[Toll-like receptor 4 promotes macrophage foam cell formation induced by oxidized low-density/β₂-glycoprotein I/β₂-glycoprotein I antibodies complex].
OBJECTIVE
To explore the role of toll-like receptor 4 (TLR4) on oxidized low-density/β₂-glycoprotein I/β₂-glycoprotein I (ox-LDL/β₂GPI/anti-β₂GPI) antibodies complex induced macrophage foam cell formation.


METHODS
The peritoneal macrophages were separated from TLR4 intact C3H/HeN mice and TLR4 defective C3H/HeJ mice. The cells were treated with ox-LDL, ox-LDL/β₂GPI, ox-LDL/anti-β₂GPI, anti-β₂GPI/β₂GPI, ox-LDL/β₂GPI/anti-β₂GPI, lipopolysaccharide (LPS) for 48 h and the foam cells were identified by Oil red O staining for intracellular lipids. The total cellular RNA and the protein lysates were collected. The levels of tissue factor (TF) mRNA in two groups were detected by real-time PCR (RT-PCR), and the expression of phosphorylated nuclear factor-κB (NF-κB) p65 was detected by Western blotting. Monocyte chemotactic protein-1 (MCP-1) secretion from peritoneal macrophages was determined by enzyme linked immunosorbent assay (ELISA) kits.


RESULTS
Compared with C3H/HeJ mice, lipid droplets in the cytoplasm of peritoneal macrophages from C3H/HeN mice were significantly increased and phosphorylation-NF-κB expression was significantly upregulated after stimulating by ox-LDL/β₂GPI/anti-β₂GPI complex (P < 0.01). TF mRNA and MCP-1 expression were also upregulated post ox-LDL/β₂GPI/anti-β₂GPI complex stimulation [TF mRNA: 0.041 ± 0.023 vs. 0.005 ± 0.003; MCP-1: (6 200.2 ± 6.4) pg/ml vs. (803.3 ± 5.5) pg/ml, P < 0.01].


CONCLUSIONS
TLR4 can enhance ox-LDL/β₂GPI/anti-β₂GPI complex induced peritoneal macrophage foam cell formation via upregulating phosphorylation-NF-κB, TF and MCP-1 expression.
School of Medical Science and Laboratory Medicine, Jiangsu University, Zhenjiang 212013, China.
Xiaolei
X
Zhang
Email: hongzhou@ujs.edu.cn.
Hong
H
Zhou
Ya
Y
Xu
Jingjing
J
Liu
Hongxiang
H
Xie
Xiangmin
X
Kong
Yachao
Y
Xie
Jinchuan
J
Yan
D000818:Animals; D000936:Antigen-Antibody Complex / Q000276:immunology*; D050197:Atherosclerosis / Q000276:immunology / Q000378:metabolism; D002478:Cells, Cultured; D005487:Foam Cells / Q000276:immunology* / Q000378:metabolism; D008077:Lipoproteins, LDL / Q000276:immunology; D017737:Macrophages, Peritoneal / Q000276:immunology* / Q000378:metabolism; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D016328:NF-kappa B / Q000378:metabolism; D013925:Thromboplastin / Q000378:metabolism; D051197:Toll-Like Receptor 4 / Q000276:immunology* / Q000378:metabolism; D053482:beta 2-Glycoprotein I / Q000276:immunology
D000936:Antigen-Antibody Complex; D008077:Lipoproteins, LDL; D016328:NF-kappa B; C493487:Tlr4 protein, mouse; D051197:Toll-Like Receptor 4; D053482:beta 2-Glycoprotein I; C099252:oxidized low density lipoprotein; D013925:Thromboplastin