substantia Gelatinosa; Techniques; Testing; Therapeutic; Time; Veterans; Work; allodynia; arm; base; behavioral study; chronic neuropathic pain; chronic pain; clinically significant; dorsal horn; effective therapy; gene therapy; improved; inflammatory neuropathic pain; inflammatory pain; inhibitor/antagonist; neuromechanism; neuropathology; neuropeptide Y; novel; novel strategies; oncology; pain inhibition; painful neuropathy; preference; protein kinase C gamma; receptor; research study; response; substance P-saporin; success; targeted delivery; vector

DESCRIPTION (provided by applicant): Successful management of chronic pain is a major ongoing and unmet clinical challenge. The superficial dorsal horn (SDH) of the spinal cord has long been identified as the first key gateway for nociceptive information entering the CNS. Interventions applied at the level of the dorsal horn have the potential to selectively interdict the flow of specific types of nociceptive information to the brain with greater efficacy and fewer side effects than the currently available alternatives, medications or surgery. The focus of the present proposal are two types of inhibitory nocifensive neurons in the SDH and the therapeutic potential of two neuropeptides, which given intrathecally activate receptors on inhibitory SDH interneurons and produce analgesia in humans, somatostatin (SST), or anti-nociception in animals, neurotensin (NTS). Both of these neuropeptides are abundantly present in the SDH, and neurons with the cognate receptors are located in lamina II (substantia gelatinosa). SST receptors (sst2a) are expressed entirely on GABAergic inhibitory interneurons suggesting that SST produces naloxone-insensitive analgesia by exciting inhibitory interneurons that normally inhibit nociceptive projection neurons. Neurotensin is primarily excitatory, is produced/released by glutamatergic (excitatory) interneurons and also produces naloxone-insensitive anti-nociception by presumably exciting inhibitory interneurons which, in turn, inhibit nociceptive projection neurons. The aim of the present proposal is to evaluate SDH inhibitory interneurons as targets for achieving sustained, but ultimately reversible, non-opioid analgesia by enhancing the activity of these inhibitory nociceptive interneurons, i.e. reversing the inhibitory deficit thought important in the pathogenesis of chronic neuropathic pain. The specific study objectives for SST are: 1 - determine the precise anatomic effects (target cell loss, neuropathology) and nocifensive behavioral effects produced by lumbar intrathecal injection of the targeted cytotoxin, SST-saporin, in normal rats and rat models of chronic inflammatory and neuropathic pain; 2 - determine effects of tonically activating sst2a receptor-expressing SDH interneurons with lumbar intrathecal injection of SST-cholera toxin A subunit conjugate (SST-CTA) in normal rats and rat models of chronic inflammatory and neuropathic pain; and 3 - then determine the effects of lumbar intrathecal injection of SST conjugated to the gene for CTA (SST-polyplex-CTA DNA) in normal rats and rat models of inflammatory and neuropathic pain. The specific objectives for NTS are: 1 - determine the precise anatomic effects (target cell loss, neuropathology) and nocifensive behavioral effects produced by lumbar intrathecal the targeted cytotoxin, NTS-saporin, in normal rats and rat models of chronic inflammatory and neuropathic pain; 2 - determine effects of tonically activating NTS1 receptor-expressing SDH interneurons with lumbar intrathecal injection of NTS-cholera toxin A subunit conjugate (NTS-CTA) in normal rats and rat models of chronic inflammatory and neuropathic pain; and 3 - then determine the effects of lumbar intrathecal injection of NTS conjugated to the gene for CTA (NTS-polyplex-CTA DNA) in normal rats and rat models of inflammatory and neuropathic pain. Anatomic studies will determine efficacy and selectivity of the delivery of CTA or the CTA gene using immunohistochemical markers for excitatory and inhibitory neurotransmitters and receptors and for phosphoCREB (a marker for activation of adenylyl cyclase by CTA). Behavioral analyses will include a standard reflex nociceptive test (thermal plate lick/guard) and operant tests (thermal escape and thermal preference) that require cerebral participation in making choices based on the degree of discomfort. Preliminary results with NTS-saporin produces robust spontaneous behaviors (scratching) highly suggestive of ongoing discomfort and increased hotplate responses while lumbar intrathecal SST-saporin also showed spontaneous scratching. These novel strategies for tonically exciting inhibitory interneurons with CTA,may open a new chapter in the search for safer, more effective ways to manage chronic, intractable pain.

