The Cytoskeletal Structure in Cardiomyocyte Maturation and Proliferation.

The adult heart has a limited ability to regenerate, which is partly due to the structural and metabolic specialization that cardiomyocytes (CMs) acquire during postnatal maturation. In this review, we explore how cytoskeletal remodeling, metabolic reprogramming, and interactions with the extracellular matrix (ECM) regulate CM maturation, proliferation, and the potential for regeneration. We describe how the assembly of microtubules, actin filaments, and sarcomeric structures is essential for developing contractile function, but also creates structural barriers that prevent cell division. Recent studies show that disassembling these cytoskeletal components, along with activating signaling pathways such as Hippo-YAP, Wnt, and NRG1/ErbB4, can promote CM dedifferentiation and re-entry into the cell cycle. Metabolic shifts also play a critical role. A return from oxidative phosphorylation to glycolysis also leads to CM dedifferentiation and proliferation. In addition, changes in ECM composition and mechanical signaling affect cytoskeletal dynamics and regenerative capacity. Understanding how these structural, metabolic, and signaling networks work together opens the door to new approaches for restoring heart function after injury.