TGF-β1-containing exosomes derived from bone marrow mesenchymal stem cells promote proliferation, migration and fibrotic activity in rotator cuff tenocytes

Jia Li; Zheng-Peng Liu; Cong Xu; Ai Guo

doi:10.1016/j.reth.2020.07.001

TGF-β1-containing exosomes derived from bone marrow mesenchymal stem cells promote proliferation, migration and fibrotic activity in rotator cuff tenocytes

Regen Ther. 2020 Jul 21:15:70-76. doi: 10.1016/j.reth.2020.07.001. eCollection 2020 Dec.

Authors

Jia Li^{1

2}, Zheng-Peng Liu^{1

2}, Cong Xu², Ai Guo¹

Affiliations

¹ Department of Orthopedics, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, PR China.
² Affiliated Hospital of Chengde Medical College, Chengde 067000, PR China.

Abstract

Objective: This study aimed to investigate effects of TGF-β1-containing exosomes derived from bone marrow mesenchymal stem cells (BMSC) on cell function of rotator cuff tenocytes and its implication to rotator cuff tear.

Methods: The primary BMSC and rotator cuff tenocytes were extracted and cultured. Identification of BMSC were performed by observing cell morphology and measurement of surface biomarkers by flow cytometry. BMSC-derived exosomes were extracted and identified by using electron microscopy, nanoparticle-tracking analysis (NTA) and western blotting. Cell proliferation and cell cycle were measured by CCK-8 assay and flow cytometry assay, respectively. Transwell assay was used for detection of tenocytes migration. The fibrotic activity of tenocytes was determined via qPCR and western blotting assays.

Results: BMSC and BMSC-derived exosomes were successfully extracted. Treatment of BMSC-derived exosomes or TGF-β1 promoted cell proliferation, migration and increased cell ratio of (S + G2/M) phases in tenocytes, as well as enhanced the expression levels of fibrotic activity associated proteins. However, inhibition of TGF-β1 by transfection of sh-TGF-β1 or treatment of TGFβR I/II inhibitor partially reversed the impact of BMSC-derived exosomes on tenocytes function.

Conclusion: Taken together, TGF-β1-containing exosomes derived from BMSC promoted proliferation, migration and fibrotic activity in rotator cuff tenocytes, providing a new direction for treatment of rotator cuff tendon healing.

Keywords: BMSC; BMSC, Bone mesenchymal stem cells; CCK8, Cell counting kit-8; Col I, Collagen I; Col III, Collagen III; DMEM, Dulbecco's modified Eagle's medium; Exosomes; FBS, Fetal bovine serum; Fibrotic activity; Migration; PVDF, Polyvinylidene fluoride; Proliferation; Rotator cuff tear; SDS-PAGE, Sodium dodecyl sulfate polyacrylamide gel electrophoresis; Scx, Scleraxis; Smad7, Mothers against decapentaplegic homolog 7; TGF-β1; TGF-β1, Transforming growth factors β1; TGF-βR I/II, Transforming growth factors β1 receptor type I/II; Tnc, Tenascin C; qPCR, Quantitative reverse-transcription polymerase chain reaction; α-SMA, α-smooth muscle actin.