Eicosapentaenoic acid increases proportion of type 1 muscle fibers through PPARδ and AMPK pathways in rats

Yusuke Komiya; Yuka Sakazaki; Tsuyoshi Goto; Fuminori Kawabata; Takahiro Suzuki; Yusuke Sato; Shoko Sawano; Mako Nakamura; Ryuichi Tatsumi; Yoshihide Ikeuchi; Keizo Arihara; Wataru Mizunoya

doi:10.1016/j.isci.2024.109816

Eicosapentaenoic acid increases proportion of type 1 muscle fibers through PPARδ and AMPK pathways in rats

iScience. 2024 Apr 26;27(6):109816. doi: 10.1016/j.isci.2024.109816. eCollection 2024 Jun 21.

Authors

Affiliations

¹ Department of Animal Science, School of Veterinary Medicine, Kitasato University, Towada, Japan.
² Department of Animal and Marine Bioresource Sciences, Faculty of Agriculture, Graduate School of Agriculture, Kyushu University, Fukuoka, Japan.
³ Division of Food Science & Biotechnology, Kyoto University, Kyoto, Japan.
⁴ Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki, Japan.
⁵ Department of Animal Science, School of Agriculture, Tokai University, Kumamoto, Japan.
⁶ Department of Food and Life Science, School of Life and Environmental Science, Azabu University, Sagamihara, Japan.
⁷ Department of Animal Science and Biotechnology, School of Veterinary Medicine, Azabu University, Sagamihara, Japan.

Abstract

Muscle fiber type composition (% slow-twitch and % fast-twitch fibers) is associated with metabolism, with increased slow-twitch fibers alleviating metabolic disorders. Previously, we reported that dietary fish oil intake induced a muscle fiber-type transition in a slower direction in rats. The aim of this study was to determine the functionality of eicosapentaenoic acid (EPA), a unique fatty acid in fish oil, to skeletal muscle fiber type and metabolism in rats. Here, we showed that dietary EPA promotes whole-body oxidative metabolism and improves muscle function by increasing proportion of slow-twitch type 1 fibers in rats. Transcriptomic and metabolomic analyses revealed that EPA supplementation activated the peroxisome proliferator-activated receptor δ (PPARδ) and AMP-activated protein kinase (AMPK) pathways in L6 myotube cultures, which potentially increasing slow-twitch fiber share. This highlights the role of EPA as an exercise-mimetic dietary component that improves metabolism and muscle function, with potential benefits for health and athletic performance.

Keywords: Dietary supplement; Metabolomics; Molecular biology; Transcriptomics.