Native low density lipoprotein promotes lipid raft formation in macrophages

• Type of Material: Article
• Authors: Jian Song, Wuhan University; Lingyan Ping, Emory University; Duc M. Duong, Emory University; Xiao-Yan Gao, Wuhan University; Chun-Yan He, Wuhan University; Lei Wei, Wuhan University; Jun-Zhu Wu, Wuhan University
• Language: English
• Date: 2016-03-01
• Publisher: SPANDIDOS PUBL LTD
• Publication Version: Final Published Version
• Copyright Statement: © Song et al.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.3892/mmr.2016.4781
• Title of Journal or Parent Work: MOLECULAR MEDICINE REPORTS
• Volume: 13
• Issue: 3
• Start Page: 2087
• End Page: 2093
• Grant/Funding Information: The present study was supported by grants from the National Natural Science Foundation of China (grant no. 81170273).
• Keywords: MONOCYTES; MECHANISMS; LDL; low density lipoprotein; Life Sciences & Biomedicine; macrophages; Oncology; PLASMA-MEMBRANE; lipid rafts; ERP29; atherosclerosis; proteomics; Research & Experimental Medicine; OXIDATION; Medicine, Research & Experimental; Science & Technology; MYELOPEROXIDASE
• Research Categories: Health Sciences, Oncology; Biology, Molecular; Physics, Molecular; Chemistry, Biochemistry

Abstract

Oxidized low-density lipoprotein (LDL) has an important role in atherogenesis; however, the mechanisms underlying cell-mediated LDL oxidation remain to be elucidated. The present study investigated whether native-LDL induced lipid raft formation, in order to gain further insight into LDL oxidation. Confocal microscopic analysis revealed that lipid rafts were aggregated or clustered in the membrane, which were colocalized with myeloperoxidase (MPO) upon native LDL stimulation; however, in the presence of methyl-β-cyclodextrin (MβCD), LDL-stimulated aggregation, translocation, and colocalization of lipid rafts components was abolished.. In addition, lipid raft disruptors MβCD and filipin decreased malondialdehyde expression levels. Density gradient centrifugation coupled to label-free quantitative proteomic analysis identified 1,449 individual proteins, of which 203 were significantly upregulated following native-LDL stimulation. Functional classification of the proteins identified in the lipid rafts revealed that the expression levels of translocation proteins were upregulated. In conclusion, the results of the present study indicated that native-LDL induced lipid raft clustering in macrophages, and the expression levels of several proteins were altered in the stimulated macrophages, which provided novel insights into the mechanism underlying LDL oxidation.