Reactive oxygen species mediates disialoganglioside GD3-induced inhibition of ERK1/2 and matrix metalloproteinase-9 expression in vascular smooth muscle cells
Reactive oxygen species mediates disialoganglioside GD3-induced inhibition of ERK1/2 and matrix metalloproteinase-9 expression in vascular smooth muscle cells
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DOI：
10.1096/fj.05-4618com
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发表时间：
2006-07-01
期刊：
影响因子：
4.8
通讯作者：
Kim, Cheorl-Ho
中科院分区：
文献类型：
--
作者：
Moon, Sung-Kwon;Kang, Sung-Koo;Kim, Cheorl-Ho
含有唾液酸的鞘糖脂（神经节苷脂）被认为在动脉粥样硬化等各种生物现象的功能中发挥重要作用。我们以前已经表明，过表达的二唾液酸神经节苷脂（GD 3）合酶基因有效地抑制细胞增殖，细胞周期的进展，和MMP-9在血管平滑肌细胞（VSMC）的表达。然而，GD 3合酶基因的过表达如何导致VSMC的细胞反应抑制的问题仍然不清楚。本文的研究结果表明，GD 3合酶基因的过表达通过产生活性氧（ROS）抑制VSMC反应。与空载体（EV）转染的VSMC相比，GD 3合酶基因转染体产生的超氧化物和过氧化氢水平增加。这种现象被抗氧化剂如N-乙酰-L-半胱氨酸（NAC）和吡咯烷二硫代氨基甲酸酯（PDTC）阻断。ROS生成增加与内源性抗氧化活性降低、脂质过氧化作用增加和线粒体DNA损伤有关。进一步的研究表明，用抗氧化剂阻断ROS功能可以逆转GD 3合酶基因过表达对血小板源性生长因子（PDGF）诱导的VSMC增殖和细胞周期调节的影响。此外，我们发现，抗氧化剂治疗逆转了基质金属蛋白酶-9（MMP-9）表达的下降，在GD 3合酶基因转染的TNF-α的酶谱和免疫印迹测定。这种恢复作用的特征在于MMP-9启动子活性的上调，其在MMP-9启动子中的NF-κ B和活化蛋白-1（活化蛋白（AP）-1）位点处被转录调节。这些结果表明，ROS可能在GD 3合酶基因介导的VSMC表型变化中发挥作用，可能导致动脉粥样硬化斑块不稳定。
Sialic acid containing glycosphingolipids (gangliosides) are thought to play important roles in the function of various biological phenomena such as atherosclerosis. We have previously shown that the overexpression of the disialoganglioside (GD3) synthase gene effectively suppresses cell proliferation, cell cycle progression, and MMP-9 expression in vascular smooth muscle cells (VSMC). However, the issue of how the overexpression of GD3 synthase gene results in the inhibition of cellular responses in VSMC remains unclear. The findings herein demonstrate that overexpression of the GD3 synthase gene suppresses VSMC responses through the generation of reactive oxygen species (ROS). Superoxide and hydrogen peroxide were generated at increased levels in GD3 synthase gene transfectants in comparison with empty vector (EV) -transfected VSMC. This phenomenon was blocked by antioxidants such as N-acetyl-L-cysteine (NAC) and pyrrolidine dithiocarbamate (PDTC). Increased ROS generation was associated with a decreased endogenous antioxidant activity, increased lipid peroxidation, and mitochondrial DNA damage. Further studies revealed that the blockade of ROS function with antioxidants reversed the effect of GD3 synthase gene overexpression on VSMC proliferation and cell cycle regulation in response to platelet-derived growth factor (PDGF). In addition, we found that treatment with antioxidants reversed the decreased matrix metalloproteinase-9 (MMP-9) expression in response to TNF-alpha as determined by zymography and immunoblot in GD3 synthase gene transfectants. This recovery effect was characterized by the up-regulation of MMP-9 promoter activity, which was transcriptionally regulated at NF-kappa B and activation protein-1 (activating protein (AP) -1) sites in the MMP-9 promoter. These findings suggest that ROS may play a role in GD3 synthase gene-mediated VSMC phenotypic changes that may contribute to plaque instability in atherosclerosis.