Cell Physiology Laboratory, Biochemistry Unit, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi, 221005, U.P., India.
Cell Physiology Laboratory, Biochemistry Unit, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi, 221005, U.P., India.
Biomed Pharmacother. 2016 Dec;84:680-686. doi: 10.1016/j.biopha.2016.09.059. Epub 2016 Oct 1.
Present study was designed to investigate the in vitro effects of nitric oxide (NO) donor such as S-nitroso-N-acetyl penicillamine (SNAP) on spontaneous exit from metaphase-II arrest (SEM-II) in rat eggs cultured in vitro.
Ovulated eggs were denuded and then exposed to various concentrations (0.0, 0.01, 0.1 and 1.0mM) of SNAP for 3h under in vitro culture conditions. The percentage of SEM-II, specific and total phosphorylated cyclin-dependent kinase-1 (Cdk1), cyclin B1 and anaphase promoting complex/cyclosome (APC/C) levels as well as Cdk1 activity were analyzed.
The SEM-II was associated with a decrease of Thr-161 phosphorylated Cdk1 as well as cyclin B1 levels and increase of Thr-14/Tyr-15 phosphorylated Cdk1, APC/C levels and Cdk1 activity in aged eggs cultured in vitro. On the other hand, SNAP treatment prevented a decrease of Thr-161 phosphorylated Cdk1 as well as cyclin B1 levels and increase of Thr-14/Tyr-15 phosphorylated Cdk1, Cdk1 activity that finally prevented SEM-II in a concentration-dependent manner. However, APC/C level was not affected by SNAP during the course of treatment in vitro.
Present data suggest that SNAP prevented SEM-II possibly by increasing high level of NO and thereby maturation promoting factor (MPF) stabilization in rat eggs cultured in vitro. Hence, SNAP could be used to prevent SEM-II that reduces reproductive outcome in several mammalian species.
本研究旨在探讨一氧化氮（NO）供体如 S-亚硝基-N-乙酰青霉胺（SNAP）对体外培养的大鼠卵从中期 II 阻滞（SEM-II）自发退出的体外影响。
卵母细胞去卵丘后，在体外培养条件下，分别用 0.0、0.01、0.1 和 1.0mM 的 SNAP 处理 3 小时。分析 SEM-II 的比例、特异性和总周期蛋白依赖性激酶-1（Cdk1）、细胞周期蛋白 B1 和后期促进复合物/细胞周期蛋白（APC/C）水平以及 Cdk1 活性。
体外培养的老化卵 SEM-II 与 Thr-161 磷酸化 Cdk1 以及细胞周期蛋白 B1 水平降低以及 Thr-14/Tyr-15 磷酸化 Cdk1、APC/C 水平和 Cdk1 活性增加有关。另一方面，SNAP 处理以浓度依赖的方式防止 Thr-161 磷酸化 Cdk1 以及细胞周期蛋白 B1 水平降低以及 Thr-14/Tyr-15 磷酸化 Cdk1、Cdk1 活性增加，最终防止 SEM-II。然而，在体外处理过程中，APC/C 水平不受 SNAP 影响。
本研究数据表明，SNAP 可能通过增加高水平的 NO 并稳定体外培养的大鼠卵中的成熟促进因子（MPF）来防止 SEM-II。因此，SNAP 可用于防止 SEM-II，从而降低几种哺乳动物的生殖结果。
