Rossmann Christine, Nusshold Christoph, Paar Margret, Ledinski Gerhard, Tafeit Erwin, Koestenberger Martin, Bernhart Eva Maria, Sattler Wolfgang, Cvirn Gerhard, Hallström Seth
Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria.
Department of Pediatrics, Medical University of Graz, Graz, Austria.
PLoS One. 2018 Jan 25;13(1):e0191477. doi: 10.1371/journal.pone.0191477. eCollection 2018.
Ethyl pyruvate (EP) exerts anti-inflammatory and anti-oxidative properties. The aim of our study was to investigate whether EP is capable of inhibiting the oxidation of LDL, a crucial step in atherogenesis. Additionally, we examined whether EP attenuates the cytotoxic effects of highly oxidized LDL in the human vascular endothelial cell line EA.hy926.
Native LDL (nLDL) was oxidized using Cu2+ ions in the presence of increasing amounts of EP. The degree of LDL oxidation was quantified by measuring lipid hydroperoxide (LPO) and malondialdehyde (MDA) concentrations, relative electrophoretic mobilities (REMs), and oxidation-specific immune epitopes. The cytotoxicity of these oxLDLs on EA.hy926 cells was assessed by measuring cell viability and superoxide levels. Furthermore, the cytotoxicity of highly oxidized LDL on EA.hy926 cells under increasing concentrations of EP in the media was assessed including measurements of high energy phosphates (ATP).
Oxidation of nLDL using Cu2+ ions was remarkably inhibited by EP in a concentration-dependent manner, reflected by decreased levels of LPO, MDA, REM, oxidation-specific epitopes, and diminished cytotoxicity of the obtained oxLDLs in EA.hy926 cells. Furthermore, the cytotoxicity of highly oxidized LDL on EA.hy926 cells was remarkably attenuated by EP added to the media in a concentration-dependent manner reflected by a decrease in superoxide and an increase in viability and ATP levels.
EP has the potential for an anti-atherosclerotic drug by attenuating both, the oxidation of LDL and the cytotoxic effect of (already formed) oxLDL in EA.hy926 cells. Chronic administration of EP might be beneficial to impede the development of atherosclerotic lesions.
丙酮酸乙酯（EP）具有抗炎和抗氧化特性。我们研究的目的是调查EP是否能够抑制低密度脂蛋白（LDL）的氧化，这是动脉粥样硬化形成中的关键步骤。此外，我们还研究了EP是否能减轻高度氧化的LDL对人血管内皮细胞系EA.hy926的细胞毒性作用。
在存在递增剂量EP的情况下，使用铜离子（Cu2+）氧化天然LDL（nLDL）。通过测量脂质过氧化氢（LPO）和丙二醛（MDA）浓度、相对电泳迁移率（REM）以及氧化特异性免疫表位来量化LDL的氧化程度。通过测量细胞活力和超氧化物水平来评估这些氧化型LDL（oxLDL）对EA.hy926细胞的细胞毒性。此外，评估了在培养基中EP浓度递增的情况下，高度氧化的LDL对EA.hy926细胞的细胞毒性，包括测量高能磷酸盐（ATP）。
EP以浓度依赖性方式显著抑制了用铜离子氧化nLDL，这表现为LPO、MDA、REM、氧化特异性表位水平降低，以及所获得的oxLDL对EA.hy926细胞的细胞毒性减弱。此外，添加到培养基中的EP以浓度依赖性方式显著减轻了高度氧化的LDL对EA.hy926细胞的细胞毒性，这表现为超氧化物减少、活力增加以及ATP水平升高。
EP有可能成为一种抗动脉粥样硬化药物，因为它既能减轻EA.hy926细胞中LDL的氧化，又能减轻（已形成的）oxLDL的细胞毒性作用。长期给予EP可能有助于阻止动脉粥样硬化病变的发展。
