ABSTRACT

Cryopreservation can induce damage in human spermatozoa through reactive oxygen species (ROS) generation. To reduce the potential risk of oxidative stress-induced sperm DNA damage, addition of different epigallocatechin-3-gallate (EGCG) concentrations were performed to determine the optimum concentration which was beneficial for IVF outcome for both fresh and frozen-thawed sperm. Next, the mouse sperm model exhibiting oxidative stress-induced DNA damage by exogenously treating with H₂O₂ but overcoming the low fertilization rate of frozen-thawed sperm was used to investigate the effect of EGCG on the embryonic development and the potential EGCG-mediated effects on ataxia telangiectasia mutated (ATM) pSer-1981 in zygotes, the latter was known for leading to the activation of major kinases involved in the DNA repair pathway and the cell cycle checkpoint pathway. We found the fertilization and embryonic development of embryos inseminated with frozen-thawed sperm was impaired compared to fresh sperm. EGCG promoted the development of embryos inseminated with both types of sperm at optimum concentration. In embryos inseminated with the H₂O₂ sperm, fertilization, embryonic development, and the time at which the cleavage rate of one-cell embryos reached ≥95% were not affected by EGCG treatment. However, the EGCG-treated group required less time to achieve 50% cleavage rate of one-cell embryos, and the EGCG-treated zygotes showed enhanced expression of ATM (pSer-1981) than the untreated group. EGCG at optimum concentrations may exert beneficial effects by modulating the ATM activation and moving up the time to enter into mitotic (M) phase.

Abbreviations

ROS: reactive oxygen species; EGCG: epigallocatechin-3-gallate; ATM: ataxia telangiectasia mutated; M: mitotic

中文翻译：

---

表没食子儿茶素-3-没食子酸酯（EGCG）对被氧化应激诱导的DNA损伤精子授精的胚胎的影响。

摘要

冷冻保存可通过产生活性氧（ROS）诱导人类精子受损。为了降低氧化应激诱导的精子DNA损伤的潜在风险，添加了不同的表没食子儿茶素-3-没食子酸酯（EGCG）浓度以确定最佳浓度，该浓度对新鲜和冻融精子均有利于IVF结果。接下来，通过用H ₂ O ₂外源处理，小鼠精子模型表现出氧化应激诱导的DNA损伤但克服了冻融精子的低受精率，研究了EGCG对胚胎发育的影响以及EGCG介导的共济失调毛细血管扩张突变（ATM）pSer-1981在合子中的作用，后者因导致DNA修复途径和细胞周期检查点途径中涉及的主要激酶的激活。我们发现与新鲜精子相比，用冷冻融化的精子授精的胚胎的受精和胚胎发育受到了损害。EGCG促进了两种浓度的精子受精的胚胎的发育。在用H ₂ O ₂授精的胚胎中精子，受精，胚胎发育以及单细胞胚胎分裂率达到≥95％的时间不受EGCG处理的影响。但是，EGCG处理组需要较少的时间来达到单细胞胚胎50％的裂解率，并且EGCG处理的受精卵显示出ATM的表达增强（pSer-1981）。最佳浓度的EGCG可通过调节ATM激活并增加进入有丝分裂（M）期的时间发挥有益作用。

缩略语

ROS：活性氧；EGCG：表没食子儿茶素-3-没食子酸酯；ATM：共济失调毛细血管扩张突变；M：有丝分裂