描述（由申请人提供）： 成功管理慢性疼痛是一项持续不断的临床挑战。长期以来，脊髓的表面背角（SDH）已被确定为进入中枢神经系统的伤害感受信息的第一个关键门户。与当前可用的替代方法，药物或手术相比，在背喇叭水平上采用的干预措施具有选择性地阻止特定类型的伤害性信息流向大脑的特定类型的伤害性信息。本提案的重点是SDH中的两种抑制性单次神经元以及两种神经肽的治疗潜力，它们胸然激活受体对抑制性SDH中间神经元的受体并在人，生长抑素（SST）或动物，神经，神经，NTS）中的人类，生成抑制素（SST）或抗肿瘤感中产生镇痛。这两种神经肽都大量存在于SDH中，并且具有同源受体的神经元位于Lamina II（质量明胶）中。 SST受体（SST2A）完全在GABA能抑制性中间神经元上表达，这表明SST通过刺激的抑制性抑制性神经元通常抑制伤害性投射神经元。 Neurotensin主要是兴奋性的，是由谷氨酸能（兴奋性）中间神经元产生/释放的，还通过可能令人兴奋的抑制性抑制性神经元产生纳洛酮不敏感的抗伤害感受，而这些抑制性神经元反过来抑制了伤害性投射神经元。本提案的目的是通过增强这些抑制性伤害性中性神经元的活性来评估SDH抑制性中间神经元作为实现持续但最终可逆的非阿片类镇痛的靶标，即逆转抑制性缺陷，认为抑制性缺陷在慢性神经疗法的病原质中很重要。 SST的具体研究目标是：1-确定术语炎症性和神经病性疼痛的正常大鼠和大鼠大鼠对靶标的细胞毒素，SST-舒张蛋白的腰部术鞘内注射术的腰椎鞘内注射所产生的精确解剖作用（靶细胞丧失，神经病理学）和可分散的行为作用； 2-确定在正常大鼠和慢性炎症性和神经性疼痛的大鼠模型中，用腰椎鞘内注射SST-Cholera毒素A亚基毒素A亚基毒素的SST2A受体中间神经元的影响； 3-然后确定在正常大鼠的CTA（SST-POLYPLEX-CTA DNA）和炎症性和神经性疼痛的大鼠模型中，与基因相结合的SST的腰椎注射的腰椎注射的影响。 NTS的特定目标是：1-确定腰椎术中靶向细胞毒素，NTS-紫就是在正常的老鼠和慢性炎症性和神经病变疼痛的大鼠模型中产生的精确解剖作用（靶细胞丧失，神经病理学）和靶向细胞毒素NTS-紫就是产生的单化行为效应； 2-确定在正常大鼠和慢性炎症性和神经性疼痛的大鼠模型中，用腰椎鞘内注射NTS-CHOLERA毒素A亚基毒素A亚基毒素A亚基毒素（NTS-CTA）对表达NTS1受体表达SDH的SDH中间神经元的影响； 3-然后确定在正常大鼠中与CTA（NTS-POLYPLEX-CTA DNA）结合到基因的NTS的腰椎注射的影响，以及炎症和神经性疼痛的大鼠模型。解剖学研究将确定使用免疫组织化学标志物和抑制性神经递质和受体以及磷酸的功效和CTA基因递送的功效和CTA基因的选择性（CTA激活腺苷环酶的激活标记）。行为分析将包括标准反射伤害性测试（热板舔/防护板）和操作测试（热逃逸和热偏好），该测试需要大脑参与根据不适程度做出选择。 NTS-萨帕林的初步结果会产生强大的自发行为（刮擦）高度暗示了持续的不适和增加的热板反应，而腰椎鞘内SST-saporin也表现出自发的划痕。这些与CTA进行色调令人兴奋的抑制性中间神经元的新型策略可能会为寻找更安全，更有效的方法来管理慢性，棘手的疼痛。