Department of Rehabilitation Medicine, Qujing No.1 Hospital, Qujing 655000, China.
Department of Rehabilitation Medicine, The Second Affiliated Hospital of Kunming Medical University, Kunming 650101, China.
Neuroscience. 2024 Apr 5;543:13-27. doi: 10.1016/j.neuroscience.2024.02.013. Epub 2024 Feb 19.
This study aimed to explore the effects of miR-10b-5p on autophagy and apoptosis in neuronal cells after spinal cord injury (SCI) and the molecular mechanism. Bioinformatics was used to analyze the differentially expressed miRNAs. The expression of related genes and proteins were detected by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) and Western blot, respectively. Cell proliferation was detected by 5-ethynyl-2'-deoxyuridine (EdU), and apoptosis was detected by flow cytometry or terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay (TUNEL). Coimmunoprecipitation confirmed the interaction between UBR7 and Wnt1 or Beclin1. Autophagy was detected by the dansylcadaverine (MDC). The Basso Beattie Bresnahan (BBB) score was used to evaluate motor function, and hematoxylin-eosin (H&E) and Nissl staining were used to detect spinal cord tissue repair and neuronal changes. The result shows that the expression of miR-10b-5p was downregulated in the SCI models, and transfection of a miR-10b-5p mimic inhibited neuronal cell apoptosis. MiR-10b-5p negatively regulated the expression of UBR7, and the inhibitory effect of the miR-10b-5p mimic on neuronal cell apoptosis was reversed by overexpressing UBR7. In addition, UBR7 can regulate apoptosis by affecting the Wnt/β-catenin pathway by promoting Wnt1 ubiquitination. Treatment with the miR-10b-5p mimic effectively improved motor function, inhibited neuronal cell apoptosis, and promoted spinal cord tissue repair in SCI rats. Overall, miR-10b-5p can alleviate SCI by downregulating UBR7 expression, inhibiting Wnt/β-catenin signaling pathway ubiquitination to reduce neuronal apoptosis, or inhibiting Beclin 1 ubiquitination to promote autophagy.
本研究旨在探讨 miR-10b-5p 对脊髓损伤(SCI)后神经元细胞自噬和凋亡的影响及其分子机制。利用生物信息学分析差异表达的 miRNA。实时荧光定量聚合酶链反应(RT-qPCR)和 Western blot 分别检测相关基因和蛋白的表达。5-乙炔基-2'-脱氧尿苷(EdU)检测细胞增殖,流式细胞术或末端脱氧核苷酸转移酶介导的 dUTP-生物素 nick 末端标记法(TUNEL)检测细胞凋亡。免疫共沉淀验证 UBR7 与 Wnt1 或 Beclin1 的相互作用。用dansylcadaverine(MDC)检测自噬。Basso Beattie Bresnahan(BBB)评分用于评估运动功能,苏木精-伊红(H&E)和尼氏染色用于检测脊髓组织修复和神经元变化。结果表明,miR-10b-5p 在 SCI 模型中的表达下调,转染 miR-10b-5p 模拟物抑制神经元细胞凋亡。miR-10b-5p 负调控 UBR7 的表达,过表达 UBR7 逆转了 miR-10b-5p 模拟物对神经元细胞凋亡的抑制作用。此外,UBR7 可以通过促进 Wnt1 泛素化来调节 Wnt/β-catenin 通路,从而调节凋亡。miR-10b-5p 模拟物治疗有效改善了运动功能,抑制了神经元细胞凋亡,促进了 SCI 大鼠脊髓组织修复。综上所述,miR-10b-5p 可以通过下调 UBR7 表达,抑制 Wnt/β-catenin 信号通路泛素化以减少神经元凋亡,或抑制 Beclin1 泛素化以促进自噬,从而减轻 SCI。