Genetic lineage tracing reveals poor angiogenic potential of cardiac endothelial cells

Cardiac ischemia does not elicit an efficient angiogenic response. Indeed, lack of surgical revascularization upon myocardial infarction results in cardiomyocyte death, scarring and loss of contractile function. Clinical trials aimed at inducing therapeutic revascularization through the delivery of pro-angiogenic molecules after cardiac ischemia have invariably failed, suggesting that endothelial cells in the heart cannot mount an efficient angiogenic response. To understand why the heart is a poorly angiogenic environment, here we compare the angiogenic response of the cardiac and skeletal muscle using a lineage tracing approach to genetically label sprouting endothelial cells.