title: Modelling atherosclerosis by proteomics: Molecular changes in the ascending aortas of cholesterol-fed rabbits.
abstract: The cholesterol-fed rabbit is commonly used as a model to study the vascular effects of hypercholesterolemia and resulting atherosclerotic lesions. Here we undertook a proteomic case-control investigation of ascending aortas from male New Zealand White rabbits after 10 weeks on a high-cholesterol (2% w/w) diet (HCD, n = 5) or control diet (n = 5), in order to determine the changes in response to the HCD. Histology confirmed intimal thickening in the HCD group consistent with atherosclerosis, and LC-MS/MS analysis of individually-obtained ascending aortic extracts labelled with isobaric (iTRAQ) tags enabled the identification and quantitation of 453 unique proteins above the 1% false discovery rate threshold. Of 67 proteins showing significant differences in relative abundance (p < 0.05), 62 were elevated and five decreased in ascending aortas from HCD-fed rabbits compared to controls. Six proteins were selected for validation using Multiple Reaction Monitoring, which confirmed the iTRAQ results. Many of the observed protein changes are consistent with known molecular perturbations in the ascending aorta that occur in response to hypercholesterolemia, e.g. elevation of tissue levels of apolipoproteins, extracellular matrix adhesion proteins, glycolytic enzymes, heat shock proteins and proteins involved in immune defense. We also made a number of novel observations, including a 15-fold elevation of glycoprotein (trans-membrane) nmb-like (Gpnmb) in response to HCD. Gpnmb has previously been linked to angiogenesis but not to atherosclerosis. This and additional novel observations merit further investigation as these perturbations may play important and as yet undiscovered roles in the pathogenesis of atherosclerosis in rabbits as well as humans.
authors.affiliation: School of Biological Sciences, University of Auckland, Auckland, New Zealand; Maurice Wilkins Centre for Molecular BioDiscovery, Faculty of Science, University of Auckland, Auckland, New Zealand. Electronic address: jingshu.xu@auckland.ac.nz.
authors.forename: Jingshu
authors.initials: J
authors.lastname: Xu
authors.affiliation: School of Biological Sciences, University of Auckland, Auckland, New Zealand; Maurice Wilkins Centre for Molecular BioDiscovery, Faculty of Science, University of Auckland, Auckland, New Zealand; Auckland Science Analytical Services, Faculty of Science, University of Auckland, Auckland, New Zealand. Electronic address: m.jullig@auckland.ac.nz.
authors.forename: Mia
authors.initials: M
authors.lastname: Jüllig
authors.affiliation: School of Biological Sciences, University of Auckland, Auckland, New Zealand; Auckland Science Analytical Services, Faculty of Science, University of Auckland, Auckland, New Zealand. Electronic address: m.middleditch@auckland.ac.nz.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Middleditch
authors.affiliation: School of Biological Sciences, University of Auckland, Auckland, New Zealand; Maurice Wilkins Centre for Molecular BioDiscovery, Faculty of Science, University of Auckland, Auckland, New Zealand; Department of Pharmacology, Medical Sciences Division, University of Oxford, Oxford, UK; Centre for Advanced Discovery and Experimental Therapeutics, NIHR Manchester Biomedical Research Centre, the University of Manchester, Manchester, UK. Electronic address: g.cooper@auckland.ac.nz.
authors.forename: Garth J S
authors.initials: GJ
authors.lastname: Cooper
mesh_terms: D000818:Animals; D001011:Aorta / Q000378:metabolism* / Q000473:pathology; D001018:Aortic Diseases / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D050197:Atherosclerosis / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D015415:Biomarkers / Q000378:metabolism; D002791:Cholesterol, Dietary; D002851:Chromatography, High Pressure Liquid; D004195:Disease Models, Animal; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D040901:Proteomics / Q000379:methods; D011817:Rabbits; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry
chemical_list: D015415:Biomarkers; D002791:Cholesterol, Dietary; D008562:Membrane Glycoproteins; D011506:Proteins
keywords: Ascending aorta; Atherosclerosis; Gpnmb; Histology; Proteomics; Rabbit model; iTRAQ