Objective: To induce embryonic stem cell (ESC) to differentiate into endothelioid cells using a simple adhesive culture method, and to provide a new cells seed source for vascular tissue engineering or cell therapy.
Methods: SV129-derived ESC were seeded at 2 x 10(4)/cm2 and maintained undifferentiated on ESC culture medium in the presence of 1000 U/mL leukaemia inhibitory factor (LIF). Embryoid body (EB) formatted when ESC cultured in suspension in the lack of LIF. At 4 days, EB was transferred to 0.1% gelatin coated dish and cultured with medium supplementary of VEGF to be induced differentiation. The characteristics of differentiated cells were determined by immunohistochemistry staining, flow cytometry (FCM), 1, 1-dioctadecyl-3, 3, 3, 3-tetramethylindocarbocyanine-labeled acetylated low density lipoprotein (DiI-Ac-LDL) take up test, and TEM detection.
Results: Differentiated cells were morphologically characterized as endothelial cells. They could take up DiI-Ac-LDL, be stained positive by Flk-1 and CD31. The CD31 positive cells reached above 90% when measured by FCM. Furthermore, Weibel-Palade bodies were detected and tight junctions were found when differentiated cells were examined by TEM.
Conclusion: Using a simple adhesive culture method and by supplied with VEGF alone, ESCs can be induced to differentiate into endothelioid cells. The differentiation method is simple and economic, and can provide seed cells for vascular tissue engineering or cell-therapy.