Lipid kinase regulation of pain signaling and sensitization

脂质激酶对疼痛信号传导和敏化的调节

• 批准号: 8627903
• 负责人: Mark J. Zylka
• 金额: $ 32.99万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2018-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8627903
• 关键词: Acute Pain; Adult; Adverse effects; Affect; Afferent Neurons; Analgesics; Behavioral; Biochemical; Bradykinin; Brain; Bypass; Chemicals; Complex; Data; Dependence; Development; Enzymes; Figs - dietary; Future; G-Protein-Coupled Receptors; Genetic; Gold; Human; Hydrolysis; Hypersensitivity; Individual; Inflammation; Inflammatory; Ion Channel; Knockout Mice; Lead; Lipids; Lysophospholipids; Maintenance; Medical; Membrane; Modeling; Mus; Nerve Growth Factors; Neurons; Nociception; Opioid; Pain; Pathway interactions; Pharmaceutical Preparations; Phenotype; Phosphatidylinositol 4,5-Diphosphate; Phosphatidylinositols; Phosphotransferases; Property; Receptor Activation; Receptor Protein-Tyrosine Kinases; Receptor Signaling; Regulation; Research; Second Messenger Systems; Signal Pathway; Signal Transduction; Spinal Ganglia; Stimulus; Structure of trigeminal ganglion; Symptoms; TRP channel; Tamoxifen; Testing; Thermal Hyperalgesias; Time; Tissues; base; chronic pain; effective therapy; in vivo; inflammatory pain; inhibitor/antagonist; innovation; knock-down; lysophosphatidic acid; mechanical allodynia; mouse model; nerve injury; nociceptive response; novel; novel strategies; painful neuropathy; phosphatidylinositol 4-phosphate; public health relevance; receptor; research study; response; second messenger; spontaneous pain; tissue processing

PROJECT SUMMARY New approaches for treating chronic pain are needed, particularly since existing analgesics have serious side effects and are not always effective at treating inflammatory pain and neuropathic pain-the two most common forms of chronic pain in humans. Inflammation and nerve injury lead to the release of a complex mix of chemicals that signal through molecularly diverse pronociceptive (pain-producing) receptors. Activation of these receptors increases the excitability and sensitivity of nociceptive dorsal root ganglia (DRG) and trigeminal ganglia neurons. Unfortunately, efforts to block individual pronociceptive receptors have so far failed to produce effective treatments for chronic pain. Here, we propose an innovative approach to reduce pain hypersensitivity that bypasses this long-standing problem associated with receptor diversity. Our approach is based on selectively reducing the level of the lipid second messenger phosphatidylinositol 4,5- bisphosphate (PIP2) in DRG neurons. Most pronociceptive receptors require PIP2 to initiate downstream signaling. Moreover, many TRP channels that detect noxious stimuli and ion channels that regulate membrane excitability require PIP2 for activity. PIP2 thus sits at a key convergence point for diverse receptors, ion channels and signaling pathways that promote and maintain chronic pain. In preliminary studies with mice, we identified a lipid kinase that generates at least 50% of all PIP2 in DRG neurons. Moreover, inactivation of this lipid kinase profoundly reduced nociceptive sensitization in response to an inflammatory agent. Based on our preliminary data, we hypothesize that this lipid kinase acts through PIP2 dependent mechanisms to regulate pronociceptive receptor signaling in DRG neurons and pain sensitization in vivo. To test this hypothesis we will: 1. Evaluate the extent to which this lipid kinase regulates nociceptive sensitization in vivo, using mouse models of acute, chronic and spontaneous pain, including models of inflammatory pain and neuropathic pain. We will use an innovative genetic approach to knock-down kinase activity. This approach selectively reduces PIP2 concentration in DRG but does not affect PIP2 concentration in other tissues that process pain signals. We will further evaluate PIP2-dependence using biochemical rescue experiments. 2. Evaluate the extent to which this kinase regulates signaling through diverse pronociceptive receptors, including G protein-coupled receptors, a tyrosine kinase receptor, and TRP channels that detect noxious stimuli. 3. Utilize a new conditional knockout mouse to inducibly delete this kinase only in sensory neurons of adults and to evaluate the extent to which this kinase regulates initiation and maintenance of inflammatory pain and neuropathic pain. We will be the first to rigorously study the importance of this kinase in the setting of chronic pain. Our preliminary data suggest this lipid kinase is a master regulator of pain signaling and sensitization.

项目摘要 需要治疗慢性疼痛的新方法，特别是因为现有的镇痛药 严重的副作用，并不总是有效地治疗炎症性疼痛和神经性疼痛-这两个 最常见的人类慢性疼痛形式。炎症和神经损伤导致释放一种 通过分子多样的感受器（疼痛产生）传递信号的化学物质的复杂混合物。 这些受体的激活增加了伤害性背根神经节（DRG）的兴奋性和敏感性 和三叉神经节神经元。不幸的是，到目前为止，阻断个体原伤害感受器的努力 未能对慢性疼痛产生有效的治疗。在这里，我们提出了一种创新的方法，以减少 疼痛超敏反应，绕过这个长期存在的问题与受体的多样性。我们 该方法是基于选择性地降低脂质第二信使磷脂酰肌醇4，5- 二磷酸（PIP 2）。大多数原伤害感受受体需要PIP 2启动下游 发信号。此外，许多检测伤害性刺激的TRP通道和调节细胞膜的离子通道， 兴奋性需要PIP 2的活动。因此，PIP 2位于不同受体、离子 促进和维持慢性疼痛的通道和信号通路。在对小鼠的初步研究中，我们 鉴定了在DRG神经元中产生至少50%的所有PIP 2的脂质激酶。此外，这种失活 脂质激酶显著降低了对炎性物质的伤害性敏感性。基于我们 根据初步数据，我们假设这种脂质激酶通过PIP 2依赖性机制调节 DRG神经元中的原伤害感受受体信号传导和体内疼痛敏化。为了验证这一假设， 意志：1.评价这种脂质激酶在体内调节伤害性敏化的程度，使用小鼠 急性、慢性和自发性疼痛模型，包括炎性疼痛和神经性疼痛模型。 我们将使用一种创新的遗传方法来敲低激酶活性。这种方法选择性地减少了 PIP 2在DRG中的浓度，但不影响PIP 2在处理疼痛信号的其他组织中的浓度。 我们将使用生化拯救实验进一步评估PIP 2依赖性。2.评估程度， 这种激酶通过不同的原伤害感受受体调节信号传导，包括G蛋白偶联受体。 受体、酪氨酸激酶受体和检测有害刺激的TRP通道。3.利用新的 条件性基因敲除小鼠诱导性地删除仅在成人感觉神经元中的这种激酶，并评估 该激酶调节炎性疼痛和神经性疼痛的起始和维持的程度。 我们将是第一个严格研究这种激酶在慢性疼痛中的重要性的人。我们 初步数据表明，这种脂质激酶是疼痛信号传导和致敏的主要调节剂。