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

doi:10.4252/wjsc.v11.i10.859

Characterization of inflammatory factor-induced changes in mesenchymal stem cell exosomes and sequencing analysis of exosomal microRNAs

World J Stem Cells. 2019 Oct 26;11(10):859-890. doi: 10.4252/wjsc.v11.i10.859.

Authors

Chen Huang¹, Wen-Feng Luo¹, Yu-Feng Ye¹, Li Lin², Zhe Wang³, Ming-Hua Luo⁴, Qi-De Song¹, Xue-Ping He¹, Han-Wei Chen¹, Yi Kong³, Yu-Kuan Tang⁵

Affiliations

¹ Department of Minimally Invasive Interventional Radiology, Guangzhou Panyu Central Hospital, Guangzhou 511400, Guangdong Province, China.
² Jinan University Biomedical Translational Research Institute, Jinan University, Guangzhou 510632, Guangdong Province, China.
³ Department of Pharmacy, the First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou 510080, Guangdong Province, China.
⁴ Department of Radiology, Shiyan People's Hospital, Shenzhen 518108, Guangdong Province, China.
⁵ Department of Minimally Invasive Interventional Radiology, Guangzhou Panyu Central Hospital, Guangzhou 511400, Guangdong Province, China. tyk20126@126.com.

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: Angiogenesis; Exosomes; Inflammatory cytokines; Mesenchymal stem cells; MiRNA.