Fig. 1

Characterization of EPCs and endogenous expression of β2AR on EPCs. a Representative photographs of EPCs at 7 days that were labeled with DAPI (blue), FITC-labeled BS-1 lectin (green), and DiI-acLDL uptake (red). Double-labeled cells were identified as EPCs (yellow) (×200). b Cells were tested for the ability to express the endothelial markers CD31, vWF, KDR, and CD14 by using flow cytometry analysis (IgG isotype control is shown in blue, n = 4 per group). c The expression of β2AR protein was confirmed on EPC surfaces by using immunofluorescence. The expression of β2AR (green) and eNOS (red) and colocalization of both receptors on EPCs (yellow) are shown. d Representative photographs and quantitative analyses of the β2AR protein expressed on EPCs after stimulation with FENO. The results show that β2AR expression was not changed in the EPCs that were stimulated by using FENO. DAPI 4‘,6-diamidino-2-phenylindole, DiI-ac-LDL DiI-labeled acetylated low-density lipoprotein, eNOS endothelial nitric oxide synthase, EPC endothelial progenitor cell, FENO fenoterol, FITC fluorescein isothiocyanate, KDR kinase-insert domain receptor, vWF von Willebrand factor, β2AR β2 adrenergic receptor