Mitochondrial transfer from bone mesenchymal stem cells protects against tendinopathy both in vitro and in vivo

Bing Wei; Mingliang Ji; Yucheng Lin; Shanzheng Wang; Yuxi Liu; Rui Geng; Xinyue Hu; Li Xu; Zhuang Li; Weituo Zhang; Jun Lu

doi:10.1186/s13287-023-03329-0

Mitochondrial transfer from bone mesenchymal stem cells protects against tendinopathy both in vitro and in vivo

Stem Cell Res Ther. 2023 Apr 26;14(1):104. doi: 10.1186/s13287-023-03329-0.

Authors

Bing Wei^{1

2}, Mingliang Ji^{1

2}, Yucheng Lin^{1

2}, Shanzheng Wang^{1

2}, Yuxi Liu^{1

2}, Rui Geng^{1

2}, Xinyue Hu^{1

2}, Li Xu^{1

2}, Zhuang Li^{1

2}, Weituo Zhang^{1

2}, Jun Lu^{3

4}

Affiliations

¹ School of Medicine, Southeast University, No. 87 Dingjiaqiao Road, Gulou District, Jiangsu Province, 210009, Nanjing, People's Republic of China.
² Department of Orthopaedic Surgery/Joint and Sports Medicine Center, Zhongda Hospital, Southeast University, Nanjing, 210009, Jiangsu Province, People's Republic of China.
³ School of Medicine, Southeast University, No. 87 Dingjiaqiao Road, Gulou District, Jiangsu Province, 210009, Nanjing, People's Republic of China. lujun-joint@seu.edu.cn.
⁴ Department of Orthopaedic Surgery/Joint and Sports Medicine Center, Zhongda Hospital, Southeast University, Nanjing, 210009, Jiangsu Province, People's Republic of China. lujun-joint@seu.edu.cn.

Abstract

Background: Although mesenchymal stem cells (MSCs) have been effective in tendinopathy, the mechanisms by which MSCs promote tendon healing have not been fully elucidated. In this study, we tested the hypothesis that MSCs transfer mitochondria to injured tenocytes in vitro and in vivo to protect against Achilles tendinopathy (AT).

Methods: Bone marrow MSCs and H₂O₂-injured tenocytes were co-cultured, and mitochondrial transfer was visualized by MitoTracker dye staining. Mitochondrial function, including mitochondrial membrane potential, oxygen consumption rate, and adenosine triphosphate content, was quantified in sorted tenocytes. Tenocyte proliferation, apoptosis, oxidative stress, and inflammation were analyzed. Furthermore, a collagenase type I-induced rat AT model was used to detect mitochondrial transfer in tissues and evaluate Achilles tendon healing.

Results: MSCs successfully donated healthy mitochondria to in vitro and in vivo damaged tenocytes. Interestingly, mitochondrial transfer was almost completely blocked by co-treatment with cytochalasin B. Transfer of MSC-derived mitochondria decreased apoptosis, promoted proliferation, and restored mitochondrial function in H₂O₂-induced tenocytes. A decrease in reactive oxygen species and pro-inflammatory cytokine levels (interleukin-6 and -1β) was observed. In vivo, mitochondrial transfer from MSCs improved the expression of tendon-specific markers (scleraxis, tenascin C, and tenomodulin) and decreased the infiltration of inflammatory cells into the tendon. In addition, the fibers of the tendon tissue were neatly arranged and the structure of the tendon was remodeled. Inhibition of mitochondrial transfer by cytochalasin B abrogated the therapeutic efficacy of MSCs in tenocytes and tendon tissues.

Conclusions: MSCs rescued distressed tenocytes from apoptosis by transferring mitochondria. This provides evidence that mitochondrial transfer is one mechanism by which MSCs exert their therapeutic effects on damaged tenocytes.

Keywords: Achilles tendinopathy; Apoptosis; Mesenchymal stem cells; Mitochondrial dysfunction; Mitochondrial transfer; Tenocytes.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Achilles Tendon*
Animals
Cells, Cultured
Cytochalasin B
Hydrogen Peroxide / pharmacology
Mesenchymal Stem Cells* / metabolism
Mitochondria / metabolism
Rats
Tendinopathy* / therapy

Substances

Hydrogen Peroxide
Cytochalasin B