Use of xenofree matrices and molecularly-defined media to control human embryonic stem cell pluripotency: effect of low physiological TGF-beta concentrations.
Stem Cells Dev
; 17(3): 519-33, 2008 Jun.
Article
em En
| MEDLINE
| ID: mdl-18513159
ABSTRACT
To monitor human embryonic stem cell (hESC) self-renewal without differentiation, we used quantitative RT-PCR to study a selection of hESC genes, including markers for self-renewal, commitment/differentiation, and members of the TGF-beta superfamily and DAN gene family. Indeed, low commitment/differentiation gene expression, together with a significant self-renewal gene expres sion, provides a better pluripotency index than self-renewal genes alone. We demonstrate that matrices derived from human mesenchymal stem cells (hMSCs) can advantageously replace murine embryonic fibroblasts (MEF) or hMSC feeders. Moreover, a xenofree molecularly-defined SBX medium, containing a synthetic lipid carrier instead of albumin, can replace SR medium. The number of selected differentiation genes expressed by hESCs in these culture conditions was significantly lower than those expressed on MEF feeders in SR medium. In SBX, the positive effect of a non-physiological concentration of activin A (10-30 ng/mL) to reduce differentiation during self-renewal could also be obtained by physiological concentrations of TGF-beta(100-300 pg/mL). In contrast, these TGF-beta concentrations added to activin favored differentiation as previously observed with TGF-beta concentrations of 1 ng/mL or more. Compared to SR-containing medium, SBX medium promoted down-regulation of CER1 and LEFTIES and up-regulation of GREM1. Thus these genes better control self-renewal and pluripotency and prevent differentiation. A strategy is proposed to analyze, in more physiological, xenofree, molecularly-defined media and matrices, the numerous genes with still unknown functions controlling hESCs or human-induced pluripotent stem cells (iPS).
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fator de Crescimento Transformador beta
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Células-Tronco Pluripotentes
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Células-Tronco Embrionárias
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Matriz Extracelular
Limite:
Animals
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Humans
Idioma:
En
Revista:
Stem Cells Dev
Assunto da revista:
HEMATOLOGIA
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
França