Isolation of endothelial progenitor cells (Epcs)

Endothelial progenitor cells (EPCs) are defined as non-endothelial cells which are capable of differentiating into cells with endothelial phenotypes, adhere to matrix molecules and demonstrate acetylated Low Density Lipoprotein (acLDL) uptake and lectin positivity. EPCs consist of two different cell types with distinct cell growth pattern and angiogenic secretory capability, leading to enhanced vascular regeneration. They can be isolated from various sources including bone marrow, peripheral blood, and umbilical cord blood. Quantification of EPCs and assessment of function have been used as a surrogate marker for endothelial dysfunction, as the quantity and quality of EPCs inversely correlate with the number of cardiovascular risk factors. Preclinical and early human trials have shown that EPC-based therapy is safe and feasible for the treatment of several vascular disease states including restenosis, ischaemia and pulmonary hypertension. We describe a protocol for EPC isolation and characterisation from peripheral mononuclear cells which can be used for direct quantification of EPC number as a surrogate marker of cardiovascular risk factors, and in vitro and in vivo assessment of EPC biology.