Department of Physical Education, University of Las Palmas de Gran Canaria, Campus Universitario de Tafira s/n, Las Palmas de Gran Canaria, 35017, Spain; Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Paseo Blas Cabrera Felipe "Físico" s/n, 35017, Las Palmas de Gran Canaria, Spain.
Department of Physical Education, University of Las Palmas de Gran Canaria, Campus Universitario de Tafira s/n, Las Palmas de Gran Canaria, 35017, Spain.
Free Radic Biol Med. 2023 Nov 20;209(Pt 2):282-291. doi: 10.1016/j.freeradbiomed.2023.10.393. Epub 2023 Oct 17.
Ageing, a sedentary lifestyle, and obesity are associated with increased oxidative stress, while regular exercise is associated with an increased antioxidant capacity in trained skeletal muscles. Whether a higher aerobic fitness is associated with increased expression of antioxidant enzymes and their regulatory factors in skeletal muscle remains unknown. Although oestrogens could promote a higher antioxidant capacity in females, it remains unknown whether a sex dimorphism exists in humans regarding the antioxidant capacity of skeletal muscle. Thus, the aim was to determine the protein expression levels of the antioxidant enzymes SOD1, SOD2, catalase and glutathione reductase (GR) and their regulatory factors Nrf2 and Keap1 in 189 volunteers (120 males and 69 females) to establish whether sex differences exist and how age, VOmax and adiposity influence these. For this purpose, vastus lateralis muscle biopsies were obtained in all participants under resting and unstressed conditions. No significant sex differences in Nrf2, Keap1, SOD1, SOD2, catalase and GR protein expression levels were observed after accounting for VOmax, age and adiposity differences. Multiple regression analysis indicates that the VOmax in mL.kg LLM.mincan be predicted from the levels of SOD2, Total Nrf2 and Keap1 (R = 0.58, P < 0.001), with SOD2 being the main predictor explaining 28 % of variance in VOmax, while Nrf2 and Keap1 explained each around 3 % of the variance. SOD1 protein expression increased with ageing in the whole group after accounting for differences in VOmax and body fat percentage. Overweight and obesity were associated with increased pSer-Nrf2, pSer-Nrf2/Total Nrf2 ratio and SOD1 protein expression levels after accounting for differences in age and VOmax. Overall, at the population level, higher aerobic fitness is associated with increased basal expression of muscle antioxidant enzymes, which may explain some of the benefits of regular exercise.
年龄增长、久坐不动的生活方式和肥胖与氧化应激增加有关，而规律运动与训练有素的骨骼肌抗氧化能力增加有关。高有氧健身是否与骨骼肌中抗氧化酶及其调节因子的表达增加有关尚不清楚。虽然雌激素可以促进女性更高的抗氧化能力，但关于人类骨骼肌的抗氧化能力是否存在性别二态性仍不清楚。因此，本研究旨在确定 189 名志愿者（120 名男性和 69 名女性）骨骼肌中抗氧化酶 SOD1、SOD2、过氧化氢酶和谷胱甘肽还原酶（GR）及其调节因子 Nrf2 和 Keap1 的蛋白表达水平，以确定是否存在性别差异，以及年龄、VOmax 和肥胖如何影响这些差异。为此，在所有参与者休息和无应激状态下，从股外侧肌获取肌肉活检。在考虑了 VOmax、年龄和肥胖差异后，Nrf2、Keap1、SOD1、SOD2、过氧化氢酶和 GR 蛋白表达水平在男性和女性之间没有显著差异。多元回归分析表明，SOD2、总 Nrf2 和 Keap1 水平可以预测 VOmax（mL.kg LLM.min）（R=0.58，P<0.001），其中 SOD2 是解释 VOmax 方差的主要预测因子，占 28%，而 Nrf2 和 Keap1 分别解释方差的 3%左右。在考虑了 VOmax 和体脂百分比的差异后，整个组中 SOD1 蛋白表达随年龄增长而增加。超重和肥胖与 pSer-Nrf2、pSer-Nrf2/总 Nrf2 比值和 SOD1 蛋白表达水平的增加有关，在考虑了年龄和 VOmax 的差异后。总的来说，在人群水平上，较高的有氧健身能力与基础肌肉抗氧化酶表达增加有关，这可能解释了规律运动的一些益处。
