| First Author | Zhang X | Year | 2014 |
| Journal | J Atheroscler Thromb | Volume | 21 |
| Issue | 11 | Pages | 1140-51 |
| PubMed ID | 24998486 | Mgi Jnum | J:331850 |
| Mgi Id | MGI:6829697 | Doi | 10.5551/jat.24372 |
| Citation | Zhang X, et al. (2014) Involvement of TLR4 in oxidized LDL/beta2GPI/anti-beta2GPI-induced transformation of macrophages to foam cells. J Atheroscler Thromb 21(11):1140-51 |
| abstractText | AIM: It has been reported that oxidized low-density lipoprotein (oxLDL) forms a stable and non-dissociable complex with beta2-glycoprotein I (beta2GPI) and that IgG anti-beta2GPI autoantibodies are able to recognize this complex, thus facilitating macrophage-derived foam cell formation in patients with antiphospholipid syndrome (APS). However, the immunopathological mechanisms of oxLDL/beta2GPI complexes in promoting foam cell formation are not fully understood. In this study, we examined the role of toll-like receptor 4 (TLR4) in the oxLDL/beta2GPI/anti-beta2GPI complex-induced transformation of mouse peritoneal macrophages to foam cells. METHODS: Oil red O staining and optical density (OD) measurements of intracellular stained oil red O solution were used to monitor the transformation of peritoneal macrophages to foam cells in TLR4-competent C3H/HeN and TLR4-mutant C3H/HeJ mice. During foam cell formation induced by the oxLDL/beta2GPI/anti-beta2GPI complex, the expression of TLR4 and activation of nuclear factor kappa B (NF-kappaB) were confirmed by analyzing the protein and mRNA levels of these compounds. Furthermore, the related active molecule expression during foam cell formation induced by the oxLDL/beta2GPI/anti-beta2GPI complex was examined in the presence or absence of TLR4. RESULTS: The data showed that treatment with the oxLDL/beta2GPI/anti-beta2GPI complex markedly increased foam cell formation, the TLR4 expression, NF-kappaB activation, the tissue factor (TF) expression and tumor necrosis factor-alpha (TNF-alpha) and monocyte chemotactic protein-1 (MCP-1) secretion in the C3H/HeN mice. However, the transformation of macrophages to foam cells and the expression levels of phosphorylated NF-kappaB, TF, TNF-alpha and MCP-1 were significantly reduced in the C3H/HeJ mice treated with the oxLDL/beta2GPI/anti-beta2GPI complex. In addition, compared with that achieved by oxLDL alone, the oxLDL/beta2GPI complex decreased foam cell formation and the related signaling molecule expression in the C3H/HeN mice. CONCLUSIONS: Our results indicate that TLR4 plays an important role in the process of oxLDL/beta2GPI/anti-beta2GPI complex-induced transformation of macrophages to foam cells, which may accelerate the development of atherosclerosis in the setting of APS. However, beta2GPI alone functions as an antiatherogenic protein by preventing the foam cell formation induced by oxLDL. |
