Transcriptional Programs and Regeneration Enhancers Underlying Heart Regeneration

The heart plays the vital role of propelling blood to the entire body, which is essential to life. While maintaining heart function is critical, adult mammalian hearts poorly regenerate damaged cardiac tissue upon injury and form scar tissue instead. Unlike adult mammals, adult zebrafish can regenerate injured hearts with no sign of scarring, making zebrafish an ideal model system with which to study the molecular mechanisms underlying heart regeneration. Investigation of heart regeneration in zebrafish together with mice has revealed multiple cardiac regeneration genes that are induced by injury to facilitate heart regeneration. Altered expression of these regeneration genes in adult mammals is one of the main causes of heart regeneration failure. Previous studies have focused on the roles of these regeneration genes, yet the regulatory mechanisms by which the expression of cardiac regeneration genes is precisely controlled are largely unknown. In this review, we will discuss the importance of differential gene expression for heart regeneration, the recent discovery of cardiac injury or regeneration enhancers, and their impact on heart regeneration.