Autophagy in the cardiovascular system

The heart is crucial to sustaining life, as it pumps blood throughout the entire body. The heart generates electrical impulses to promote contraction of the cardiac tissue with a specific strength and rhythm. Because postmitotic cardiomyocytes must perform contractile functions under continuous mechanical stress, the modulation of intracellular stress–response mechanisms like autophagy is crucial. Autophagy is a recycling process for proteins and organelles that makes various contributions to heart physiology for the specific cargos targeted for degradation. Autophagy has different roles over the damage-induced repair of the heart by orchestrating a response between cardiomyocytes and other cardiac cells, such as fibroblasts, immune cells, and stem cells. The role of autophagy in cardiac diseases is pathology dependent. In some cases, autophagy is required to fight back the disease (e.g., ischemic heart disease) but in others mediates disease progression (e.g., hypertension). This chapter will summarize the evidence about the physiologic role of autophagy over homeostatic maintenance and growth of the heart, emphasizing its contribution during aging and the participation of autophagy in arrhythmic disorders, myocardial infarction, cardiac regeneration, cardiac fibrosis, and heart failure.