title: Exposure to atheroma-relevant 7-oxysterols causes proteomic alterations in cell death, cellular longevity, and lipid metabolism in THP-1 macrophages.
abstract: The 7-oxysterols are recognised as strong enhancers of inflammatory processes in foamy macrophages. Atheroma-relevant 7-oxysterol mixtures induce a mixed type of cell death in macrophages, and trigger cellular oxidative stress responses, which mimic oxidative exposures observed in atherosclerotic lesions. However, the macrophage proteome has not previously been determined in the 7-oxysterol treated cell model. The aim of the present study was to determine the specific effects of an atheroma-relevant 7-oxysterol mixture on human macrophage proteome. Human THP-1 macrophages were exposed to an atheroma-relevant mixture of 7β-hydroxycholesterol and 7-ketocholesterol. Two-dimensional gel electrophoresis and mass spectrometry techniques were used to analyse the alterations in macrophage proteome, which resulted in the identification of 19 proteins with significant differential expression upon oxysterol loading; 8 increased and 11 decreased. The expression patterns of 11 out of 19 identified significant proteins were further confirmed by tandem-mass spectrometry, including further validation of increased histone deacetylase 2 and macrophage scavenger receptor types I and II expressions by western blot analysis. Identified proteins with differential expression in the cell model have been associated with i) signalling imbalance in cell death and cellular longevity; ii) lipid uptake and metabolism in foam cells; and iii) inflammatory proteins. The presented findings highlight a new proteomic platform for further studies into the functional roles of macrophages in atherosclerosis, and present a cell model for future studies to modulate the macrophage proteome by potential anti-atherosclerotic agents.
authors.affiliation: Occupational and Environmental Medicine Center, and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.|Division of Obstetrics and Gynaecology, and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
authors.forename: Liam J
authors.identifier: http://orcid.org/0000-0002-3320-1461
authors.initials: LJ
authors.lastname: Ward
authors.affiliation: Occupational and Environmental Medicine Center, and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
authors.forename: Stefan A
authors.initials: SA
authors.lastname: Ljunggren
authors.affiliation: Occupational and Environmental Medicine Center, and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
authors.forename: Helen
authors.initials: H
authors.lastname: Karlsson
authors.affiliation: Division of Obstetrics and Gynaecology, and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.affiliation: Occupational and Environmental Medicine Center, and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
authors.forename: Xi-Ming
authors.initials: XM
authors.lastname: Yuan
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D001343:Autophagy / Q000187:drug effects; D015153:Blotting, Western; D016923:Cell Death / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D015180:Electrophoresis, Gel, Two-Dimensional; D006801:Humans; D006888:Hydroxycholesterols / Q000494:pharmacology; D007653:Ketocholesterols / Q000494:pharmacology; D050356:Lipid Metabolism / Q000187:drug effects*; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism; D000072376:Oxysterols / Q000378:metabolism / Q000494:pharmacology*; D058226:Plaque, Atherosclerotic / Q000378:metabolism; D020543:Proteome / Q000378:metabolism*; D040901:Proteomics / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D053719:Tandem Mass Spectrometry; D013997:Time Factors
chemical_list: D006888:Hydroxycholesterols; D007653:Ketocholesterols; D000072376:Oxysterols; D020543:Proteome; C003001:7-ketocholesterol