AimTo investigate the potential of mouse fibroblast cell-derived embryonic-like induced pluripotent stem cells (iPS cells) to differentiate into endothelial cells.MethodsO9 iPS cells were induced to differentiate into endothelial cells by monolayer culture, FACS sorting Flk1+ cells, followed by OP9 stromal cell co-culture, and purified by FACS sorting VE-cadherin+ cells(O9-EC).The endothelial specific protein expression were examined by immunofluorescence.The functions of angiogenesis in vitro, uptaking DiI-Ac-LDL and binding UEA1 were also tested.Gene expression during differentiation process were tested by real-time PCR.ResultsMouse O9 iPS cells derived Flk1+cells could differentiate into endothelial-like cells on OP9 stromal cells.VE-cadherin could be used as a marker to purify O9-EC.O9-EC could express CD31, VE-cadherin and vWF, uptake DiI-Ac-LDL, bind UEA1 and form tube-like structures on matrigel.The endothelial specific genes such as CD31, Tie2 and eNOS were up-regulated in the endothelial differentiation process.Four reprogramming factors (Oct4, Sox2, Klf4 and c-Myc) that induce the generation of iPS cells were significantly down-regulated in this process.ConclusionThis study supports that iPS cells can differentiate into endothelial cells in vitro.This procedure may contribute to clinic application of patient-specific iPS cells derived endothelial cells in vascular degeneration diseases.