Granulocyte colony-stimulating factor regulates myeloid differentiation through CCAAT/enhancer-binding protein epsilon

Blood ◽  
2001 ◽  
Vol 98 (4) ◽  
pp. 897-905 ◽  
Author(s):  
H. Nakajima
Keyword(s):  
Binding Protein ◽  
Myeloid Differentiation ◽  
Granulocyte Colony Stimulating Factor ◽  
Colony Stimulating Factor ◽  
Enhancer Binding Protein ◽  
Ccaat Enhancer Binding Protein ◽  
Stimulating Factor

Granulocyte colony-stimulating factor regulates myeloid differentiation through CCAAT/enhancer-binding protein ε

Blood ◽  
2001 ◽  
Vol 98 (4) ◽  
pp. 897-905 ◽  
Author(s):  
Hideaki Nakajima ◽  
James N. Ihle
Keyword(s):  
Molecular Mechanisms ◽  
Binding Protein ◽  
Hematopoietic Cells ◽  
Myeloid Differentiation ◽  
Granulocyte Colony Stimulating Factor ◽  
Colony Stimulating Factor ◽  
Granulocytic Differentiation ◽  
Enhancer Binding Protein ◽  
Ccaat Enhancer Binding Protein ◽  
Stimulating Factor

Granulocyte colony-stimulating factor (G-CSF) is a major cytokine that regulates proliferation and differentiation of myeloid cells, although the underlying mechanisms by which G-CSF controls myeloid differentiation are largely unknown. Differentiation of hematopoietic cells is regulated by lineage-specific transcription factors, and gene-targeting studies previously revealed the critical roles of CCAAT/enhancer-binding protein (C/EBP) α and C/EBPε, respectively, in the early and mid-late stages of granulocyte differentiation. The expression of C/EBPε in 32Dcl3 cells and FDCP1 cells expressing mutant G-CSF receptors was examined and it was found that G-CSF up-regulates C/EBPε. The signal for this expression required the region containing the first tyrosine residue of G-CSF receptor. Dominant-negative signal transducers and activators of transcription 3 blocked G-CSF–induced granulocytic differentiation in 32D cells but did not block induction of C/EBPε, indicating that these proteins work in different pathways. It was also found that overexpression of C/EBPε greatly facilitated granulocytic differentiation by G-CSF and, surprisingly, that expression of C/EBPε alone was sufficient to make cells differentiate into morphologically and functionally mature granulocytes. Overexpression of c-myc inhibits differentiation of hematopoietic cells, but the molecular mechanisms of this inhibition are not fully understood. In 32Dcl3 cells overexpressing c-myc that do not differentiate by means of G-CSF, induction of C/EBPε is completely abrogated. Ectopic expression of C/EBPε in these cells induced features of differentiation, including changes in nuclear morphologic characteristics and the appearance of granules. These data show that C/EBPε constitutes a rate-limiting step in G-CSF–regulated granulocyte differentiation and that c-myc antagonizes G-CSF–induced myeloid differentiation, at least partly by suppressing induction of C/EBPε.

scholarly journals Upregulation of Interleukin 6 and Granulocyte Colony-Stimulating Factor Receptors by Transcription Factor CCAAT Enhancer Binding Protein α (C/EBPα) Is Critical for Granulopoiesis

1998 ◽  
Vol 188 (6) ◽  
pp. 1173-1184 ◽  
Author(s):  
Pu Zhang ◽  
Atsushi Iwama ◽  
Milton W. Datta ◽  
Gretchen J. Darlington ◽  
Daniel C. Link ◽  
...  
Keyword(s):  
Interleukin 6 ◽  
Target Genes ◽  
Binding Protein ◽  
Granulocyte Colony Stimulating Factor ◽  
Colony Stimulating Factor ◽  
Enhancer Binding Protein ◽  
Ccaat Enhancer Binding Protein ◽  
Stimulating Factor ◽  
Deficient Mice

