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.

在周围神经系统中神经受伤后，再生通常会在某些功能恢复中发生，具体取决于受伤的严重程度。但是，神经损伤后的异常再生反应可能导致神经性疼痛。研究表明，在周围神经损伤后发生了脊髓疼痛感受层中中央感觉轴突的附带发芽，这可能有助于神经性疼痛的发展。我们实验室和其他人的最新工作表明，受伤后需要直接在周围神经系统中翻译的mRNA。但是，尚未探索外围刺激可以改变中央投射DRG轴突中的mRNA转运或翻译的可能性。我假设对周围神经神经触发的损伤会导致感觉神经元基因表达的变化以及mRNA随后将轴突转移到轴突中，从而导致这些轴突的生长能力变化。我将使用RT-PCR和原位杂交来定量轴突mRNA，以在周围神经损伤之前和之后中心突出的轴突中编码与生长相关和神经元信号蛋白。为了确定中央投射DRG轴突中的轴突mRNA水平是否有任何变化，由损伤诱导的转录驱动I将使用importinβ13'-UTR敲除小鼠，其中转录调节被减弱。我还将使用病毒介导的基因转移来增加或降低编码相关蛋白的mRNA的轴突水平，以检查这如何影响中心投射感觉轴突的发芽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MRNA是否将蛋白质局部产生的中央感觉轴突运输有助于脊髓中的发芽并进展为神经性疼痛。