Multipotent hematopoietic cell lines derived from C/EBPalpha(-/-) knockout mice display granulocyte macrophage-colony-stimulating factor, granulocyte- colony-stimulating factor, and retinoic acid-induced granulocytic differentiation

Blood. 2001 Oct 15;98(8):2382-8. doi: 10.1182/blood.v98.8.2382.

Abstract

The transcription factor C/EBPalpha is an important mediator of granulocyte differentiation and regulates the expression of multiple granulocyte-specific genes including the granulocyte-colony-stimulating factor (G-CSF) receptor, neutrophil elastase, and myeloperoxidase. Indeed C/EBPalpha knockout mice display a profound block in granulocyte differentiation. To study this block in granulocytic differentiation in more detail, retroviral vector-mediated transduction of a dominant-negative retinoic acid receptor was used to establish hematopoietic growth factor-dependent, lympho-myeloid progenitor cell lines from the fetal livers of both the C/EBPalpha knockout animals (C/EBPalpha(-/-)) and their heterozygous littermates (C/EBPalpha(+/-)). Surprisingly, the C/EBPalpha(-/-) cell lines displayed significant spontaneous granulocytic differentiation, and this differentiation was markedly enhanced when the cells were stimulated with granulocyte macrophage (GM)-CSF. This GM-CSF-mediated differentiation was associated with the up-regulation of G-CSF receptor mRNA, and the combination of GM-CSF and G-CSF generated more than 95% mature neutrophils in the C/EBPalpha(-/-) cultures. The addition of all-trans retinoic acid also enhanced this granulocytic differentiation of the cultured C/EBPalpha(-/-) cells, indicating that the activated retinoic acid receptors can enhance granulocytic differentiation through a molecular pathway that is independent of C/EBPalpha. These studies clearly indicate that terminal granulocytic differentiation associated with the up-regulation of C/EBPalpha-responsive genes can occur in the absence of C/EBPalpha, and they indicate the existence of multiple independent molecular pathways potentially used by primitive hematopoietic precursors that can lead to the development of mature granulocytes.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Blotting, Northern
  • CCAAT-Enhancer-Binding Protein-alpha / deficiency
  • CCAAT-Enhancer-Binding Protein-alpha / genetics
  • CCAAT-Enhancer-Binding Protein-alpha / physiology*
  • Cell Differentiation / physiology*
  • Cell Line
  • Genotype
  • Granulocyte Colony-Stimulating Factor / blood*
  • Granulocyte-Macrophage Colony-Stimulating Factor / blood*
  • Granulocytes / cytology*
  • Liver / cytology
  • Liver / embryology
  • Mice
  • Mice, Knockout
  • RNA / blood
  • RNA / genetics
  • RNA / isolation & purification
  • Reference Values
  • Retroviridae / genetics
  • Up-Regulation
  • Virus Integration

Substances

  • CCAAT-Enhancer-Binding Protein-alpha
  • Granulocyte Colony-Stimulating Factor
  • RNA
  • Granulocyte-Macrophage Colony-Stimulating Factor