Basic Study
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Stem Cells. Oct 26, 2019; 11(10): 859-890
Published online Oct 26, 2019. doi: 10.4252/wjsc.v11.i10.859
Characterization of inflammatory factor-induced changes in mesenchymal stem cell exosomes and sequencing analysis of exosomal microRNAs
Chen Huang, Wen-Feng Luo, Yu-Feng Ye, Li Lin, Zhe Wang, Ming-Hua Luo, Qi-De Song, Xue-Ping He, Han-Wei Chen, Yi Kong, Yu-Kuan Tang
Chen Huang, Wen-Feng Luo, Yu-Feng Ye, Qi-De Song, Xue-Ping He, Han-Wei Chen, Yu-Kuan Tang, Department of Minimally Invasive Interventional Radiology, Guangzhou Panyu Central Hospital, Guangzhou 511400, Guangdong Province, China
Chen Huang, Han-Wei Chen, Jinan University, Guangzhou 510632, Guangdong Province, China
Chen Huang, Wen-Feng Luo, Yu-Feng Ye, Han-Wei Chen, Medical Imaging Institute of Panyu, Guangzhou 511400, Guangdong Province, China
Li Lin, Jinan University Biomedical Translational Research Institute, Jinan University, Guangzhou 510632, Guangdong Province, China
Zhe Wang, Yi Kong, Department of Pharmacy, the First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou 510080, Guangdong Province, China
Ming-Hua Luo, Department of Radiology, Shiyan People’s Hospital, Shenzhen 518108, Guangdong Province, China
Author contributions: Huang C designed the research and wrote the manuscript; Huang C, Luo WF, and Lin L performed all the experiments; Huang C, Wang Z, Kong Y, Chen HW, and Tang YK performed the analysis; Ye YF, He XP, Luo MH, and Song QD performed data collection and pre-processing; all authors approved the manuscript.
Supported by Panyu Science and Technology Plan Medical General Project, No. 2018-Z04-47; and Guangzhou Health Science and Technology Project, No. 20191A011120.
Conflict-of-interest statement: The authors declare that they have no conflict of interest.
Open-Access: 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/
Corresponding author: Yu-Kuan Tang, MD, Doctor, Department of Minimally Invasive Interventional Radiology, Guangzhou Panyu Central Hospital, 8 East Fuyu Road, Qiaonan Street, Panyu District, Guangzhou 511400, Guangdong Province, China. tyk20126@126.com
Telephone: +86-20-34858815 Fax: +86-20-84824443
Received: January 29, 2019
Peer-review started: January 29, 2019
First decision: March 14, 2019
Revised: March 24, 2019
Accepted: July 30, 2019
Article in press: July 30, 2019
Published online: October 26, 2019
Abstract
BACKGROUND

Treatments utilizing stems cells often require stem cells to be exposed to inflammatory environments, but the effects of such environments are unknown.

AIM

To examine the effects of inflammatory cytokines on the morphology and quantity of mesenchymal stem cell exosomes (MSCs-exo) as well as the differential expression of microRNAs (miRNAs) in the exosomes.

METHODS

MSCs were isolated from human umbilical tissue by enzymatic digestion. Exosomes were then collected after a 48-h incubation period in a serum-free medium with one of the following the inflammatory cytokines: None (control), vascular cell adhesion molecule-1 (VCAM-1), tumor necrosis factor (TNF) α, and interleukin (IL) 6. The morphology and quantity of each group of MSC exosomes were observed and measured. The miRNAs in MSCs-exo were sequenced. We compared the sequenced data with the miRBase and other non-coding databases in order to detect differentially expressed miRNAs and explore their target genes and regulatory mechanisms. In vitro tube formation assays and Western blot were performed in endothelial cells which were used to assess the angiogenic potential of MSCs-exo after inflammatory cytokine stimulation.

RESULTS

MSCs-exo were numerous, small, and regularly shaped in the VCAM-1 group. TNFα stimulated MSCs to secrete larger and irregular exosomes. IL6 led to a reduced quantity of MSCs-exo. Compared to the control group, the TNFα and IL6 groups had more downregulated differentially expressed miRNAs, particularly angiogenesis-related miRNAs. The angiogenic potential of MSCs-exo declined after IL6 stimulation.

CONCLUSION

TNFα and IL6 may influence the expression of miRNAs that down-regulate the PI3K-AKT, MAPK, and VEGF signaling pathways; particularly, IL6 significantly down-regulates the PI3K-AKT signaling pathway. Overall, inflammatory cytokines may lead to changes in exosomal miRNAs that abnormally impact cellular components, molecular function, and biological processes.

Keywords: Mesenchymal stem cells, Exosomes, MiRNA, Inflammatory cytokines, Angiogenesis

Core tip: The morphology and quantity of mesenchymal stem cell exosomes (MSCs-exo) are impacted in different inflammatory cytokine environments. Inflammatory cytokines impair the ability of MSCs-exo to promote angiogenesis. For instance, the tumor necrosis factor α and interleukin 6 groups exhibited decreased numbers of angiogenesis-related microRNAs (miRNAs), such as miR-196a-5p, miR-17-5p, miR-146b-5p, miR-21-3p, and miR-320. The same groups also had downregulated angiogenesis-related signaling pathways, such as PI3K-AKT and VEGF. Inflammatory cytokines may lead to changes in exosomal miRNAs that abnormally impact cellular components, molecular function, and biological processes, particularly angiogenesis-related miRNAs.