The Neurosecretory Protein VGF: Contributions to Pain

描述（由申请人提供）：拟议的项目将表征疼痛通路中的新型信号系统。VGF（non-acronymic）是一种神经分泌蛋白，类似于嗜铬粒蛋白家族。它在受调节的分泌途径中被分选，并被蛋白水解加工成在刺激时释放的片段。目前，VGF生物活性片段的确切身份及其作用机制尚不清楚。我们的初步研究表明，VGF在神经性疼痛和炎症性疼痛模型中迅速上调。此外，我们已经发现，一个VEGF衍生的肽（VGF-C30）诱导热痛觉过敏脊髓给药后。这些发现使我们假设VGF参与慢性疼痛条件下的疼痛信号传导。该项目的目的是为深入分析VGF在慢性疼痛中的作用奠定基础。具体目标1将通过解决以下假设来评估VGF在疼痛通路中的生理相关性：1）在刺激时，VGF衍生的片段从感觉神经元释放。在这些实验中，VGF片段释放的感觉神经元在去极化依赖的方式将使用生化方法，包括质谱法的特点。2)VGF-C30的行为效应是受体介导的细胞内信号传导途径活化的结果。由VEGF衍生的生物活性分子激活的潜在受体及其信号传导机制完全未知。拟开展的研究将以生物化学方法评价脊髓膜制剂中VGF-C30的结合位点。此外，基于初步证据，将检查脊髓中VGF-C30信号传导机制中丝裂原活化蛋白激酶通路的贡献。具体目标2将解决VGF有助于慢性疼痛机制的假设。拟议的研究将采用两种方法来解决这一假设：1）已经建立的VGF敲除小鼠系，以及2）siRNA介导的VGF表达敲低。这两种方法的结合将允许VGF在慢性疼痛的发展和维持中的作用的综合评价。总之，拟议的项目将研究一种新的信号系统对慢性疼痛机制的贡献。所获得的信息可能将VGF确立为慢性疼痛病症的潜在治疗靶点。拟议的项目将表征疼痛通路中的一种新的信号系统：神经分泌蛋白VGF（非首字母缩写）。这些研究将为深入分析VGF在慢性疼痛中的作用机制奠定基础。所获得的信息可能将VGF确立为慢性疼痛病症的潜在治疗靶点。

DESCRIPTION (provided by applicant): The proposed project will characterize a novel signaling system in the pain pathway. VGF (non-acronymic) is a neurosecretory protein similar to the family of chromogranins. It is sorted in the regulated secretory pathway and proteolytically processed into fragments that are released upon stimulation. Currently the precise identity of VGF bioactive fragments and their mechanisms of action are unknown. Our preliminary studies indicate that VGF is rapidly upregulated in models of neuropathic and inflammatory pain. Furthermore, we have found that a VGF-derived peptide (VGF-C30) induces thermal hyperalgesia following spinal administration. These findings have lead us to hypothesize that VGF is involved in pain signaling under conditions of chronic pain. The objective of the proposed project is to establish foundations for in-depth mechanistic analysis of the role of VGF in chronic pain. Specific Aim 1 will evaluate the physiological relevance of VGF in the pain pathway by addressing the following hypotheses: 1) VGF-derived fragments are released from sensory neurons upon stimulation. In these experiments, VGF fragments released from sensory neurons in a depolarization-dependent manner will be characterized using biochemical approaches, including mass spectrometry. 2) The behavioral effects of VGF- C30 are the result of a receptor-mediated activation of an intracellular signaling pathway. The potential receptors activated by VGF-derived bioactive molecules and their signaling mechanisms are completely uncharacterized. The proposed studies will evaluate the binding site(s) of VGF-C30 in spinal cord membrane preparations pharmacologically and biochemically. In addition, based on preliminary evidence, the contribution of mitogen-activated protein kinase pathways to the mechanisms if VGF-C30 signaling in spinal cord will be examined. Specific Aim 2 will address the hypothesis that VGF contributes to mechanisms of chronic pain. The proposed studies will employ two approaches to address this hypothesis: 1) an already established line of VGF knockout mice, and 2) siRNA-mediated knock-down of VGF expression. The combination of these two approaches will allow comprehensive evaluation of the role of VGF in the development and maintenance of chronic pain. In summary, the proposed project will examine the contribution of a novel signaling system to mechanism of chronic pain. The information gained may establish VGF as a potential therapeutic target for chronic pain conditions. The proposed project will characterize a novel signaling system in the pain pathway: the neurosecretory protein VGF (non-acronymic). These studies will lay the foundations for in-depth mechanistic analysis of the role of VGF in chronic pain. The information gained may establish VGF as a potential therapeutic target for chronic pain conditions.