Cardiovascular diseases (CVDs) such as ischemic heart disease, stroke, and peripheral artery disease are the leading cause of mortality and morbidity around the world: about 30% of global deaths and 10% of global disease burden a year are due to CVDs [1, 2]. In the past three decades, these diseases have been increasing in underdeveloped and developing countries. Although deaths from CVDs have declined in some developed countries with better healthcare interventions and systems and primary prevention, population growth and aging will drive up global CVDs in coming decades [1, 2].
Atherosclerosis is a chronic inflammatory disease resulting in clogged arteries or unstable plaque rupture [3, 4]. Currently, treatment of atherosclerosis includes reducing risk factors such as treatment of hypercholesterolemia and hypertension [1, 2] and, for advanced disease, surgery such as stent implantation and bypass surgery using autologous vessels or tissue-engineered vascular grafts [5]. However, thrombosis and secondary atherosclerosis are common complications following stent and graft implantation, particularly in small-diameter arteries and grafts [6]. New therapies are thus rgently needed for better prevention and treatment of atherosclerosis. It is widely accepted that endothelial cell (EC) dysfunction, inflammatory cell recruitment, and vascular smooth muscle cell (SMC) de-differentiation contribute to atherogenesis [3, 4, 7]. In the past two decades, several types of vascular stem cells (VSCs), in addition to circulating progenitors, have been identified and characterized, with evidence that they are not only involved, but also play pivotal roles in blood vessel remodeling and disease development. VSCs or similar stem cells in mesenchymal tissues, for instance, also participate in the regeneration of blood vessels following the implantation of vascular grafts.