MiR-223-5p inhibitor suppresses microglia inflammation and promotes Nrg-1 in rats of spinal cord injury
MiR-223-5p inhibitor suppresses microglia inflammation and promotes Nrg-1 in rats of spinal cord injury
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MiR-223-5p 抑制剂抑制脊髓损伤大鼠小胶质细胞炎症并促进 Nrg-1
DOI：
10.26355/eurrev_201911_19537
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发表时间：
2019-01-01
影响因子：
3.3
通讯作者：
Jiang, J. -Y.
中科院分区：
文献类型：
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作者：
Guan, Y-Z.;Sun, C.;Jiang, J. -Y.
目的：本研究旨在探讨微小RNA-233-5p（miR-233-5p）在脊髓损伤（SCI）中的作用，并探讨其可能的机制。 材料与方法：首先从新生大鼠体内分离小胶质细胞，并在合适的体外环境中培养。脂多糖 (LPS) 和白细胞介素 4 (IL-4) 用于激活小胶质细胞。 miR-223-5p的表达。分别通过 qRT-PCR 测量诱导型一氧化氮合酶 (iNOS) 和精氨酸酶 1 (Arg-1)。转染miR-233-5p抑制剂后，检测细胞中miR-223-5p、iNOS和Arg-1的表达水平。成功建立大鼠中度SCI模型（10g落在T10脊髓5cm高度处）。随后，观察miR-223-5p峰值时刻的炎症指标。同时评估其在SCI后28天的神经保护作用。最后采用Basso、Beattie和Bresnahan（BBB）评定量表评估SCI后1、3、7、14、21、28天大鼠的后肢运动功能。结果：MiR-223-5p抑制剂在体外显着促进M2小胶质细胞表达并退化M1小胶质细胞表达。 SCI在1周内使损伤脊髓组织中miR-223-5p水平明显升高。受伤后5天达到顶峰。同时，miR-223-5p抑制剂在SCI后3天显着降低炎症因子的表达，包括白介素1β（IL-1β）、白细胞介素6（IL-6）和肿瘤坏死因子α（TNF-α），并增加神经调节蛋白1（NRG-1）的表达。然而，miR-223-5p抑制剂在SCI后7天和28天显着降低了凋亡关键酶Caspase-3和胶质细胞反应标志物胶质纤维酸性蛋白（GFAP）的水平。分别。结果，BBB评分量表显示miR-223-5p注射组后肢运动功能显着恢复。结论：MiR-223-5p在M1小胶质细胞中上调，而在M2小胶质细胞中下调。 MiR-223-5p抑制剂可以显着增加M2小胶质细胞的表达。同时降低体外M1小胶质细胞的表达。在体内，miR-223-5p抑制剂抑制炎症反应并增强NRG-1水平，以减少胶质细胞反应和神经元凋亡。因此，其治疗促进了大鼠的后肢运动功能。
OBJECTIVE: The aim of this study was to investigate the role of microRNA-233-5p (miR-233-5p) in spinal cord injury (SCI), and to explore the possible underlying mechanism.MATERIALS AND METHODS: Microglia were first isolated from neonate rats and cultured in a suitable environment in vitro. Lipopolysaccharide (LPS) and interleukin-4 (IL-4) were used to activate microglia. The expressions of miR-223-5p. inducible nitric oxide synthase (iNOS) and arginase 1 (Arg-1) were measured by qRT-PCR, respectively. After transfection of miR-233-5p inhibitor, the expression levels of miR-223-5p, iNOS and Arg-1 in cells were detected as well. A moderate SCI model was successfully established in rats (10 g fallen on T10 spinal cord at the height of 5 cm). Subsequently, inflammation indexes at miR-223-5p peak moment were observed. Meanwhile, its neuro-protective effect at 28 days after SCI was estimated. Finally, Basso, Beattie, and Bresnahan (BBB) rating scale was applied to evaluate the hindlimb locomotor function of rats at 1, 3, 7, 14, 21, 28 days after SCI.RESULTS: MiR-223-5p inhibitor significantly promoted M2 microglia expression and degenerated M1 microglia expression in vitro. SCI obviously elevated the level of miR-223-5p in injured spinal cord tissues within one week. which reached a peak at 5 days after injury. Meanwhile, miR-223-5p inhibitor remarkably reduced the expressions of inflammatory factors, including interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-alpha) at 3 days after SCI, as well as increased neuregulinl (NRG-1) expression. However, miR-223-5p inhibitor significantly declined the levels of apoptosis key enzyme-caspase-3 and glia reaction marker-glial fibrillary acidic protein (GFAP) at 7 and 28 days after SCI. respectively. As a result, BBB rating scale demonstrated that hindlimb locomotor function was significantly recovered in miR-223-5p injection group.CONCLUSIONS: MiR-223-5p was up-regulated in M1 microglia, whereas down-regulated in M2 microglia. MiR-223-5p inhibitor could significantly increase M2 microglia expression. while decrease M1 microglia expression in vitro. In vivo, miR-223-5p inhibitor suppressed the inflammatory response and reinforced NRG-1 level to reduce glia reaction and neuron apoptosis. Thereby, its treatment promoted the hindlimb locomotor function of rats.