Mobilization of stem and progenitor cells in cardiovascular diseases.

Circulating bone marrow (BM)-derived stem and progenitor cells (SPCs) participate in turnover of vascular endothelium and myocardial repair after acute coronary syndromes. Acute myocardial infarction (MI) produces a generalized inflammatory reaction, including mobilization of SPCs, increased local production of chemoattractants in the ischemic myocardium, as well as neural and humoral signals activating the SPC egress from the BM. Several types of circulating BM cells were identified in the peripheral blood, including hematopoietic stem cells, endothelial progenitor cells, mesenchymal stromal cells, circulating angiogenic cells and pluripotent very small embryonic-like cells; however, the contribution of circulating cells to the myocardial and endothelial repair is still unknown. The number and function of these cells is impaired in patients with diabetes and other cardiovascular risk factors, but can be improved by physical exercise and use of statins. The mobilization of SPCs in acute coronary syndromes and stable coronary artery disease seems to predict the clinical outcomes in selected groups of patients. Interpretation of the findings has to incorporate other factors that modulate the process of mobilization, such as coexisting diseases, age and medications. This review discusses the mobilization of SPCs in acute ischemia (MI, stroke), as well as in stable cardiovascular disease, and highlights the possibility of using the SPC as a marker of cardiovascular risk.