Signalling, cell cycle and pluripotency in embryonic stem cells

Burdon, Tom; Smith, Austin; Savatier, Pierre

doi:10.1016/s0962-8924(02)02352-8

Cited by 662 publications

(584 citation statements)

References 64 publications

(79 reference statements)

Supporting

Mentioning

550

Contrasting

Unclassified

Order By: Relevance

“…ES cells have an unusually rapid cell cycle, with a large S phase population, and are refractory to many normal aspects of cell cycle control [26]. Nevertheless, a G2/M arrest could clearly be seen when PDK1 +/+ ES cells were incubated with BX-795, which was also observed using Nocodazole, a positive control (Fig.…”

Section: Resultsmentioning

confidence: 63%

Analysis of 3-phosphoinositide-dependent kinase-1 signaling and function in ES cells

Tamgüney

Zhang

Fiedler

et al. 2008

Experimental Cell Research

View full text Add to dashboard Cite

Abstract3-Phosphoinositide-dependent kinase-1 (PDK1) phosphorylates and activates several kinases in the cAMP-dependent, cGMP-dependent and protein kinase C(AGC) family. Many putative PDK1 substrates have been identified, but have not been analyzed following transient and specific inhibition of PDK1 activity. Here, we demonstrate that a previously characterized PDK1 inhibitor, BX-795, shows biological effects that are not consistent with PDK1 inhibition. Therefore, we describe the creation and characterization of a PDK1 mutant, L159G, which can bind inhibitor analogues containing bulky groups that hinder access to the ATP binding pocket of wild type (WT) kinases. When expressed in PDK1 −/− ES cells, PDK1 L159G restored phosphorylation of PDK1 targets known to be hypophosphorylated in these cells. Screening of multiple inhibitor analogues showed that 1-NM-PP1 and 3,4-DMB-PP1 optimally inhibited the phosphorylation of PDK1 targets in PDK1 −/− ES cells expressing PDK1 L159G but not WT PDK1. These compounds confirmed previously assumed PDK1 substrates, but revealed distinct dephosphorylation kinetics. While PDK1 inhibition had little effect on cell growth, it sensitized cells to apoptotic stimuli. Furthermore, PDK1 loss abolished growth of allograft tumors. Taken together we describe a model system that allows for acute and reversible inhibition of PDK1 in cells, to probe biochemical and biological consequences.

show abstract

Section: Resultsmentioning

confidence: 63%

Analysis of 3-phosphoinositide-dependent kinase-1 signaling and function in ES cells

Tamgüney

Zhang

Fiedler

et al. 2008

Experimental Cell Research

View full text Add to dashboard Cite

show abstract

“…LIF also activates additional signals including the Ras/ERK kinase pathway (8,9), ribosomal S 6 kinases (10), phosphoinositide 3-kinases (11), and Src kinases (12). However, whereas LIF-induced STAT3 activation promotes self-renewal, LIF-induced ERK activation appears to promote differentiation (8), leading to the proposal that the balance between STAT3 and ERK signals contributes to the determination of mES cell fate (13).…”

mentioning

confidence: 99%

Regulation of Nanog Expression by Phosphoinositide 3-Kinase-dependent Signaling in Murine Embryonic Stem Cells

