In mice that had their ovaries removed (a model for menopause), giving the tiny mitochondrial peptide MOTS‑c stopped weight gain, kept blood sugar normal, and helped fat tissue stay healthy. It did this by turning on brown fat and the AMPK energy‑regulating pathway, which together boost calorie burning and reduce inflammation.

The postmenopausal state is associated with an increased risk of metabolic disorder including reduced energy expenditure and weight gain, leading to higher cardiovascular and cancer risks among other diseases. Mitochondrial-derived peptide (MOTS-c) is a 16-amino acid peptide encoded by mitochondrial DNA. Here, we showed that MOTS-c treatment in mice prevented ovariectomy-induced obesity and insulin resistance. After ovariectomy, low levels of estrogens increased fat mass overload and disturbed normal adipose function, forcing the development of insulin resistance. MOTS-c treatment increased brown fat activation and reduced OVX-induced fat accumulation and inflammatory invasion in white adipose tissue, which contributes to the lower level of fatty acid in serum and liver. Moreover, MOTS-c activated AMPK pathway to improve energy dissipation and insulin sensitivity. And a blocker of AMPK pathway was found to attenuate the role of MOTS-c in the regulation of adipocyte lipid metabolism. In conclusion, MOTS-c is a high potential candidate for chronic treatment of menopausal induced metabolic dysfunction. KEY MESSAGES: • MOTS-c prevents ovariectomy (OVX)-induced body weight gain and insulin resistance. • MOTS-c reduces fat mass and suppresses inflammatory response under OVX condition. • MOTS-c sustains the activity of the brown adipose under OVX condition. • MOTS-c mediates AMPK pathway activation to control adipose metabolic homeostasis.