Glycoxidized low-density lipoprotein downregulates endothelial nitricoxide synthase in human coronary cells.
Glycoxidized low-density lipoprotein downregulates endothelial nitricoxide synthase in human coronary cells.
复制标题
糖氧化低密度脂蛋白下调人冠状细胞中的内皮一氧化氮合酶。
DOI：
10.1016/s0735-1097(02)02306-9
复制
发表时间：
2002
影响因子：
24
通讯作者：
Ignarro,LouisJ
中科院分区：
文献类型：
--
作者：
Napoli,Claudio;Lerman,LilachO;deNigris,Filomena;Loscalzo,Joseph;Ignarro,LouisJ
目的我们研究了氧化和糖基化的低密度脂蛋白（LDL）对人冠状动脉内皮细胞内皮型一氧化氮合酶III（NOSIII）表达的下调作用。但这些过程的潜在相互作用或这些修饰的脂蛋白对动脉的病理生理作用知之甚少。体外糖基化高密度脂蛋白，Western和北方印迹分析检测人冠状动脉内皮细胞中NOSIII的表达。一氧化氮（NO）生物活性表现为基础和缓激肽刺激的细胞环磷酸鸟苷积累和L-精氨酸转化为L-瓜氨酸。核运行的实验进行研究新生NOSIII信使核糖核酸（mRNA）的转录率。结果数据显示，24小时后，与糖基化低密度脂蛋白（glycLDL）和氧化低密度脂蛋白（oxLDL）治疗NOSIII的表达显着下降。因此，我们观察到NO生物活性的显著剂量依赖性降低（相对于未处理的细胞、天然低密度脂蛋白[nLDL]、glycLDL和oxLDL，p < 0.05至p < 0.001）。Glyc-oxLDL没有降低NOSIII mRNA的半衰期或显著增强瓜氨酸转化。核连续实验表明，高剂量的glyc-oxLDL可降低新生NOSIII mRNA的转录速率（光密度分析显示，用300 μg/ml glyc-oxLDL处理细胞后，与未处理细胞、nLDL和glycLDL相比，降低25% [p < 0.05]）。glyc-oxLDL的影响是不相关的氧化化合物的更高的水平相比，oxLDL.ConclusionsThese结果表明，glyc-oxLDL本身，可能会影响信号转导途径，涉及NO介导的调节信号和NOSIII活性在人内皮细胞。这种现象会对糖尿病患者的临床血管并发症、冠心病和动脉粥样硬化的进展产生不利影响。
ObjectivesWe examined the hypothesis that low-density lipoprotein (LDL) that is both oxidized and glycosylated potently downregulates the expression of endothelial nitric oxide synthase III (NOSIII) in human coronary endothelial cells.BackgroundDiabetes mellitus is accompanied by both oxidation and glycosylation of LDL, but the potential interaction of these processes or the pathophysiologic effects of these modified lipoproteins on arteries are poorly understood.MethodsLow-density lipoprotein was glycoxidized in vitro, and Western and Northern blot analyses were used to investigate NOSIII expression in human coronary endothelial cells. Nitric oxide (NO) bioactivity was represented by both basal and bradykinin-stimulated cellular cyclic guanosine monophosphate accumulation andl-citrulline conversion froml-arginine. Nuclear run-on experiments were performed to study the transcription rate of nascent NOSIII messenger ribonucleic acid (mRNA).ResultsData showed a significant decrease in NOSIII expression after 24-h treatment with glycosylated low-density lipoprotein (glycLDL) and oxidized low-density lipoprotein (oxLDL). Accordingly, we observed a significant dose-dependent reduction in NO bioactivity (p < 0.05 to p < 0.001 vs. untreated cells, native low density lipoprotein [nLDL], glycLDL, and oxLDL). Glyc-oxLDL did not reduce the half-life of NOSIII mRNA or significantly enhancel-citrulline conversion. Nuclear run-on experiments showed that high doses of glyc-oxLDL can reduce the transcription rate of nascent NOSIII mRNA (densitometric analysis revealed a reduction of 25% [p < 0.05 vs. untreated cells, nLDL, and glycLDL] after treatment of cells with 300 μg/ml glyc-oxLDL). The effects of glyc-oxLDL are not related to the higher levels of oxidative compounds in comparison to those of oxLDL.ConclusionsThese results indicate that glyc-oxLDL, per se, may influence signal transduction pathways involving NO-mediated regulatory signals and NOSIII activity in human endothelial cells. This phenomenon can adversely influence the evolution of clinical vascular complications, coronary heart disease, and atherogenesis in diabetic patients.