Elucidation of Molecular Mechanisms of Pain : Role of PKC and NGF on spinal sensitization in the pathological state following peripheral tissue injury

阐明疼痛的分子机制：PKC 和 NGF 对周围组织损伤后病理状态下脊髓敏化的作用

• 批准号: 06454444
• 负责人: ISHIKAWA Toshizo
• 金额: $ 2.82万
• 依托单位: Yamaguchi University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06454444/
• 关键词: Pain; Spinal sensitization; Hyperalgesia; Spinal glutamate; PKC; NGF; 疼痛; 脊髄過敏; 痛覚過敏; 触覚過敏; 脊髄マイクロダイアリス; グルタメート放出; プロテインキナーゼC; 神経成長因子; 細胞内情報伝達系; Cキナーゼ; 細胞骨格蛋白; 神経栄養因子; シナプス可塑性; 脱抑制機構

The somatosensory system of spinal cord are directly involved into the modulation of peripheral nociceptive input with acute and/or chronic peripheral C-fibers activation following tissue injury. However, under certain condition, there is a pathological state which is functionally characterized by an increased response to noxious stimuli (hyperalgesia), and the reduction of pain threshold (allodynia). The aim of the present study was to examine the molecullar mechanism of the observed pathological pain state may reflect an abnormal intracellular signaling resulting in increased intracellular Ca ion caused by excessive release of glutamate and substance P and increased syntheses of a variety of growth factors (NGF) using well-established rat model.The followings are possible mechanisms based on the present study.1.Pain and neuronal plasticity following peripheral tissue inflammationIncreased peripheral C-fiber activity resulting from formalin or mustard oil hind paw injection evokes 1) … More excessive release of spinal glutamate (by microdialysis), 2) NMDA antagonist blocked hyperalgesia-> increased neuronal activity of dorsal horn resulting from activation of NMDA receptor and corresponding massive increase in intracellular Ca^<++>,3) Staurosporine (PKC inhivitor) supressed glutamate release and hyperalgesia -> activation of PLA2, PLC which evokes synthesis of arachidonic acid (PGs) and protein kinase C (PKC), these substances and enzyme iniciate positive feed back in spinal cord (sustained facilitation), 4) "up-regulation" of synaptic transmission within the spinal cord functionally expressed as 5) increased responsivity of spinal cord neurons to peripheral stimulus i.c. "central sensitization" : allodynia and/or hyperalgesia.2.Involvement of nerve growth factor (NGF) in facilitated pain state.The biological role of NGF in the developing and restoring processes after peripheral nerve injury has been most intensively studied. There is evidence suggesting its role as a target-derived neurotrophic factor, regulating the density of innervation in a variety of peripheral tissues. The role of NGF in the adult animal is less well characterized, but there is increasing evidence including present results to suggest that NGF is a peripheral mediator in facilitated inflammatory pain states. 1) the high affinity NGF receptor is expressed with sP in C-fiber (trkA),2) 4-methyl cathechol (4MC), which increases NGF,caused enhancement of hyperalgesia in a dosc deppendent manner produced by injecting mustard oil. -> NGF treatment can facilitate glutamate and sP mediated synaptic transmission, and can lead to central sensitization. 3) NGF immunoreactivity of spinal cord was increased to compensate dendritic damage of neuron (decreased MAP-2 immunoreactivity) after formalin injection -> this may be caused by interacting with interleukin-1 (IL-1) * activated macrophage where the IL-1 is the key mediator on NGF-mRNA levels.Taken together, these evidences strongly suggest that NGF is necessary for the maintenance of the up-regulation can lead to a peripheral and central sensitization. In the future study, we need to elucidate further such as the theories proposed to explain how the peripheral injury or noxicious stimulation lead to the alteration in neuronal plasticity and how to play a role of NGF in facilitating state and neuronal degeneration in chronic state. Less

