Ps-99: Endothelial Differentiation of Human Amniotic Epithelial Cells

Yazdanpanah GH *, Khayat-Khoei M , Niknejad H ,


Objective: Amniotic epithelial cells (AECs) are closest layer of the placenta to the foetus. There are several reports that amniotic derived epithelial cells are pluripotent cells which can differentiate into different types of cells from three germ layers. However, there is no report on the differentiation of the AECs into endothelial lineage. Our goal was to evaluate the potential inducing effect of growth factors on differentiation of the AECs into endothelial cells. Materials and Methods: The amniotic membrain (AM) was detached from human placenta and was digested by trypsin-EDTA for the AECs to be extracted. The extracted AECs were characterized, based on their expression of pan-cytokerain, assessd by immunocytochemistry. They were cultured in gelatin coated plates, in DMEM/F12 medium contained 10% FBS, 1% penicillin/ streptomycin, and growth factors including EGF, VEGF, bFGF and BMP-4. The expressions of endothelial markers were evaluated by immunocytochemisty. Results: The extracted AECs had more than 90% viability confirmed by Trypan Blue and MTT assay. Expression of pan-cytokeratin confirmed that isolated cells were AECs. Endothelial differentiation was induced within 12 days in the AECs and their morphology was changed after addition of growth factors. 20% expression of Von Willebrand factor (vWF) was considered the minimum acceptable expression achieved by 25 ng/ml of VEGF. The percentage of this marker was increased by induction of BMP-4 signaling. Conclusion: The AECs are embryonic stem cell-like cells that have pluripotent properties. Since the AECs do not express HLA-A, B or DR, the in vivo immunologic rejection of them has not been reported. Based on these properties and also differentiation characteristic of the AECs to endothelial lineage, they are suitable cell source for future pre-clinical and clinical studies on vascular diseases.