KDM1A 介导的 METTL3 上调通过增强 p-Tau 的自噬清除来改善阿尔茨海默病，其通过 m6A 依赖性调节 STUB1 实现。

KDM1A-mediated upregulation of METTL3 ameliorates Alzheimer's disease via enhancing autophagic clearance of p-Tau through m6A-dependent regulation of STUB1.

机构信息

The First Affiliated Hospital of Harbin Medical University, Harbin, 150081, Heilongjiang, PR China.

Harbin First Hospital, Harbin, 150081, Heilongjiang, PR China.

出版信息

Free Radic Biol Med. 2023 Feb 1;195:343-358. doi: 10.1016/j.freeradbiomed.2022.12.099. Epub 2022 Dec 30.

DOI:10.1016/j.freeradbiomed.2022.12.099

PMID:36587923

Abstract

BACKGROUND

Alzheimer's disease (AD) is a severe neurodegenerative disorder that progressively destroys cognitive skills. Exploring the mechanism underlying autophagic clearance of phosphorylated tau (p-Tau) contributes to developing novel therapeutic strategies for AD.

METHODS

SH-SY5Y and HT22 cells were treated with Aβ to establish an in vitro model of AD. Cell viability was examined using CCK-8. TUNEL staining was applied to evaluate cell apoptosis. LC3 puncta was examined by IF staining. m6A modification level was evaluated through MeRIP. RNA pull-down and RIP assays were used for analyzing the interaction between IGF2BP1 and STUB1 transcripts. The binding of KDM1A to the promoter of METTL3 was confirmed by ChIP assays. APP/PS1 transgenic mice were used as an in vivo model of AD. Cognitive skills of mice were evaluated with the Morris water maze. Hippocampal damage and Aβ deposition were detected through H&E and IHC staining.

RESULTS

Dysregulated levels of autophagy, p-Tau and m6A was observed in an in vitro model of AD. Overexpression of METTL3 or STUB1 enhanced autophagy but reduced p-Tau level in Aβ-treated cells. METTL3 stabilized STUB1 mRNA through the m6A-IGF2BP1-dependent mechanism and naturally promoted STUB1 expression, thereby enhancing autophagic p-Tau clearance in Aβ-treated cells. Overexpression of KDM1A enhanced autophagy, m6A modification and autophagic p-Tau clearance in Aβ-treated cells. KDM1A-mediated upregulation of METTL3 promoted autophagic p-Tau clearance and ameliorated Alzheimer's disease both in vitro and in vivo.

CONCLUSION

KDM1A-mediated upregulation of METTL3 enhances autophagic clearance of p-Tau through m6A-dependent regulation of STUB1, thus ameliorating Alzheimer's disease. Our study provides novel mechanistic insights into AD pathogenesis and potential drug targets for AD.

摘要

背景

阿尔茨海默病（AD）是一种严重的神经退行性疾病，会逐渐破坏认知能力。探索自噬清除磷酸化 tau（p-Tau）的机制有助于开发 AD 的新治疗策略。

方法

用 Aβ处理 SH-SY5Y 和 HT22 细胞，建立 AD 的体外模型。用 CCK-8 检测细胞活力。用 TUNEL 染色评估细胞凋亡。用 IF 染色检测 LC3 斑点。用 MeRIP 评估 m6A 修饰水平。用 RNA 下拉和 RIP 测定分析 IGF2BP1 和 STUB1 转录本之间的相互作用。用 ChIP 测定证实 KDM1A 与 METTL3 启动子的结合。用 APP/PS1 转基因小鼠作为 AD 的体内模型。用 Morris 水迷宫评估小鼠的认知能力。用 H&E 和 IHC 染色检测海马损伤和 Aβ沉积。

结果

在 AD 的体外模型中观察到自噬、p-Tau 和 m6A 水平失调。METTL3 或 STUB1 的过表达增强了自噬，但降低了 Aβ 处理细胞中的 p-Tau 水平。METTL3 通过 m6A-IGF2BP1 依赖的机制稳定 STUB1 mRNA，并自然促进 STUB1 表达，从而增强 Aβ 处理细胞中的自噬 p-Tau 清除。KDM1A 的过表达增强了 Aβ 处理细胞中的自噬、m6A 修饰和自噬 p-Tau 清除。KDM1A 介导的 METTL3 上调促进了自噬 p-Tau 清除，并在体外和体内改善了 AD。