Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, Shaanxi, China.
Key Laboratory for Efficient Ruminant Breeding Technology of Higher Education Institutions in Shaanxi Province, The Youth Innovation Team of Shaanxi Universities, Zhang Yong Academician Animal Biotechnology Engineering Center, Yangling Vocational & Technical College, Yangling, 712100, Shaanxi, China.
Theriogenology. 2024 Dec;230:330-340. doi: 10.1016/j.theriogenology.2024.09.030. Epub 2024 Sep 27.
During cryopreservation, a substantial portion of spermatozoa undergoes apoptosis due to cryoinjury, resulting in decreased fertility. Boar spermatozoa are highly sensitive to temperature, with low temperature triggering reactive oxygen species (ROS) generation, leading to oxidative stress and apoptosis. Sulforaphane (SFN), a potent natural compound found in cruciferous vegetables, is efficacious in mitigating oxidative stress. We here supplemented different SFN concentrations (0, 1.25, 2.5, 5, 10, and 20 μM) into the freezing extender to explore its effect on boar sperm during cryopreservation and determine the optimal SFN concentration. Supplementation of 5 μM SFN exhibited the highest sperm motility, motion performance, plasma membrane integrity, acrosome integrity, and antioxidant properties (total antioxidant capacity (T-AOC) and antioxidant enzyme activity) after freezing and thawing. Then, RT group, C group and C + SFN group were established to explore the effect of SFN on the cryopreservation-induced sperm apoptosis level and fertilizing capacity of post-thawed sperms. SFN effectively rescued the apoptosis and fertilizing capacity of post-thawed sperms. Mechanistically, SFN activated the redox-sensitive nuclear factor erythroid 2-related factor 2 (NRF2/NFE2L2) by promoting adenosine monophosphate-activated protein kinase (AMPK) phosphorylation. This activation improved antioxidant defenses, ultimately improving cryoinjury in boar spermatozoa. In summary, SFN suppressed cryopreservation-induced apoptosis of spermatozoa by activating antioxidant defenses and the AMPK/NFE2L2 signaling pathway. These findings suggest a novel approach for augmenting the cryoprotective efficiency and spermatozoa fertility after cryopreservation.
在冷冻保存过程中，由于冷冻损伤，大量精子经历细胞凋亡，导致生育力下降。猪精子对温度非常敏感，低温会引发活性氧（ROS）的产生，导致氧化应激和细胞凋亡。萝卜硫素（SFN）是十字花科蔬菜中发现的一种有效的天然化合物，可有效缓解氧化应激。本研究在冷冻液中添加不同浓度（0、1.25、2.5、5、10 和 20 μM）SFN，以探讨其在猪精子冷冻保存过程中的作用，并确定最佳 SFN 浓度。结果表明，在冷冻和解冻后，添加 5 μM SFN 组的精子活力、运动性能、质膜完整性、顶体完整性和抗氧化特性（总抗氧化能力（T-AOC）和抗氧化酶活性）最高。然后，建立 RT 组、C 组和 C+SFN 组，以探讨 SFN 对冷冻诱导的精子凋亡水平和解冻后精子受精能力的影响。SFN 有效挽救了解冻后精子的凋亡和受精能力。机制上，SFN 通过促进腺苷单磷酸激活蛋白激酶（AMPK）磷酸化激活氧化还原敏感的核因子红细胞 2 相关因子 2（NRF2/NFE2L2）。这种激活改善了抗氧化防御，最终改善了猪精子的冷冻损伤。综上所述，SFN 通过激活抗氧化防御和 AMPK/NFE2L2 信号通路抑制冷冻保存诱导的精子凋亡。这些发现为提高冷冻保护效率和冷冻后精子活力提供了一种新方法。
