School of Pharmaceutical Science, Shanxi Medical University, No. 56 Xinjian South Road, Taiyuan 030001, China; School of Public Health Science, Shanxi Medical University, No. 56 Xinjian South Road, Taiyuan 030001, China.
School of Pharmaceutical Science, Shanxi Medical University, No. 56 Xinjian South Road, Taiyuan 030001, China.
Eur J Pharmacol. 2014 Jul 5;734:9-14. doi: 10.1016/j.ejphar.2014.03.054. Epub 2014 Apr 13.
Endothelial tight junction is a crucial intracellular junctional structure that controls paracellular permeability across vascular endothelium. Oxidative stress-mediated elevation in endothelial permeability is associated with pathogenesis of several cardiovascular diseases. In the present research, the regulation of farrerol on occludin, a transmembrane proteins associated with endothelial tight junction, was investigated in hydrogen peroxide-induced human endothelium-derived EA.hy926 cells. Western blot analysis demonstrated that H2O2 exposure caused a significant decrease in occludin expression, but had little effect on ZO-1 expression, and the decrease of occludin expression was significantly attenuated by farrerol in a dose-dependent manner. Meanwhile, immunofluorescent staining assay also demonstrated that the loss of occludin expression induced by H2O2 exposure was restored by farrerol pretreatment. Further investigations showed that farrerol prevented H2O2-induced activation of extracellular signal-regulated kinase (ERK) 1/2 in a dose-dependent manner. The use of U0126, a specific inhibitor of MEK1/2, proved that H2O2-induced decrease of occludin in EA.hy926 cells was likely associated with activation of ERK1/2, which indicated that the regulation of farrerol on occludin expression in H2O2-induced EA.hy926 cells was likely related to the modulation of ERK1/2 activation. In conclusion, the present study demonstrates for the first time that farrerol has potential effects on oxidative stress-induced endothelial tight junction disruption and suggests that farrerol is a potential candidate for the intervention of endothelial permeability-associated cardiovascular diseases.
内皮紧密连接是一种控制血管内皮细胞旁通透性的关键细胞内连接结构。氧化应激介导的内皮通透性增加与几种心血管疾病的发病机制有关。在本研究中，研究了法呢醇对过氧化氢诱导的人内皮细胞 EA.hy926 中紧密连接相关跨膜蛋白 occludin 的调节作用。Western blot 分析表明，H2O2 暴露导致 occludin 表达显著下降，但对 ZO-1 表达影响不大，法呢醇呈剂量依赖性显著减轻 occludin 表达的下降。同时，免疫荧光染色试验也表明，H2O2 暴露诱导的 occludin 表达缺失可被法呢醇预处理所恢复。进一步的研究表明，法呢醇可呈剂量依赖性抑制 H2O2 诱导的细胞外信号调节激酶（ERK）1/2 的激活。使用 MEK1/2 的特异性抑制剂 U0126 证明，H2O2 诱导的 EA.hy926 细胞中 occludin 的减少可能与 ERK1/2 的激活有关，这表明法呢醇对 H2O2 诱导的 EA.hy926 细胞中 occludin 表达的调节可能与 ERK1/2 激活的调节有关。总之，本研究首次证明法呢醇对氧化应激诱导的内皮紧密连接破坏具有潜在作用，并提示法呢醇可能是干预与内皮通透性相关的心血管疾病的潜在候选药物。
