Reduced beta2-glycoprotein I protects macrophages from ox-LDL-induced foam cell formation and cell apoptosis

Abstract

BackgroundReduced beta2-glycoprotein I (beta2-GPI) is a free thiol-containing form of beta2-GPI that displays a powerful effect in protecting endothelial cells from oxidative stress-induced cell death. The present study aims to investigate the effect of beta2-GPI or reduced beta2-GPI on ox-LDL-induced foam cell formation and on cell apoptosis and to determine the possible mechanisms.MethodsThe RAW264.7 macrophage cell line was selected as the experimental material. Oil red O staining and cholesterol measurement were used to detect cholesterol accumulation qualitatively and quantitatively, respectively. Flow cytometry was used to detect cell apoptosis. Real-time quantitative PCR was used to detect the mRNA expression of the main proteins that are associated with the transport of cholesterol, such as CD36, SRB1, ABCA1 and ABCG1. Western blot analysis was used to detect the protein expression of certain apoptosis-related proteins, such as caspase-9, caspase-3, p38 MAPK/p-p38 MAPK and JNK/p-JNK.ResultsBeta2-GPI or reduced beta2-GPI decreased ox-LDL-induced cholesterol accumulation (96.45 ± 8.51 μg/mg protein vs. 114.35 ± 10.38 μg/mg protein, p < 0.05;74.44 ± 5.27 μg/mg protein vs. 114.35 ± 10.38 μg/mg protein, p < 0.01) and cell apoptosis (30.00 ± 5.10% vs. 38.70 ± 7.76%, p < 0.05; 20.66 ± 2.50% vs. 38.70 ± 7.76%, p < 0.01), and there are significant differences between beta2-GPI and reduced beta2-GPI (p < 0.05). Reduced beta2-GPI decreased the ox-LDL-induced expression of CD36 mRNA and ABCA1 mRNA (p < 0.05), as well as CD36, cleaved caspase-9, cleaved caspase-3, p-p38 MAPK and p-JNK proteins (p < 0.05 or p < 0.01). Beta2-GPI did not significantly decrease the expression of ABCA1 mRNA and the p-p38 MAPK protein.ConclusionsBoth beta2-GPI and reduced beta2-GPI inhibit ox-LDL-induced foam cell formation and cell apoptosis, and the latter exhibits a stronger inhibition effect. Both of these glycoproteins reduce the lipid intake of macrophages by downregulating CD36 as well as protein expression. Reduced beta2-GPI inhibits cell apoptosis by reducing the ox-LDL-induced phosphorylation of p38 MAPK and JNK, and the amount of cleaved caspase-3 and caspase-9. Beta2-GPI does not inhibit the ox-LDL-induced phosphorylation of p38 MAPK.

Resveratrol Suppresses Oxidised Low-Density Lipoprotein-Induced Macrophage Apoptosis through Inhibition of Intracellular Reactive Oxygen Species Generation, LOX-1, and the p38 MAPK Pathway

“…Despite its lower expression, p38β can potentially perform overlapping roles with p38α, whereas p38γ and p38δ have more restricted expression patterns [45]. Recently, many studies have reported that the inhibition of p38 MAPK phosphorylation could either lead to or explain the beneficial effects of particular compound and proteins on cell apoptosis [46,47,48]. In the present investigation, we focussed on the relationship between RSV and p38 MAPK in the ox-LDL-mediated apoptosis of RAW264.7 macrophages.…”

Dilate Kardiyomiyopatili Köpeklerde Serum ve Asites Sıvısı Proteomlarının Araştırılması

“…Among connected results, decreased level of serum Apo-H might be a result of protection mechanism against oxidative stress induced by apoptotic ischemic cells. Consistent with this hypothesis, Apo-H was shown to be present in atherosclerotic plaques [22] and involved in apoptosis process at surfaces of cells undergoing apoptosis [21,23] .…”

Redox Status ofβ2GPI in Different Stages of Diabetic Angiopathy

“…Reduced β 2 GPI can inhibit the formation of foam cells, reduce macrophage apoptosis [5], and protect endothelial cells from oxidative stress-induced cell injury [4]. Our results implicated that the change of redox state of β 2 GPI would affect its functions.…”

“…Research shows that the APS patients have significantly higher serum oxidized β 2 GPI level than that in healthy controls, and reduced β 2 GPI level is significantly reduced in APS patients. Our previous work has shown that reduced β 2 GPI could inhibit the formation of foam cells and macrophage apoptosis [5], protect endothelial cells from oxidative stress-induced cell injury [4], inhibit retinal angiogenesis in diabetic rats, and reduce expression of collagen type IV in diabetic kidney. Conversely, an imbalanced redox state of β 2 GPI may be important to increase thrombotic events in APS, and β 2 GPI levels could form the basis of thrombosis risk [2].…”