Exploring the Function of Epicardial Cells Beyond the Surface

The epicardium, once considered a passive heart layer, is now seen as crucial for heart development, regeneration, and repair. This review highlights its role in heart regeneration in zebrafish and salamanders and its activation in mammals. The epicardium regulates cardiomyocyte proliferation, fibrosis, and neovascularization, but replicating these processes in nonregenerative mammals remains challenging. During myocardial infarction, epicardial cells influence cardiac repair through signaling factors. Recent studies reveal the epicardium's cellular and molecular diversity, offering insights into potential therapies for cardiovascular diseases. Advances include using human pluripotent stem cells and cardiac organoids to model heart repair, promising new strategies for heart disorders and regenerative therapies.