Coculture with Late, but Not Early, Human Endothelial Progenitor Cells Up Regulates IL-1β Expression in THP-1 Monocytic Cells in a Paracrine Manner
Figure 1
Culture and characterization of human EPCs. EPCs were generated by culture of PBMNCs in EC growth medium (EGM-2 medium). Spindle-shaped early EPCs appeared in culture at days 4–7 (a). At around week 2, sporadic cell colonies formed (b), which were expanded to generate cobblestone-shaped late EPCs (c). Early EPCs were characterized by cell uptake of Dil-Ac-LDL ((d) red) and stain of FITC-UEA-lectin (e) green). Over 80% early EPCs were Dil-Ac-LDL/FITC-UEA-lectin double positive ((f) orange). Late EPCs expressed a series of EC protein markers, that is, VEGFR2 (g), Tie2 (h), and eNOS (i), as determined by western blotting. Human umbilical vein endothelial cells (HUVEC) were used as control for 2 isolations (EPC1 and EPC2) of late EPCs.
