Feng XD, Zhu JQ, Zhou JH, Lin FY, Feng B, Shi XW, Pan QL, Yu J, Li LJ, Cao HC. Hypoxia-inducible factor-1α–mediated upregulation of CD99 promotes the proliferation of placental mesenchymal stem cells by regulating ERK1/2. World J Stem Cells 2021; 13(4): 317-330 [PMID: 33959221 DOI: 10.4252/wjsc.v13.i4.317]
Corresponding Author of This Article
Hong-Cui Cao, MD, PhD, Professor, State Key Laboratory for the Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, No. 79 Qingchun Road, Hangzhou 310003, Zhejiang Province, China. hccao@zju.edu.cn
Research Domain of This Article
Cell Biology
Article-Type of This Article
Basic Study
Open-Access Policy of This Article
This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Xu-Dong Feng, Jia-Qi Zhu, Jia-Hang Zhou, Fei-Yan Lin, Bing Feng, Xiao-Wei Shi, Qiao-Ling Pan, Jiong Yu, Lan-Juan Li, Hong-Cui Cao, State Key Laboratory for the Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, Zhejiang Province, China
Author contributions: Feng XD contributed to the experimental design, cellular and molecular biology experiments, and manuscript writing; Zhu JQ, Zhou JH and Lin FY contributed to the cellular experiment; Feng B and Shi XW joined in the molecular biology experiment; Feng XD, Pan QL and Yu J participated in analysis, interpretation of data and manuscript writing; Li LJ and Cao HC participated in the conception, design, study supervision, and manuscript writing; all authors reviewed and approved the final version of the manuscript.
Supported byStem Cell and Translational Research from the National Key Research and Development Program of China, No. 2020YFA0113003; and National Natural Science Foundation of China, No. 81971756.
Institutional review board statement: The study was reviewed and approved by the Research Ethics Committee of The First Affiliated Hospital, College of Medicine, Zhejiang University Institutional Review Board (Approval No. 2013-272).
Conflict-of-interest statement: The authors declare that they have no conflicts of interest.
Data sharing statement: The data used to support the findings of this study are available from the corresponding authors upon request.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Hong-Cui Cao, MD, PhD, Professor, State Key Laboratory for the Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, No. 79 Qingchun Road, Hangzhou 310003, Zhejiang Province, China. hccao@zju.edu.cn
Received: February 1, 2021 Peer-review started: February 1, 2021 First decision: February 28, 2021 Revised: March 11, 2021 Accepted: March 29, 2021 Article in press: March 29, 2021 Published online: April 26, 2021 Processing time: 80 Days and 6.7 Hours
Abstract
BACKGROUND
As human placenta-derived mesenchymal stem cells (hP-MSCs) exist in a physiologically hypoxic microenvironment, various studies have focused on the influence of hypoxia. However, the underlying mechanisms remain to be further explored.
AIM
The aim was to reveal the possible mechanisms by which hypoxia enhances the proliferation of hP-MSCs.
METHODS
A hypoxic cell incubator (2.5% O2) was used to mimic a hypoxic microenvironment. Cell counting kit-8 and 5-ethynyl-20-deoxyuridine incorporation assays were used to assay the proliferation of hP-MSCs. The cell cycle was profiled by flow cytometry. Transcriptome profiling of hP-MSCs under hypoxia was performed by RNA sequencing. CD99 mRNA expression was assayed by reverse transcription-polymerase chain reaction. Small interfering RNA-mediated hypoxia-inducible factor 1α (HIF-1α) or CD99 knockdown of hP-MSCs, luciferase reporter assays, and the ERK1/2 signaling inhibitor PD98059 were used in the mechanistic analysis. Protein expression was assayed by western blotting; immunofluorescence assays were conducted to evaluate changes in expression levels.
RESULTS
Hypoxia enhanced hP-MSC proliferation, increased the expression of cyclin E1, cyclin-dependent kinase 2, and cyclin A2, and decreased the expression of p21. Under hypoxia, CD99 expression was increased by HIF-1α. CD99-specific small interfering RNA or the ERK1/2 signaling inhibitor PD98059 abrogated the hypoxia-induced increase in cell proliferation.
CONCLUSION
Hypoxia promoted hP-MSCs proliferation in a manner dependent on CD99 regulation of the MAPK/ERK signaling pathway in vitro.
Core Tip: This study demonstrated the potential of hypoxic conditions to enhance the proliferation capacity of human placenta-derived mesenchymal stem cells (hP-MSCs). RNA sequencing assays and molecular biology experiments found that a novel CD99 gene was involved in hypoxia-mediated promotion of hP-MSC proliferation. Furthermore, CD99 activated pathways that transported ERK1/2 to the nucleus, increasing the activity of cell cycle-associated proteins. Hypoxia-inducible factor 1α-mediated CD99 played a role in proliferation by regulating the MAPK/ERK signaling pathway.
