In rats, daily injections of the tiny mitochondrial peptide MOTS‑c (5 mg per kg body weight) for four weeks reduced the hardening of blood vessels caused by excess vitamin D3 and nicotine. The peptide boosted a protective protein called AMPK and lowered two receptors (AT‑1 and ET‑B) that normally promote blood‑vessel damage.

Vascular calcification (VC) is a complex, regulated process involved in many disease entities. So far, there are no treatments to reverse it. Exploring novel strategies to prevent VC is important and necessary for VC-related disease intervention. In this study, we evaluated whether MOTS-c, a novel mitochondria-related 16-aa peptide, can reduce vitamin D3 and nicotine-induced VC in rats. Vitamin D3 plus nicotine-treated rats were injected with MOTS-c at a dose of 5 mg/kg once a day for 4 weeks. Blood pressure, heart rate, and body weight were measured, and echocardiography was performed. The expression of phosphorylated adenosine monophosphate-activated protein kinase (AMPK) and the angiotensin II type 1 (AT-1) and endothelin B (ET-B) receptors was determined by Western blot analysis. Our results showed that MOTS-c treatment significantly attenuated VC. Furthermore, we found that the level of phosphorylated AMPK was increased and the expression levels of the AT-1 and ET-B receptors were decreased after MOTS-c treatment. Our findings provide evidence that MOTS-c may act as an inhibitor of VC by activating the AMPK signaling pathway and suppressing the expression of the AT-1 and ET-B receptors.