bioRxiv. 2026 Apr 28. pii: 2026.04.27.718938. [Epub ahead of print]
Ashlesha Kadam,
Shiridhar Kashyap,
Kunal Samantaray,
Natasha Jaiswal,
Shanikumar Goyani,
Philip A Kramer,
Pourhadi Hadi,
Jingyun Lee,
Cristina M Furdui,
Pooja Jadiya,
Dhanendra Tomar.
Metabolic reprogramming is a hallmark of myocardial infarction (MI), in which cardiomyocytes shift from fatty acid oxidation to anaerobic glycolysis, leading to elevated lactate production and mitochondrial dysfunction. Lactylation, a recently described lysine post-translational modification, has emerged as a metabolic signaling mechanism; however, its role within mitochondria during MI remains poorly understood. Here, we define the mitochondrial lactylome following MI and examine how modulation of lactate transport influences mitochondrial metabolism and redox homeostasis. Using quantitative proteomics, we identify extensive remodeling of mitochondrial protein lactylation after MI, affecting enzymes involved in bioenergetics, redox regulation, and metabolic control. Pharmacological inhibition of monocarboxylate transporter-1 (MCT1) using AZD3965 further reshapes the mitochondrial lactylome, increasing lactylation of specific metabolic and redox-associated proteins without uniformly exacerbating mitochondrial dysfunction. Despite sustained impairment of global cardiac function, MCT1 inhibition attenuates post-MI fibrosis and inflammation and partially restores mitochondrial respiratory capacity. Consistent with in vivo findings, genetic or pharmacological inhibition of MCT1 in hypoxic cardiomyocytes-derived cells reduces mitochondrial reactive oxygen species, decreases inhibitory pyruvate dehydrogenase phosphorylation, and improves mitochondrial bioenergetics. Together, these findings reveal that mitochondrial lactylation is a context-dependent regulator of mitochondrial metabolism and redox balance following MI. Rather than acting solely as a pathological modification, lactylation integrates lactate availability with mitochondrial function to influence inflammatory and fibrotic remodeling, highlighting mitochondrial metabolic plasticity as a potential therapeutic target in ischemic heart disease.
Highlights: Myocardial infarction (MI) increases mitochondrial protein lactylation, with 361 identified lactylated proteins.AZD3965-mediated MCT1 inhibition further elevates mitochondrial lactylation.Distinct alterations in mitochondrial proteins and pathways (TCA cycle, amino acid metabolism, gene expression) were observed.AZD3965 reduces cardiac fibrosis and inflammation and partly improves mitochondrial respiration post-MI, but cardiac function remains impaired.