An autonomous CEBPA enhancer specific for myeloid-lineage priming and neutrophilic differentiation

• Published in: Blood 2016-06, Vol.127 (24), p.2991-3003
• Main Authors: Avellino, Roberto, Havermans, Marije, Erpelinck, Claudia, Sanders, Mathijs A., Hoogenboezem, Remco, van de Werken, Harmen J.G., Rombouts, Elwin, van Lom, Kirsten, van Strien, Paulina M.H., Gebhard, Claudia, Rehli, Michael, Pimanda, John, Beck, Dominik, Erkeland, Stefan, Kuiken, Thijs, de Looper, Hans, Gröschel, Stefan, Touw, Ivo, Bindels, Eric, Delwel, Ruud
• Format: Article
• Language: English
• Subjects: Animals; CCAAT-Enhancer-Binding Protein-alpha - genetics; CCAAT-Enhancer-Binding Protein-alpha - metabolism; Cell Differentiation - genetics; Cell Line, Tumor; Cell Lineage - genetics; Enhancer Elements, Genetic; Gene Expression Regulation, Developmental; HEK293 Cells; HeLa Cells; Hematopoiesis and Stem Cells; Hep G2 Cells; HL-60 Cells; Humans; Jurkat Cells; K562 Cells; Mice; Mice, Knockout; Myeloid Cells - physiology; Myelopoiesis - genetics; Neutrophils - physiology; U937 Cells
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2016-01-695759

Neutrophilic differentiation is dependent on CCAAT enhancer-binding protein α (C/EBPα), a transcription factor expressed in multiple organs including the bone marrow. Using functional genomic technologies in combination with clustered regularly-interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 genome editing and in vivo mouse modeling, we show that CEBPA is located in a 170-kb topological-associated domain that contains 14 potential enhancers. Of these, 1 enhancer located +42 kb from CEBPA is active and engages with the CEBPA promoter in myeloid cells only. Germ line deletion of the homologous enhancer in mice in vivo reduces Cebpa levels exclusively in hematopoietic stem cells (HSCs) and myeloid-primed progenitor cells leading to severe defects in the granulocytic lineage, without affecting any other Cebpa-expressing organ studied. The enhancer-deleted progenitor cells lose their myeloid transcription program and are blocked in differentiation. Deletion of the enhancer also causes loss of HSC maintenance. We conclude that a single +42-kb enhancer is essential for CEBPA expression in myeloid cells only. •The CEBPA locus harbors 14 enhancers of which distinct combinations are active in different CEBPA-expressing tissues.•A +42-kb enhancer is required for myeloid-lineage priming to drive adequate CEBPA expression levels necessary for neutrophilic maturation.