Research Paper Volume 11, Issue 17 pp 6714—6733

MeCP2 inhibits cell functionality through FoxO3a and autophagy in endothelial progenitor cells

Siyuan Zha 1, *, , Zhen Li 1, *, , Shuyan Chen 1, , Fang Liu 1, , Fei Wang 1, ,

  • 1 Department of Geriatrics, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
* Equal contribution

received: March 25, 2019 ; accepted: August 10, 2019 ; published: September 2, 2019 ;

https://doi.org/10.18632/aging.102183
How to Cite

Copyright © 2019 Zha et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Abstract

Objectives: Autophagy is an evolutionarily conserved intracellular degradation mechanism in which cell constituents are phagocytosed to maintain cellular homeostasis. Forkhead box O 3a (FoxO3a) promotes autophagy to protect cells from environmental stress. Methylated CpG binding protein 2 (MeCP2) is a nuclear protein that binds DNA and represses transcription. However, the mechanism and interplay between FoxO3a and MeCP2 underlying endothelial progenitor cell (EPC) function are not fully understood.

Results: In EPCs, MeCP2 overexpression attenuated autophagy and cell functionality, which were reversed by the autophagy activator rapamycin or co-transfection with FoxO3a. FoxO3a promoted cell function, which was reversed by the autophagy inhibitor chloroquine. Following MeCP2 overexpression, MeCP2 was found enriched on the FoxO3a promoter, resulting in promoter hypermethylation and enhanced H3K9 histone modification in nucleosomes of the FoxO3a promoter.

Conclusions: MeCP2 attenuated cell functionality via DNA hypermethylation and histone modification of the FoxO3a promoter to inhibit FoxO3a transcription and autophagy.

Materials and Methods: EPCs were isolated from human umbilical cord blood and treated with adenoviral vectors containing interference sequences. The effects and mechanism of MeCP2 and FoxO3a were analyzed by utilizing western blotting, cell counting kit-8, transwell plates, Matrigel, matrix adhesion, transmission electron microscopy, and chromatin immunoprecipitation.

Abbreviations

FoxO3a: Forkhead box O 3a; MeCP2: Methylated CpG binding protein 2; EPCs: Endothelial progenitor cells; ATG5: Autophagy-related 5; ATG7: Autophagy-related 7; HDAC: Histone deacetylase; H3K9me2: Histone 3 Lysine 9 dimethylation; VWF: von Willebrand factor; VEGFR2: Vascular endothelial growth factor receptor 2; Ac-LDL: Acetylated low-density lipoprotein; FITC: Fluorescein isothiocyanate; PVDF: Polyvinylidene fluoride; Ad-GFP: Adenoviral vectors containing green fluorescent protein; Ad-MeCP2: Adenoviral vectors harboring wild-type MeCP2; Ad-sh-MeCP2: Adenoviral vectors harboring MeCP2 short hairpin RNA; Ad-FoxO3a: Adenoviral vectors harboring wild-type FoxO3a; Ad-sh-FoxO3a: Adenoviral vectors harboring FoxO3a short hairpin RNA; TEM: Transmission electron microscopy; ChIP: Chromatin immunoprecipitation; BSP: Bisulfite sequencing PCR; AS: Atherosclerosis.