The effect of aging on the DNA damage and repair capacity in 2BS cells undergoing oxidative stress (Publication with Expression of Concern. See JAN, 2023)
The effect of aging on the DNA damage and repair capacity in 2BS cells undergoing oxidative stress (Publication with Expression of Concern. See JAN, 2023)
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DOI：
10.1007/s11033-011-0731-4
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发表时间：
2012-01-01
影响因子：
2.8
通讯作者：
Wang, Pei-Chang
中科院分区：
文献类型：
--
作者：
Wang, Jin-Ling;Wang, Pei-Chang
衰老与氧化应激下 DNA 修复能力的降低有关。然而，DNA损伤和修复能力是否可以作为衰老的生物标志物仍存在争议。在这项研究中，我们证明了两种因果关系，一种是DNA损伤和修复能力与细胞年龄之间的关系，另一种是暴露于不同剂量过氧化氢（H2O2）的人胚胎肺成纤维细胞（2BS）中DNA损伤和修复能力与氧化应激水平之间的关系。为了阐明与年龄相关的DNA损伤和修复能力下降的机制，我们初步评估了两种经典DNA修复途径中涉及的六种关键酶的表达。使用彗星实验观察人成纤维细胞的DNA修复能力；通过RT-PCR选择与年龄相关的DNA修复酶，然后通过体外Western blot验证。结果表明，DNA 修复能力与（i）仅在低浓度过氧化氢处理组中的累积群体倍增（PD）水平呈负线性相关，（ii）仅在年轻 PD 细胞组中与氧化应激水平呈负相关。衰老细胞中 DNA 聚合酶 delta 1 的 mRNA 表达显着下降，并与 PD 水平呈负线性相关；蛋白表达水平与mRNA水平高度一致。总而言之，DNA 损伤和修复能力可以作为衰老的生物标志物。 DNA 聚合酶 delta 1 表达的减少可能是衰老细胞 DNA 修复能力下降的原因。
Aging is associated with a reduction in the DNA repair capacity under oxidative stress. However, whether the DNA damage and repair capacity can be a biomarker of aging remains controversial. In this study, we demonstrated two cause-and-effect relationships, the one is between the DNA damage and repair capacity and the cellular age, another is between DNA damage and repair capacity and the level of oxidative stress in human embryonic lung fibroblasts (2BS) exposed to different doses of hydrogen peroxide (H2O2). To clarify the mechanisms of the age-related reduction in DNA damage and repair capacity, we preliminarily evaluated the expressions of six kinds of pivotal enzymes involved in the two classical DNA repair pathways. The DNA repair capacity was observed in human fibroblasts cells using the comet assay; the age-related DNA repair enzymes were selected by RT-PCR and then verified by Western blot in vitro. Results showed that the DNA repair capacity was negatively and linearly correlated with (i) cumulative population doubling (PD) levels only in the group of low concentration of hydrogen peroxide treatment, (ii) with the level of oxidative stress only in the group of young PD cells. The mRNA expression of DNA polymerase delta 1 decreased substantially in senescent cells and showed negative linear-correlation with PD levels; the protein expression level was well consistent with the mRNA level. Taken together, DNA damage and repair capacity can be a biomarker of aging. Reduced expression of DNA polymerase delta 1 may be responsible for the decrease of DNA repair capacity in senescent cells.