title: Oxidized LDL induces phosphorylation of non-muscle myosin IIA heavy chain in macrophages.
abstract: Oxidized LDL (oxLDL) performs critical roles in atherosclerosis by inducing macrophage foam cell formation and promoting inflammation. There have been reports showing that oxLDL modulates macrophage cytoskeletal functions for oxLDL uptake and trapping, however, the precise mechanism has not been clearly elucidated. Our study examined the effect of oxLDL on non-muscle myosin heavy chain IIA (MHC-IIA) in macrophages. We demonstrated that oxLDL induces phosphorylation of MHC-IIA (Ser1917) in peritoneal macrophages from wild-type mice and THP-1, a human monocytic cell line, but not in macrophages deficient for CD36, a scavenger receptor for oxLDL. Protein kinase C (PKC) inhibitor-treated macrophages did not undergo the oxLDL-induced MHC-IIA phosphorylation. Our immunoprecipitation revealed that oxLDL increased physical association between PKC and MHC-IIA, supporting the role of PKC in this process. We conclude that oxLDL via CD36 induces PKC-mediated MHC-IIA (Ser1917) phosphorylation and this may affect oxLDL-induced functions of macrophages involved in atherosclerosis.
authors.affiliation: Department of Molecular Medicine, Ewha Womans University School of Medicine; Global Top 5 Research Program, Ewha Womans University, Seoul 158-710, Korea.
authors.forename: Young Mi
authors.initials: YM
authors.lastname: Park
mesh_terms: D000818:Animals; D018955:CD36 Antigens / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D006801:Humans; D047468:Immunoprecipitation; D008077:Lipoproteins, LDL / Q000494:pharmacology*; D008264:Macrophages / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D024507:Nonmuscle Myosin Type IIA / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D047428:Protein Kinase Inhibitors / Q000494:pharmacology
chemical_list: D018955:CD36 Antigens; D008077:Lipoproteins, LDL; D047428:Protein Kinase Inhibitors; C099252:oxidized low density lipoprotein; D011493:Protein Kinase C; D024507:Nonmuscle Myosin Type IIA