Proliferation and survival of human amniotic epithelial cells during their hepatic differentiation

Abstract

Stem cells derived from placental tissues are an attractive source of cells for regenerative medicine. Amniotic epithelial cells isolated from human amnion (hAECs) have desirable and competitive characteristics that make them stand out between other stem cells. They have the ability to differentiate toward all three germ layers, they are not tumorigenic and they have immunosuppressive properties. Although liver transplantation is the best way to treat acute and chronic hepatic failure patients, there are several obstacles. Recently, stem cells have been spotlighted as alternative source of hepatocytes because of their potential for hepatogenic differentiation. In this work, we aimed to study the proliferation and survival of the hAECs during their hepatic differentiation. We have also analyzed the changes in pluripotency and hepatic markers. We differentiated amniotic cells applying a specific hepatic differentiation (HD) protocol. We determined by qRT-PCR that hAECs express significant levels of SOX-2, OCT-4 and NANOG during at least 15 days in culture and these pluripotent markers diminish during HD. SSEA-4 expression was reduced during HD, measured by immunofluorescence. Morphological characteristics became more similar to hepatic ones in differentiated cells and representative hepatic markers significantly augmented their expression, measured by qRT-PCR and Western blot. Cells achieved a differentiation efficiency of 75%. We observed that HD induced proliferation and promoted survival of hAECs, during 30 days in culture, evaluated by 3H-thymidine incorporation and MTT assay. HD also promoted changes in hAECs cell cycle. Cyclin D1 expression increased, while p21 and p53 levels were reduced. Immunofluorescence analysis showed that Ki-67 expression was upregulated during HD. Finally, ERK 1/2 phosphorylation, which is intimately linked to proliferation and cell survival, augmented during all HD process and the inhibition of this signaling pathway affected not only proliferation but also differentiation. Our results suggest that HD promotes proliferation and survival of hAECs, providing important evidence about the mechanisms governing their hepatic differentiation. We bring new knowledge concerning some of the optimal transplantation conditions for these hepatic like cells.

Proliferative, Migratory, and Transition Properties Reveal Metastate of Human Amnion Cells

“…AECs are unique because of their pluripotent status as stem cells, 45 as well as their co-expression and localization of epithelial and mesenchymal markers. The ability of cells to express both epithelial and mesenchymal phenotypes was first reported by Savagner as a metastable phenotype, documented in his studies of Rac distribution in cancer cells.…”

Evaluation of different routes of administration and biodistribution of human amnion epithelial cells in mice

“…It has also been reported that hAEC can differentiate into hepatocyte-like cells under certain conditions (18,25,44). hAEC express significant levels of SOX-2, OCT-4, and NANOG and these genes diminish at the end of hepatic differentiation procedures and the cells begin to express mature hepatic genes.…”

Therapeutic Effects of Human Amniotic Epithelial Stem Cells in a Transgenic Mouse Model of Alzheimer’s Disease

“…Moreover, hAESCs can be readily obtained and isolated from the placenta and are non-tumorigenic upon transplantation. They are almost entirely free from ethical and legal considerations [10,14,16]. In previous studies, hAESCs have been differentiated into neurons, glial cells, cardiomyocytes, and hepatocytes [8,10,[16][17][18][19][20].…”

“…They are almost entirely free from ethical and legal considerations [10,14,16]. In previous studies, hAESCs have been differentiated into neurons, glial cells, cardiomyocytes, and hepatocytes [8,10,[16][17][18][19][20]. In particular, recent studies have suggested that hAESCs are a promising candidate for the treatment of neurological diseases [18,21].…”