Functional Expression Cloning of Nanog, a Pluripotency Sustaining Factor in Embryonic Stem Cells

Abstract

Embryonic stem (ES) cells undergo extended proliferation while remaining poised for multilineage differentiation. A unique network of transcription factors may characterize self-renewal and simultaneously suppress differentiation. We applied expression cloning in mouse ES cells to isolate a self-renewal determinant. Nanog is a divergent homeodomain protein that directs propagation of undifferentiated ES cells. Nanog mRNA is present in pluripotent mouse and human cell lines, and absent from differentiated cells. In preimplantation embryos, Nanog is restricted to founder cells from which ES cells can be derived. Endogenous Nanog acts in parallel with cytokine stimulation of Stat3 to drive ES cell self-renewal. Elevated Nanog expression from transgene constructs is sufficient for clonal expansion of ES cells, bypassing Stat3 and maintaining Oct4 levels. Cytokine dependence, multilineage differentiation, and embryo colonization capacity are fully restored upon transgene excision. These findings establish a central role for Nanog in the transcription factor hierarchy that defines ES cell identity.

Esrrb extinction triggers dismantling of naïve pluripotency and marks commitment to differentiation

“…NANOG is the pluripotency TF for which a direct quantitative correlation between levels of expression and ESC self‐renewal efficiency has been most clearly demonstrated (Chambers et al , 2003, 2007; Abranches et al , 2014). Accordingly, NANOG is considered to act as a rheostat to tune ESC self‐renewal efficiency (Mullin & Chambers, 2012).…”

“…The period of loss of NANOG expression occurring at peri‐implantation (Chambers et al , 2003; Acampora et al , 2013) may enable cells of the epiblast to downregulate a number of pivotal naïve pluripotency determinants, including ESRRB (Adachi et al , 2013). In the post‐implantation epiblast, NANOG is re‐expressed (Hart et al , 2004; Osorno et al , 2012; Hoffman et al , 2013) but ESRRB is not (Adachi et al , 2013), likely due to differences in signaling environments between pre‐ and post‐implantation epiblasts.…”

Combined effects of the two reciprocal t(4;11) fusion proteins MLL·AF4 and AF4·MLL confer resistance to apoptosis, cell cycling capacity and growth transformation

“…This novel feature was verified in the biopsy material of t(4;11) patients. Nanog codes for an Antennapedia-class homeobox protein which is -in conjunction with Oct4 and Sox2 -necessary and sufficient for the self-renewal and maintenance of embryonic stem cells (Chambers et al, 2003;Mitsui et al, 2003). The consequences of these novel findings will be discussed.…”

Research of cardiomyocyte precursors in adult rat heart

“…ESC highly express genes and candidates that can serve as markers to identify lineageuncommitted stem cells and may also contribute to assess the differentiation degree (Bhattacharya et al, 2004). For example, pluripotent ESC showed a high expression level of nanog, taube nuss and CD9, that are involved, respectively, in the propagation of ESC and maintaining their pluripotency (Chambers et al, 2003), in the survival of pluripotent cells of mouse early embryos (Voss et al, 2000) and in embryonic stem cell colony formation and cell viability increasement (Oka et al, 2002). In addition, it has been seen that CD9 protein binds c-Kit receptor in bone marrow stem cells (Oka et al, 2002) and it may have a critical role in etiology of testicular germ cell tumors (TGCT s ), suggesting a link between enforced pluripotency and transformation (Giuliano et al, 2005).…”