Abstract
Adult cardiomyocytes (CMs) lose their proliferative capacity shortly after birth, posing a major challenge for cardiac repair following injury such as myocardial infarction (MI). Despite significant advances over the past decade, many strategies for promoting cardiac regeneration have faced limitations, underscoring the need to identify novel molecular pathways and targets. Pyruvate kinase muscle isoform 2 (PKM2), a key metabolic enzyme, has emerged as a compelling candidate in this context due to its multifaceted roles in cellular metabolism, proliferation, redox balance, angiogenesis, and master gene regulator in repair. Recent studies highlight the critical function of PKM2 in cardiac repair and regeneration. PKM2 not only promotes the proliferation of CMs but also protects the heart from oxidative stress by redirecting glycolytic intermediates toward the pentose phosphate pathway (PPP), thereby increasing nicotinamide adenine dinucleotide phosphate (NADPH) levels, reducing reactive oxygen species (ROS), and minimizing DNA damage. Moreover, PKM2 interacts with key signaling molecules, including β-catenin, hypoxia-inducible factor 1α (HIF-1a), and checkpoint kinase 1 (CHK1), to promote CM cell cycle reentry, angiogenesis, and enhanced cell survival. Collectively, these multifaceted actions highlight PKM2 as both a metabolic and signaling hub in cardiac repair by promoting myocardial remuscularization, protection, and revascularization and position PKM2 as a promising therapeutic. This review explores the diverse roles of PKM2 in myocardial repair and discusses its potential as a novel avenue for advancing regenerative therapies in cardiovascular medicine.