• endothelium;
  • regeneration;
  • statin;
  • stem cell

EPCs (endothelial progenitor cells) exert vasculoprotective effects and can be used for regenerative therapies. However, several isolation protocols have been described, with inconsistent results. Statins are among the most effective compounds that stimulate EPC numbers in vivo and ex vivo. We aim to describe the effects of rosuvastatin on different subtypes of putative EPCs. EPCs were cultured from mononuclear cells of blood donors and isolated according to three protocols: CFU-EC (colony forming units-endothelial cells), early (or ‘monocytic’) EPCs and late outgrown EPCs. Rosuvastatin (0.1–100 nM) was added at the beginning of culture (T0) or after the initial adhesion step (T1). Polarization of monocytic EPCs was assessed as expression of proinflammatory M1 markers (CD68 and CCR2) or anti-inflammatory M2 markers (CX3CR1, CD163, CD206). We found that 1 nM rosuvastatin increased the number of CFU-EC and late EPCs by about 3-fold, while lower concentrations had no significant effects. Rosuvastatin (0.1 nM) increased AcLDL+Lectin+ early EPCs by about 60%, while higher concentrations exerted inhibitory effects on early EPCs. Addition of rosuvastatin at T0 was more effective in stimulating CFU-EC and early EPCs, while addition at T1 was more effective in stimulating late EPCs. Rosuvastatin had no effects on proliferation rate of CFU-EC, early EPCs and late EPCs. We also found that 0.1 nM rosuvastatin reduced the M1/M2 ratio in early EPCs, which retain monocytic features. In conclusion, we show that rosuvastatin had significant stimulatory effects on EPCs irrespective of the culture protocol. Rosuvastatin also induced anti-inflammatory polarization of monocytic EPCs.