Regulation of satellite cells by exercise in hypoxic conditions, a narrative review of the literature

Details

Supervisors

Deldicque, Louise

Faculty

Faculté des sciences de la motricité

Degree label

Master [120] en sciences de la motricité, orientation générale

Abstract

Satellite cells are muscle stem cells that contribute to muscle regeneration and hypertrophy in response to external stimuli such as exercise or hypoxia. Exercise training in acute hypoxia induces muscle hypertrophy and increases VO2max and muscle strength, whereas exercise training in chronic hypoxia improves oxygen transport and vascularization but induces muscle atrophy. After acute hypoxic exercise, mRNA levels of myogenic regulatory factors Mrf4, Myf5, MyoD and myogenin increased, leading to satellite cell activation and proliferation. Activation of inflammatory pathway and upregulation of angiogenic factors were observed. Eccentric contractions may potentiate the inflammatory response and angiogenesis appears to be tightly coordinated with myogenesis. Increased satellite cell number but impaired satellite cell proliferation, fusion and myogenicity were observed following endurance exercise training, such as trekking, in chronic hypoxia. This may be induced by excessive oxidative stress and proteolysis. Modulation of autophagy by exercise in hypoxia may regulate satellite cell quiescence and self-renewal, but also satellite cell activation, differentiation and fusion. More human studies are necessary to understand the regulation of satellite cells by resistance and/or endurance exercise in acute and chronic hypoxia.