Department of Anesthesiology, 74540The First Affiliated Hospital of Bengbu Medical College, Bengbu, Anhui, China.
Department of Anesthesiology and Pain Research Center, 417382The First Affiliated Hospital of Jiaxing University, Jiaxing, China.
Mol Pain. 2022 Apr;18:17448069221127811. doi: 10.1177/17448069221127811.
Noncoding microRNAs have emerged as critical players of gene expression in the nervous system, where they contribute to regulating nervous disease. As stated in previous research, the miR-155-5p upregulation happens in the spinal cord at the nociceptive state. It was unclear if miR-155-5p is linked to bone cancer pain (BCP). Herein, we aimed at investigating the miR-155-5p functional regulatory function in BCP process and delineating the underlying mechanism.
The miRNA-155-5p levels and cellular distribution were determined by RNA sequencing, fluorescent in situ hybridization (FISH), and quantitative real-time PCR (qPCR). Immunoblotting, qPCR, dual-luciferase reporter gene assays, immunofluorescence, recombinant overexpression adeno-associated virus, small interfering RNA, intraspinal administration, and behavioral tests were utilized for exploring the downstream signaling pathway.
The miR-155-5p high expression in spinal neurons contributes to BCP maintenance. The miR-155-5p blockage via the intrathecal injection of miR-155-5p antagomir alleviated the pain behavior; in contrast, upregulating miR-155-5p by agomir induced pain hypersensitivity. The miR-155-5p bounds directly to TCF4 mRNA's 3' UTR. BCP significantly reduced protein expression of TCF4 versus the Sham group. The miR-155-5p inhibition relieved the spinal TCF4 protein's down-expression level, while miR-155-5p upregulation by miR-155-5p agomir intrathecal injection decreased TCF4 protein expression in naïve rats. Additionally, TCF4 overexpression in BCP rats could increase Kv1.1. Moreover, TCF4 knockdown inhibited Kv1.1 expression in BCP rats. Indeed, TCF4 and Kv1.1 were co-expressed in BCP spinal cord neurons.
The study findings stated the miR-155-5p pivotal role in regulating BCP by directly targeting TCF4 in spinal neurons and suggested that miR-155-5p could be a promising target in treating BCP.
非编码 microRNAs 已成为神经系统中基因表达的关键调控因子，它们参与调节神经疾病。先前的研究表明，miR-155-5p 在痛觉状态下脊髓中上调。miR-155-5p 是否与骨癌痛（BCP）有关尚不清楚。在此，我们旨在研究 miR-155-5p 在 BCP 过程中的功能调控作用，并阐明其潜在机制。
通过 RNA 测序、荧光原位杂交（FISH）和实时定量 PCR（qPCR）测定 miR-155-5p 的水平和细胞分布。免疫印迹、qPCR、双荧光素酶报告基因检测、免疫荧光、重组过表达腺相关病毒、小干扰 RNA、鞘内给药和行为测试用于探索下游信号通路。
脊髓神经元中 miR-155-5p 的高表达有助于 BCP 的维持。鞘内注射 miR-155-5p 拮抗剂阻断 miR-155-5p 可减轻痛行为；相反，agomir 上调 miR-155-5p 可诱导痛觉过敏。miR-155-5p 直接与 TCF4 mRNA 的 3'UTR 结合。BCP 组与 Sham 组相比，TCF4 蛋白表达显著降低。miR-155-5p 抑制减轻了脊髓 TCF4 蛋白的下调水平，而鞘内注射 miR-155-5p agomir 可使 naïve 大鼠 TCF4 蛋白表达降低。此外，在 BCP 大鼠中过表达 TCF4 可增加 Kv1.1。而且，TCF4 敲低抑制了 BCP 大鼠中 Kv1.1 的表达。事实上，TCF4 和 Kv1.1 在 BCP 脊髓神经元中共同表达。
该研究结果表明，miR-155-5p 通过直接靶向脊髓神经元中的 TCF4 来调节 BCP，表明 miR-155-5p 可能是治疗 BCP 的有前途的靶点。
