272 - Shotgun proteomics-identified alternations in glycosylation patterns in LDL-R KO aorta. (ID 1223)
Abstract
Background and Aims
Background: Vascular wall proteins undergo several post-translation modifications, including N glycosylation. Our aim was to investigate changes in N-glycosylation pathways during atherosclerotic plaque development in animal models.
Methods
Methods: Shotgun proteomics was performed in aorta from LDL-R KO mice, fed in chow or WTD diet using orbitrap Fusion™ Tribrid ™ Mass Spectrometer followed by protein inference, label free quantification and pathway enrichment analysis.
Results
Results: Apoptosis, fibrosis, and ROS production were upregulated (z-score 2,9 to 2.2) while cholesterol efflux, phagocytosis and ATP production resulted decreased (z-score -1.6 to -2.7) in the aorta of WTD fed mice compared to chow. When the analysis was focused on enzymes for N-glycosylation cascade, OST1, which controls glycans transfer from Dolicol-P-P to asparagine in ER, was up-regulated (p=0.02) while glucosidases (Ganab, Prkcsh) which favor proper protein folding in concert with the lectin chaperon Calnexin/Calreticulin and ERp57 were downregulated. In parallel ERGIC-53 that operates the transport of glycoproteins from ER to Golgi was significantly down-regulated (p<0.01) while BiP which increases during unfolding proteins response was up-regulated. These data suggest that a reduced production of glycosylated proteins occurs during atherosclerosis coupled to an increased unfolded protein response in the plaque. Indeed, the abundance and side-specific N-glycosylation of integrin β-1, laminin subunit γ -1, integrin α-8 were reduced in the plaque of WTD fed mice.
Conclusions
Conclusion: Our data suggest that altered protein glycosylation takes place in the aorta of WTD fed LDL-R KO mice. This can further affect the synthesis of atheroprotective glycoproteins.
