Identification of a novel DRG-specific long noncoding RNA and its role in neuropathic pain

项目摘要 长非编码RNA(LncRNAs)调控基因表达。周围神经损伤对其功能的影响 表达于痛相关区域，包括背根神经节(DRG)。然而，大多数人的作用 神经病理性疼痛中已识别的lncRNAs仍不确定。识别新的lncRNA并探索其 对神经病理性疼痛的贡献可能为这种疾病的治疗提供新的策略。我们最近 使用了新一代RNA测序方法，并在 老鼠和人类。由于它在DRG中高度表达，我们将其命名为DRG特定的长非编码 RNA(ds-IncRNA)。我们的初步数据显示，周围神经损伤可能下调ds-lncRNA 这是由于转录激活因子Pou4f3在损伤的DRG中表达减少所致。拯救这一切 下调调节可减轻神经损伤引起的疼痛过敏，可能是通过阻断 RALY(一种转录辅助因子)与RNA聚合酶II(RNA II)之间的相互作用增加，以及 RALY/RNA II触发的Ehmt2 mRNA及其编码蛋白G9a(A)表达的随后沉默 神经病理性疼痛的关键人物)。鉴于DS-lncRNA可以直接与RALY结合，我们的 初步结果表明，神经病理性疼痛可能需要DRG ds-lncRNA下调。 通过负调控DRG RALY/RNA II触发G9a表达。这项提议将进一步 研究ds-lncRNA是否以及如何导致神经病理性疼痛。在具体目标1中，我们将首先 抢救损伤背根神经节ds-lncRNA表达下调是否能减轻神经病理性疼痛 开发和维护。然后，我们将研究模仿神经损伤是否导致基因下调 在没有神经损伤的情况下，DRG ds-lncRNA的存在会导致神经病理性疼痛症状。在具体目标2中，我们 将研究周围神经损伤是否导致ds-lncRNA及其受体的时间依赖性下调 转录因子Pou4f3在DRG中。我们还将研究ds-lncRNA下调是否归因于 导致周围神经损伤后损伤背根神经节Pou4f3表达减少。在具体目标3中，我们将 检测ds-lncRNA对Ehmt2、G9a及其下游痛相关基因表达的影响 周围神经损伤后损伤背根神经节中的基因。我们还将确定ds-lncRNA是否 下调增强RALY与RNA II的结合导致RALY/RNA II触发Ehmt2/G9a 周围神经损伤后损伤背根神经节中G9a调控的疼痛相关基因表达增加和减少。我们的 这项研究可能会确定一种以前未知的神经病理性疼痛的调节机制。考虑到这种病毒- 介导性基因治疗已应用于临床试验，本研究将具有潜在的临床应用价值。 在神经病理性疼痛管理中的应用。

Project Abstract Long noncoding RNAs (lncRNAs) regulate gene expression. Peripheral nerve injury dysregulated their expression in the pain-related regions including dorsal root ganglion (DRG). However, the role of most identified lncRNAs in neuropathic pain is still uncertain. Identifying novel lncRNAs and exploring their contribution to neuropathic pain may provide novel strategies for management of this disorder. We recently used a next generation RNA sequencing approach and identified a large, native, full-length non-coding RNA in mice and human. Because it is expressed highly in the DRG, we named it as DRG specific long noncoding RNA (DS-lncRNA). Our preliminary data revealed that peripheral nerve injury downregulated DS-lncRNA likely due to a decrease in the expression of a transcriptional activator Pou4f3 in the injured DRG. Rescuing this downregulation attenuated the nerve injury-induced pain hypersensitivity, likely through blockade of the increased interaction between RALY (a transcription co-factor) and the RNA polymerase II (RNA II) and consequent silence of the RALY/RNA II-triggered expression of Ehmt2 mRNA and its coding protein G9a (a key player in neuropathic pain) in the injured DRG. Given that DS-lncRNA can directly bind to RALY, our preliminary results indicate that DRG DS-lncRNA downregulation is required for neuropathic pain likely through negative regulation of DRG RALY/RNA II-triggered G9a expression. This proposal will further examine whether and how DS-lncRNA contributes to neuropathic pain. In Specific Aim 1, we will first investigate whether rescuing downregulation of DS-lncRNA in the injured DRG attenuates neuropathic pain development and maintenance. We will then examine whether mimicking nerve injury-induced downregulation of DRG DS-lncRNA leads to neuropathic pain symptoms in the absence of nerve injury. In Specific Aim 2, we will examine whether peripheral nerve injury results in time-dependent downregulation of DS-lncRNA and its transcription factor Pou4f3 in the DRG. We will also examine whether DS-lncRNA downregulation is attributed to a decrease of Pou4f3 expression in the injured DRG after peripheral nerve injury. In Specific Aim 3, we will test the effect of DS-lncRNA on the expression of Ehmt2 mRNA, G9a and their downstream pain-related genes in the injured DRG after peripheral nerve injury. We will also determine whether DS-lncRNA downregulation enhances the binding of RALY to RNA II leading to RALY/RNA II-triggered Ehmt2/G9a increase and G9a-controlled pain-related gene decrease in the injured DRG after peripheral nerve injury. Our study will likely identify a previously unknown regulatory mechanism for neuropathic pain. Given that virus- mediated gene therapy has been used in clinical trial, the present study will have a potential clinical application in neuropathic pain management.