Vascular progenitor cells and translational research: the role of endothelial and smooth muscle progenitor cells in endogenous arterial remodelling in the adult.

There has been much recent research into the therapeutic use of stem and progenitor cells for various diseases. Alongside this, there has also been considerable interest in the normal roles that endogenous precursor cells may play in both physiological and pathological settings. In the present review, we focus on two types of progenitor cell which are of potential relevance to vascular homoeostasis, namely the EPC (endothelial progenitor cell) and the smooth muscle progenitor cell. We discuss evidence for their existence and sources in adults, and the various techniques currently used to identify these cells. We examine data obtained from studies using different methods of progenitor identification and relate these to each other, in order to provide a framework in which to interpret the literature in this area. We review evidence for the influence of these vascular progenitor cells upon vascular function and the development and progression of atherosclerosis.