Novel STAT3 target genes exert distinct roles in the inhibition of mesoderm and endoderm differentiation in cooperation with Nanog.
Leukemia inhibitory factor (LIF) activates the transcription factor signal transducer and activator of transcription 3 (STAT3), which results in the maintenance of mouse embryonic stem cells in the pluripotent state by inhibiting both mesodermal and endodermal differentiation. How the LIF/STAT3 pathway inhibits commitment to both mesoderm and endoderm lineages is presently unknown. Using a hormone-dependent STAT3 and with microarray analysis, we identified 58 targets of STAT3 including 20 unknown genes. Functional analysis showed that 22 among the 23 STAT3 target genes analyzed contribute to the maintenance of the undifferentiated state, as evidenced by an increase in the frequency of differentiated colonies in a self-renewal assay and a concomitant elevation of early differentiation markers upon knockdown. Fourteen of them, including Dact1, Klf4, Klf5, Rgs16, Smad7, Ccrn4l, Cnnm1, Ocln, Ier3, Pim1, Cyr61, and Sgk, were also regulated by Nanog. Analysis of lineage-specific markers showed that the STAT3 target genes fell into three distinct categories, depending on their capacity to inhibit either mesoderm or endoderm differentiation or both. The identification of genes that harness self-renewal and are downstream targets of both STAT3 and Nanog shed light on the mechanisms underlying functional redundancy between STAT3 and Nanog in mouse embryonic stem cells.
Bourillot
Pierre-Yves
PY
Institut National de la Santé et de la Recherche Médicale, U846, Bron, France. pierre.savatier@inserm.fr
Aksoy
Irène
I
Schreiber
Valerie
V
Wianny
Florence
F
Schulz
Herbert
H
Hummel
Oliver
O
Hubner
Norbert
N
Savatier
Pierre
P
D000818:Animals; D002454:Cell Differentiation / Q000235:genetics; D048708:Cell Growth Processes / Q000235:genetics; D002460:Cell Line; D004475:Ectoderm / Q000166:cytology / Q000502:physiology*; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D005786:Gene Expression Regulation; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D000090062:Kruppel-Like Factor 4; D053605:Leukemia Inhibitory Factor; D008648:Mesoderm / Q000166:cytology / Q000502:physiology*; D051379:Mice; D016513:Mice, SCID; D000071317:Nanog Homeobox Protein; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050796:STAT3 Transcription Factor / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction; D015533:Transcriptional Activation
D018398:Homeodomain Proteins; C000715468:Klf4 protein, mouse; D000090062:Kruppel-Like Factor 4; D053605:Leukemia Inhibitory Factor; C507838:Lif protein, mouse; D000071317:Nanog Homeobox Protein; C475540:Nanog protein, mouse; D050796:STAT3 Transcription Factor; C494087:Stat3 protein, mouse