ABSTRACT

This study aims to investigate the effects and underlying mechanisms of overexpression microRNA-9-5p (miR-9-5p) on the Aβ-induced mouse hippocampal neuron cell line HT22. Different concentrations of Aβ_25-35 (10, 20, 40, 80, and 160 μM) treatment were used to establish AD model in HT22 cells. The CCK-8 assay was used to measure the cell viability. The mRNA expression levels of miR-9-5p and glycogen synthase kinase-3β (GSK-3β) were determined by RT-qPCR. HT22 cell apoptosis was analyzed flow cytometry. MiR-9-5p was down-regulated in Aβ_25-35-induced HT22 cells. GSK-3β is a functional target for miR-9-5p. MiR-9-5p overexpression inhibited Aβ_25-35-induced mitochondrial dysfunction, cell apoptosis, and oxidative stress by regulating GSK-3β expression in HT22 cells. Furthermore, through targeting GSK-3β, overexpression of miR-9-5p partly activated nuclear factor Nrf2/Keap1 signaling, including part increases of Nrf2, HO-1, SOD-1, GCLC expression and slight decrease of Keap1 expression. Our results showed miR-9-5p may play a powerful role in the pathogenesis of AD.

摘要

这项研究旨在调查过表达microRNA-9-5p（miR-9-5p）对Aβ诱导的小鼠海马神经元细胞HT22的作用及其潜在机制。使用不同浓度的_Aβ25-35（10、20、40、80和160μM）处理在HT22细胞中建立AD模型。CCK-8测定法用于测量细胞活力。RT-qPCR检测miR-9-5p和糖原合酶激酶3β（ GSK-3β）的mRNA表达水平。流式细胞仪分析HT22细胞凋亡。在AβMIR-9-5p是下调_25-35诱导HT22细胞。GSK-3β是miR-9-5p的功能靶标。MIR-9-5p表达抑制Aβ _25-35调节HT22细胞中GSK-3β的表达诱导线粒体功能异常，细胞凋亡和氧化应激。此外，通过靶向GSK-3β，miR-9-5p的过表达部分激活了核因子Nrf2 / Keap1信号转导，包括Nrf2，HO-1，SOD-1，GCLC表达的部分增加和Keap1表达的轻微降低。我们的结果表明，miR-9-5p可能在AD的发病机制中发挥重要作用。