Examining mRNA localization in central sensory axons after peripheral nerve injury

检查周围神经损伤后中枢感觉轴突的 mRNA 定位

• 批准号: 9893038
• 负责人: Terika Smith
• 金额: $ 9.94万
• 依托单位: UNIVERSITY OF SOUTH CAROLINA AT COLUMBIA
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-04-01 至 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9893038
• 关键词: 3' Untranslated Regions; Affect; Afferent Neurons; Area; Attenuated; Axon; Axotomy; Behavior; Binding Proteins; Biology; Career Mobility; Complication; Data; Development; Exposure to; Gene Expression; Gene Transfer; Generations; Genetic Transcription; Glutamates; Growth; Immunofluorescence Immunologic; Importins; In Situ Hybridization; In Vitro; Injury; Knockout Mice; Knowledge; Laboratories; Lead; Link; Mediating; Messenger RNA; Methodology; Molecular Neurobiology; Natural regeneration; Nerve; Nerve Regeneration; Neuraxis; Neurites; Neurobiology; Neurons; Neuropathy; Nociception; Pain; Patients; Peripheral; Peripheral Nerves; Peripheral Nervous System; Peripheral nerve injury; Primates; Protein Biosynthesis; Proteins; RNA; RNA-Binding Proteins; Recovery of Function; Refractory; Regenerative response; Research; Reverse Transcriptase Polymerase Chain Reaction; Rodent; Sensory; Severities; Signaling Protein; Spinal; Spinal Cord; Spinal cord injury; Stimulus; Structure; Techniques; Testing; Time; Training; Transcriptional Regulation; Translating; Translations; Untranslated Regions; Viral; Work; axon growth; axon regeneration; axonal sprouting; chronic pain; cost; dorsal horn; effective therapy; experience; in vivo; insight; nerve injury; neurotransmission; pain relief; painful neuropathy; protein expression

Following injury to nerves in the peripheral nervous system, regeneration readily occurs oftentimes with some functional recovery depending on the severity of the injury; however, aberrant regenerative responses after nerve injury could lead to neuropathic pain. Research has suggested that collateral sprouting of central sensory axons in pain receptive lamina of the spinal cord occurs after peripheral nerve injury and this may contribute to the development of neuropathic pain. Recent works from our laboratory and others have shown that mRNAs translated directly within peripheral nerves are needed for regeneration after injury. However, the possibility that peripheral stimuli can alter mRNA transport or translation in centrally projecting DRG axons has not been explored. I hypothesize that injury to peripheral nerves triggers changes in sensory neuron gene expression and subsequent transport of mRNAs into centrally projecting axons that result in changes in the growth capacity of those axons. I will use RT-PCR and in situ hybridization to quantify axonal mRNAs encoding growth-associated and neuronal signaling proteins in centrally projecting axons before and after peripheral nerve injury. To determine if any changes in axonal mRNA levels in centrally projecting DRG axons are driven by injury-induced transcription I will use Importin β1 3’-UTR knockout mice in which transcriptional regulation is attenuated. I will also use viral-mediated gene transfer to increase or decrease the axonal levels of mRNAs encoding growth associated proteins to examine how this influences sprouting of centrally projecting sensory axons and the development of neuropathic pain. Overall, the work in this proposal will provide training in molecular neurobiology techniques and will serve to tell us if transport of mRNAs into central sensory axons with localized generation of proteins contributes to sprouting in the spinal cord and progression to neuropathic pain.

周围神经系统神经损伤后，根据损伤的严重程度，通常很容易发生再生，并有一定的功能恢复；然而，神经损伤后异常的再生反应可能导致神经性疼痛。研究表明，周围神经损伤后，脊髓疼痛感受层中的中央感觉轴突会侧生，这可能会导致神经性疼痛的发生。我们实验室和其他实验室的最新研究表明，损伤后的再生需要直接在周围神经内翻译的 mRNA。然而，外周刺激可以改变中心突出的 DRG 轴突中 mRNA 运输或翻译的可能性尚未被探索。我假设周围神经损伤会引发感觉神经元基因表达的变化，并随后将 mRNA 转运到中心突出的轴突中，从而导致这些轴突生长能力的变化。我将使用 RT-PCR 和原位杂交来量化周围神经损伤前后中心突出轴突中编码生长相关蛋白和神经元信号蛋白的轴突 mRNA。为了确定中心突出的 DRG 轴突中轴突 mRNA 水平的任何变化是否是由损伤诱导的转录驱动的，我将使用 Importin β1 3'-UTR 敲除小鼠，其中转录调节减弱。我还将使用病毒介导的基因转移来增加或减少编码生长相关蛋白的 mRNA 的轴突水平，以研究这如何影响中央突出的感觉轴突的萌发和神经性疼痛的发展。总体而言，该提案中的工作将提供分子神经生物学技术的培训，并将告诉我们将 mRNA 转运到中枢感觉轴突并局部生成蛋白质是否有助于脊髓发芽并进展为神经性疼痛。