血 homocysteine 层次(hyperhomocysteinemia ) 的举起是为心血管的混乱的一个风险因素。homocysteine 由导致动脉粥样硬化的机制之一是在反应的氧种(ROS ) 支持脉管的光滑的肌肉细胞(VSMC ) 的增长依赖的举止。homocysteine 在 VSMC 通过 NAD (P) H oxidases 的激活导致 ROS 的生产,这被显示出。在这研究,我们调查了涉及 NAD (P) H oxidases 的激活的信号 transduction 小径。Homocysteine 在 VSMC 支持了 DNA 合成。由 N-acetyl-l-cysteine (一种抗氧化剂) 和 apocynin (NAD (P) H oxidases 的一个禁止者) 的 ROS 的抑制显著地在 VSMC 堵住了导致 homocysteine 的增长。Homocysteine 在 p38-mitogen-activated 蛋白质 kinase (p38 MAPK ) 的 phosphorylation 导致了快速的增加。p38 MAPK 接着由导致 p47phox 的 phosphorylation 激活 NAD (P) H oxidases,导致 ROS 的产生。ROS 导致了 Akt 的 phosphorylation,它为在 VSMC 的增长可能负责。这些调查结果证明 homocysteine 由激活 p38 MAPK 并且提高 p47phox 的 phosphorylation 在 VSMC 在 NAD (P) H oxidases 的活动导致增加。
Elevation of blood homocysteine levels (hyperhomocysteinemia) is a risk factor for cardiovascular disorders. One of the mechanisms by which homocysteine induces atherosclerosis is to promote the proliferation of vascular smooth muscle cells (VSMCs) in a reactive oxygen species (ROS)- dependent manner. It has been shown that homocysteine induces the production of ROS through the activation of NAD(P)H oxidases in VSMCs. In this study, we investigated the signal transduction pathways involved in the activation of NAD(P)H oxidases. Homocysteine promoted DNA synthesis in VSMCs. Inhibition of ROS by N-acetyl-L- cysteine (an antioxidant) and apocynin (an inhibitor of NAD(P)H oxidases) significantly blocked homocysteineinduced proliferation in VSMCs. Homocysteine induced a rapid increase in the phosphorylation of p38-mitogen-activated protein kinase (p38 MAPK). p38 MAPK in turn activated NADOP)H oxidases by inducing the phosphorylation of p47phox, resulting in the generation of ROS. ROS induced the phosphorylation of Akt, which was probably responsible for proliferation in VSMCs. These findings demonstrate that homocysteine induces an increase in the activity of NAD(P)H oxidases in VSMCs by activating p38 MAPK and enhancing the phosphorylation of p47phox.