Mitochondrial-derived microprotein MOTS-c attenuates immobilization-induced skeletal muscle atrophy by suppressing lipid infiltration

Am J Physiol Endocrinol Metab. 2024 Jan 3. doi: 10.1152/ajpendo.00285.2023. Online ahead of print.ABSTRACTMOTS-c, a mitochondrial microprotein, has been described as a novel regulator of glucose and lipid metabolism. In addition to its role as a metabolic regulator, MOTS-c prevents skeletal muscle atrophy in high-fat-fed mice. Here, we examined the preventive effect of MOTS-c on skeletal muscle mass using an immobilization-induced muscle atrophy model and explored its underlying mechanisms. Male C57BL/6J mice (10-week-old) were randomly assigned to one of the three experimental groups: non-immobilization control group (sterilized water injection), immobilization control group (sterilized water injection), and immobilization and MOTS-c treated group (15 mg/kg/day MOTS-c injection). We used casting tape for the immobilization experiment. After eight days of the experimental period, skeletal muscle samples were collected and used for the Western blotting, RNA sequencing, lipid, and collagen assays. Immobilization reduced ~15% of muscle mass, while MOTS-c treatment attenuated muscle loss with only a 5% reduction. MOTS-c treatment also normalized phospho-AKT, phospho-FOXO1, and phospho-FOXO3a expression levels, and reduced circulating inflammatory cytokines, such as interleukin-1b (IL-1β), interleukin-6 (IL-6), chemokine C-X-C motif ligand 1 (CXCL1), and monocyte chemoattractant protein 1 (MCP-1), in immobilized mice. An unbiased RNA sequencing and its downstream analyses demonst...
Source: Am J Physiol Endocri... - Category: Endocrinology Authors: Source Type: research