A change of heart: understanding the mechanisms regulating cardiac proliferation and metabolism before and after birth

Mammalian cardiomyocytes undergo major maturational changes in preparation for birth and postnatal life. Immature cardiomyocytes contribute to cardiac growth via proliferation and thus the heart has the capacity to regenerate. To prepare for postnatal life, structural and metabolic changes associated with increased cardiac output and function must occur. This includes exit from the cell cycle, hypertrophic growth, mitochondrial maturation and sarcomeric protein isoform switching. However, these changes come at a price: the loss of cardiac regenerative capacity such that damage to the heart in postnatal life is permanent. This is a significant barrier to the development of new treatments for cardiac repair and contributes to heart failure. The transitional period of cardiomyocyte growth is a complex and multifaceted event. In this review, we focus on studies that have investigated this critical transition period as well as novel factors that may regulate and drive this process. We also discuss the potential use of new biomarkers for the detection of myocardial infarction and, in the broader sense, cardiovascular disease.

Automated summary

Mammalian cardiomyocytes undergo significant maturational changes before and after birth. Immature cardiomyocytes can contribute to cardiac growth through proliferation, allowing the heart to regenerate. However, these changes come at the cost of losing cardiac regenerative capacity, leading to permanent damage in postnatal life. This poses a barrier to developing new treatments for cardiac repair and contributes to heart failure. This review focuses on studying the critical transition period of cardiomyocyte growth, exploring novel factors that may regulate and drive this process, and discussing the potential use of new biomarkers for detecting myocardial infarction and cardiovascular disease.