title: Inhibiting epigenetic enzymes to improve atherogenic macrophage functions.
abstract: Macrophages determine the outcome of atherosclerosis by propagating inflammatory responses, foam cell formation and eventually necrotic core development. Yet, the pathways that regulate their atherogenic functions remain ill-defined. It is now apparent that chromatin remodeling chromatin modifying enzymes (CME) governs immune responses but it remains unclear to what extent they control atherogenic macrophage functions. We hypothesized that epigenetic mechanisms regulate atherogenic macrophage functions, thereby determining the outcome of atherosclerosis. Therefore, we designed a quantitative semi-high-throughput screening platform and studied whether the inhibition of CME can be applied to improve atherogenic macrophage activities. We found that broad spectrum inhibition of histone deacetylases (HDACs) and histone methyltransferases (HMT) has both pro- and anti-inflammatory effects. The inhibition of HDACs increased histone acetylation and gene expression of the cholesterol efflux regulators ATP-binding cassette transporters ABCA1 and ABCG1, but left foam cell formation unaffected. HDAC inhibition altered macrophage metabolism towards enhanced glycolysis and oxidative phosphorylation and resulted in protection against apoptosis. Finally, we applied inhibitors against specific HDACs and found that HDAC3 inhibition phenocopies the atheroprotective effects of pan-HDAC inhibitors. Based on our data, we propose the inhibition of HDACs, and in particular HDAC3, in macrophages as a novel potential target to treat atherosclerosis.
authors.affiliation: Department of Medical Biochemistry, Experimental Vascular Biology, Academic Medical Center, Amsterdam, The Netherlands. Electronic address: j.vandenbossche@amc.uva.nl.
authors.forename: Jan
authors.initials: J
authors.lastname: Van den Bossche
authors.affiliation: Department of Medical Biochemistry, Experimental Vascular Biology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Annette E
authors.initials: AE
authors.lastname: Neele
authors.affiliation: Department of Medical Biochemistry, Experimental Vascular Biology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Marten A
authors.initials: MA
authors.lastname: Hoeksema
authors.affiliation: Department of Medical Biochemistry, Experimental Vascular Biology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Femke
authors.initials: F
authors.lastname: de Heij
authors.affiliation: Department of Medical Biochemistry, Experimental Vascular Biology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Marieke C S
authors.initials: MC
authors.lastname: Boshuizen
authors.affiliation: Department of Medical Biochemistry, Experimental Vascular Biology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Saskia
authors.initials: S
authors.lastname: van der Velden
authors.affiliation: Laboratory Genetic Metabolic Diseases, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Vincent C
authors.initials: VC
authors.lastname: de Boer
authors.affiliation: Department of Rheumatology and Clinical Immunology, Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Kris A
authors.initials: KA
authors.lastname: Reedquist
authors.affiliation: Department of Medical Biochemistry, Experimental Vascular Biology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Menno P J
authors.initials: MP
authors.lastname: de Winther
mesh_terms: D000107:Acetylation; D000818:Animals; D017209:Apoptosis; D050197:Atherosclerosis / Q000378:metabolism*; D002460:Cell Line; D002843:Chromatin / Q000378:metabolism; D044127:Epigenesis, Genetic; D005269:Femur / Q000378:metabolism; D005487:Foam Cells / Q000166:cytology; D005786:Gene Expression Regulation; D056572:Histone Deacetylase Inhibitors / Q000737:chemistry; D006655:Histone Deacetylases / Q000378:metabolism; D006657:Histones / Q000737:chemistry; D008264:Macrophages / Q000166:cytology* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D010641:Phenotype; D013977:Tibia / Q000378:metabolism
chemical_list: D002843:Chromatin; D056572:Histone Deacetylase Inhibitors; D006657:Histones; D006655:Histone Deacetylases
keywords: Atherosclerosis; Chromatin modifying enzymes (CME); Epigenetics; Histone deacetylases (HDACs); Inflammation; Macrophages