Mouse Skeletal Muscle Sarcopenia

ABSTRACT: Our study aimed to characterize sarcopenia in C57BL/6J mice using a clinically relevant definition and age range and investigate the underlying mechanisms leading to sarcopenia. Aged male C57BL/6J mice (23-32 months) were classified as non-sarcopenic (no deficit), probable sarcopenic (1 deficit), and sarcopenic (2-3 deficits) based on assessments of grip strength, muscle mass, and treadmill running time and using 2 standard deviations below the mean of the young (4-9 months) as cut-off points. A 9-22% prevalence of sarcopenia was identified in 23-26-month-old mice. Age-related declines in muscle function were more severe than in muscle mass and outcomes of all three assessments were positively correlated in aged mice. As sarcopenia progressed, there were decreases in specific force as well as fiber size and number of IIB skeletal muscle fibers. Mitochondrial biogenesis, oxidative capacity, and AMPK-autophagy signaling decreased significantly while no increase in atrogenes was detected. Our study is the first to characterize sarcopenia in C57BL/6J mice using a clinically relevant definition and highlights the different trajectories of age-related declines in muscle mass and function. These critical insights into the molecular changes associated with sarcopenia progression will facilitate future development of therapeutic interventions.

ORGANISM(S): Mus Musculus

SUBMITTER: Gennifer Merrihew  

PROVIDER: PXD048723 | panorama | Mon Aug 19 00:00:00 BST 2024

REPOSITORIES: PanoramaPublic