MicroRNA-21-3p Engineered Umbilical Cord Stem Cell-Derived Exosomes Inhibit Tendon Adhesion

Abstract

Purpose

As a common complication of tendon injury, tendon adhesion is an unresolved problem in clinical work. The aim of this study was to investigate whether human umbilical cord mesenchymal stem cell-derived exosomes (HUMSC-Exos), one of the most promising new-generation cell-free therapeutic agents, can improve tendon adhesion and explore potential-related mechanisms.

Methods

The rat Achilles tendon injury adhesion model was constructed in vivo, and the localization of HUMSC-Exos was used to evaluate the tendon adhesion. Rat fibroblast cell lines were treated with transforming growth factor β1 (TGF-β1) and/or HUMSC-Exos in vitro, and cell proliferation, apoptosis and gene expression were measured. MicroRNA (miRNA) sequencing and quantitative PCR (qPCR) analysis confirmed differential miRNAs. A specific miRNA antagonist (antagomir-21a-5p) was used to transform HUMSC-Exos and obtain modified exosomes to verify its efficacy and related mechanism of action.

Results

In this study, we found HUMSC-Exos reduced rat fibroblast proliferation and inhibited the expression of fibrosis genes: collagen III (COL III) and α-smooth muscle actin (α-SMA) in vitro. In the rat tendon adhesion model, topical application of HUMSC-Exos contributed to relief of tendon adhesion. Specifically, the fibrosis and inflammation-related genes were simultaneously inhibited by HUMSC-Exos. Further, miRNA sequencing of HUMSCs and HUMSC-Exos showed that miR-21a-3p was expressed at low abundance in HUMSC-Exos. The antagonist targeting miR-21a-3p was recruited for treatment of HUMSCs, and harvested HUMSC-Exos, which expressed low levels of miR-21a-3p, and expanded the inhibition of tendon adhesion in subsequent in vitro experiments.

Conclusion

Our results indicate that HUMSC-Exos may manipulate p65 activity by delivering low-abundance miR-21a-3p, ultimately inhibiting tendon adhesion. The findings may be promising for dealing with tendon adhesion.

Keywords:

• HUMSC
• exosome
• tendon adhesion
• TGF-β1
• p65
• miR-21a-3p
• NF-κB

Acknowledgments

The study was supported by the National Natural Science Foundation of China (No. 81830076 and No. 81672146) and the Projects of Science and Technology Development Foundation of Pudong New District, Shanghai, China (Grant No. PWZxq2017-03). We appreciate the support from Youth Science and Technology Innovation Studio of Shanghai Jiao Tong University School of Medicine.

Abbreviations

HUMSC(s), human umbilical cord mesenchymal stem cell(s); HUMSC-Exo(s), human umbilical cord mesenchymal stem cell-derived exosome(s); COL III, collagen III; α-SMA, α-smooth muscle actin; TGF-β1, transforming growth factor-β1; NF-κB, nuclear factor-κB; COX2, cyclooxygenase-2; NTA, nanoparticle tracking analysis.

Disclosure

The authors report no conflicts of interest in this work.