Department of Physical Education, University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain.
Research Institute of Biomedical and Health Sciences (IUIBS), University of Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain.
Scand J Med Sci Sports. 2021 Dec;31(12):2249-2258. doi: 10.1111/sms.14061. Epub 2021 Oct 4.
The study aimed to determine the levels of skeletal muscle angiotensin-converting enzyme 2 (ACE2, the SARS-CoV-2 receptor) protein expression in men and women and assess whether ACE2 expression in skeletal muscle is associated with cardiorespiratory fitness and adiposity. The level of ACE2 in vastus lateralis muscle biopsies collected in previous studies from 170 men (age: 19-65 years, weight: 56-137 kg, BMI: 23-44) and 69 women (age: 18-55 years, weight: 41-126 kg, BMI: 22-39) was analyzed in duplicate by western blot. VO max was determined by ergospirometry and body composition by DXA. ACE2 protein expression was 1.8-fold higher in women than men (p = 0.001, n = 239). This sex difference disappeared after accounting for the percentage of body fat (fat %), VO max per kg of legs lean mass (VO max-LLM) and age (p = 0.47). Multiple regression analysis showed that the fat % (β = 0.47) is the main predictor of the variability in ACE2 protein expression in skeletal muscle, explaining 5.2% of the variance. VO max-LLM had also predictive value (β = 0.09). There was a significant fat % by VO max-LLM interaction, such that for subjects with low fat %, VO max-LLM was positively associated with ACE2 expression while as fat % increased the slope of the positive association between VO max-LLM and ACE2 was reduced. In conclusion, women express higher amounts of ACE2 in their skeletal muscles than men. This sexual dimorphism is mainly explained by sex differences in fat % and cardiorespiratory fitness. The percentage of body fat is the main predictor of the variability in ACE2 protein expression in human skeletal muscle.
本研究旨在测定男性和女性骨骼肌血管紧张素转换酶 2（ACE2，SARS-CoV-2 受体）蛋白表达水平，并评估骨骼肌中 ACE2 表达与心肺功能适应性和肥胖的关系。通过 Western blot 对之前从 170 名男性（年龄：19-65 岁，体重：56-137kg，BMI：23-44）和 69 名女性（年龄：18-55 岁，体重：41-126kg，BMI：22-39）的股外侧肌活检样本中 ACE2 水平进行了重复分析。通过测功计测定最大摄氧量（VO2max），通过 DXA 测定身体成分。结果发现，女性的 ACE2 蛋白表达水平比男性高 1.8 倍（p=0.001，n=239）。然而，在考虑体脂百分比（% fat）、每公斤腿部瘦体重的最大摄氧量（VO2max-LLM）和年龄后，这种性别差异消失（p=0.47）。多元回归分析显示，% fat（β=0.47）是骨骼肌 ACE2 蛋白表达变异性的主要预测因素，解释了 5.2%的方差。VO2max-LLM 也具有预测价值（β=0.09）。% fat 与 VO2max-LLM 之间存在显著的交互作用，即对于低% fat 的受试者，VO2max-LLM 与 ACE2 表达呈正相关，而随着% fat 的增加，VO2max-LLM 与 ACE2 之间的正相关斜率降低。总之，女性骨骼肌中的 ACE2 表达量高于男性。这种性别差异主要是由体脂百分比和心肺功能适应性的性别差异引起的。体脂百分比是人类骨骼肌中 ACE2 蛋白表达变异性的主要预测因素。