脊髓体感觉系统在组织损伤后通过急性和/或慢性外周c -纤维激活直接参与外周伤害性输入的调节。然而，在某些情况下，存在一种病理状态，其功能特征是对有害刺激的反应增加（痛觉过敏），痛阈降低（异常性痛觉）。本研究的目的是利用成熟的大鼠模型，探讨观察到的病理性疼痛状态的分子机制，该状态可能反映了细胞内信号异常导致细胞内钙离子增加，这是由谷氨酸和P物质的过度释放和多种生长因子（NGF）合成增加引起的。基于目前的研究，以下是可能的机制：外周组织炎症引起的疼痛和神经元可塑性外周c -纤维活性增加（福尔马林或芥末油后爪注射引起1）…更多的脊髓谷氨酸过度释放（通过微透析）。2) NMDA拮抗剂阻断痛觉过敏->，使NMDA受体激活，细胞内Ca^<++>大量增加，增加背角神经元活性；3)Staurosporine （PKC抑制剂）抑制谷氨酸释放和痛觉过敏->激活PLA2， PLC，引起花生四烯酸（PGs）和蛋白激酶C （PKC）的合成，这些物质和酶在脊髓中引发正反馈（持续促进）。4)脊髓内突触传递的“上调”在功能上表现为5)脊髓神经元对外周刺激等的反应性增加。“中枢致敏”：异常性痛觉和/或痛觉过敏。神经生长因子（NGF）在促进性疼痛状态中的作用。神经生长因子在周围神经损伤后的发育和恢复过程中的生物学作用是目前研究最多的。有证据表明其作为靶源性神经营养因子的作用，调节各种外周组织的神经支配密度。神经生长因子在成年动物中的作用尚不清楚，但越来越多的证据（包括目前的结果）表明，神经生长因子是促进炎性疼痛状态的外周介质。1)高亲和力NGF受体与sP在c -纤维（trkA）中表达，2)4-甲基儿茶酚（4MC）增加NGF，使注射芥菜油产生的痛觉过敏呈剂量依赖性增强。-> NGF处理可促进谷氨酸和sP介导的突触传递，并可导致中枢致敏。3)注射福尔马林->后，脊髓NGF免疫反应性增加，以补偿神经元树突损伤（MAP-2免疫反应性降低），这可能与白细胞介素-1 (IL-1) *活化的巨噬细胞相互作用有关，IL-1是NGF- mrna水平的关键介质。综上所述，这些证据有力地表明，NGF是维持上调所必需的，可以导致外周和中枢敏化。在未来的研究中，我们需要进一步阐明，如外周损伤或毒性刺激如何导致神经元可塑性改变的理论，以及NGF如何在促进状态和慢性状态下神经元变性中发挥作用。少

项目成果

Sakabe T. et al: "Concurrent characterization of regional pattern on spinal cord glucose utilization, ^<125>I-Bolton Hunter substance P (NK-1) and ^3H-phorbol 12, 13 dibutylate bindings related to flinches produced by paw injection of mustard oil in rats"

Sakabe T. 等人：“脊髓葡萄糖利用、^125I-Bolton Hunter P 物质 (NK-1) 和^3H-佛波醇 12、13 二丁酯结合的区域模式的同时特征，与爪子注射产生的畏缩有关

Ishikawa T.et al: "Role of presynaptic regulation of spinal cord by protein kinase C and w-sensitive Ca channel modulating hyperalgesia : Concurrent amino acid release and pain related response" Neuroscience letter. (in preparation).

Ishikawa T.等人：“蛋白激酶 C 和 w 敏感 Ca 通道调节痛觉过敏对脊髓突触前调节的作用：同时氨基酸释放和疼痛相关反应”神经科学信函。

石川敏三 他: "アデノシンA_1受容体活性化によるspinal sensitizationの抑制" 日本麻酔・薬理学会誌. 8 (2). 31-32 (1995)

Toshizo Ishikawa 等人：“通过激活腺苷 A_1 受体抑制脊髓敏化”日本麻醉药理学会杂志 8 (2) (1995)。

Ishikawa T. et al: "Role of presynaptic regulation of spinal cord by protein kinase C and w-sensitive Ca channel in modulating hyperalgesia : Concurrent amino acid release and pain related response" Neuroscience letter. (投稿予定).

Ishikawa T. 等人：“蛋白激酶 C 和 w 敏感 Ca 通道在调节痛觉过敏中对脊髓的突触前调节的作用：并发氨基酸释放和疼痛相关反应”神经科学信件（待提交）。

Ishikawa T.et al: "Involvement of intracellular signaling in N_2O-induced analgesia." J Jap Dent Soc Anethesiology. 23 (1). 71-77 (1995)

Ishikawa T.et al：“细胞内信号传导参与 N_2O 诱导的镇痛。”