Cytokines stimulate granulopoiesis through signaling via receptors whose expression is controlled by lineage-specific transcription factors. Previously, we demonstrated that granulocyte colony-stimulating factor (G-CSF) receptor mRNA was undetectable and granulocyte maturation blocked in CCAAT enhancer binding protein α (C/EBPα)-deficient mice. This phenotype is distinct from that of G-CSF receptor−/− mice, suggesting that other genes are likely to be adversely affected by loss of C/EBPα. Here we demonstrate loss of interleukin 6 (IL-6) receptor and IL-6–responsive colony-forming units (CFU-IL6) in C/EBPα−/− mice. The observed failure of granulopoiesis could be rescued by the addition of soluble IL-6 receptor and IL-6 or by retroviral transduction of G-CSF receptors, demonstrating that loss of both of these receptors contributes to the absolute block in granulocyte maturation observed in C/EBPα-deficient hematopoietic cells. The results of these and other studies suggest that additional C/EBPα target genes, possibly other cytokine receptors, are also important for the block in granulocyte differentiation observed in vivo in C/EBPα-deficient mice.

scholarly journals CCAAT enhancer-binding protein (C/EBP) and AML1 (CBF alpha2) synergistically activate the macrophage colony-stimulating factor receptor promoter.

1996 ◽  
Vol 16 (3) ◽  
pp. 1231-1240 ◽  
Author(s):  
D E Zhang ◽  
C J Hetherington ◽  
S Meyers ◽  
K L Rhoades ◽  
C J Larson ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Protein C ◽  
Binding Protein ◽  
Colony Stimulating Factor ◽  
Enhancer Binding Protein ◽  
Ccaat Enhancer Binding Protein ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Stimulating Factor

Transcription factors play a key role in the development and differentiation of specific lineages from multipotential progenitors. Identification of these regulators and determining the mechanism of how they activate their target genes are important for understanding normal development of monocytes and macrophages and the pathogenesis of a common form of adult acute leukemia, in which the differentiation of monocytic cells is blocked. Our previous work has shown that the monocyte-specific expression of the macrophage colony-stimulating factor (M-CSF) receptor is regulated by three transcription factors interacting with critical regions of the M-CSF receptor promoter, including PU.1 and AML1.PU.1 is essential for myeloid cell development, while the AML1 gene is involved in several common leukemia-related chromosome translocations, although its role in hematopoiesis has not been fully identified. Along with AML1, a third factor, Mono A, interacts with a small region of the promoter which can function as a monocyte-specific enhancer when multimerized and linked to a heterologous basal promoter. Here, we demonstrate by electrophoretic mobility shift assays with monocytic nuclear extracts, COS-7 cell-transfected factors, and specific antibodies that the monocyte-enriched factor Mono A is CCAAT enhancer-binding protein (C/EBP). C/EBP has been shown previously to be an important transcription factor involved in hepatocyte and adipocyte differentiation; in hematopoietic cells, C/EBP is specifically expressed in myeloid cells. In vitro binding analysis reveals a physical interaction between C/EBP and AML1. Further transfection studies show that C/EBP and AML1 in concert with the AML1 heterodimer partner CBF beta synergistically activate M-CSF receptor by more then 60 fold. These results demonstrate that C/EBP and AML1 are important factors for regulating a critical hematopoietic growth factor receptor, the M-CSF receptor, suggesting a mechanism of how the AML1 fusion protein could contribute to acute myeloid leukemia. Furthermore, they demonstrate physical and functional interactions between AML1 and C/EBP transcription factor family members.

AML1-MTG8 leukemic protein induces the expression of granulocyte colony-stimulating factor (G-CSF) receptor through the up-regulation of CCAAT/enhancer binding protein epsilon

Blood ◽  
2000 ◽  
Vol 96 (1) ◽  
pp. 288-296 ◽  
Author(s):  
Kimiko Shimizu ◽  
Issay Kitabayashi ◽  
Nanao Kamada ◽  
Tatsuo Abe ◽  
Nobuo Maseki ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Binding Protein ◽  
Ectopic Expression ◽  
Precursor Cells ◽  
Granulocyte Colony Stimulating Factor ◽  
Colony Stimulating Factor ◽  
G Cells ◽  
Enhancer Binding Protein ◽  
Dependent Cell ◽  
Stimulating Factor

