miR-335-5p 通过靶向 c-jun-N 末端激酶 3 抑制β-淀粉样蛋白（Aβ）积累，从而减轻阿尔茨海默病中的认知障碍。

MiR-335-5p Inhibits β-Amyloid (Aβ) Accumulation to Attenuate Cognitive Deficits Through Targeting c-jun-N-terminal Kinase 3 in Alzheimer's Disease.

机构信息

Department of Geriatrics, Hefei Binhu Hospital, Hefei, Anhui, China.

Department of Internal Medicine, Yingshang County People's Hospital, Fuyang, Anhui, China.

出版信息

Curr Neurovasc Res. 2020;17(1):93-101. doi: 10.2174/1567202617666200128141938.

DOI:10.2174/1567202617666200128141938

PMID:32003672

Abstract

OBJECTIVE

Alzheimer's disease (AD), also known as senile dementia, is a common neurodegenerative disease characterized by progressive cognitive impairment and personality changes. Numerous evidences have suggested that microRNAs (miRNAs) are involved in the pathogenesis and development of AD. However, the exact role of miR-335-5p in the progression of AD is still not clearly clarified.

METHODS

The protein and mRNA levels were measured by western blot and RNA extraction and quantitative real-time PCR (qRT-PCR), respectively. The relationship between miR-335-5p and c-jun-N-terminal kinase 3 (JNK3) was confirmed by dual-luciferase reporter assay. SH-SY5Y cells were transfected with APP mutant gene to establish the in vitro AD cell model. Flow cytometry and western blot were performed to evaluate cell apoptosis. The APP/PS1 transgenic mice were used as an in vivo AD model. Morris water maze test was performed to assess the effect of miR- 335-5p on the cognitive deficits in APP/PS1 transgenic mice.

RESULTS

The JNK3 mRNA expression and protein levels of JNK3 and β-Amyloid (Aβ) were significantly up-regulated, and the mRNA expression of miR-335-5p was down-regulated in the brain tissues of AD patients. The expression levels of miR-335-5p and JNK3 were significantly inversely correlated. Further, the dual Luciferase assay verified the relationship between miR-335- 5p and JNK3. Overexpression of miR-335-5p significantly decreased the protein levels of JNK3 and Aβ and inhibited apoptosis in SH-SY5Y/APPswe cells, whereas the inhibition of miR-335-5p obtained the opposite results. Moreover, the overexpression of miR-335-5p remarkably improved the cognitive abilities of APP/PS1 mice.

CONCLUSION

The results revealed that the increased JNK3 expression, negatively regulated by miR-335-5p, may be a potential mechanism that contributes to Aβ accumulation and AD progression, indicating a novel approach for AD treatment.

摘要

目的

阿尔茨海默病（AD），又称老年性痴呆，是一种常见的神经退行性疾病，其特征为进行性认知功能障碍和人格改变。大量证据表明，microRNAs（miRNAs）参与 AD 的发病机制和发展。然而，miR-335-5p 在 AD 进展中的确切作用仍不清楚。

方法

通过蛋白质印迹和 RNA 提取及实时定量 PCR（qRT-PCR）分别测量蛋白质和 mRNA 水平。通过双荧光素酶报告基因检测证实 miR-335-5p 与 c-jun-N-末端激酶 3（JNK3）的关系。用 APP 突变基因转染 SH-SY5Y 细胞建立体外 AD 细胞模型。通过流式细胞术和蛋白质印迹法评估细胞凋亡。用 APP/PS1 转基因小鼠作为体内 AD 模型。采用 Morris 水迷宫试验评估 miR-335-5p 对 APP/PS1 转基因小鼠认知缺陷的影响。

结果

AD 患者脑组织中 JNK3 mRNA 表达和 JNK3 及β-淀粉样蛋白（Aβ）的蛋白水平显著升高，miR-335-5p 的 mRNA 表达水平降低。miR-335-5p 和 JNK3 的表达水平呈显著负相关。进一步的双荧光素酶检测证实了 miR-335-5p 与 JNK3 之间的关系。miR-335-5p 的过表达显著降低了 SH-SY5Y/APPswe 细胞中 JNK3 和 Aβ的蛋白水平并抑制了细胞凋亡，而 miR-335-5p 的抑制则得到了相反的结果。此外，miR-335-5p 的过表达显著改善了 APP/PS1 小鼠的认知能力。