Muscle unloading: A comparison between spaceflight and ground‐based models

• Published in: Acta Physiologica Vol. 228; no. 3; pp. e13431 - n/a
• Main Authors: Qaisar, Rizwan, Karim, Asima, Elmoselhi, Adel B.
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01-03-2020
• Subjects: Atrophy; bed rest; disuse muscle atrophy; hindlimb unloading; Immobilization; Mechanical unloading; Molecular modelling; Muscle contraction; Musculoskeletal system; signalling pathways; Skeletal muscle; Space flight; Structure-function relationships; Therapeutic applications; therapeutic countermeasures; disuse muscle atrophy; therapeutic countermeasures; hindlimb unloading; signalling pathways; bed rest
• ISSN: 1748-1708; 1748-1716
• DOI: 10.1111/apha.13431

Prolonged unloading of skeletal muscle, a common outcome of events such as spaceflight, bed rest and hindlimb unloading, can result in extensive metabolic, structural and functional changes in muscle fibres. With advancement in investigations of cellular and molecular mechanisms, understanding of disuse muscle atrophy has significantly increased. However, substantial gaps exist in our understanding of the processes dictating muscle plasticity during unloading, which prevent us from developing effective interventions to combat muscle loss. This review aims to update the status of knowledge and underlying mechanisms leading to cellular and molecular changes in skeletal muscle during unloading. We have also discussed advances in the understanding of contractile dysfunction during spaceflights and in ground‐based models of muscle unloading. Additionally, we have elaborated on potential therapeutic interventions that show promising results in boosting muscle mass and strength during mechanical unloading. Finally, we have identified key gaps in our knowledge as well as possible research direction for the future.