An LXR – NCOA 5 gene regulatory complex directs inflammatory crosstalk‐dependent repression of macrophage cholesterol efflux
| Autor: | Alan Aderem, Jeffrey A. Ranish, Stephen A. Ramsey, Elizabeth S. Gold, Irina Podolsky, Mark A. Gillespie |
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| Rok vydání: | 2015 |
| Předmět: |
Nuclear Receptor Coactivators
Mass Spectrometry General Biochemistry Genetics and Molecular Biology Gene expression polycyclic compounds Animals Promoter Regions Genetic Liver X receptor Molecular Biology Liver X Receptors Inflammation Mice Knockout Regulation of gene expression General Immunology and Microbiology biology Macrophages General Neuroscience Articles Orphan Nuclear Receptors Toll-Like Receptor 3 Mice Inbred C57BL Crosstalk (biology) Cholesterol ATP Binding Cassette Transporter 1 Gene Expression Regulation ABCA1 biology.protein Cancer research Female lipids (amino acids peptides and proteins) RNA Polymerase II Signal transduction Corepressor Signal Transduction |
| Zdroj: | The EMBO Journal. 34:1244-1258 |
| ISSN: | 1460-2075 0261-4189 |
| DOI: | 10.15252/embj.201489819 |
| Popis: | LXR–cofactor complexes activate the gene expression program responsible for cholesterol efflux in macrophages. Inflammation antagonizes this program, resulting in foam cell formation and atherosclerosis; however, the molecular mechanisms underlying this antagonism remain to be fully elucidated. We use promoter enrichment‐quantitative mass spectrometry (PE‐QMS) to characterize the composition of gene regulatory complexes assembled at the promoter of the lipid transporter Abca1 following downregulation of its expression. We identify a subset of proteins that show LXR ligand‐ and binding‐dependent association with the Abca1 promoter and demonstrate they differentially control Abca1 expression. We determine that NCOA5 is linked to inflammatory Toll‐like receptor (TLR) signaling and establish that NCOA5 functions as an LXR corepressor to attenuate Abca1 expression. Importantly, TLR3–LXR signal crosstalk promotes recruitment of NCOA5 to the Abca1 promoter together with loss of RNA polymerase II and reduced cholesterol efflux. Together, these data significantly expand our knowledge of regulatory inputs impinging on the Abca1 promoter and indicate a central role for NCOA5 in mediating crosstalk between pro‐inflammatory and anti‐inflammatory pathways that results in repression of macrophage cholesterol efflux. |
| Databáze: | OpenAIRE |
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