Talkin’ ‘bout regeneration: new advances in cardiac regeneration using the zebrafish

The adult human heart has a very poor capacity to repair itself following injury. During heart attack, an enormous amount of cardiac tissue is lost from ischaemia. Whilst a low level of proliferation exists within the heart, the rate is insufficient to restore what is lost following ischaemic injury. In contrast to mammals, the zebrafish can completely grow back its heart following injury. This discovery, almost two decades ago, has resulted in something of a renaissance in the study of cardiac regeneration. Using the zebrafish, study has moved from observation of the phenomenon, to the application of different injury methods, tracing the origin of regenerated tissue, analysis of the different cellular contributions to regeneration and ongoing investigations onto the genetic cues that instruct the repair process (Figure 1). Progress has been considerable and provides us with important insights into a process we hope to one day apply to the injured human heart.