Hu R, Jin H, Zhou S, Yang P, Li X
Obstetrics & Gynecology Hospital, Fudan University, 419 Fangxie Road, Shanghai 200011, China.
Placenta. 2007 May-Jun;28(5-6):399-407. doi: 10.1016/j.placenta.2006.07.005. Epub 2006 Nov 13.
Syncytiotrophoblast formation is affected by a number of pathological conditions and suppressed syncytiotrophoblast formation due to hypoxia may play a role in the pathogenesis of preeclampsia. However, the molecular basis of hypoxia-inhibited trophoblast syncytialization is poorly understood. To determine the effect of hypoxia on trophoblast syncytialization, a proteomic analysis was performed in the human cytotrophoblast cell line BeWo using two-dimensional electrophoresis and MALDI-TOF-TOF-MS. Hypoxia induced marked inhibition of BeWo cell fusion and differentiation. The proteomic profiling was established under hypoxia in BeWo cell syncytialization. The results showed that twenty proteins were significantly up-or down-regulated under hypoxia, compared with cells under normoxia. In response to hypoxia, three antioxidants, peroxiredoxin 1, peroxiredoxin 2 and 1-Cys peroxiredoxin, were down-regulated, two proteins involved in glycolysis pathway (malate dehydrogenase and enolase) were up-regulated. The expression of two members of the annexin family (annexin A2 and annexin A5) increased. We also found a decreased expression of 14-3-3 tau protein in hypoxia treated cells. Proteins implied in protein degradation and folding were also identified. The expression of two cytoskeleton components (keratin 1 and beta-actin) was found to be down-regulated. In addition, galectin-3 was up-regulated. These proteins have been implicated in regulating cellular oxidative stress, glycolysis, signal transduction, protein folding and degradation, cell mobility and cytoskeletal structure formation. Western blot analysis revealed that the levels of peroxiredoxin 1 and 14-3-3 tau decreased, whereas the levels of annexin A5 and annexin A2 increased in BeWo cells under hypoxia. These findings provided new insights into the molecular mechanisms in mediating cellular response to hypoxia in trophoblast syncytialization.
合体滋养层细胞的形成受多种病理状况影响，而因缺氧导致的合体滋养层细胞形成受抑制可能在子痫前期的发病机制中起作用。然而，缺氧抑制滋养层细胞融合的分子基础尚不清楚。为了确定缺氧对滋养层细胞融合的影响，利用二维电泳和基质辅助激光解吸电离飞行时间串联质谱（MALDI-TOF-TOF-MS）对人细胞滋养层细胞系BeWo进行了蛋白质组学分析。缺氧显著抑制了BeWo细胞的融合与分化。在BeWo细胞融合过程中建立了缺氧条件下的蛋白质组图谱。结果显示，与常氧条件下的细胞相比，缺氧条件下有20种蛋白质显著上调或下调。缺氧时，三种抗氧化剂过氧化物还原酶1、过氧化物还原酶2和1-半胱氨酸过氧化物还原酶下调，两种参与糖酵解途径的蛋白质（苹果酸脱氢酶和烯醇化酶）上调。膜联蛋白家族的两个成员（膜联蛋白A2和膜联蛋白A5）表达增加。我们还发现缺氧处理的细胞中14-3-3 tau蛋白表达降低。还鉴定出了与蛋白质降解和折叠相关的蛋白质。发现两种细胞骨架成分（角蛋白1和β-肌动蛋白）的表达下调。此外，半乳糖凝集素-3上调。这些蛋白质参与调节细胞氧化应激、糖酵解、信号转导、蛋白质折叠与降解、细胞迁移以及细胞骨架结构形成。蛋白质印迹分析显示，缺氧条件下BeWo细胞中过氧化物还原酶1和14-3-3 tau的水平降低，而膜联蛋白A5和膜联蛋白A2的水平升高。这些发现为介导滋养层细胞融合中细胞对缺氧反应的分子机制提供了新的见解。
