Enhanced functional response of CD133+ circulating progenitor cells in patients early after acute myocardial infarction

Aims: Circulating progenitor cells (PC) may contribute to myocardialrecovery following infarction. Growth factors including VEGFare produced during ischaemia and stimulate PC release and activation.In this study, we focused on the functional chemotactic responseof PC to VEGF in subjects early after myocardial ischaemia. Methods and results: Number and phenotype of PC were characterized using flow-cytometry.CD133⁺PC were isolated from peripheral blood using positiveMACS isolation. The chemotactic response towards members ofthe VEGF family (VEGF-A, PlGF-1, and VEGF-E) was analysed inthree groups: (i) early period following acute myocardial infarction(days 2–4) treated with primary PCI (AMI) (n = 35), (ii)stable coronary artery disease (CAD) (n = 35), and (iii) controls(CTR) (n = 20). CD133⁺PC number was 2-fold higher in AMI whencompared with CAD and CTR (P = 0.0001), whereas CAD was notdifferent from CTR. The chemotactic response of CD133⁺PC toVEGF-A, PlGF-1, and VEGF-E was significantly enhanced (2-fold)in AMI when compared with CAD (P = 0.0001). While the increaseof the VEGFR-1-mediated/PlGF-triggered response was rapid (2days following infarction), the VEGFR-2-mediated/VEGF-E-triggeredresponse was maximally increased on day 4 post-AMI, thus correlatingwith the kinetics of maximal inflammatory activation reflectedby increased CRP levels (P = 0.019). Conclusion: The enhanced chemotactic response of CD133⁺PC following myocardialinfarction represents a novel principle potentially involvedin cardiovascular repair early after myocardial infarction.Acute inflammatory processes are closely associated with thisincreased cellular function.