China Institute of Sport Science (CISS), Sport Health and Rehabilitation Center, Beijing, China.
Int J Sports Med. 2017 Nov;38(13):959-966. doi: 10.1055/s-0043-118343. Epub 2017 Oct 1.
Brain-derived neurotrophic factor (BDNF) is a myokine. However, its role in skeletal muscle has not been well elucidated. In this study, we aimed to investigate its expression profile in skeletal muscle following downhill running and to explore its functions. Male Sprague Dawley rats were assigned to sedentary and downhill running groups. Tail vein blood, total mRNA and protein from soleus muscle was obtained from rats at different time points post-exercise (1d, 3d, 5d, 7d and 14d). We found a significant elevation of BDNF mRNA level 5d and 7d post-exercise (p<0.05), increased BDNF protein level 1d, 3d, 7d and 14d post-exercise (p<0.05), and continuously elevated serum BDNF level (p<0.05). In addition, serum creatine kinase activity was increased 5d following exercise (p<0.05); expression of MyoD was elevated (p<0.05); disruption of myofibers and centralized nuclei in damaged myofibers were clearly observed 1d and 5d post-exercise, respectively. Moreover, AMPK phosphorylation was present 1d post-exercise (p<0.05), while AKT was phosphorylated for 5d post-exercise (p<0.05). In conclusion, downhill running induces a time-dependent up-regulation of BDNF in skeletal muscle, which is involved in exercise-induced skeletal muscle regeneration.
脑源性神经营养因子（BDNF）是一种肌因子。然而，其在骨骼肌中的作用尚未得到充分阐明。在本研究中，我们旨在研究下坡跑步后骨骼肌中 BDNF 的表达谱，并探讨其功能。雄性 Sprague Dawley 大鼠被分为安静组和下坡跑步组。运动后不同时间点（1d、3d、5d、7d 和 14d）从大鼠的尾静脉采血、提取比目鱼肌总 mRNA 和蛋白。我们发现，运动后 5d 和 7d BDNF mRNA 水平显著升高（p<0.05），运动后 1d、3d、7d 和 14d BDNF 蛋白水平升高（p<0.05），血清 BDNF 水平持续升高（p<0.05）。此外，运动后 5d 血清肌酸激酶活性升高（p<0.05）；MyoD 表达上调（p<0.05）；运动后 1d 和 5d 分别观察到肌纤维破裂和损伤肌纤维中央核化。此外，运动后 1d AMPK 磷酸化（p<0.05），而 AKT 则在运动后 5d 磷酸化（p<0.05）。综上所述，下坡跑步诱导骨骼肌中 BDNF 的时间依赖性上调，参与运动诱导的骨骼肌再生。
