MOTS‑c, a tiny protein made by mitochondria, helped protect lung cells from damage caused by heart‑lung machine use during surgery. It did this by turning on a sugar‑burning pathway (AMPK‑HIF‑1α‑PFKFB3) that kept cells energized and stopped a type of cell death called ferroptosis. Patients who got lung injury had lower blood levels of MOTS‑c, and giving the peptide before injury reduced inflammation and oxidative stress in lab models.

Cardiopulmonary bypass (CPB) is essential during cardiac surgery but frequently leads to lung ischemia-reperfusion injury (LIRI), a significant contributor to postoperative complications. We investigated the protective effects of mitochondrial open reading frame of the 12S ribosomal RNA type C (MOTS-c), a mitochondrial-derived peptide, against LIRI-induced acute lung injury (ALI), emphasizing glycolytic reprogramming and ferroptosis in pulmonary microvascular endothelial cells. We hypothesized that MOTS-c exerts its protective effects by regulating glycolysis and suppressing ferroptosis via metabolic signaling pathways. We conducted a prospective, controlled trial involving 107 patients undergoing CPB, evaluating plasma concentrations of MOTS-c and inflammatory markers. MOTS-c concentrations were significantly reduced in patients with ALI. <i>In vivo</i> and <i>in&#xa0;vitro</i> experiments demonstrated that MOTS-c pretreatment alleviated LIRI by enhancing glycolytic flux, reducing oxidative stress, and suppressing ferroptosis in pulmonary microvascular endothelial cells. In particular, MOTS-c reinstated the expression of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3), an essential glycolytic enzyme, thus preserving cellular energy homeostasis and diminishing lipid peroxidation. The findings further emphasize the involvement of the AMPK (AMP-activated protein kinase)-hypoxia inducible factor-1&#x3b1; (HIF-1&#x3b1;) signaling pathway in the protective benefits facilitated by MOTS-c. MOTS-c elevated phosphorylated AMPK&#x3b1; and HIF-1&#x3b1; expression, indicating a vital function for these pathways in enhancing glycolysis and antioxidant defenses. Genetic and pharmacological inhibition of PFKFB3 abrogated the protective effects of MOTS-c, thereby confirming the essential role of PFKFB3-mediated glycolysis in alleviating LIRI. Our research indicates that MOTS-c could serve as a potential therapeutic agent for the prevention or treatment of LIRI-induced ALI by enhancing glycolysis, suppressing ferroptosis, and activating the AMPK-HIF-1&#x3b1; pathway. Future study should explore the clinical application of MOTS-c, potentially improving outcomes for patients undergoing high-risk cardiac operations.