Department of Anesthesia, Peking University International Hospital, Beijing 102206, China.
Department of Anesthesia, Dongzhimen Hospital, Beijing University of Chinese Medcine, Beijing 100700, China.
J Neuroimmunol. 2021 Feb 15;351:577458. doi: 10.1016/j.jneuroim.2020.577458. Epub 2020 Dec 8.
Recent studies have elucidated the instrumental role of microRNAs (miRNAs) in neuropathic pain (NP) progression. As one member of miRNAs, miR-130a-3p has been proved as a mediator in inflammation and neuronal maturation. The present study attempted to elucidate what effect miR-130a-3p exerts on NP.
The miR-130a-3p expression in the spinal cord tissues of rat with spinal cord compression injury (SCI) and LPS-induced BV2 microglia was determined with RT-PCR, which was further applied to analyze the clinical relevance between miR-130a-3p and neuropathic pain. Besides, the expression of IGF-1, IL-1β, IL-6, and TNF-α in the spinal cord tissues of rats was measured using RT-PCR and ELISA after intrathecal injection of miR-130a-3p inhibitors and tail vein injection of IGF-1 low-expression lentivirus (Lv-shIGF-1). Further, neuronal apoptosis (labeled by Caspase3) and microglial activation (labeled by Iba1) were examined by immunohistochemistry (IHC), and the levels of IGF-1, IGF-1R, NF-κB were determined by western blot. Additionally, bioinformatic was employed to analyze the potential target genes of miR-130a-3p. Furthermore, the dual luciferase activity assay and RNA immunoprecipitation assay were conducted to further substantiate whether miR-130a-3p targets IGF-1.
In comparison with the sham group, the miR-130a-3p expression was remarkably up-regulated in the spinal cord lesions of SCI rats. The ELISA results showed that inhibiting the miR-130a-3p significantly reduced NP symptoms of SCI rats, mitigated neuronal apoptosis, microglial activation, repressed NF-κB phosphorylation and the IL-1β, IL-6 and TNF-α expressions in SCI rats. Contrarily, downregulation of miR-130a-3p increased IGF-1 and IGF-1R expression. What's more, we observed the same effects in BV2 microglia. In addition, the bioinformatics analysis showed that miR-130-3p targeted at the 3'-untranslated region of IGF-1 and inhibiting its expression. However, abolishing IGF-1 not only promoted the inflammatory responses in the SCI lesions, but also aggravated NP of SCI rats, while those effects were attenuated by the downregulation of miR-130a-3p.
The inhibition of miR-130a-3p expression up-regulates the IGF-1/IGF-1R signaling pathway, thus reducing neuropathic pain caused by spinal cord injury.
最近的研究阐明了 microRNAs（miRNAs）在神经病理性疼痛（NP）进展中的作用。miR-130a-3p 作为 miRNAs 的一个成员，已被证明是炎症和神经元成熟的介质。本研究试图阐明 miR-130a-3p 对 NP 的影响。
通过 RT-PCR 测定大鼠脊髓压迫损伤（SCI）和 LPS 诱导的 BV2 小胶质细胞中脊髓组织中 miR-130a-3p 的表达，并进一步应用于分析 miR-130a-3p 与神经病理性疼痛之间的临床相关性。此外，通过 RT-PCR 和 ELISA 测定鞘内注射 miR-130a-3p 抑制剂和尾静脉注射 IGF-1 低表达慢病毒（Lv-shIGF-1）后大鼠脊髓组织中 IGF-1、IL-1β、IL-6 和 TNF-α的表达。进一步通过免疫组织化学（IHC）检测神经元凋亡（Caspase3 标记）和小胶质细胞激活（Iba1 标记），通过 Western blot 检测 IGF-1、IGF-1R、NF-κB 水平。此外，还进行了生物信息学分析以分析 miR-130a-3p 的潜在靶基因。此外，进行了双荧光素酶活性测定和 RNA 免疫沉淀测定，以进一步证实 miR-130a-3p 是否靶向 IGF-1。
与假手术组相比，SCI 大鼠脊髓损伤部位的 miR-130a-3p 表达明显上调。ELISA 结果表明，抑制 miR-130a-3p 可显著减轻 SCI 大鼠的 NP 症状，减轻神经元凋亡、小胶质细胞激活，抑制 SCI 大鼠 NF-κB 磷酸化及 IL-1β、IL-6 和 TNF-α的表达。相反，下调 miR-130a-3p 可增加 IGF-1 和 IGF-1R 的表达。更重要的是，我们在 BV2 小胶质细胞中观察到了相同的效果。此外，生物信息学分析表明，miR-130-3p 靶向 IGF-1 的 3'-非翻译区并抑制其表达。然而，抑制 IGF-1 不仅促进了 SCI 病变中的炎症反应，而且加重了 SCI 大鼠的 NP，而 miR-130a-3p 的下调则减弱了这些作用。
抑制 miR-130a-3p 的表达可上调 IGF-1/IGF-1R 信号通路，从而减轻脊髓损伤引起的神经病理性疼痛。
