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establishment of intercellular connections that result in the in vitro formation of
three-dimensional spheroids as reported for human amniotic stem cells (Yen et al
2005
). Moreover, the cells display a diffuse expression of stemness markers that is
consistent with the rapid osteogenic differentiation that the cells undergo when
exposed to inducing medium. Osteogenic differentiation can be achieved after
prolonged expansion in vitro, and this process can be potentiated by simple
molecules, such as 17
-estradiol, as described by others (Olivier et al.
2006
;
Kawaguchi et al
2005
), and that could be used to improve the regenerative potential
of the cells. Collectively, the data reported for the sheep model confirm that AECs
represent a promising source of stem cells for the development of regenerative
strategies. This investigation has demonstrated that after prolonged expansion, both
the expression of stemness markers and osteogenic plasticity are reduced, thus
suggesting that improved culture conditions are required whenever an extended
amplification in vitro is necessary to obtain very large cell numbers.
b
Acknowledgments This research was carried out with funds from Fondazione Tercas.
References
Kawaguchi J, Mee PJ, Smith AG (2005) Osteogenic and chondrogenic differentiation of embry-
onic stem cells in response to specific growth factors. Bone 36:758-769
Miki T, Lehmann T, Cai H, Stolz DB, Stom SC (2005) Stem cell characteristics of amniotic
epithelial cells. Stem Cells 23:1549-1559
Olivier EN, Rybicki AC, Bouhassira EE (2006) Differentiation of human embryonic stem cells
into bipotent mesenchymal stem cells. Stem Cells 24:1914-1922
Stocum DL (2001) Stem cells in regenerative biology and medicine. Wound Repair Regen
9:429-442
Thomas RJ, Chandra A, Liu Y, Hourd PC, Conway PP, Williams DJ (2007) Manufacture of a
human mesenchymal stem cell population using an automated cell culture platform. Cytotech-
nology 55:31-39
Yen BL, Huang HI, Chien CC, Jui HY, Ko BS, Yao M, Shun CT, Yen ML, Lee MC, Chen YC
(2005) Isolation of multipotent cells from human term placenta. Stem Cells 23:3-9
