Deciphering Caenorhabditis elegans molecular nociception using mass spectrometry-based proteomics and network biology

秀丽线虫(C.elegans)是一种与哺乳动物生物学相关的功能基因组学的强大动物模型系统，被广泛用于研究伤害性行为。有趣的是，成年线虫由959个细胞组成，其中302个是神经元，这使得该模型对于从生理和分子水平研究伤害性感受具有吸引力。瞬时受体电位(Trp)通道在处理伤害性化学和热刺激过程中起着核心作用。在哺乳动物中，Trp通道的激活触发了感觉信息的传播回中枢神经系统，从而导致痛感。促炎感觉神经肽，如速激肽，从这些激活的神经末梢释放出来，导致神经源性炎症。在脊髓水平，神经肽在疼痛传递和突触化学中发挥核心作用。线虫基因组编码几个Trp通道，覆盖所有七个Trp亚家族，包括TRPV类似物(如OSM-9和OCR1-4)。最近发现线虫的Trp通道与包括感觉转导在内的行为和生理过程有关。许多线虫的Trp通道与脊椎动物有相似的激活和调节机制。此外，最近的研究表明，MSFamide家族的神经肽(NLP)和FMRamide相关肽(FLPs)与哺乳动物神经肽在功能上有相似之处，但很少被完全表征。神经肽参与了几乎所有行为的调节，包括运动、机械和化学感觉。神经肽作为神经调节剂和快速神经递质发挥作用。这些神经肽在线虫中的广泛存在表明了神经肽能信号在线虫中的基本作用，但机制知识仍然非常有限。拟议研究的目标将是：(1)量化野生型和目标突变体(例如OSM-9，OCR1-4)线虫与热和化学刺激相关的伤害行为；(2)利用蛋白质组自下而上的方法和SILAC归一化，通过质谱学表征线虫；(3)利用蛋白质组数据产生全面的生物信息学分析(例如，独创性路径分析，GeneMANIA)，以确定相关的关系、机制、功能、生物网络和途径。我们相信，这将为线虫伤害行为和化学突触所涉及的分子事件提供重要的见解。更好地理解线虫的这些机制将改变我们的研究能力，使我们和其他人能够在分子水平上更全面地研究伤害性感受。

Caenorhabditis elegans (C.elegans) is a powerful animal model system for functional genomics relevant to mammalian biology and it is extensively used to study nociceptive behavior. Interestingly, adult C.elegans consists of 959 cells, of which 302 are neurons, which make this model attractive to study nociception at the physiological and molecular levels. Transient receptor potential (TRP) channels have a central role in the processing of nociceptive chemical and thermal stimuli. In mammals, the activation of TRP channels triggers the propagation of sensory information back to the central nervous system, which leads to pain sensation. Pro-inflammatory sensory neuropeptides, such as tachykinins are released from these activated nerve endings resulting in neurogenic inflammation. At the spinal level, neuropeptides play a central role in pain transmission and in the synaptic chemistry. The C.elegans genome encodes several TRP channels covering all of the seven TRP subfamilies including TRPV analogs (e.g. OSM-9 and OCR1-4). It has been recently established that C.elegans TRP channels are associated with behavioral and physiological processes, including sensory transduction. Many C.elegans TRP channels share similar activation and regulatory mechanisms with their vertebrate counterparts. Moreover, recent studies revealed that neuropeptides from the MSFamide family (NLPs) and FMRamide-related peptides (FLPs) share functional similarities with mammal neuropeptides but very few have been thoroughly characterized. Neuropeptides are involved in the modulation of essentially all behaviors including locomotion, mechano- and chemosensation. Neuropeptides are acting as neuromodulators and as fast neurotransmitters. The broad existence of these neuropeptides in nematodes suggests a fundamental role of neuropeptidergic signalling in C.elegans but the mechanistic knowledge remains very limited. The objectives of the proposed research will be to (1) Quantify nociceptive behaviors of wild type and targeted mutant (e.g. OSM-9, OCR1-4) C.elegans associated with thermal and chemical stimuli; (2) Characterize C.elegans by mass spectrometry using proteomic bottom-up approaches and SILAC normalization; (3) Generate comprehensive bioinformatics analyses (e.g. Ingenuity Pathway Analysis, GeneMANIA) using the proteomic data to identify relationships, mechanisms, functions, biological networks and pathways of relevance. We believed it will provide significant insight in the molecular events implicated in C.elegans nociceptive behaviors and chemical synapses. A better comprehension of these mechanisms in C.elegans will transform our powers of investigation, allowing us, and others, to pursue more comprehensive study of nociception at the molecular level.**