Myonuclear accretion is a determinant of exercise-induced remodeling in skeletal muscle
Myonuclear accretion is a determinant of exercise-induced remodeling in skeletal muscle
复制标题
DOI：
10.7554/elife.44876
复制
发表时间：
2019-04-23
期刊：
影响因子：
7.7
通讯作者：
Millay, Douglas P.
中科院分区：
文献类型：
--
作者：
Goh, Qingnian;Song, Tajeong;Millay, Douglas P.
骨骼肌适应外部刺激，如增加工作。肌肉祖细胞（MP）控制由于严重损伤的肌肉修复，但MP融合和相关的肌肉增生在运动过程中的作用尚不清楚。虽然我们之前使用超生理模型证明了MP融合是生长所必需的（Goh和Millay，2017），但在生理环境中肌肉适应期间需要肌纤维增加的问题仍然存在。在这里，我们开发了一个8周的高强度间歇训练（HIIT）协议，并评估MP融合的重要性。在8个月大的小鼠中，HIIT在整个方案中导致进行性肌纤维增生和功能性肌肉肥大。HIIT发作时MP融合的消除导致运动不耐受和纤维化。相比之下，消融MP融合4周进入HIIT，保留了运动耐量，但减轻了肥大。我们的结论是，肌肉增生是需要不同方面的运动诱导的适应性反应，影响肌肉修复和肥大性生长。
Skeletal muscle adapts to external stimuli such as increased work. Muscle progenitors (MPs) control muscle repair due to severe damage, but the role of MP fusion and associated myonuclear accretion during exercise are unclear. While we previously demonstrated that MP fusion is required for growth using a supra-physiological model (Goh and Millay, 2017), questions remained about the need for myonuclear accrual during muscle adaptation in a physiological setting. Here, we developed an 8 week high-intensity interval training (HIIT) protocol and assessed the importance of MP fusion. In 8 month-old mice, HIIT led to progressive myonuclear accretion throughout the protocol, and functional muscle hypertrophy. Abrogation of MP fusion at the onset of HIIT resulted in exercise intolerance and fibrosis. In contrast, ablation of MP fusion 4 weeks into HIIT, preserved exercise tolerance but attenuated hypertrophy. We conclude that myonuclear accretion is required for different facets of exercise-induced adaptive responses, impacting both muscle repair and hypertrophic growth.