Myokine-mediated exercise effects: the role of myokine meteorin-like hormone (Metrnl)

Meterorin-like hormone (Metrnl), as a novel secreted factor, has been shown to be involved in physiological and pathophysiological processes. The behaviour of Metrnl in metabolic conditions like type 2 diabetes is conflicting. Metrnl-mediated (treatment with Metrnl) auto/paracrine actions in skeletal muscle are glucose uptake, fat oxidation and muscle regeneration. Exercise-induced Metrnl actions are increased fat oxidation in both skeletal muscle and adipose tissue, the control of inflammation in adipose tissue (metainflammation), and the regulation of muscle regeneration. Based on the current knowledge, Metrnl as a myokine can establish the muscle-fat crosstalk; however, the ability of Metrnl as a myokine to create other crosstalks remains unclear yet. Additionally, given the considerable anti-inflammatory roles of Metrnl in muscle regeneration, it could be a potential therapeutic candidate for muscle-related inflammatory diseases and ageing skeletal muscle which need to be addressed in the future studies.