Although the therapeutic potential of miRNA-mediated gene regulation has been investigated, its precise functional regulatory mechanism in neuropathic pain remains incompletely understood. In this study, we elucidate that miR-216a-3p serves as a critical non-coding RNA involved in the modulation of trigeminal-mediated neuropathic pain. By conducting RNA-seq and qPCR analysis, we observed a notable decrease of miR-216a-3p in the injured trigeminal ganglia (TG) of male rats. Intra-TG administration of miR-216a-3p agomir or lentiviral-mediated overexpression of miR-216a-3p specifically in sensory neurons of injured TGs alleviated established neuropathic pain behaviors, while downregulation of miR-216a-3p (pharmacologically or genetically) in naïve rats induced pain behaviors. Moreover, nerve injury significantly elevated the H3K27 trimethylation (H3K27me3) levels in the ipsilateral TG, thereby suppressing the SRY-box transcription factor 10 (SOX10) binding to the miR-216a-3p promoter and resulting in the reduction of miR-216a-3p. Inhibiting the enzymes that responsible for catalyzing H3K27me3 restored the nerve injury-induced reduction in miR-216a-3p expression and markedly ameliorated neuropathic pain behaviors. Furthermore, miR-216a-3p targeted stromal interaction molecule 1 (STIM1), and the decreased miR-216a-3p associated with neuropathic pain caused a significant upregulation in the protein abundance of STIM1. Conversely, overexpression of miR-216a-3p in the injured TG suppressed the upregulation of STIM1 expression and reversed the mechanical allodynia. Together, the mechanistic understanding of H3K27me3-dependent SOX10/miR-216a-3p/STIM1 signaling axial in sensory neurons may facilitate the discovery of innovative therapeutic strategies for neuropathic pain management.Significance Statement miRNAs are posttranscriptional regulators of gene expression that play critical roles in the pathogenesis of neuropathic pain. However, the detailed mechanisms by which most pain-associated miRNAs operate and their therapeutic potential are incompletely understood. Our present study revealed that nerve injury-induced trimethylation of lysine 27 on histone H3 (H3K27me3) reduces the binding of SOX10, a transcription factor, to the promoter region of the miR-216a-3p gene, leading to decreased expression of the microRNA, miR-216a-3p. This reduction subsequently promotes neuropathic pain by regulating STIM1. Given that miRNA-mediated gene regulation is a proposed therapeutic approach for treating neuropathic pain, our findings suggest that replenishing miR-216a-3p could serve as a novel strategy for treating chronic neuropathic pain.

中文翻译：

---

H3K27 三甲基化介导的感觉神经元中 miR-216a-3p 的下调通过靶向 STIM1 调节神经性疼痛行为。


尽管已经研究了 miRNA 介导的基因调控的治疗潜力，但其在神经性疼痛中的确切功能调节机制仍不完全清楚。在这项研究中，我们阐明了 miR-216a-3p 是一种关键的非编码 RNA，参与调节三叉神经介导的神经性疼痛。通过进行 RNA-seq 和 qPCR 分析，我们观察到雄性大鼠受伤的三叉神经节 （TG） 中 miR-216a-3p 显着降低。miR-216a-3p agomir 的 TG 内给药或慢病毒介导的 miR-216a-3p 过表达，特别是在受伤 TG 的感觉神经元中缓解了已建立的神经性疼痛行为，而幼稚大鼠中 miR-216a-3p （药理学或遗传学） 的下调诱导了疼痛行为。此外，神经损伤显著提高同侧 TG 中的 H3K27 三甲基化 （H3K27me3） 水平，从而抑制 SRY-box 转录因子 10 （SOX10） 与 miR-216a-3p 启动子的结合，导致 miR-216a-3p 降低。抑制负责催化 H3K27me3 的酶恢复了神经损伤诱导的 miR-216a-3p 表达减少，并显着改善了神经性疼痛行为。此外，miR-216a-3p 靶向基质相互作用分子 1 （STIM1），与神经性疼痛相关的 miR-216a-3p 降低导致 STIM1 蛋白质丰度显着上调。相反，在受伤的 TG 中过表达 miR-216a-3p 抑制了 STIM1 表达的上调并逆转了机械异常性疼痛。 总之，对感觉神经元中 H3K27me3 依赖性 SOX10/miR-216a-3p/STIM1 信号轴向的机制理解可能有助于发现神经性疼痛管理的创新治疗策略。意义声明 miRNA 是基因表达的转录后调节因子，在神经性疼痛的发病机制中起关键作用。然而，大多数与疼痛相关的 miRNA 起作用的详细机制及其治疗潜力尚不完全清楚。我们目前的研究表明，神经损伤诱导的组蛋白 H3 （H3K27me3） 上赖氨酸 27 的三甲基化降低了转录因子 SOX10 与 miR-216a-3p 基因启动子区域的结合，导致 microRNA miR-216a-3p 的表达降低。这种减少随后通过调节 STIM1 促进神经性疼痛。鉴于 miRNA 介导的基因调控是治疗神经性疼痛的一种拟议治疗方法，我们的研究结果表明，补充 miR-216a-3p 可以作为治疗慢性神经性疼痛的新策略。