Pluripotency markers in tissue and cultivated cells in vitro of different regions of human amniotic epithelium.

Studies have described the presence of pluripotent markers in vivo and in vitro in human amnion. However, the amnion can be divided into reflected, placental and umbilical regions that are anatomically and functionally heterogeneous. Here, we evaluated the expression of pluripotency markers in tissue and cultivated cells in vitro of different regions of human amnion. To this end, we determined the presence of the core pluripotency factors OCT-4, NANOG and SOX-2 by immunofluorescence and RT-PCR and also performed transcriptome analysis of the different regions of amnion tissue. We identified the mRNA and protein of the pluripotency factors in the different regions of human amnion tissue. However, the OCT-4 and NANOG immunolocalization was cytoplasmic, whereas SOX-2 immunolocalization was nuclear regardless of the region analyzed. Moreover, we found three subpopulations of cells in the in vitro cultures of reflected and placental amnion: cells with immunostaining only in the nucleus, only in the cytoplasm, or in both compartments. Yet no statistically significant differences were found between the reflected and placental amnion. These results suggest a homogeneous distribution of the pluripotency transcription factors of the different regions of human amnion to isolate stem cells that can be used in regenerative medicine.