Articles

  • the Korean Society for Brain and Neural Sciences

Article

Original Article

Exp Neurobiol 2020; 29(2): 150-163

Published online April 30, 2020

https://doi.org/10.5607/en19078

© The Korean Society for Brain and Neural Sciences

Alternatively Polarized Macrophages Regulate the Growth and Differentiation of Ependymal Stem Cells through the SIRT2 Pathway

Yonggang Ma1, Ming Deng1, Xiao-qi Zhao2 and Min Liu3*

1Department of Orthopaedics, Renmin Hospital, Wuhan University, Wuhan 430060, 2Department of Pharmacology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, 3Department of Immunology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071, China

Correspondence to: *To whom correspondence should be addressed.
TEL: 86-18271910659, FAX: 86-2768759986
e-mail: lliumin2002@163.com

Received: November 27, 2019; Revised: April 15, 2020; Accepted: April 16, 2020

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License
(http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and
reproduction in any medium, provided the original work is properly cited.

Ependymal stem cells (EpSCs) are dormant stem cells in the adult spinal cord that proliferate rapidly and migrate to the site of injury after spinal cord injury (SCI). Although they can differentiate into neurons under appropriate conditions in vitro, EpSCs mainly differentiate into astrocytes in vivo. Our previous study confirmed that alternatively polarized macrophages (M2) facilitate the differentiation of EpSCs towards neurons, but the detailed mechanism remains elusive. In the present study, we found that M2 conditioned medium could upregulate the expression of Sirtuin 2 (SIRT2) in EpSCs in vitro through the BDNF/TrkB-MEK/ERK signaling pathway. As an important deacetylase, SIRT2 deacetylated stable Ac-α-tubulin (Acetyl alpha Tubulin) in microtubules and thus promoted EpSC differentiation into neurons. The present study provides a theoretical basis and a new way to improve neural recovery, such as regulating the growth and differentiation of EpSCs by increasing the proportion of M2 cells in the local microenvironment or upregulating the expression of SIRT2 in EpSCs.

Graphical Abstract


Keywords: Alternatively polarized macrophages, Ependymal stem cells, SIRT2