Storm

Bone

Beck

et al. 2007

Journal of Biological Chemistry

Self Cite

138

141

View full text Add to dashboard Cite

Embryonic stem (ES) cell pluripotency is regulated by a combination of extrinsic and intrinsic factors. Previously we have demonstrated that phosphoinositide 3-kinase (PI3K)-dependent signaling is required for efficient self-renewal of murine ES cells. In the study presented here, we have investigated the downstream molecular mechanisms that contribute to the ability of PI3Ks to regulate pluripotency. We show that inhibition of PI3K activity with either pharmacological or genetic tools results in decreased expression of RNA for the homeodomain transcription factor Nanog and decreased Nanog protein levels. Inhibition of glycogen synthase kinase 3 (GSK-3) activity by PI3Ks plays a key role in regulation of Nanog expression, because blockade of GSK-3 activity effectively reversed the effects of PI3K inhibition on Nanog RNA, and protein expression and self-renewal under these circumstances were restored. Furthermore, GSK-3 mutants mimicked the effects of PI3K or GSK-3 inhibition on Nanog expression. Importantly, expression of an inducible form of Nanog prevented the loss of self-renewal observed upon inhibition of PI3Ks, supporting a functional relationship between PI3Ks and Nanog expression. In addition, expression of a number of putative Nanog target genes was sensitive to PI3K inhibition. Thus, the new evidence provided in this study shows that PI3K-dependent regulation of ES cell self-renewal is mediated, at least in part, by the ability of PI3K signaling to maintain Nanog expression. Regulation of GSK-3 activity by PI3Ks appears to play a key role in this process.Embryonic stem cell pluripotency underpins their potential utility as a source of differentiated progeny for use in regenerative medicine. Leukemia inhibitory factor (LIF) 2 plays an important role in maintaining self-renewal of murine ES (mES) cells (1, 2) via activation of STAT3 (3-6) and induction of c-Myc (7). LIF also activates additional signals including the Ras/ERK kinase pathway (8, 9), ribosomal S 6 kinases (10), phosphoinositide 3-kinases (11), and Src kinases (12). However, whereas LIF-induced STAT3 activation promotes self-renewal, LIF-induced ERK activation appears to promote differentiation (8), leading to the proposal that the balance between STAT3 and ERK signals contributes to the determination of mES cell fate (13).Other extrinsic factors that also play a role in maintenance of mES cell self-renewal include bone morphogenic protein 4 (BMP4), which acts in synergy with LIF to maintain self-renewal via Smad-mediated induction of Id transcriptional repressor expression (14). A further report suggests BMP4 inhibition of p38 mitogen-activated protein kinase (MAPK) may also contribute to maintenance of self-renewal (15). Wnt signaling has been implicated in regulation of pluripotency of both mES and human ES (hES) cells, work stemming largely from use of the GSK-3 inhibitor 5-bromoindirubin-3-oxime (BIO) (16,17).A number of intrinsic regulators in the form of transcription factors have been identified that play important roles in regulatio...

show abstract

“…[1][2][3] These pluripotent cells recapitulate the complete mouse developmental program when injected into fertilized eggs. 4,5 In addition, upon aggregation in the absence of LIF, ES cells formed a three-dimensional ball-like cell structure (embryoid bodies, EBs), mimicking the first steps of post-implantation embryos.…”

mentioning

confidence: 99%

Bcl2, a transcriptional target of p38α, is critical for neuronal commitment of mouse embryonic stem cells

et al. 2008

View full text Add to dashboard Cite

Mouse embryonic stem (ES) cells remain pluripotent in vitro when grown in the presence of leukemia inhibitory factor (LIF) cytokine. LIF starvation leads to cell commitment, and part of the ES-derived differentiated cells die by apoptosis together with caspase3-cleavage and p38a activation. Inhibition of p38 activity by chemical compounds (PD169316 and SB203580), along with LIF withdrawal, leads to different outcomes on cell apoptosis, giving the opportunity to study the influence of apoptosis on cell differentiation. By gene profiling studies on ES-derived differentiated cells treated or not with these inhibitors, we have characterized the common and specific set of genes modulated by each inhibitor. We have also identified key genes that might account for their different survival effects. In addition, we have demonstrated that some genes, similarly regulated by both inhibitors (upregulated as Bcl2, Id2, Cd24a or downregulated as Nodal), are bona fide p38a targets involved in neurogenesis and found a correlation with their expression profiles and the onset of neuronal differentiation triggered upon retinoic acid treatment. We also showed, in an embryoid body differentiation protocol, that overexpression of EGFP (enhanced green fluorescent protein)-BCL2 fusion protein and repression of p38a are essential to increase formation of TUJ1-positive neuronal cell networks along with an increase in Map2-expressing cells.

show abstract

Signalling, cell cycle and pluripotency in embryonic stem cells

Cited by 662 publications

References 64 publications

Analysis of 3-phosphoinositide-dependent kinase-1 signaling and function in ES cells

Analysis of 3-phosphoinositide-dependent kinase-1 signaling and function in ES cells

Regulation of Nanog Expression by Phosphoinositide 3-Kinase-dependent Signaling in Murine Embryonic Stem Cells

Bcl2, a transcriptional target of p38α, is critical for neuronal commitment of mouse embryonic stem cells

Contact Info

Product

Resources

About