S-Adenosylhomocysteine induces apoptosis and phosphatidylserine exposure in endothelial cells independent of homocysteine
S-Adenosylhomocysteine induces apoptosis and phosphatidylserine exposure in endothelial cells independent of homocysteine
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DOI：
10.1016/j.atherosclerosis.2011.11.032
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发表时间：
2012-03-01
期刊：
影响因子：
5.3
通讯作者：
Niessen, Hans W. M.
中科院分区：
文献类型：
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作者：
Sipkens, Jessica A.;Hahn, Nynke E.;Niessen, Hans W. M.
目的：我们之前的研究表明，同型半胱氨酸（Hcy）可诱导人内皮细胞的磷脂酰丝氨酸（PS）暴露、凋亡和坏死。由于有研究表明s -腺苷型同型半胱氨酸（SAH）是Hcy诱导的心血管疾病发病机制的主要致病因素，我们在此评估内皮细胞中的细胞毒性Hcy作用是否也依赖于SAH。方法与结果：将人脐静脉内皮细胞（HUVECs）暴露于以下条件下：(1)未处理的对照（细胞内SAH 2.8 nM，细胞外l-Hcy 3.1 μ M）；(2) 50 μ M腺苷-2,3-二醛（ADA），细胞内SAH为17.7 nM，细胞外l-Hcy为3.1 μ M; (3) 2.5 mM Hcy（细胞内SAH为20.9 nM，细胞外l-Hcy为1.8 mM）；(4) 1、10和100 μ M SAH。然后，我们测定了处理对膜联蛋白v阳性、caspase-3活性、细胞色素c释放（亚）细胞中NOX2、NOX4、p47（phox）、硝基酪氨酸和H2O2的表达的影响。Hcy和ADA均显著增加PS暴露（n = 5）、caspase-3活性（n = 6）和细胞色素c释放（n = 3）。单独与细胞外SAH孵育不影响细胞活力。Hcy和ADA也诱导了核NOX2和（周围）核NOX4的类似增加，与（周围）核p47（phox）表达和局部活性氧（ROS）一致（n = 3）。黄酶抑制剂二苯基碘（DPI）抑制nox介导的ROS可显著降低细胞凋亡诱导（n = 3）和ROS生成（n = 3）。结论：SAH诱导内皮细胞的PS暴露和凋亡不依赖于Hcy。因此，我们的研究表明，在所使用的细胞模型中确定的hcy介导的内皮功能障碍主要是由于SAH积聚。2011爱思唯尔爱尔兰有限公司版权所有。
Objective: We have previously shown that homocysteine (Hcy) induces phosphatidylserine (PS) exposure, apoptosis and necrosis in human endothelial cells. Since it has been suggested that S-Adenosylhomocysteine (SAH) is the main causative factor in Hcy-induced pathogenesis of cardiovascular disease, we evaluate here whether the cytotoxic Hcy effect in endothelial cells is also SAH dependent.Methods and results: Human umbilical vein endothelial cells (HUVECs) were exposed to the following conditions: (1) non-treated control (resulting in 2.8 nM intracellular SAH and 3.1 mu M extracellular l-Hcy); and incubation with (2) 50 mu M adenosine-2,3-dialdehyde (ADA; resulting in 17.7 nM intracellular SAH and 3.1 mu M extracellular l-Hcy), (3) 2.5 mM Hcy (resulting in 20.9 nM intracellular SAH and 1.8 mM extracellular l-Hcy), and (4) 1, 10 and 100 mu M SAH. We then determined the effect of treatment on annexin V-positivity, caspase-3 activity, cytochrome c release (sub) cellular expression of NOX2, NOX4, p47(phox) and nitrotyrosine, and H2O2. Both Hcy and ADA significantly increased PS exposure (n = 5), caspase-3 activity (n = 6) and cytochrome c release (n = 3). Incubation with extracellular SAH alone did not affect cell viability. Both Hcy and ADA also induced similar increases in nuclear NOX2 and (peri) nuclear NOX4, coinciding with (peri) nuclear p47(phox) expression and local reactive oxygen species (ROS) (n = 3). Inhibition of NOX-mediated ROS by the flavoenzyme inhibitor diphenylene iodonium (DPI) significantly decreased apoptosis induction (n = 3) and ROS production (n = 3).Conclusion: SAH induces PS exposure and apoptosis in endothelial cells independently of Hcy. Our study therefore shows that Hcy-mediated endothelial dysfunction, as determined in the cell model used, is mainly due to SAH accumulation. (C) 2011 Elsevier Ireland Ltd. All rights reserved.