Denimal Damien, Monier Serge, Brindisi Marie-Claude, Petit Jean-Michel, Bouillet Benjamin, Nguyen Amandine, Demizieux Laurent, Simoneau Isabelle, Pais de Barros Jean-Paul, Vergès Bruno, Duvillard Laurence
From the University Bourgogne Franche-Comté, LNC UMR1231, Dijon, France (D.D., S.M., M.-C.B., J.-M.P., B.B., A.N., L.D., I.S., B.V., L.D.); INSERM, LNC UMR1231, Dijon, France (D.D., S.M., M.-C.B., J.-M.P., B.B., L.D., I.S., J.-P.P.d.B., B.V., L.D.); Department of Biochemistry, University Hospital Dijon-Burgundy, Dijon, France (D.D., L.D.); Department of Endocrinology and Metabolic Diseases, University Hospital Dijon-Burgundy, Dijon, France (M.-C.B., J.-M.P., B.B., A.N., I.S., B.V.); and Lipidomic Analytical Platform, Bâtiment B3, Dijon, France (J.-P.P.d.B.).
Arterioscler Thromb Vasc Biol. 2017 May;37(5):804-811. doi: 10.1161/ATVBAHA.117.309287. Epub 2017 Mar 30.
High-density lipoprotein (HDL) from nondiabetic patients with metabolic syndrome (MetS) displays abnormalities in their lipidome, such as triglyceride enrichment and sphingosine-1-phosphate depletion. We hypothesized that these abnormalities could impair the ability of HDL to stimulate endothelial nitric oxide synthase (eNOS).
Compared with HDL from control subjects, HDL from normoglycemic patients with MetS was 39% richer in triglycerides (<0.01) and 15% poorer in sphingosine-1-phosphate (<0.05; n=23 in each group). eNOS activity, assessed by the conversion of L-[H]arginine to L-[H]citrulline, was 69% lower in human umbilical vein endothelial cells incubated with HDL from MetS patients than in cells incubated with HDL from controls (<0.0001). In addition, the activating phosphorylation of eNOS at serine (Ser) 1177 and of Akt (protein kinase B) at Ser473 was 37% (<0.001) and 39% (<0.05) lower, respectively, with HDL from MetS patients. Sphingosine-1-phosphate enrichment of HDL from MetS patients restored their ability to stimulate eNOS activity (<0.05), in relation with a significant increase in eNOS phosphorylation at Ser1177 (<0.05) and in Akt phosphorylation at Ser473 (=0.05). By contrast, triglyceride enrichment of HDL from control subjects did not modify eNOS activity (=0.90) and phosphorylation at Ser1177 (=0.87).
We provide evidence that the activation of eNOS by HDL is decreased in MetS patients before the appearance of diabetes mellitus and that sphingosine-1-phosphate depletion of HDL is the main factor responsible for this defect. This has important consequences on the impairment of HDL functionality and antiatherogenic properties in these patients.
非糖尿病代谢综合征（MetS）患者的高密度脂蛋白（HDL）在脂质组方面存在异常，如甘油三酯富集和1 -磷酸鞘氨醇耗竭。我们推测这些异常可能会损害HDL刺激内皮型一氧化氮合酶（eNOS）的能力。
与对照组受试者的HDL相比，血糖正常的MetS患者的HDL甘油三酯含量高39%（<0.01），1 -磷酸鞘氨醇含量低15%（<0.05；每组n = 23）。通过L - [H]精氨酸转化为L - [H]瓜氨酸来评估eNOS活性，与用对照组HDL孵育的细胞相比，用MetS患者HDL孵育的人脐静脉内皮细胞中eNOS活性低69%（<0.0001）。此外，MetS患者HDL使eNOS丝氨酸（Ser）1177位点和Akt（蛋白激酶B）Ser473位点的激活磷酸化分别降低37%（<0.001）和39%（<0.05）。MetS患者HDL的1 -磷酸鞘氨醇富集恢复了其刺激eNOS活性的能力（<0.05），这与Ser1177位点eNOS磷酸化显著增加（<0.05）以及Ser473位点Akt磷酸化增加（=0.05）有关。相比之下，对照组HDL的甘油三酯富集并未改变eNOS活性（=0.90）和Ser1177位点的磷酸化（=0.87）。
我们提供的证据表明，在糖尿病出现之前，MetS患者中HDL对eNOS的激活作用降低，且HDL的1 -磷酸鞘氨醇耗竭是导致这一缺陷的主要因素。这对这些患者HDL功能和抗动脉粥样硬化特性的损害具有重要影响。
