Connexin 43 and Mitochondria in Cardiovascular Health and Disease

Connexin 43 (Cx43) is the major connexin protein in ventricular cardiomyocytes. Six Cx43 proteins assemble into so-called hemichannels at the sarcolemma and opposing hemichannels form gap junctions, which allow the passage of small molecules and electrical current flow between adjacent cells. Apart from its localization at the plasma membrane, Cx43 is also present in cardiomyocyte mitochondria, where it is important for mitochondrial function in terms of oxygen consumption and potassium fluxes. The expression of gap junctional and mitochondrial Cx43 is altered under several pathophysiological conditions among them are hypertension, hypertrophy, hypercholesterolemia, ischemia/reperfusion injury, post-infarction remodeling, and heart failure. The present review will focus on the role of Cx43 in cardiovascular diseases and will highlight the importance of mitochondrial Cx43 in cardioprotection.