The transcriptome profile in skeletal muscle of young male mice and aging male mice fed with or without eicosapentaenoic acid (EPA)

Age-related sarcopenia is associated with a variety of changes in skeletal muscle. These changes are interrelated with each other and associated with systemic metabolism, the details of which, however, are largely unknown. Eicosapentaenoic acid (EPA) is a promising nutrient against sarcopenia and has multifaceted effects on systemic metabolism. Although several human studies have suggested that EPA supplementation protects against sarcopenia, the causal relationship of EPA supplementation and an increase of muscle strength has poor evidence in vivo. We demonstrated that aging skeletal muscle in male mice shows lower grip strength and fiber type changes, both of which can be inhibited by EPA supplementation irrespective of muscle mass alteration. We hypothesized that the aging process in skeletal muscle can be intervened by the administration of EPA, via transcriptomic changes in skeletal muscle. This analysis revealed fast-to-slow fiber type transition in aging muscle, which was partially inhibited by EPA. Seventy-five-week-old male mice were randomly assigned to groups fed with EPA-deprived control diet (EPA-) or EPA-enriched diet with 1wt% EPA (EPA+) for 12 weeks. Twenty-four-week-old male mice were also analyzed (Young). Pooled RNA samples extracted from Gas+Pl muscle were used (Young, n = 3; EPA-, n = 6; EPA+, n = 6).