Activin A maintains pluripotency markers and proliferative potential of human induced pluripotent stem cells.

To investigate the role of Activin A in the embryoid bodies (EBs) of human induced pluripotent stem (iPS) cells, EBs were transferred onto dishes coated with Matrigel after 4 days of incubation with Activin A and observed under a microscope. Alkaline phosphatase staining and immunostaining were performed to analyze the pluripotency of the cells, and the MTS assay was performed to analyze their proliferative potential. Fourteen days after EB formation, cells cultured with Activin A (100 ng/ml) showed no morphological alterations. Cells cultured with 10-100 ng/ml of Activin A were positive for alkaline phosphatase staining, while cells cultured with 0-3 ng/ml showed negative staining. Cells cultured with 10 ng/ml of Activin A were positive for Oct3/4, Nanog, SSEA-4 and TRA-1-60, while cells cultured with 0 ng/ml Activin A were negative. Cells cultured with 3-30 ng/ml of Activin A maintained their proliferative potential, while loss of proliferative potential was observed in cells cultured with 100 ng/ml Activin A. In conclusion, Activin A maintained pluripotency markers in human iPS cells cultured as EBs with Activin A.