title: Absence of suppressor of cytokine signalling 3 reduces self-renewal and promotes differentiation in murine embryonic stem cells.
abstract: Leukemia inhibitory factor (LIF) is required to maintain pluripotency and permit self-renewal of murine embryonic stem (ES) cells. LIF binds to a receptor complex of LIFR-beta and gp130 and signals via the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway, with signalling attenuated by suppressor of cytokine signalling (SOCS) proteins. Recent in vivo studies have highlighted the role of SOCS-3 in the negative regulation of signalling via gp130. To determine the role of SOCS-3 in ES cell biology, SOCS-3-null ES cell lines were generated. When cultured in LIF levels that sustain self-renewal of wild-type cells, SOCS-3-null ES cell lines exhibited less self-renewal and greater differentiation into primitive endoderm. The absence of SOCS-3 enhanced JAK-STAT and extracellular signal-related kinase 1/2 (ERK-1/2)-mitogen-activated protein kinase (MAPK) signal transduction via gp130, with higher levels of phosphorylated STAT-1, STAT-3, SH-2 domain-containing cytoplasmic protein tyrosine phosphatase 2 (SHP-2), and ERK-1/2 in steady state and in response to LIF stimulation. Attenuation of ERK signalling by the addition of MAPK/ERK kinase (MEK) inhibitors to SOCS-3-null ES cell cultures rescued the differentiation phenotype, but did not restore proliferation to wild-type levels. In summary, SOCS-3 plays a crucial role in the regulation of the LIF signalling pathway in murine ES cells. Its absence perturbs the balance between activation of the JAK-STAT and SHP-2-ERK-1/2-MAPK pathways, resulting in less self-renewal and a greater potential for differentiation into the primitive endoderm lineage.
authors.affiliation: The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3050, Australia.
authors.forename: Ariel
authors.initials: A
authors.lastname: Forrai
authors.forename: Kristy
authors.initials: K
authors.lastname: Boyle
authors.forename: Adam H
authors.initials: AH
authors.lastname: Hart
authors.forename: Lynne
authors.initials: L
authors.lastname: Hartley
authors.forename: Steven
authors.initials: S
authors.lastname: Rakar
authors.forename: Tracy A
authors.initials: TA
authors.lastname: Willson
authors.forename: Ken M
authors.initials: KM
authors.lastname: Simpson
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Roberts
authors.forename: Warren S
authors.initials: WS
authors.lastname: Alexander
authors.forename: Anne K
authors.initials: AK
authors.lastname: Voss
authors.forename: Lorraine
authors.initials: L
authors.lastname: Robb
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics*; D019070:Cell Lineage / Q000235:genetics; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D004622:Embryo, Mammalian / Q000166:cytology / Q000378:metabolism*; D004707:Endoderm / Q000166:cytology / Q000378:metabolism; D015850:Interleukin-6 / Q000494:pharmacology; D053605:Leukemia Inhibitory Factor; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000235:genetics*; D051379:Mice; D008817:Mice, Mutant Strains; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D000071223:Suppressor of Cytokine Signaling 3 Protein; D050826:Suppressor of Cytokine Signaling Proteins / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism
chemical_list: D015850:Interleukin-6; C507837:LIF protein, human; D053605:Leukemia Inhibitory Factor; C507838:Lif protein, mouse; C106644:SOCS3 protein, human; D000071223:Suppressor of Cytokine Signaling 3 Protein; D050826:Suppressor of Cytokine Signaling Proteins; D011505:Protein-Tyrosine Kinases