Proteomic analysis of plasma apolipoproteins in relation to atherosclerosis

Introduction: atherosclerosis is a chronic inflammatory conditioncharacterized by the accumulation of lipids and fibrous elements in the large arteries. It is known that high levels of LDL cholesterol and low levels of HDL cholesterol associate with an increased risk of developing atherosclerosis.Aim of the study: to characterize the apolipoprotein component of plasma lipoproteins isolated from atherosclerotic patients undergoing carotid endarterectomy and to identify differentially expressed apolipoproteins between patients and controls.Methods: analyses were performed on 4 pooled plasma samples from 57 healthy volunteers and 79 patientsundergoing carotid endarterectomy. Lipoproteins were isolated by isopycnic ultracentrifugation and subjected to two dimensional electrophoresis analysis followed by peptide mass fingerprinting. Moreover, on HDL fraction mono- and bi-dimensional western blotting analysis was performed.Results: several lipoprotein associated proteins were identified. Some of them were differently expressed in patients compared to controls. In particular, SAA levels were higher in VLDL, LDL and HDL and apo E levels were higher in VLDL and LDL.Conclusions: improving the knowledge on apolipoprotein composition and structure may help in revealing the role of lipoproteins in atherogenesis. Moreover the identification of new biomarkers could be useful in diagnosis and could improve the therapeutic approaches adopted for the treatment of atherosclerosis.