Paracrine induction of stem cell renewal by LIF-deficient cells: a new ES cell regulatory pathway.
The propagation of pluripotential mouse embryonic stem (ES) cells is sustained by leukemia inhibitory factor (LIF) or related cytokines that act through a common receptor complex comprising the LIF receptor subunit (LIF-R) and the signal transducer gp130. However, the findings that embryos lacking LIF-R or gp130 can develop beyond gastrulation argue for the existence of an alternative pathway(s) governing the maintenance of pluripotency in vivo. In order to define those factors that contribute to self-renewal in ES cell cultures, we have generated ES cells in which both copies of the lif gene are deleted. These cells showed a significantly reduced capacity for regeneration of stem cell colonies when induced to differentiate, confirming that LIF is the major endogenous regulatory cytokine in ES cell cultures. However, self-renewal was not abolished and undifferentiated ES cell colonies were still obtained in the complete absence of LIF. A differentiated, LIF-deficient, parietal endoderm-like cell line was derived and shown to support ES cell propagation via production of a soluble, macromolecular, trypsin-sensitive activity. This activity, which we name ES cell renewal factor (ESRF), is distinct from members of the IL-6/LIF family because (i) it is effective on ES cells lacking LIF-R; (ii) it is not blocked by anti-gp130 neutralizing antibodies; and (iii) it acts without activation of STAT3. ES cells propagated clonally using ESRF alone can contribute fully to chimaeras and engender germline transmission. These findings establish that ES cell pluripotency can be sustained via a LIF-R/gp130-independent, STAT-3 independent, signaling pathway. Operation of this pathway in vivo could play an important role in the regulation of pluripotency in the epiblast and account for the viability of lifr -/- and gp130 -/- embryos.
Dani
C
C
Centre for Genome Research, University of Edinburgh, King's Buildings, West Mains Road, Edinburgh, EH9 3JQ, Scotland.
Chambers
I
I
Johnstone
S
S
Robertson
M
M
Ebrahimi
B
B
Saito
M
M
Taga
T
T
Li
M
M
Burdon
T
T
Nichols
J
J
Smith
A
A
D000818:Animals; D015703:Antigens, CD / Q000502:physiology; D001549:Benzamides / Q000494:pharmacology; D002454:Cell Differentiation / Q000502:physiology; D002460:Cell Line; D002678:Chimera / Q000235:genetics; D050822:Cytokine Receptor gp130; D004268:DNA-Binding Proteins / Q000502:physiology; D005314:Embryonic and Fetal Development; D006131:Growth Inhibitors / Q000172:deficiency / Q000235:genetics*; D015850:Interleukin-6 / Q000502:physiology; D053605:Leukemia Inhibitory Factor; D053680:Leukemia Inhibitory Factor Receptor alpha Subunit; D008222:Lymphokines / Q000172:deficiency / Q000235:genetics*; D008562:Membrane Glycoproteins / Q000502:physiology; D051379:Mice; D012333:RNA, Messenger / Q000235:genetics; D018121:Receptors, Cytokine / Q000502:physiology; D053606:Receptors, OSM-LIF; D015183:Restriction Mapping; D050796:STAT3 Transcription Factor; D013234:Stem Cells / Q000502:physiology*; D015534:Trans-Activators / Q000502:physiology
D015703:Antigens, CD; D001549:Benzamides; D004268:DNA-Binding Proteins; D006131:Growth Inhibitors; C494200:Il6st protein, mouse; D015850:Interleukin-6; D053605:Leukemia Inhibitory Factor; D053680:Leukemia Inhibitory Factor Receptor alpha Subunit; C507838:Lif protein, mouse; C507841:Lifr protein, mouse; D008222:Lymphokines; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D018121:Receptors, Cytokine; D053606:Receptors, OSM-LIF; D050796:STAT3 Transcription Factor; C494087:Stat3 protein, mouse; D015534:Trans-Activators; D050822:Cytokine Receptor gp130; C025159:3-methoxybenzamide