Comparison of the biological characteristics of early and late endothelial progenitor cells derived from mouse bone marrow

Abstract

Objective To observe the biological characteristics and precise role in angiogenesis of endothelial progenitor cells (EPCs).Methods Bone marrow-derived mononuclear cells were isolated and cultured.EPCs were identified by using immunohistochemistry,immunofluorescence and confocal microscopy.Using methyl thiazol tetrazolium(MTT) method,three-dimensional culture and flow cytometry,the characteristics of early and late EPCs were compared.The features of EPCs were observed by transmission electron microscopy.Results EPCs expressed cell surface antigen positive markers.After two weeks the late EPCs had greater proliferation,achieving 1 × 1011/L,and could form vascular-like structure.Leukocyte differentiation antigen 133 (CD133) expression of the early EPCs was up to (88.7 ± 2.4)％,then late EPCs was gradually decreased to (46.4 ± 3.6) ％.But vascular endothelial growth factor receptor-2 (VEGFR-2) expression was increased from (55.3 ±2.5)％ up to (81.1 ± 1.6)％,and there was significant difference between early EPCs and late EPCs (P ＜ 0.05).The late EPCs could be seen in the endothelial cells characteristic cell-Weible-Palade (WP) bodies.Conclusion There are different qualities of early EPCs and late EPCs in the bone marrow.They show some of the same phenotypes but there are also differences.The late EPCs may be an attractive candidate cell for angiogenesis. Key words: Bone marrow; Endothelial progenitor cells ; Endothelial cells ; Angiogenesis