The role of atypical PKCs in sensitization of sensory neurons by NGF

非典型 PKC 在 NGF 感觉神经元敏化中的作用

• 批准号: 8439097
• 负责人: GRANT D NICOL
• 金额: $ 53.01万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2016-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8439097
• 关键词: Action Potentials; Acute; Adult; Afferent Neurons; Affinity; Animals; Behavior; Behavioral; Binding; Biochemical; Biological Models; Brain-Derived Neurotrophic Factor; Caliber; Capsaicin; Cells; Ceramides; Chemicals; Chronic; Collaborations; Electrophysiology (science); Event; Exudate; Fire - disasters; Future; Goals; Hyperalgesia; Inflammation; Inflammatory; Injury; Ion Channel; Knowledge; Laboratories; Lead; Maintenance; Mechanics; Mediating; Membrane; Modality; Molecular; NGFR Protein; Nerve; Nerve Growth Factors; Neurons; Nociception; Pain; Pathway interactions; Phosphatidylinositols; Phosphorylation; Phosphotransferases; Play; Property; Protein Isoforms; Proteins; Rattus; Receptor Activation; Receptor Protein-Tyrosine Kinases; Receptor Signaling; Regulation; Reporting; Role; Scaffolding Protein; Seminal; Signal Pathway; Signal Transduction; Signaling Molecule; Site; Small Interfering RNA; Sphingolipids; Sphingomyelins; Spinal Ganglia; Techniques; Testing; Therapeutic; Time; Tissues; Translating; Tumor Necrosis Factor Receptor; Universities; Viral; Work; atypical protein kinase C; base; cell type; chemical release; design; functional outcomes; in vivo; knock-down; member; neuronal excitability; neurotrophic factor; novel; pain behavior; paracrine; protein protein interaction; receptor-mediated signaling; research study; response; small hairpin RNA; therapeutic target

DESCRIPTION (provided by applicant): Seminal studies suggested that the heightened sensitivity associated with inflammation may, in part, result from nerve growth factor (NGF) activation of nociceptive sensory neurons. My laboratory demonstrated that NGF/BDNF can rapidly increase the ability of sensory neurons to fire action potentials (APs) via p75 neurotrophin receptor (p75NTR) activation of the sphingolipid signaling cascade. The cellular mechanisms and downstream signaling pathways resulting from p75NTR activation are poorly understood. Our results demonstrate that p75NTR/ceramide activation of the novel atypical PKC, PKM¿ plays a key role in augmenting excitability and suggest that PKM¿ may have a critical role in the transition of acute to persistent sensitization as a result of PKM¿ becoming constitutively active. Proposed studies will use sensory neurons isolated from DRG of adult rats as a model system to explore the functional impact of p75NTR activation on membrane excitability. Knowledge gained from isolated neurons will be extended to studies exploring the role of these effector molecules in regulating nociceptive behavioral responses. These studies will be done in collaboration with Dr. Gary Strichartz at Harvard University. The specific aims are: Aim 1 will establish the role of p75NTR and its synthesis/activation of PKM¿. Also, p75NTR interaction with scaffolding proteins will determine their ability to regulate the activity of PKM¿ This work will focus on PKM¿-induced modulation of ion channels and their regulation of neuronal excitability. In collaboration with Dr. Gary Strichartz Aim 2 will establish the role of p75NTR-PKM¿ signaling cascades in the regulation of nociceptive behaviors in the intact animal. The strength of this multi-dimensional approach is that biochemical and molecular techniques will establish novel protein-protein associations and electrophysiology will establish the functional outcomes of those associations. These findings will be extended to studies in the intact animal to provide an understanding of the mechanisms whereby activation of p75NTR leads to heightened neuronal sensitivity. A fundamental understanding of these events is necessary so that better compounds and therapies can be designed to facilitate treatment of chronic inflammatory conditions. PUBLIC HEALTH RELEVANCE: Tissue injury and inflammation cause release of chemicals from a variety of cells near the injury site that results in increased sensitivity to painful stimulation. One of those key chemicals is nerve growth factor. Studies proposed in this application seek to understand how intracellular signaling pathways activated by nerve growth factor increase nerve sensitivity and thus lead to the increased pain responses.

描述（由申请人提供）：开创性研究表明，与炎症相关的丰富敏感性可能部分是由神经生长因子（NGF）激活伤害性感觉神经元引起的。我的实验室证明，NGF/BDNF 可以快速增强感觉能力。神经元通过 p75 神经营养蛋白受体 (p75NTR) 激活鞘脂信号级联来激发动作电位 (AP) p75NTR 激活导致的细胞机制和下游信号通路。我们的结果表明 p75NTR/神经酰胺激活新型非典型 PKC、PKM¿在增强兴奋性方面发挥着关键作用，并表明 PKM¿可能在 PKM 引起的急性致敏向持续致敏的转变中发挥关键作用¿拟议的研究将使用从成年大鼠 DRG 分离的感觉神经元作为模型系统，探索 p75NTR 激活对膜兴奋性的功能影响，并将扩展到探索这些效应分子在细胞膜兴奋性中的作用的研究。这些研究将与哈佛大学的 Gary Strichartz 博士合作进行，具体目标是： 目标 1 将确定 p75NTR 的作用及其合成/激活。 PKM??此外，p75NTR 与支架蛋白的相互作用将决定它们调节 PKM 活性的能力¿这项工作将重点关注 PKM¿离子通道的诱导调节及其对神经元兴奋性的调节与 Gary Strichartz 博士合作，Aim 2 将确定 p75NTR-PKM 的作用。这种多维方法的优势在于，生化和分子技术将建立新的蛋白质-蛋白质关联，而电生理学将建立这些关联的功能结果。在完整动物中进行研究，以了解 p75NTR 激活导致细菌神经元敏感性的机制，有必要对这些事件有基本的了解，以便设计出更好的化合物和疗法来促进慢性炎症的治疗。 公共健康相关性：组织损伤和炎症会导致损伤部位附近的多种细胞释放化学物质，从而导致对疼痛刺激的敏感性增加。本申请中提出的研究旨在了解细胞内如何发挥作用。神经生长因子激活的信号通路增加了神经敏感性，从而导致疼痛反应增加。