Table_1_Comparison of Mechanisms of Endothelial Cell Protections Between High-Density Lipoprotein and Apolipoprotein A-I Mimetic Peptide.docx

Apolipoprotein A-I (apoA-I) mimetic peptide, D-4F, exhibits anti-atherogenic effects similar to high-density lipoprotein (HDL). However, it remains elusive whether D-4F and HDL share similar molecular mechanisms underlying anti-atherogenic effects and endothelial cell protections. We here compared the metabolic changes in endothelial cells induced by D-4F and HDL against oxidized low-density lipoprotein (ox-LDL), which may be of benefit to understanding the protective mechanisms of HDL and D-4F. Functional assays, including wound healing, transwell migration, and tube formation, were used to evaluate the pro-angiogenic effects of HDL and D-4F. NMR-based metabolomic analysis was employed to explore the protective mechanisms underlying HDL and D-4F. Partial least-squares discriminant analysis (PLS-DA) was performed to assess metabolic profiles, and orthogonal PLS-DA (OPLS-DA) was carried out to identify characteristic metabolites. Moreover, significantly altered metabolic pathways were also analyzed. We found that ox-LDL impaired the migration and tube formation of endothelial cells. Metabolomic analysis showed that ox-LDL triggered oxidative stress, impaired glycolysis, and enhanced glycerophospholipid metabolism. Both HDL and D-4F improved the migration and angiogenesis of endothelial cells, alleviated oxidative stress, and ameliorated disordered glycolysis impaired by ox-LDL. Strikingly, HDL partially attenuated the disturbed glycerophospholipid metabolism, whereas D-4F did not show this effect. In summary, although D-4F shared the similar protective effects with HDL on the migration and angiogenesis of endothelial cells, it could not deduce the molecular mechanisms of HDL completely. Nevertheless, D-4F possesses the potentiality to be exploited as clinically applicable agent for endothelial cell protection and cardiovascular disease treatment.

载脂蛋白A-I（Apolipoprotein A-I, apoA-I）模拟肽D-4F的抗动脉粥样硬化效应与高密度脂蛋白（high-density lipoprotein, HDL）相似，但目前仍不清楚二者发挥抗动脉粥样硬化效应及保护内皮细胞的分子机制是否一致。本研究比较了D-4F与HDL在氧化型低密度脂蛋白（oxidized low-density lipoprotein, ox-LDL）刺激下诱导的内皮细胞代谢变化，以期为解析HDL与D-4F的保护机制提供参考。采用划痕愈合、Transwell迁移及管形成实验等功能学手段，评估HDL与D-4F的促血管生成效应；运用基于核磁共振（NMR）的代谢组学分析，探究二者的保护作用机制。通过偏最小二乘判别分析（partial least-squares discriminant analysis, PLS-DA）评估代谢谱特征，并借助正交偏最小二乘判别分析（orthogonal PLS-DA, OPLS-DA）鉴定差异特征代谢物；此外还分析了显著扰动的代谢通路。研究结果显示，ox-LDL可损伤内皮细胞的迁移与管形成能力。代谢组学分析表明，ox-LDL能够诱导氧化应激、抑制糖酵解过程并增强甘油磷脂代谢。HDL与D-4F均能改善内皮细胞的迁移与血管生成能力，减轻氧化应激，并修复ox-LDL诱导的糖酵解紊乱。值得注意的是，HDL可部分逆转紊乱的甘油磷脂代谢，而D-4F无此效应。综上，尽管D-4F在保护内皮细胞迁移与血管生成方面与HDL效应相似，但无法完全复刻HDL的分子作用机制。不过，D-4F具备开发为临床可用的内皮细胞保护剂及心血管疾病治疗药物的潜力。