Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
Biochem Biophys Res Commun. 2011 Mar 4;406(1):36-41. doi: 10.1016/j.bbrc.2011.01.096. Epub 2011 Feb 1.
Subendothelial retention of lipoproteins by proteoglycans (PGs) is the initiating event in atherosclerosis. The elongation of chondroitin sulfate (CS) chains is associated with increased low-density lipoprotein (LDL) binding and progression of atherosclerosis. Recently, it has been shown that 2 Golgi enzymes, chondroitin 4-O-sulfotransferase-1 (C4ST-1) and chondroitin N-acetylgalactosaminyltransferase-2 (ChGn-2), play a critical role in CS chain elongation. However, the roles of C4ST-1 and ChGn-2 during the progression of atherosclerosis are not known. The aim of this study was to analyze the expression of C4ST-1 and ChGn-2 in atherosclerotic lesions in vivo and determine whether their expression correlated with CS chain elongation. Low-density lipoprotein receptor knockout (LDLr KO) mice were fed a western diet for 2, 4, and 8weeks to stimulate development of atherosclerosis. The binding of LDL and CS PG in this mouse model was confirmed by chondroitinase ABC (ChABC) digestion and apolipoprotein B (apo B) staining. Gel filtration analysis revealed that the CS chains began to elongate as early as 2weeks after beginning a western diet and continued as the atherosclerosis progressed. Furthermore, quantitative real-time polymerase chain reaction (qRT-PCR) showed that the mRNA levels of C4ST-1 and ChGn-2 increased after 8weeks of this diet. In contrast, the mRNA levels of their homologs, C4ST-2 and ChGn-1, were unchanged. In addition, immunohistochemical analysis demonstrated that the expression of C4ST-1 and ChGn-2 appeared to have similar site-specific patterns and coincided with biglycan expression at the aortic root. Our results suggested that C4ST-1 and ChGn-2 may be involved in the elongation of CS chains in the arterial wall during the progression of atherosclerosis. Therefore, modulating their expression and activity might be a novel therapeutic strategy for atherosclerosis.
蛋白聚糖（PGs）对脂蛋白的亚内皮保留是动脉粥样硬化的起始事件。硫酸软骨素（CS）链的延长与低密度脂蛋白（LDL）结合增加和动脉粥样硬化进展有关。最近，已经表明 2 种高尔基体酶，硫酸软骨素 4-O-磺基转移酶-1（C4ST-1）和硫酸软骨素 N-乙酰半乳糖胺基转移酶-2（ChGn-2），在 CS 链延长中起关键作用。然而，C4ST-1 和 ChGn-2 在动脉粥样硬化进展中的作用尚不清楚。本研究旨在分析体内动脉粥样硬化病变中 C4ST-1 和 ChGn-2 的表达，并确定其表达是否与 CS 链延长相关。用西方饮食喂养 LDL 受体敲除（LDLr KO）小鼠 2、4 和 8 周，以刺激动脉粥样硬化的发展。通过软骨素酶 ABC（ChABC）消化和载脂蛋白 B（apo B）染色证实了这种小鼠模型中 LDL 和 CS PG 的结合。凝胶过滤分析显示，早在开始西方饮食 2 周后，CS 链就开始延长，并随着动脉粥样硬化的进展而继续延长。此外，定量实时聚合酶链反应（qRT-PCR）显示，这种饮食 8 周后 C4ST-1 和 ChGn-2 的 mRNA 水平增加。相比之下，其同源物 C4ST-2 和 ChGn-1 的 mRNA 水平不变。此外，免疫组织化学分析表明，C4ST-1 和 ChGn-2 的表达似乎具有相似的特异性模式，并与大动脉根部 biglycan 的表达相吻合。我们的结果表明，C4ST-1 和 ChGn-2 可能参与动脉粥样硬化进展过程中动脉壁 CS 链的延长。因此，调节其表达和活性可能是动脉粥样硬化的一种新的治疗策略。
