CREB coactivators CRTC2 and CRTC3 modulate bone marrow hematopoiesis

Proc Natl Acad Sci U S A. 2017 Oct 31;114(44):11739-11744. doi: 10.1073/pnas.1712616114. Epub 2017 Oct 16.


Populations of circulating immune cells are maintained in equilibrium through signals that enhance the retention or egress of hematopoietic stem cells (HSCs) from bone marrow (BM). Prostaglandin E2 (PGE2) stimulates HSC renewal and engraftment through, for example, induction of the cAMP pathway. Triggering of PGE2 receptors increases HSC survival in part via the PKA-mediated induction of the cAMP response element-binding protein (CREB) signaling pathway. PKA stimulates cellular gene expression by phosphorylating CREB at Ser133 and by promoting the dephosphorylation of the cAMP- responsive transcriptional coactivators (CRTCs). We show here that disruption of both CRTC2 and CRTC3 causes embryonic lethality, and that a single allele of either CRTC2 or CRTC3 is sufficient for viability. CRTC2 knockout mice that express one CRTC3 allele (CRTC2/3m mice) develop neutrophilia and splenomegaly in adulthood due to the up-regulation of granulocyte-colony stimulating factor (G-CSF); these effects are reversed following administration of neutralizing anti-G-CSF antiserum. Adoptive transfer of CRTC2/3m BM conferred the splenomegaly/neutrophilia phenotype in WT recipients. Targeted disruption of both CRTC2 and CRTC3 in stromal cells with a mesenchymal Prx1-Cre transgene also promoted this phenotype. Depletion of CRTC2/3 was found to decrease the expression of Suppressor of Cytokine Signaling 3 (SOCS3), leading to increases in STAT3 phosphorylation and to the induction of CEBPβ, a key regulator of the G-CSF gene. As small molecule inhibition of JAK activity disrupted CEBPβ induction and reduced G-CSF expression in CRTC2/3m stromal cells, our results demonstrate how cross-coupling between the CREB/CRTC and JAK/STAT pathways contributes to BM homeostasis.

Keywords: C/EBPβ; CREB; CRTC; G-CSF; cAMP.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bone Marrow / physiology*
  • Bone Marrow Transplantation
  • Cyclic AMP Response Element-Binding Protein / metabolism*
  • Embryonic Development
  • Gene Expression Regulation, Developmental / physiology
  • Granulocyte Colony-Stimulating Factor / metabolism
  • Hematopoiesis / physiology*
  • Janus Kinases / genetics
  • Janus Kinases / metabolism
  • Mice
  • Mice, Knockout
  • NF-kappa B / genetics
  • NF-kappa B / metabolism
  • STAT3 Transcription Factor / genetics
  • STAT3 Transcription Factor / metabolism
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*


  • CRTC3 protein, mouse
  • Crtc2 protein, mouse
  • Cyclic AMP Response Element-Binding Protein
  • NF-kappa B
  • STAT3 Transcription Factor
  • Stat3 protein, mouse
  • Transcription Factors
  • Granulocyte Colony-Stimulating Factor
  • Janus Kinases