The t(8;21) translocation is one of the most frequent chromosomal abnormalities associated with acute myeloid leukemia (AML). In this translocation, the AML1 (CBFA2/PEBP2aB) gene is disrupted and fused to the MTG8 (ETO) gene. The ectopic expression of the resulting AML1-MTG8 fusion gene product in L-G and 32Dcl3 murine myeloid precursor cells stimulates cell proliferation without inducing morphologic terminal differentiation into mature granulocytes in response to granulocyte-colony stimulating factor (G-CSF). This study found that the ectopic expression of AML1-MTG8 elevates the expression of the G-CSF receptor (G-CSFR). Analysis of the promoter region of the G-CSFR gene revealed that up-regulation of G-CSFR expression by AML1-MTG8 does not depend on the AML1-binding sequence, but on the C/EBP (CCAAT/enhancer binding protein) binding site. The results suggest that the overproduction of G-CSFR is at least partly mediated by C/EBPɛ, whose expression is activated by AML1-MTG8. The ectopic expression of G-CSFR in L-G cells induced cell proliferation in response to G-CSF, but did not inhibit cell differentiation into mature neutrophils. Overexpression of C/EBPɛ in L-G cells also stimulated G-CSF–dependent cell proliferation. High expression levels of G-CSFR were also found in the leukemic cells of AML patients with t(8;21). Therefore, G-CSF–dependent cell proliferation of myeloid precursor cells may be implicated in leukemogenesis.

AML1-MTG8 leukemic protein induces the expression of granulocyte colony-stimulating factor (G-CSF) receptor through the up-regulation of CCAAT/enhancer binding protein epsilon

Blood ◽  
2000 ◽  
Vol 96 (1) ◽  
pp. 288-296 ◽  
Author(s):  
Kimiko Shimizu ◽  
Issay Kitabayashi ◽  
Nanao Kamada ◽  
Tatsuo Abe ◽  
Nobuo Maseki ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Binding Protein ◽  
Ectopic Expression ◽  
Precursor Cells ◽  
Granulocyte Colony Stimulating Factor ◽  
Colony Stimulating Factor ◽  
G Cells ◽  
Enhancer Binding Protein ◽  
Dependent Cell ◽  
Stimulating Factor

Abstract The t(8;21) translocation is one of the most frequent chromosomal abnormalities associated with acute myeloid leukemia (AML). In this translocation, the AML1 (CBFA2/PEBP2aB) gene is disrupted and fused to the MTG8 (ETO) gene. The ectopic expression of the resulting AML1-MTG8 fusion gene product in L-G and 32Dcl3 murine myeloid precursor cells stimulates cell proliferation without inducing morphologic terminal differentiation into mature granulocytes in response to granulocyte-colony stimulating factor (G-CSF). This study found that the ectopic expression of AML1-MTG8 elevates the expression of the G-CSF receptor (G-CSFR). Analysis of the promoter region of the G-CSFR gene revealed that up-regulation of G-CSFR expression by AML1-MTG8 does not depend on the AML1-binding sequence, but on the C/EBP (CCAAT/enhancer binding protein) binding site. The results suggest that the overproduction of G-CSFR is at least partly mediated by C/EBPɛ, whose expression is activated by AML1-MTG8. The ectopic expression of G-CSFR in L-G cells induced cell proliferation in response to G-CSF, but did not inhibit cell differentiation into mature neutrophils. Overexpression of C/EBPɛ in L-G cells also stimulated G-CSF–dependent cell proliferation. High expression levels of G-CSFR were also found in the leukemic cells of AML patients with t(8;21). Therefore, G-CSF–dependent cell proliferation of myeloid precursor cells may be implicated in leukemogenesis.

scholarly journals Granulocyte Colony Stimulating Factor Induces Lipopolysaccharide (LPS) Sensitization via Upregulation of LPS Binding Protein in Rat

PLoS ONE ◽  
2013 ◽  
Vol 8 (2) ◽  
pp. e56654 ◽  
Author(s):  
Haoshu Fang ◽  
Anding Liu ◽  
Jian Sun ◽  
Alexandra Kitz ◽  
Olaf Dirsch ◽  
...  
Keyword(s):  
Binding Protein ◽  
Granulocyte Colony Stimulating Factor ◽  
Colony Stimulating Factor ◽  
Stimulating Factor ◽  
Lps Binding

