miR-146a-3p抑制胰岛素样生长因子1表达调控星形胶质细胞增殖、迁移和凋亡

miR-146a-3p regulates astrocyte proliferation,migration and apoptosis by inhibiting insulin-like growth factor 1 expression

背景:mi R-146a-3p水平改变是大多数神经系统疾病发病机制中的常见事件,mi R-146a-3p调节星形胶质细胞的具体机制尚未被研究。目的:验证mi R-146a-3p通过胰岛素样生长因子1调控星形胶质细胞的增殖、迁移和凋亡。方法:将12只SD大鼠随机分为假手术组和脊髓损伤组,每组6只。术后2周对大鼠脊髓组织进行了RNA-Seq测序分析,筛选出差异基因(log2FC>2),同时挑选出Genecards数据库中脊髓损伤相关基因(Score>20),再通过Targetscan预测mi R-146a-3p的靶基因,取这3个基因集交集,筛选出胰岛素样生长因子1为其中一个重要的目的基因。q PCR、Western blot和免疫组化分析脊髓组织中胰岛素样生长因子1的表达水平。将原代星形胶质细胞分为NC组、NC-mimics组和mi R-146a-3p mimics组,用Annexin-V/PI染色法检测细胞凋亡情况、CCK-8法检测细胞增殖情况、Transwell法检测细胞的迁移能力。结果与结论:脊髓损伤组大鼠脊髓组织中mi R-146a-3p的表达较假手术组下降(P<0.05),胰岛素样生长因子1的表达较假手术组上升(P<0.05)。与NC组和NC-mimics组比较,mi R-146a-3p mimics组星形胶质细胞凋亡率增加(P<0.01),增殖能力下降(P<0.01),迁移数量减少(P<0.01)。结果表明,脊髓损伤后脊髓组织中mi R-146a-3p表达量下降,胰岛素样生长因子1表达量上升;在星形胶质细胞中mi R-146a-3p靶向调节胰岛素样生长因子1抑制星形胶质细胞的增殖和迁移,促进其凋亡。

BACKGROUND:The alteration of miR-146a-3p level is a common event in the pathogenesis of most neurological diseases,and the specific mechanism of miR-146a-3p regulation of astrocytes has not been studied.OBJECTIVE:To verify that miR-146a-3p regulates astrocyte proliferation,migration and apoptosis through insulin-like growth factor 1.METHODS:12 SD rats were divided into a sham operation group and a spinal cord injury group,with six rats in each group.RNA sequencing analysis was performed on the spinal cord tissues of all groups 2 weeks after surgery to screen out the differential genes(log2FC>2),and to select spinal cord injury-related genes(Score>20)in the Genecards database,and then to predict the target genes of miR-146a-3p by Targetscan.The intersection of three gene sets was obtained to screen out insulin-like growth factor 1 as one of the important target genes.qPCR,western blot assay and immunohistochemistry were performed to analyze the expression level of insulin-like growth factor 1 in spinal cord tissues.The primary astrocytes were divided into NC group,NC-mimics group and miR-146a-3p mimics group.Annexin-V/PI staining was used to detect cell apoptosis.CCK-8 assay was used to detect cell proliferation.Transwell assay was used to detect cell migration ability.RESULTS AND CONCLUSION:The expression of miR-146a-3p in the spinal cord tissue of the spinal cord injury group was lower than that of the sham operation group(P<0.05).The expression of insulin-like growth factor 1 in the spinal cord tissue of the spinal cord injury group was higher than that of the sham operation group(P<0.05).Compared with the NC group and NC-mimics group,the apoptotic rate of astrocytes was increased(P<0.01);the proliferation of astrocytes was decreased(P<0.01)and the number of migration was decreased(P<0.01)in the miR-146a-3p mimics group.To conclude,the expression of miR-146a-3p decreased and the expression of insulin-like growth factor 1 increased in spinal cord tissue after spinal cord injury.miR-146a-3p targeted regulation of insulin-like growth factor 1 in astrocytes,inhibited the proliferation and migration of astrocytes and promoted their apoptosis.