Department of Exercise Sciences, University of Auckland, Auckland, New Zealand.
Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia.
J Appl Physiol (1985). 2021 Mar 1;130(3):545-561. doi: 10.1152/japplphysiol.00711.2020. Epub 2020 Dec 24.
Little is known about the molecular responses to power resistance exercise that lead to skeletal muscle remodeling and enhanced athletic performance. We assessed the expression of titin-linked putative mechanosensing proteins implicated in muscle remodeling: muscle ankyrin repeat proteins (Ankrd 1, Ankrd 2, and Ankrd 23), muscle-LIM proteins (MLPs), muscle RING-finger protein-1 (MuRF-1), and associated myogenic proteins (MyoD1, myogenin, and myostatin) in skeletal muscle in response to power resistance exercise with or without a postexercise meal, in fed, resistance-trained men. A muscle sample was obtained from the vastus lateralis of seven healthy men on separate days, 3 h after 90 min of rest (Rest) or power resistance exercise with (Ex + Meal) or without (Ex) a postexercise meal to quantify mRNA and protein levels. The levels of phosphorylated HSP27 (pHSP27-Ser15) and cytoskeletal proteins in muscle and creatine kinase activity in serum were also assessed. The exercise increased ( ≤ 0.05) pHSP27-Ser15 (∼6-fold) and creatine kinase (∼50%), whereas cytoskeletal protein levels were unchanged ( > 0.05). Ankrd 1 (∼15-fold) and MLP (∼2-fold) mRNA increased, whereas Ankrd 2, Ankrd 23, MuRF-1, MyoD1, and myostatin mRNA were unchanged. Ankrd 1 (∼3-fold, Ex) and MLPb (∼20-fold, Ex + Meal) protein increased, but MLPa, Ankrd 2, Ankrd 23, and the myogenic proteins were unchanged. The postexercise meal did not affect the responses observed. Power resistance exercise, as performed in practice, induced subtle early responses in the expression of MLP and Ankrd 1 yet had little effect on the other proteins investigated. These findings suggest possible roles for MLP and Ankrd 1 in the remodeling of skeletal muscle in individuals who regularly perform this type of exercise. This is the first study to assess the early changes in the expression of titin-linked putative mechanosensing proteins and associated myogenic regulatory factors in skeletal muscle after power resistance exercise in fed, resistance-trained men. We report that power resistance exercise induces subtle early responses in the expression of Ankrd 1 and MLP, suggesting these proteins play a role in the remodeling of skeletal muscle in individuals who regularly perform this type of exercise.
对于导致骨骼肌重塑和增强运动表现的抗阻运动引起的分子反应，人们知之甚少。我们评估了在接受抗阻运动后是否有运动后餐，在进食的抗阻训练男性中，与骨骼肌重塑相关的肌球蛋白结合的假定机械感觉蛋白的表达：肌动蛋白重复蛋白（Ankrd1、Ankrd2 和 Ankrd23）、肌 LIM 蛋白（MLPs）、肌环指蛋白 1（MuRF-1）和相关的肌原蛋白（MyoD1、myogenin 和 myostatin）。在分别的几天中，从 7 名健康男性的股外侧肌获得肌肉样本，在休息 90 分钟后 3 小时（休息）或在有（Ex+Meal）或没有（Ex）运动后餐的情况下进行抗阻运动，以定量测量 mRNA 和蛋白质水平。还评估了肌肉中磷酸化 HSP27（pHSP27-Ser15）和细胞骨架蛋白的水平以及血清中的肌酸激酶活性。运动增加（≤0.05）pHSP27-Ser15（约 6 倍）和肌酸激酶（约 50%），而细胞骨架蛋白水平不变（>0.05）。Ankrd1（约 15 倍）和 MLP（约 2 倍）mRNA 增加，而 Ankrd2、Ankrd23、MuRF-1、MyoD1 和 myostatin mRNA 不变。Ankrd1（约 3 倍，Ex）和 MLPb（约 20 倍，Ex+Meal）蛋白增加，但 MLPa、Ankrd2、Ankrd23 和肌原蛋白不变。运动后餐对观察到的反应没有影响。在实践中进行的抗阻运动引起了 MLPa 和 Ankrd1 表达的微妙早期反应，但对其他研究的蛋白质几乎没有影响。这些发现表明 MLPa 和 Ankrd1 在经常进行这种类型运动的个体的骨骼肌重塑中可能发挥作用。这是第一项研究在进食的抗阻训练男性中，评估抗阻运动后肌球蛋白结合的假定机械感觉蛋白和相关的肌生成调节因子在骨骼肌中的早期表达变化。我们报告说，抗阻运动引起了 Ankrd1 和 MLP 表达的微妙早期反应，这表明这些蛋白在经常进行这种类型运动的个体的骨骼肌重塑中发挥作用。
