Characterization of murine bone marrow–derived EPCs and the effect of E-selectin on EPC differentiation. (A) Sequential changes of cultured BM-derived cells from eGFP-transgenic mice. Round, floating cells had changed into spindle-like, attaching cells as times went by. (B) RT-PCR analysis showing RNA expression profiles of EC-specific markers and functional E-selectin ligands in fibroblasts (NIH-3T3), bone marrow mononuclear cells, EPCs, and EC (MS-1) (ESL-1, E-selectin ligand-1; FucT VII, fucosyltransferase-VII). (C) Surface antigens on EPC by flow cytometry. Both E-selectin and E-selectin ligands (CD44 and FucT VII), in addition to progenitor cell or EC makers, were expressed on EPCs. E-selectin expression on EPCs was totally suppressed by E-selectin siRNA, but not by control siRNA, demonstrating the reliability of both E-selectin and control siRNA action. But the expression of other EC-specific markers and progenitor cell markers, or EPC differentiation was affected little by E-selectin siRNA.