Department of Geriatrics, Zhejiang Integrated Chinese and Western Medicine Hospital, Hangzhou 310006, P.R. China
Department of Neurology, Wuhan Union Hospital, Attending Physician, Wuhan 430022, P.R. China.
Biosci Rep. 2018 Nov 13;38(6). doi: 10.1042/BSR20180051. Print 2018 Dec 21.
Alzheimer's disease (AD) is the multifactorial neurodegenerative disorder causing progressive memory loss and cognitive impairment. The aberrant accumulation of amyloid-β (Aβ) and neuroinflammation are two major events in AD. BACE1 is required for the cleavage of amyloid precursor protein (APP) to generate Aβ, which stimulates the nuclear transcription factor κB (NF-κB) signaling, leading to the secretion of inflammatory cytokines. And NF-κB can up-regulate the expression of BACE1. miRNAs are small non-coding RNAs that regulate gene transcription. miR-15b down-regulates BACE1 expression while it is unclear whether miR-15b can regulate Aβ in human neuronal cells, and if so, whether it is by targetting NF-κB. SH-SY5Y cell line was transfected with Swedish APP mutant (APPswe) as an AD model. Quantitative PCR (qPCR), WB, and ELISA were used to detected related gene expression intracellularly or in supernatant. Dual luciferase assay was used to validate miRNA and targets binding. miR-15b inhibits expression of BACE1and APP. Moreover, the reduced level of Aβ was observed in response to miR-15b mimics in SH-SH5Y/APPswe cells. miR-15b directly targetted the conserved Bace1 3'UTR to regulate its expression. In addition, the inhibition of APPswe-induced secretion of inflammatory cytokines and the suppression of NF-κB activation by miR-15b were validated. And miR-15b directly targetted the 3'UTRs of NF-κB1 and inhibitor of NF-κB (IκB) kinase α (IKK-α), encoding NF-κB1 and IKK-α, respectively. Our study suggests that miR-15b inhibits Aβ accumulation through targetting NF-κB signaling and BACE1 and serves as a potential molecular target for AD therapy.
阿尔茨海默病(AD)是一种多因素神经退行性疾病,可导致进行性记忆丧失和认知障碍。淀粉样β(Aβ)的异常积累和神经炎症是 AD 的两个主要事件。BACE1 是切割淀粉样前体蛋白(APP)生成 Aβ所必需的,Aβ 会刺激核转录因子 κB(NF-κB)信号通路,导致炎症细胞因子的分泌。NF-κB 可以上调 BACE1 的表达。miRNA 是一种调节基因转录的小非编码 RNA。miR-15b 下调 BACE1 的表达,但是尚不清楚 miR-15b 是否可以调节人神经元细胞中的 Aβ,以及如果可以,是否通过靶向 NF-κB。将瑞典 APP 突变体(APPswe)转染到 SH-SY5Y 细胞系中作为 AD 模型。通过定量 PCR(qPCR)、WB 和 ELISA 检测细胞内或上清液中相关基因的表达。双荧光素酶报告基因实验用于验证 miRNA 和靶标结合。miR-15b 抑制 BACE1 和 APP 的表达。此外,在 SH-SH5Y/APPswe 细胞中,miR-15b 模拟物可观察到 Aβ 水平降低。miR-15b 直接靶向 Bace1 的保守 3'UTR 来调节其表达。此外,验证了 miR-15b 抑制 APPswe 诱导的炎症细胞因子分泌和 NF-κB 激活。miR-15b 直接靶向 NF-κB1 和 NF-κB 激酶α(IKK-α)的 3'UTR,分别编码 NF-κB1 和 IKK-α。我们的研究表明,miR-15b 通过靶向 NF-κB 信号和 BACE1 抑制 Aβ 积累,可作为 AD 治疗的潜在分子靶标。