Inserm U-1048, Université de Toulouse, France; Pôle de Gynécologie Obstétrique, Hôpital Paule-de-Viguier, CHU de Toulouse, France.
Inserm U-1048, Université de Toulouse, France.
Free Radic Biol Med. 2019 Sep;141:416-425. doi: 10.1016/j.freeradbiomed.2019.07.015. Epub 2019 Jul 16.
Preeclampsia (PE) is a leading cause of pregnancy complications, affecting 3-7% of pregnant women worldwide. The pathophysiology of preeclampsia involves a redox imbalance, oxidative stress and a reduced nitric oxide (NO) bioavailability. The molecular and cellular mechanisms leading to the dysfunction of the placental endothelial NO synthase (eNOS) are not clarified. This study was designed to investigate whether aldehydes generated by lipid peroxidation products (LPP), may contribute to placental eNOS dysfunction in PE. The analysis of placentas from PE-affected patients and normal pregnancies, showed a significant increase in protein carbonyl content, indicative of oxidative stress-induced protein modification, as shown by the accumulation of acrolein, 4-hydroxynonenal (HNE), and 4-oxo-2(E)-nonenal (ONE) adducts in PE placentas. In contrast, the levels of these LPP-adducts were low in placentas from normal pregnancies. Immunofluorescence and confocal experiments pointed out a colocalization of eNOS with ONE-Lys adducts, whereas eNOS was not modified in normal placentas. LC-MS/MS analysis of recombinant eNOS preincubated with ONE, allowed to identify several ONE-modified Lys-containing peptides, confirming that eNOS may undergo post-translational modification by LPP. The preincubation of HTR-8/SVneo human trophoblasts (HTR8) with ONE, resulted in ONE-Lys modification of eNOS and a reduced generation of NO. ONE inhibited the migration of HTR8 trophoblasts in the wound closure model, and this was partly restored by the NO donor, NOC-18, which confirmed the important role of NO in the invasive potential of trophoblasts. In conclusion, placental eNOS is modified by ONE in PE placentas, which emphasizes the sensitivity of this protein to oxidative stress in the disturbed redox environment of preeclamptic pregnancies.
子痫前期 (PE) 是妊娠并发症的主要原因，影响全球 3-7%的孕妇。子痫前期的病理生理学涉及氧化还原失衡、氧化应激和一氧化氮 (NO) 生物利用度降低。导致胎盘内皮型一氧化氮合酶 (eNOS) 功能障碍的分子和细胞机制尚不清楚。本研究旨在探讨脂质过氧化产物 (LPP) 产生的醛是否可能导致 PE 胎盘 eNOS 功能障碍。对来自 PE 患者和正常妊娠的胎盘进行分析，显示蛋白质羰基含量显著增加，表明氧化应激诱导的蛋白质修饰，如丙烯醛、4-羟基壬烯醛 (HNE) 和 4-氧代-2(E)-壬烯醛 (ONE) 加合物在 PE 胎盘中的积累。相比之下，这些 LPP 加合物在正常妊娠的胎盘中水平较低。免疫荧光和共聚焦实验指出 eNOS 与 ONE-Lys 加合物的共定位，而 eNOS 在正常胎盘中没有被修饰。用 ONE 预孵育重组 eNOS 的 LC-MS/MS 分析，允许鉴定几个 ONE 修饰的 Lys 肽，证实 eNOS 可能受到 LPP 的翻译后修饰。将 ONE 预孵育 HTR-8/SVneo 人滋养层细胞 (HTR8)，导致 eNOS 的 ONE-Lys 修饰和 NO 生成减少。ONE 抑制 HTR8 滋养层细胞在伤口闭合模型中的迁移，而这部分被 NO 供体 NOC-18 部分恢复，这证实了 NO 在滋养层细胞侵袭潜力中的重要作用。总之，PE 胎盘中的 ONE 修饰了胎盘 eNOS，这强调了该蛋白在子痫前期妊娠中紊乱的氧化还原环境下对氧化应激的敏感性。
