Proteomic characterization of EPCs and CECs “in vivo” from acute coronary syndrome patients and control subjects

BackgroundCirculating endothelial cells (CECs) and endothelial progenitor cells (EPCs) represent two scarce blood populations that are thought to play important roles in tissue vascularization. They have also been proposed as potential markers for more than a dozen pathologies. Moreover, EPCs have arisen as a new therapeutic option for cardiovascular disease. However nowadays there is certain controversy about their roles and a better understanding of EPC biology is required to develop new strategies for forthcoming therapies.MethodsFlow cytometry analysis was performed on freshly isolated mononuclear cells from control subjects and Acute Coronary Syndrome (ACS) patients. EPCs and CECs for both groups were isolated and quantified. Statistical analyses were performed to test the potential biomarker usefulness of both populations in ACS together with the first “in vivo” proteomic characterizations of these populations.ResultsOur results do not show statistical differences in the quantification of CECs and EPCs in control subjects and ACS patients. The proteomic characterization allowed us to identify 673 proteins associated to CECs (389 in controls and 462 in ACS patients), and another 502 proteins in EPCs (350 in controls and 274 in ACS patients).ConclusionsOur data show the necessity to obtain a more accurate and specific phenotype of CECs and EPCs cells as well as a flow cytometry “golden standard” protocol, before they can be considered useful clinical markers.General significanceThe proteomic data suggest a potential effect of ACS in the protein profiles of these cells.

► CECs and EPCs might be potential biomarkers of different diseases.
► EPCs have arisen as a novel therapeutic option for cardiovascular disorders.
► Still there is controversy about their roles, potentials and capabilities.
► Proteomics is a powerful tool to decrease this controversy.
► This technology could help to improve our knowledge in EPC biology.