STAT3 activation is sufficient to maintain an undifferentiated state of mouse embryonic stem cells.
Embryonic stem (ES) cells can be maintained in an undifferentiated state in the presence of leukemia inhibitory factor (LIF). LIF acts through a receptor complex composed of a low affinity LIF receptor (LIFRbeta) and gp130. We reported that the intracellular domain of gp130 plays an important role in self-renewal of ES cells. In the present study, we examined the signaling pathway through which gp130 contributes to the self-renewal of ES cells. Mutational analysis of the cytoplasmic domain of gp130 revealed that the tyrosine residue of gp130 responsible for STAT3 activation is necessary for self-renewal of ES cells, while that required for SHP2 and MAP kinase activation was dispensable. Next, we constructed a fusion protein composed of the entire coding region of STAT3 and the ligand binding domain of the estrogen receptor. This construction (STAT3ER) induced expression of junB (one of the targets of STAT3) in ES cells in the presence of the synthetic ligand 4-hydroxytamoxifen (4HT), thereby indicating that STAT3ER is a conditionally active form. ES cells transfected with STAT3ER cultured in the presence of 4HT maintained an undifferentiated state. Taken together, these results strongly suggest that STAT3 activation is required and sufficient to maintain the undifferentiated state of ES cells.
Matsuda
T
T
Department of Stem Cell Regulation, Center for Experimental Medicine, The Institute of Medical Science, The University of Tokyo, Shirokanedai, Minato-Ku, Tokyo 108-8639, USA.
Nakamura
T
T
Nakao
K
K
Arai
T
T
Katsuki
M
M
Heike
T
T
Yokota
T
T
D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation; D002460:Cell Line; D050822:Cytokine Receptor gp130; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004622:Embryo, Mammalian / Q000166:cytology / Q000378:metabolism*; D006131:Growth Inhibitors / Q000378:metabolism; D006801:Humans; D015850:Interleukin-6; D053605:Leukemia Inhibitory Factor; D008222:Lymphokines / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D016296:Mutagenesis; D010766:Phosphorylation; D050796:STAT3 Transcription Factor; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D013629:Tamoxifen / Q000031:analogs & derivatives / Q000494:pharmacology; D015534:Trans-Activators / Q000378:metabolism*
D015703:Antigens, CD; D004268:DNA-Binding Proteins; D006131:Growth Inhibitors; C494199:IL6ST protein, human; C494200:Il6st protein, mouse; D015850:Interleukin-6; C507837:LIF protein, human; D053605:Leukemia Inhibitory Factor; C507838:Lif protein, mouse; D008222:Lymphokines; D008562:Membrane Glycoproteins; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; C494087:Stat3 protein, mouse; D015534:Trans-Activators; D013629:Tamoxifen; D050822:Cytokine Receptor gp130; C016601:afimoxifene