1型糖尿病患者低密度脂蛋白（LDL）的同型半胱氨酸化：对人内皮细胞氧化损伤的影响。

Homocysteinylation of low-density lipoproteins (LDL) from subjects with Type 1 diabetes: effect on oxidative damage of human endothelial cells.

作者信息

Ferretti G, Bacchetti T, Rabini R A, Vignini A, Nanetti L, Moroni C, Mazzanti L

机构信息

Istituto of Biochimica, Facoltà di Medicina e Chirurgia, Università Politecnica delle Marche, Ancona, Italy.

出版信息

Diabet Med. 2006 Jul;23(7):808-13. doi: 10.1111/j.1464-5491.2006.01809.x.

DOI:10.1111/j.1464-5491.2006.01809.x

PMID:16842488

Abstract

BACKGROUND

Homocysteine (Hcy) is an independent risk factor for cardiovascular disease (CVD). Individuals with Type 1 and Type 2 diabetes are more susceptible to the effects of homocysteine than non-diabetic subjects. The interaction between homocysteine-thiolactone (Hcy-thiolactone), a reactive product of Hcy, and low-density lipoproteins (LDL) induces the formation of homocystamide-LDL adducts (Hcy-LDL) and it has been suggested that homocysteinylation could increase atherogenicity of lipoproteins.

AIM

The aim of the study was to compare the effect of in vitro homocysteinylation of LDL isolated from healthy control subjects (C-LDL) and from Type 1 diabetic patients (DM-LDL) and to investigate the effect of homocysteinylated LDL (Hcy-C-LDL and Hcy-DM-LDL) on peroxynitrite production of endothelial cells.

METHODS

The in vitro homocysteinylation of LDL isolated from control (n = 12) and DM subjects (n = 12) was carried out by incubating lipoproteins with Hcy-thiolactone. The reaction was verified by quantifying the increase in sulphydryl groups (-SH groups) in Hcy-LDL with respect to control LDL. Control and homocysteinylated LDL were incubated with human aortic endothelial cells (HAEC) in culture. Peroxynitrite production in cells treated in different experimental conditions was assayed by a fluorimetric method.

RESULTS

The increase in -SH groups after incubation with homocysteine was greater in LDL from diabetic subjects compared with LDL from control subjects (P < 0.001). In addition, peroxynitrite production from HAEC incubated with Hcy-LDL from diabetic patients was greater than after incubation with Hcy-LDL from control subjects and untreated LDL from diabetic patients (P < 0.001).

CONCLUSIONS

These results show that LDL from diabetic patients is more susceptible to in vitro homocysteinylation than LDL from non-diabetic individuals and demonstrate that the compositional changes in Hcy-LDL from diabetic subjects have cytotoxic effects on human endothelial cells.

摘要

背景

同型半胱氨酸（Hcy）是心血管疾病（CVD）的一个独立风险因素。1型和2型糖尿病患者比非糖尿病受试者更容易受到同型半胱氨酸的影响。同型半胱氨酸硫内酯（Hcy-硫内酯）是Hcy的一种反应性产物，它与低密度脂蛋白（LDL）之间的相互作用会诱导同型胱氨酸-LDL加合物（Hcy-LDL）的形成，并且有人提出同型半胱氨酸化可能会增加脂蛋白的致动脉粥样硬化性。

目的

本研究的目的是比较从健康对照受试者（C-LDL）和1型糖尿病患者（DM-LDL）中分离出的LDL进行体外同型半胱氨酸化的效果，并研究同型半胱氨酸化的LDL（Hcy-C-LDL和Hcy-DM-LDL）对内皮细胞过氧亚硝酸盐产生的影响。

方法

通过将脂蛋白与Hcy-硫内酯孵育，对从对照受试者（n = 12）和糖尿病受试者（n = 12）中分离出的LDL进行体外同型半胱氨酸化。通过定量Hcy-LDL中巯基（-SH基团）相对于对照LDL的增加来验证该反应。将对照和同型半胱氨酸化的LDL与培养中的人主动脉内皮细胞（HAEC）孵育。通过荧光法测定在不同实验条件下处理的细胞中的过氧亚硝酸盐产生。