Department of Animal Sciences and Institute of Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
Department of Chemical Biology of Glycans and Lipids, Shemyakin Institute of Bioorganic Chemistry, Moscow, Russia.
Biol Reprod. 2023 Sep 12;109(3):356-366. doi: 10.1093/biolre/ioad074.
Sperm storage by females after mating for species-dependent periods is used widely among animals with internal fertilization to allow asynchrony between mating and ovulation. Many mammals store sperm in the lower oviduct where specific glycans on oviduct epithelial cells retain sperm to form a reservoir. Binding to oviduct cells suppresses sperm intracellular Ca2+ and increases sperm longevity. We investigated the mechanisms by which a specific oviduct glycan, 3-O-sulfated Lewis X trisaccharide (suLeX), prolongs the lifespan of porcine sperm. Using targeted metabolomics, we found that binding to suLeX diminishes the abundance of 4-hydroxybenzoic acid, the precursor to ubiquinone (also known as Coenzyme Q), 30 min after addition. Ubiquinone functions as an electron acceptor in the electron transport chain (ETC). 3-O-sulfated Lewis X trisaccharide also suppressed the formation of fumarate. A component of the citric acid cycle, fumarate is synthesized by succinate-coenzyme Q reductase, which employs ubiquinone and is also known as Complex II in the ETC. Consistent with the reduced activity of the ETC, the production of harmful reactive oxygen species (ROS) was diminished. The enhanced sperm lifespan in the oviduct may be because of suppressed ROS production because high ROS concentrations have toxic effects on sperm.
雌性动物在交配后会根据物种的不同储存精子一段时间，这种现象在体内受精的动物中广泛存在，以允许交配和排卵之间的不同步。许多哺乳动物将精子储存在输卵管的下部，输卵管上皮细胞上的特定糖可保留精子，形成一个储存库。与输卵管细胞的结合抑制了精子细胞内的 Ca2+并延长了精子的寿命。我们研究了一种特定的输卵管糖，3-O-硫酸化 Lewis X 三糖（suLeX），延长猪精子寿命的机制。通过靶向代谢组学，我们发现，在添加 suLeX 30 分钟后，它会减少 4-羟基苯甲酸（泛醌的前体，也称为辅酶 Q）的丰度。泛醌在电子传递链（ETC）中作为电子受体。3-O-硫酸化 Lewis X 三糖还抑制了延胡索酸盐的形成。延胡索酸盐是柠檬酸循环的一个组成部分，由琥珀酸-辅酶 Q 还原酶合成，该酶利用泛醌，在 ETC 中也被称为复合物 II。与 ETC 活性降低一致，有害的活性氧（ROS）的产生减少。在输卵管中精子寿命的延长可能是由于 ROS 产生的抑制，因为高浓度的 ROS 对精子有毒。
