In mice made to age faster with D-galactose, giving the mitochondrial peptide MOTS‑c helped clear excess fat in the liver, belly fat and skin, improved the tiny structures inside mitochondria, and reduced signs of aging in the gut, though it only slightly changed weight or blood sugar.

MOTS-c, as a mitochondria derived peptide, exerts benefits for insulin resistance in HFD mice and against various stresses in an AMPK dependent way. Here, in the D-galactose chronic injection models, exogenous MOTS-c was given to determine its direct anti-aging effects. The body weight, insulin sensitivity and blood glucose were determined with mild differences. Tissue morphology analyses disclosed that liver, visceral fat and dermal skin, all displayed aberrant lipid depositions in the D-galactose mice. MOTS-c treatment largely alleviated the lipid accumulations, corresponding with positive changes in mitochondria dynamics, observed in liver transmission electron microscopy and in altered mRNA levels of Drp1 and mitofusins. Notably, the aging phenotypes of small intestine tract were more obvious, including histological defects and lower Ki67 levels, plus with the higher levels of DNA stress, such as P21 and P16, as well as mitochondria dynamics. Collectively, these data provided the direct evidence to support that exogenous givings of MOTS-c prevented abnormal fat accumulations in D-gal mice, putatively via improvement of mitochondria dynamic related pathways.