[In vitro culture and molecular characterization of human amniotic epithelial cells]

To investigate the biological and molecular characteristics of human amniotic epithelial cells (HAECs) cultured in vitro.

HAECs were isolated by enzyme digestion from amnion after cesarean section. The growth of the cells was observed under an inverted microscope and the curve of cell growth was measured by CCK-8 assay. The colony formation efficiency of HAECs was observed by Giemsa staining. Flow cytometry was used to detect cell cycle distribution and analyze the expressions of CD29, CD31, CD44, CD59, CD105, CD117, CD133, HLA-DR in the second passage of HAECs. The expressions of CD9, E-cadherin, podocalyxin-like protein (PODXL), stage-specific embryonic antigen-4 (SSEA-4), sex determining region Y-box 2 protein (SOX2), SSEA-1, Nanog, octamer-binding protein 3/4 (Oct-3/4) were identified by immunofluorescence staining.

Pure HAECs could be obtained by enzymatic isolation method. The cells grew with adherence and polygonal shape. They entered exponential growth stage from the third day of adherence. The analysis of cell cycle distribution revealed that 66% of the cells were in G0/G1 phase, 31.69% in S phase and 2.31% in G2/M phase. In addition, the colony forming rate of HAECs was (9.33±2.00) %. Flow cytometry and immunofluorescence staining showed that the expressions of CD44, CD29, CD105, CD59, CD9, E-cadherin, PODXL, SSEA-4, SOX2, SSEA-1, Nanog, Oct-3/4 were positive. However, the expressions of CD31, CD117, CD133, HLA-DR were negative.

HAECs can be cultured and have proliferation ability for some time in vitro; HAECs express some embryonic stem cell-associated surface molecules.