来自骨髓干细胞的富含线粒体的细胞外囊泡通过巨噬细胞M2表型转化减轻大鼠模型肩袖撕裂中的肌肉退化。

Mitochondria-Rich Extracellular Vesicles From Bone Marrow Stem Cells Mitigate Muscle Degeneration in Rotator Cuff Tears in a Rat Model Through Macrophage M2 Phenotype Conversion.

作者信息

Gao Xing, Chen Yuanyuan, Wang Jingzeng, Xu Jian, Wan Hu, Li Xiao, Shi Yulong

机构信息

Animal Experimental Center, Zhongnan Hospital of Wuhan University, Wuhan, China.

Zhongnan Hospital of Wuhan University, Institute of Hepatobiliary Diseases of Wuhan University, Transplant Center of Wuhan University, Wuhan, China.

出版信息

Arthroscopy. 2025 Mar 25. doi: 10.1016/j.arthro.2025.03.033.

DOI:10.1016/j.arthro.2025.03.033

PMID:40147598

Abstract

PURPOSE

To investigate the protective effects of extracellular vesicles derived from bone marrow stem cells (BMSC-EVs) on muscle degeneration in a rat model of rotator cuff tendon and suprascapular nerve (SSN) transection (termed the RCT-SSN model), focusing on mitochondrial transfer.

METHODS

The EVs were identified and characterized. The RCT-SSN model was established by transecting the supraspinatus, infraspinatus tendons, and suprascapular nerve. Ninety-six rats were divided into 4 groups (n = 24 each): sham surgery, RCT-SSN treated with BMSC-EVs, RCT-SSN treated with EVs from rhodamine 6G-pretreated BMSCs (Rho-EVs), or phosphate-buffered saline. Intramuscular injections were administered every 2 weeks. After 12 weeks, supraspinatus muscles were analyzed for atrophy, fibrosis, oxidative stress, macrophage phenotypes, serum cytokines, and mitochondrial characteristics. In vitro experiments included EVs tracking in macrophages, macrophage phenotype characterization, and inflammatory cytokine profiling.

RESULTS

BMSC-EVs and Rho-EVs displayed similar morphology, but only BMSC-EVs contained functional mitochondria. BMSC-EVs significantly reduced muscle weight loss (0.047 ± 0.010% vs 0.145 ± 0.013%, P < .001), increased muscle fiber cross-sectional area (2037 ± 231.9 μm vs 527.9 ± 92.01 μm, P < .001), and decreased fibrosis (12.09 ± 3.31% vs 25.69 ± 4.84%, P < .001) compared with phosphate-buffered saline. BMSC-EVs enhanced superoxide dismutase activity (93.3 ± 11.8 U/mg protein vs 53.4 ± 8.0 U/mg protein, P < .001), improved mitochondrial function, density and structure, and induced an anti-inflammatory macrophage shift, suppressing proinflammatory cytokines in vitro and in vivo. Rho-EVs showed no such effects.

CONCLUSIONS

This study showed that transecting the supraspinatus, infraspinatus tendons, and suprascapular nerve in a rat model induced muscle degeneration and fibrosis. BMSC-EVs, but not Rho-EVs, mitigated these effects by promoting an anti-inflammatory macrophage phenotype and protecting mitochondrial function through mitochondrial transfer.

CLINICAL RELEVANCE

Mitochondrial transfer via BMSC-EVs may offer a therapeutic strategy to prevent muscle degeneration in patients with rotator cuff tear.

摘要

目的

研究骨髓干细胞衍生的细胞外囊泡（BMSC-EVs）对肩袖肌腱和肩胛上神经横断大鼠模型（称为RCT-SSN模型）中肌肉退变的保护作用，重点关注线粒体转移。

方法

对细胞外囊泡进行鉴定和表征。通过横断冈上肌、冈下肌腱和肩胛上神经建立RCT-SSN模型。将96只大鼠分为4组（每组n = 24只）：假手术组、接受BMSC-EVs治疗的RCT-SSN组、接受来自罗丹明6G预处理骨髓间充质干细胞的细胞外囊泡（Rho-EVs）治疗的RCT-SSN组或磷酸盐缓冲盐水组。每2周进行一次肌肉注射。12周后，分析冈上肌的萎缩、纤维化、氧化应激、巨噬细胞表型、血清细胞因子和线粒体特征。体外实验包括细胞外囊泡在巨噬细胞中的追踪、巨噬细胞表型表征和炎性细胞因子分析。

结果

BMSC-EVs和Rho-EVs表现出相似的形态，但只有BMSC-EVs含有功能性线粒体。与磷酸盐缓冲盐水相比，BMSC-EVs显著减少了肌肉重量损失（0.047±0.010%对0.145±0.013%，P <.001），增加了肌纤维横截面积（2037±231.9μm对527.9±92.01μm，P <.001），并减少了纤维化（12.09±3.31%对25.69±4.84%，P <.001）。BMSC-EVs增强了超氧化物歧化酶活性（93.3±11.8 U/mg蛋白对53.4±8.0 U/mg蛋白，P <.001），改善了线粒体功能、密度和结构，并诱导了抗炎性巨噬细胞转变，在体外和体内均抑制了促炎性细胞因子。Rho-EVs没有显示出这些作用。