Department of Cardiovascular, Respiratory, and Geriatric Medicine, Kyushu University Beppu Hospital, Beppu, Oita, Japan.
Geriatr Gerontol Int. 2013 Jul;13(3):774-82. doi: 10.1111/j.1447-0594.2012.00936.x. Epub 2012 Sep 18.
The aim of this study was to assess the biological effects of oxidative stress on human vascular endothelial cells.
The telomeric changes and the alterations of the expression of telomere-associated proteins in human umbilical venous endothelial cells (HUVEC) cultured in the presence of hydrogen peroxide (H2 O2 ) were analyzed.
During the culture, the cell growth rate decreased, whereas the telomerase activity of the surviving cells increased. As the H2 O2 level increased, long telomeres decreased proportionally, thus resulting in a telomere length distribution that was rich in short telomeres. These observations suggested that H2 O2 -affected endothelial cells bear telomeric features similar to those of aged cells. In contrast, the expression of telomere-associated proteins, TRF1 and TRF2, showed different changes. TRF1 increased in relation to H2 O2 concentration, whereas TRF2 showed no significant change. The surviving cells exposed to H2 O2 showed a H2 O2 -dose dependent increase in telomerase activity, whereas the telomere protein and RNA components were only elevated in low concentrations of H2 O2 .
The increase in telomerase activity and TRF1 protein expression of vascular endothelial cell might show an aspect of cellular protective reaction against oxygen stress.
本研究旨在评估氧化应激对人血管内皮细胞的生物学影响。
分析培养在过氧化氢（H2O2）存在下的人脐静脉内皮细胞（HUVEC）中端粒的变化和端粒相关蛋白表达的改变。
在培养过程中，细胞生长速度下降，而存活细胞的端粒酶活性增加。随着 H2O2 水平的升高，长端粒相应减少，导致端粒长度分布富含短端粒。这些观察结果表明，H2O2 影响的内皮细胞具有类似于衰老细胞的端粒特征。相比之下，端粒相关蛋白 TRF1 和 TRF2 的表达显示出不同的变化。TRF1 随 H2O2 浓度的增加而增加，而 TRF2 没有明显变化。暴露于 H2O2 的存活细胞中端粒酶活性呈 H2O2 剂量依赖性增加，而端粒蛋白和 RNA 成分仅在低浓度的 H2O2 中升高。
血管内皮细胞中端粒酶活性和 TRF1 蛋白表达的增加可能显示出细胞对氧应激的一种保护反应。
