title: Latent enhancers activated by stimulation in differentiated cells.
abstract: According to current models, once the cell has reached terminal differentiation, the enhancer repertoire is completely established and maintained by cooperatively acting lineage-specific transcription factors (TFs). TFs activated by extracellular stimuli operate within this predetermined repertoire, landing close to where master regulators are constitutively bound. Here, we describe latent enhancers, defined as regions of the genome that in terminally differentiated cells are unbound by TFs and lack the histone marks characteristic of enhancers but acquire these features in response to stimulation. Macrophage stimulation caused sequential binding of stimulus-activated and lineage-determining TFs to these regions, enabling deposition of enhancer marks. Once unveiled, many of these enhancers did not return to a latent state when stimulation ceased; instead, they persisted and mediated a faster and stronger response upon restimulation. We suggest that stimulus-specific expansion of the cis-regulatory repertoire provides an epigenomic memory of the exposure to environmental agents.
authors: Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139 Milan, Italy. renato.ostuni@ieo.eu
authors: Renato
authors: R
authors: Ostuni
authors: Viviana
authors: V
authors: Piccolo
authors: Iros
authors: I
authors: Barozzi
authors: Sara
authors: S
authors: Polletti
authors: Alberto
authors: A
authors: Termanini
authors: Silvia
authors: S
authors: Bonifacio
authors: Alessia
authors: A
authors: Curina
authors: Elena
authors: E
authors: Prosperini
authors: Serena
authors: S
authors: Ghisletti
authors: Gioacchino
authors: G
authors: Natoli
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D004742:Enhancer Elements, Genetic; D057890:Epigenomics; D005786:Gene Expression Regulation; D042421:Histone Code; D008070:Lipopolysaccharides / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D015534:Trans-Activators / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D000099232:Proto-Oncogene Protein Spi-1
chemical_list: D008070:Lipopolysaccharides; D011518:Proto-Oncogene Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D000099232:Proto-Oncogene Protein Spi-1