Department of Obstetrics and Gynecology, National Taiwan University and National Taiwan University Hospital, #8 Chung-Shan South Road, 100, Taipei, Taiwan.
J Assist Reprod Genet. 2013 Aug;30(8):1063-72. doi: 10.1007/s10815-013-0045-7. Epub 2013 Jul 6.
Previous studies reported that patients with endometriosis had excess nitric oxide (NO) in the reproductive tract and poor embryo development in IVF cycles. This study aims to elucidate the effects of NO on early embryo development.
Zygotes from superovulated B6CBF1 mice were cultured to blastocysts in a variety of media. Sodium nitroprusside (SNP) and N(G)-nitro-L-arginine (LNA) were added to the culture medium as a NO donor and a NO synthase inhibitor, respectively. The localization and fluorescence intensity of S-nitrosylated (SNO) proteins within 2-cell stage embryos were analyzed with confocal microscopy. Apoptosis and ATP production in the blastocysts were measured.
RESULT(S): Subsequent to NO exposure, the SNO proteins mainly colocalized with the mitochondria and endoplasmic reticulum and the intensity of SNO proteins increased. The addition of a quanylate cyclase inhibitor and a cyclic GMP mimic agent induced nonsignificant changes in SNO proteins, whereas addition of a superoxide scavenger or a reduced form of glutathione rescued the embryos from the effects of NO. However, superoxide scavenger supplementation resulted in decreased blastocyst ATP production.
CONCLUSION(S): Elevated NO exerts deleterious effects on embryo development, possibly through protein S-nitrosylation in the mitochondria and endoplasmic reticulum. Including glutathione as a component in the culture medium might counteract this effect.
先前的研究报道称，子宫内膜异位症患者的生殖道中存在过量的一氧化氮（NO），并且在体外受精（IVF）周期中胚胎发育不良。本研究旨在阐明 NO 对早期胚胎发育的影响。
将超排卵的 B6CBF1 小鼠的受精卵培养至囊胚，使用多种培养基。将硝普酸钠（SNP）和 N(G)-硝基-L-精氨酸（LNA）分别添加到培养基中，作为 NO 供体和一氧化氮合酶抑制剂。使用共聚焦显微镜分析 2 细胞期胚胎中 S-亚硝基化（SNO）蛋白的定位和荧光强度。测量囊胚中的细胞凋亡和 ATP 生成。
NO 暴露后，SNO 蛋白主要与线粒体和内质网共定位，且 SNO 蛋白的强度增加。添加鸟苷酸环化酶抑制剂和环磷酸鸟苷模拟物后，SNO 蛋白的变化不显著，而添加超氧化物清除剂或还原型谷胱甘肽可使胚胎免受 NO 的影响。然而，超氧化物清除剂的补充导致囊胚 ATP 生成减少。
NO 水平升高对胚胎发育有有害影响，可能是通过线粒体和内质网中的蛋白质 S-亚硝基化。在培养基中包含谷胱甘肽作为成分可能会抵消这种影响。
