PEG-Ceramide Nanomicelles Induce Autophagy and Degrade Tau Proteins in N2a Cells
Authors Gao J, Chen X, Ma T, He B, Li P, Zhao Y, Ma Y, Zhuang J, Yin Y
Received 15 April 2020
Accepted for publication 7 August 2020
Published 11 September 2020 Volume 2020:15 Pages 6779—6789
Checked for plagiarism Yes
Review by Single anonymous peer review
Peer reviewer comments 2
Editor who approved publication: Dr Lei Yang
Jie Gao,1,2,* Xiaohan Chen,1,* Tianjun Ma,1,* Bin He,1 Peng Li,1 Yucheng Zhao,1 Yuejin Ma,1 Jianhua Zhuang,1 You Yin1
1Department of Neurology, Changzheng Hospital, Second Military Medical University, Shanghai 200003, People’s Republic of China; 2Institute of Translational Medicine, Shanghai University, Shanghai 200444, People’s Republic of China
*These authors contributed equally to this work
Correspondence: You Yin; Jianhua Zhuang
Department of Neurology, Changzheng Hospital, Second Military Medical University, Shanghai 200003, People’s Republic of China
Email firstname.lastname@example.org; email@example.com
Purpose: Alzheimer’s disease (AD) is a neurodegenerative disorder that manifests as abnormal behavior and a progressive decline in memory. Although the pathogenesis of AD is due to the excessive deposition of amyloid β protein (Aβ) outside the neurons in the brain, evidence suggests that tau proteins may be a better target for AD therapy. In neurodegenerative diseases, a decrease in autophagy results in the failure to eliminate abnormally deposited or misfolded proteins. Therefore, induction of autophagy may be an effective way to eliminate tau proteins in the treatment of AD. We investigated the effects of polyethylene glycol (PEG)-ceramide nanomicelles on autophagy and on tau proteins in N2a, a murine neuroblastoma metrocyte cell line.
Methods: Ceramide is a sphingolipid bioactive molecule that induces autophagy. PEG-ceramide is a polymer that is composed of the hydrophobic chain of ceramide and the hydrophilic chain of PEG-2000. In this study, we prepared PEG-ceramide nanomicelles that were 10– 20 nm in size and had nearly neutral zeta potential.
Results: The results show that PEG-ceramide nanomicelles caused an increase in the LC3-II/LC3-I ratio, while p62 protein levels decreased. Confocal microscopy revealed a significant increase in the number of dots corresponding to autophagosomes and autolysosomes, which indicated autophagic activation. Moreover, PEG-ceramide nanomicelles induced tau degradation in N2a cells through autophagy.
Conclusion: In summary, we have confirmed that PEG-ceramide nanomicelles enhanced autophagic flux and degraded overexpressed human tau proteins in N2a cells by regulating the autophagy pathway. Thus, PEG-ceramide nanomicelles show great promise as agents to induce autophagy and degrade tau proteins in the treatment of AD.
Keywords: Alzheimer’s disease, autophagosomes, lysosome, nano-carrier, autophagic flux