Synchronous culture of rabbit bone narrow-derived endothelial progenitor cells and smooth muscle progenitor cells / 第二军医大学学报

ABSTRACT

Objective: To induce synchronous differentiation of rabbit bone marrow-derived mononuclear cells into endothelial progenitor cells (EPCs) and smooth muscle progenitor cells (SPCs), and to study their biological properties and the possibility of them as seed cells for tissue-engineered venous valves. Methods: Gradient density centrifugation was used to obtain bone marrow blood mononuclear cells, which were separately cultured with EGM-2 complete medium containing 5% FBS for differentiation of EPCs and with EBM-2 medium without vascular endothelial growth factor (VEGF) containing 5% FBS and 20 ng/mL platelet-derived growth factor-BB (PDGF-BB) for differentiation of SPCs. The differentiation of EPCs and SPCs was identified by various methods. Results: EPCs were cultured for 10 days and the cells fused into monolayer, showing a "stepping stone" appearance and expressing VEGF receptor-2 (VEGFR-2), von Willebrand factor (vWF) and CD133, but not α-smooth muscle actin (α-SMA); Weibel-Palade bodies were seen within the EPCs cytoplasm under the transmission electron microscope. Biological function tests showed visible EPCs growing on the matrigel in a blood vessel-like form. SPCs were cultured for 14 days and showed the specific features of the vascular smooth muscle growth, namely, the "peak-valley" growth way. SPCs expressed CD34 and α-SMA but not vWF and VEGFR-2. Myofilaments, paralleling with the cell longitudinal axis, were seen under the transmission electron microscope. SPCs could not form vessel-like structures on the matrigel. Conclusion: Mononuclear cells can be obtained through gradient density centrifugation of the bone marrow blood, which can be synchronously induced into EPCs and SPCs, providing economical and easy seed cels for tissue-engineered venous valves.