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）：精液研究表明，与炎症相关的敏感性升高可能部分是由神经生长因子（NGF）激活伤害性感觉神经元所致。我的实验室证明，NGF/BDNF可以通过p75神经营养因子受体（p75 NTR）激活鞘脂信号级联反应，快速增加感觉神经元激发动作电位（AP）的能力。对p75 NTR激活的细胞机制和下游信号通路知之甚少。我们的研究结果表明，p75 NTR/神经酰胺激活的新型非典型PKC，PKM <$<$在增强兴奋性中起着关键作用，并表明PKM <$可能有一个关键作用，在过渡的急性持续致敏的结果PKM <$成为组成性活跃。拟议的研究将使用从成年大鼠背根节分离的感觉神经元作为模型系统，以探索p75 NTR激活对膜兴奋性的功能影响。从分离的神经元获得的知识将扩展到探索这些效应分子在调节伤害性行为反应中的作用的研究。这些研究将与哈佛大学的加里·哈茨博士合作完成。具体目标是：目标1将确定p75 NTR及其合成/激活PKM的作用。此外，p75 NTR与支架蛋白的相互作用将决定它们调节PKM活性的能力。这项工作将集中在PKM诱导的离子通道调节及其对神经元兴奋性的调节上。在与加里博士的合作中，Aim 2将建立p75 NTR-PKM信号级联在完整动物伤害性行为调节中的作用。这种多维方法的优势在于，生物化学和分子技术将建立新的蛋白质-蛋白质关联，电生理学将建立这些关联的功能结果。这些发现将被扩展到在完整的动物的研究，以提供一个机制的理解，从而激活p75 NTR导致提高神经元的敏感性。对这些事件的基本理解是必要的，以便可以设计更好的化合物和治疗方法来促进慢性炎症性疾病的治疗。 公共卫生关系：组织损伤和炎症导致损伤部位附近的各种细胞释放化学物质，导致对疼痛刺激的敏感性增加。其中一种关键的化学物质是神经生长因子。本申请中提出的研究试图了解神经生长因子激活的细胞内信号通路如何增加神经敏感性，从而导致疼痛反应增加。