Post-Translational Modification and Differential Protein Binding Partners of CCAAT Enhancer Binding Protein Alpha (C/EBPα) p42 Versus p30 May Contribute to Aberrant C/EBPα Activity in Acute Leukemia

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3577-3577
Author(s):  
Matthew Silver ◽  
Nirmalee Abayasekara ◽  
Dylan Perry ◽  
Hong Sun ◽  
Nancy Berliner ◽  
...  
Keyword(s):  
Protein Binding ◽  
Transcriptional Activity ◽  
Binding Protein ◽  
Myeloid Cells ◽  
Leukemic Cells ◽  
Myeloid Differentiation ◽  
Differential Protein ◽  
Binding Partners ◽  
Enhancer Binding Protein ◽  
Ccaat Enhancer Binding Protein

Abstract CCAAT enhancer binding protein alpha (C/EBPα) is the founding member of a family of basic region/leucine zipper (bzip) transcription factors and has been shown to be a master regulator of granulopoiesis It is expressed at high levels throughout myeloid differentiation and has been shown to bind to the promoters of multiple myeloid- specific gene promoters at different stages of myeloid maturation. Profound hematopoietic abnormalities have been reported for mice nullizygous for including a selective early block in the differentiation of C/EBPα, granulocytes. Mutations in C/EBPα have been demonstrated in a subset of patients with AML presenting with a normal karyotype. These mutations can result in the expression of a 30kD dominant negative C/EBPα isoform which contributes to loss of C/EBPα function. We have sought to understand the molecular basis for this observation. We and others have demonstrated that C/EBPα is post-translationally modified by small ubiquitin-related modifier (SUMO) at a lysine residue (K159) that lies within a region of the C/EBPα protein that can negatively affect transcriptional activity. We have demonstrated that the levels of sumoylated p42C/EBPα decrease upon normal neutrophil maturation and that transactivation of the myeloid-specific lactoferrin (LF) promoter reporter is significantly enhanced by a p42 sumoylation mutant of C/EBPα (K159A). Additionally, in oligonucleotide pull down assays, we show that sumoylated p42C/EBPα binds to the C/EBP site in the LF promoter in immature myeloid cells (which do not express LF) while loss binding and LF of sumoylation correlates with loss of p42C/EBPα expression in more mature cells. Based on these observations we is associated with the negative conclude that sumoylated p42C/EBPα regulation of LF in early myeloid cells. We further demonstrate that sumoylated p42C/EBPα remains bound to the LF promoter following ATRA induction of the leukemic NB4 cells, which do not express LF despite induction of morphologic maturation. Based on these observations we conclude that during normal myeloid differentiation, sumoylated p42C/EBPα is associated with the negative regulation of LF in early myeloid cells, and that LF expression upon maturation is associated with loss of binding of sumoylated p42 C/EBPα In leukemic cells induced toward mature neutrophils, sumoylated p42C/EBPα remains bound to the LF promoter, contributing to the lack of expression of LF in these cells. We show in addition, that p30 C/EBPα can also be sumoylated. In transactivation assays, however, sumoylated p42C/EBPα suppresses LF promoter activity more efficiently than p30C/EBPα in 293 cells. In order to identify differential protein binding partners of p30 and p42C/EBPα that could account for the differential transcriptional activity of the two isoforms, we have used a one step purification method that allows isolation of biotinylated C/EBPα p30 and p42- containing complexes using magnetic-streptavidin beads. The K562 myelomonocytic cell line stably expressing a biotin ligase (BirA) plasmid was transfected with p30C/EBPα or p42C/EBPα each containing a 23 amino acid tag at the N-terminus that allows for in vivo biotinylation. Proteins complexed with the two C/EBP isofoms have been isolated and are currently being identified by LC- MS MS analysis. Their differential association with the two isofoms of C/EBPα will be confimed by coimmunoprecipitation assays in normal myeloid and in leukemic cells. The identification of differentially bound proteins to p30 and p42 C/EBPα may identify molecular targets for future drug development.

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