INTEGRATIVE AND MOLECULAR STUDIES OF PAIN AND PAIN CONTROL

疼痛和疼痛控制的综合分子研究

• 批准号: 6432046
• 负责人: Michael J. Iadarola
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF DENTAL & CRANIOFACIAL RESEARCH
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6432046
• 关键词: Animalia; analgesia; chronic disease /disorder; clinical research; dorsal column; functional magnetic resonance imaging; human subject; neural information processing; neural plasticity; neural transmission; pain

Our research program addresses basic molecular and physiological processes of nociceptive transmission in the central nervous system. The molecular research is performed in animal and in vitro cell-based models. We concentrate on the primary affernt pain sensing neurons and the connections in the dorsal spinal cord. The dorsal spinal cord is the first site of synaptic processing for nociceptive information processing and our research has identified it as a locus of neuronal plasticity and altered gene expression in persistent pain states. Questions related to higher CNS pain processing are performed with humans using in vivo functional brain imaging of chronic pain patients and normal volunteers. The Unit also investigates novel methods for controlling nociceptive transmission and has three novel treatments for sever intractable pain under investigation. Two main basic science issues are being addressed. The first centers on the molecular mechanisms of pain transduction through an investigation of the vanilloid receptor 1. This molecule is a heat-sensitive calcium/sodium ionophore and converts painful heat into nerve action potentials by depolarizing the pain sensing nerve terminals in the skin. Ionophore activity is stimulated by binding of capsaicin a prototypical vanilloid compound and the active ingredient in hot pepper. Point mutations within a unique region in the carboxy end of the molecule suggest the occurrence of separate molecular motifs for thermal and chemical activation. We refer to these as the "heat domain" and "vanilloid domain". This program has directly led to a bench to bedside application in which vanilloid agonists are used to kill pain neurons via ligand-induced calcium cytotoxicity and thereby provide pain control. The second program is centered on gene discovery in spinal cord. Subtraction cloning, sequencing and differential hybridization has revealed new genes enriched in spinal cord and induced by pain stimuli. We are in the process of characterizing the novel genes and placing into context the known genes. These studies have revealed large amounts of new information. For example, we observe dorsal enrichment for a specific phosphorylated subunit of an important inhibitory transmitter, a dorsal enrichment of selected stimulatory and inhibitory modulators of the Rho/Rac cell shape signal transduction pathway, and the induction of expression of two novel genes during persistent experimental pain. This project is a long term, high-risk endeavor, which is setting new directions for molecular pain research. The translational program uses our basic science findings to create new treatments for chronic pain. Three target areas emerged from our bench research. (1) In vivo gene transfer. We are getting the adenoviral-mediated gene transfer of secreted beta-endorphin ready for clinical trial. This involves a CRADA with GenVec, a local gene therapy company, in which the therapeutic cassette is placed into their adenoviral vector and preclinical toxicology is performed. (2) We developed a recombinant cytotoxic toxin-ligand fusion protein called substance P-Pseudomonas exotoxin-35 (SP-PE) as a means to kill spinal cord neurons involved in pain transmission. Complete pain control is achieved by intrathecal administration of as little as15 picomoles of SP-PE. We are currently preparing a large amount of conjugate for preclinical toxicology and clinical trial. (3) We are testing a ultrapotent vanilloid agonist, resiniferatoxin, as a pain control agent for used in removal of primary afferent pain sensing neurons. We developed an intraganglionic injection method. The results of intraganglionic RTX suggest that it will be a very effective approach to control of certain types of chronic pain.

我们的研究计划介绍了中枢神经系统中伤害感受传播的基本分子和生理过程。分子研究是在动物和基于体外细胞的模型中进行的。我们专注于主要的Affernt疼痛感应神经元和背脊髓中的连接。 背脊髓是伤害性信息处理的突触处理的第一个部位，我们的研究已将其确定为神经元可塑性的座位，并且在持续性疼痛状态下基因表达改变了。使用人类使用体内功能性脑成像对慢性疼痛患者和正常志愿者的体内功能性脑成像进行与较高的中枢神经系统疼痛处理有关的问题。该单元还研究了控制伤害性传播的新方法，并具有三种新的治疗方法，可用于严重棘手的疼痛。两个主要的基础科学问题正在解决。 第一个通过研究香草素受体1的研究以疼痛转导的分子机制为中心。该分子是一种热敏感的钙/钠离子载体，并通过使皮肤中的疼痛感测神经末端去极化，将疼痛的热量转化为神经作用电位。 辣椒素A原型香草素化合物和热胡椒中的活性成分刺激离子载活性。分子的羧基端一个独特区域内的点突变表明发生了单独的分子基序以进行热和化学激活。我们将其称为“热域”和“香草域”。该程序直接导致了床旁应用的长凳，在该床边应用中，香草素激动剂用于通过配体诱导的细胞毒性杀死疼痛神经元，从而提供疼痛控制。 第二个程序以脊髓中的基因发现为中心。 减去克隆，测序和差异杂交揭示了富含脊髓的新基因，并由疼痛刺激诱导。 我们正在表征新基因并将其置于已知基因的上下文中。 这些研究揭示了大量新信息。例如，我们观察到重要的抑制性发射器的特定磷酸化亚基的背富集，在持续实验疼痛期间，Rho/Rac细胞形状信号转导途径的选定刺激和抑制性调节剂的背侧富集以及两个新型基因表达的诱导。 该项目是一项长期的高风险努力，它为分子疼痛研究设定了新的方向。转化计划使用我们的基础科学发现为慢性疼痛创造新的治疗方法。 我们的板凳研究出现了三个目标领域。 （1）体内基因转移。我们正在获得分泌β-内啡肽的腺病毒介导的基因转移，准备进行临床试验。 这涉及与当地基因治疗公司Genvec的Crada，其中将治疗盒放入其腺病毒载体中，并进行临床前毒理学。 （2）我们开发了一种重组细胞毒性毒素 - 配体融合蛋白，称为P-pseudomonas Exotoxin-35（SP-PE），是杀死参与疼痛传播的脊髓神经元的一种手段。 通过鞘内施用SP-PE的15 picomoles可以实现完全的疼痛控制。我们目前正在为临床前毒理学和临床试验准备大量的共轭物。 （3）我们正在测试一种超能力的香草剂激动剂，树脂毒素，作为用于去除原发性传播疼痛传感神经元的疼痛控制剂。 我们开发了一种内部注射方法。 角膜内RTX的结果表明，它将是控制某些类型的慢性疼痛的一种非常有效的方法。