Stem Cells Derived from Human Fetal Membranes Display Multilineage Differentiation Potential

Abstract

The amnion is the inner of two membranes surrounding the fetus. That it arises from embryonic epiblast cells prior to gastrulation suggests that it may retain a reservoir of stem cells throughout pregnancy. We found that human amniotic epithelial cells (hAECs) harvested from term-delivered fetal membranes express mRNA and proteins present in human embryonic stem cells (hESCs), including POU domain, class 5, transcription factor 1; Nanog homeobox; SRY-box 2; and stage-specific embryonic antigen-4. In keeping with possible stem cell-like activity, hAECs were also clonogenic, and primary hAEC cultures could be induced to differentiate into cardiomyocytic, myocytic, osteocytic, adipocytic (mesodermal), pancreatic, hepatic (endodermal), neural, and astrocytic (neuroectodermal) cells in vitro, as defined by phenotypic, mRNA expression, immunocytochemical, and/or ultrastructural characteristics. However, unlike hESCs, hAECs did not form teratomas upon transplantation into severe combined immunodeficiency mice testes. Last, using flow cytometry we have shown that only a very small proportion of primary hAECs contain class IA and class II human leukocyte antigens (HLAs), consistent with a low risk of tissue rejection. However, following differentiation into hepatic and pancreatic lineages, significant proportions of cells contained class IA, but not class II, HLAs. These observations suggest that the term amnion, an abundant and easily accessible tissue, may be a useful source of multipotent stem cells that possess a degree of immune privilege.

Hepatocyte-Like Cells Derived from Human Amniotic Epithelial Cells Can Be Encapsulated Without Loss of Viability or Function In Vitro

“…Cells were cryopreserved in fetal bovine serum (FBS; Gibco) containing 10% dimethyl sulfoxide. Cells displaying typical cobble stone epithelial morphology in culture and > 98% positive for the epithelial markers cytokeratin 7 and 8/18 (Dako, Glostrup, Denmark) were used in subsequent experiments [20,33].…”

“…HLC were differentiated from hAEC in a similar manner as previously reported [20,22], except for the addition of HepG2-conditioned medium. Studies have shown that when hAEC were co-cultured with mouse hepatocytes expression of albumin, a1 anti-trypsin, and cytochrome P450 enzyme was increased [25].…”

“…hAEC are very abundant, have stem cell-like features, and differentiate into the lineages from the three embryonic germ layers including HLC originating from the endoderm [20,21]. Naïve hAEC display some relevant features of hepatic progenitors such as the lineage specification transcription factors FoxA2 and GATA-4 [22].…”

“…hAEC also display characteristic expression of mature hepatocyte markers such as albumin, a1-anti-trypsin, and OTC and also express various hepatocyte-related genes [22,23]. Upon differentiation, HLC derived from hAEC express mRNA of liver-enriched transcription factors such as C/EBP-a, CAR, RAR, and PXR [24], nuclear localization of the key transcription factor hepatocyte nuclear factor-4 alpha (HNF-4a), cytochrome P450 (CYP)1A1/2, CYP3A4, and CYP3A7 activity [20,21,25]. These HLC can also synthesize urea and breakdown testosterone [25].…”

The transplantation of mesenchymal stem cells derived from unconventional sources: an innovative approach to multiple sclerosis therapy

“…About 100-200 million of human amnion epithelial cells (hAECs) can be harvested from term placenta, which is generally discarded after birth (Murphy et al 2010) and instead could represent an important source of potential regenerative tissue. In vitro studies have shown that hAECs can develop into various cell lines, such as cardiomyocytes, myocytes, osteocytes, adipocytes, pancreatic cells, hepatocytes, as well as neural and astrocytic cells (Miki et al 2005;Ilancheran et al 2007). The hAECs pluripotency makes them suitable in treating disorders of the nervous system.…”