Zhou Hecheng, Chen Chuanshun, Hu Hai, Jiang Binbin, Yin Yuesong, Zhang Kexiang, Shen Minren, Wu Song, Wang Zili
Department of Orthopaedic Surgery, The Third Xiangya Hospital of Central South University, Changsha, China.
Xiangya Medical School of Central South University, Changsha, China.
Bone Joint Res. 2023 Aug 1;12(8):455-466. doi: 10.1302/2046-3758.128.BJR-2022-0309.R2.
Rotator cuff muscle atrophy and fatty infiltration affect the clinical outcomes of rotator cuff tear patients. However, there is no effective treatment for fatty infiltration at this time. High-intensity interval training (HIIT) helps to activate beige adipose tissue. The goal of this study was to test the role of HIIT in improving muscle quality in a rotator cuff tear model via the β3 adrenergic receptor (β3AR).
Three-month-old C57BL/6 J mice underwent a unilateral rotator cuff injury procedure. Mice were forced to run on a treadmill with the HIIT programme during the first to sixth weeks or seventh to 12th weeks after tendon tear surgery. To study the role of β3AR, SR59230A, a selective β3AR antagonist, was administered to mice ten minutes before each exercise through intraperitoneal injection. Supraspinatus muscle, interscapular brown fat, and inguinal subcutaneous white fat were harvested at the end of the 12th week after tendon tear and analyzed biomechanically, histologically, and biochemically.
Histological analysis of supraspinatus muscle showed that HIIT improved muscle atrophy, fatty infiltration, and contractile force compared to the no exercise group. In the HIIT groups, supraspinatus muscle, interscapular brown fat, and inguinal subcutaneous white fat showed increased expression of tyrosine hydroxylase and uncoupling protein 1, and upregulated the β3AR thermogenesis pathway. However, the effect of HIIT was not present in mice injected with SR59230A, suggesting that HIIT affected muscles via β3AR.
HIIT improved supraspinatus muscle quality and function after rotator cuff tears by activating systemic sympathetic nerve fibre near adipocytes and β3AR.
肩袖肌萎缩和脂肪浸润会影响肩袖撕裂患者的临床疗效。然而，目前对于脂肪浸润尚无有效的治疗方法。高强度间歇训练（HIIT）有助于激活米色脂肪组织。本研究的目的是通过β3肾上腺素能受体（β3AR）来测试HIIT在肩袖撕裂模型中改善肌肉质量的作用。
对3个月大的C57BL/6 J小鼠进行单侧肩袖损伤手术。在肌腱撕裂手术后的第1至6周或第7至12周，让小鼠按照HIIT方案在跑步机上跑步。为了研究β3AR的作用，在每次运动前10分钟通过腹腔注射向小鼠给予选择性β3AR拮抗剂SR59230A。在肌腱撕裂后第12周结束时，采集冈上肌、肩胛间棕色脂肪和腹股沟皮下白色脂肪，并进行生物力学、组织学和生化分析。
冈上肌的组织学分析表明，与无运动组相比，HIIT改善了肌肉萎缩、脂肪浸润和收缩力。在HIIT组中，冈上肌、肩胛间棕色脂肪和腹股沟皮下白色脂肪中酪氨酸羟化酶和解偶联蛋白1的表达增加，并且β3AR产热途径上调。然而，在注射SR59230A的小鼠中未出现HIIT的效果，这表明HIIT通过β3AR影响肌肉。
HIIT通过激活脂肪细胞附近的全身交感神经纤维和β3AR，改善了肩袖撕裂后的冈上肌质量和功能。
