Placenta is a complex organ that plays a significant role in the maintenance of pregnancy health. It is a dynamic organ that undergoes dramatic changes in growth and development at different stages of gestation. In the first-trimester, the conceptus develops in a low oxygen environment that favors organogenesis in the embryo and cell proliferation and angiogenesis in the placenta; later in pregnancy, higher oxygen concentration is required to support the rapid growth of the fetus. This oxygen transition, which appears unique to the human placenta, must be finely tuned through successive rounds of protein signature alterations. This study compares placental proteome in normal first-trimester (FT) and term human placentas (TP). Normal human first-trimester and term placental samples were collected and differentially expressed proteins were identified using two-dimensional liquid chromatography-tandem mass spectrometry. Despite the overall similarities, 120 proteins were differently expressed in first and term placentas. Out of these, 72 were up-regulated and 48 were down-regulated in the first when compared with the full term placentas. Twenty out of 120 differently expressed proteins were sequenced, among them seven showed increased (GRP78, PDIA3, ENOA, ECH1, PRDX4, ERP29, ECHM), eleven decreased (TRFE, ALBU, K2C1, ACTG, CSH2, PRDX2, FABP5, HBG1, FABP4, K2C8, K1C9) expression in first-trimester compared to the full-term placentas and two proteins exclusively expressed in first-trimester placentas (MESD, MYDGF). According to Reactome and PANTHER softwares, these proteins were mostly involved in response to chemical stimulus and stress, regulation of biological quality, programmed cell death, hemostatic and catabolic processes, protein folding, cellular oxidant detoxification, coagulation and retina homeostasis. Elucidation of alteration in protein signature during placental development would provide researchers with a better understanding of the critical biological processes of placentogenesis and delineate proteins involved in regulation of placental function during development.

中文翻译：

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人类胎盘的蛋白质组分析揭示蛋白质特征的发育阶段依赖性改变

胎盘是一种复杂的器官，在维持妊娠健康方面发挥着重要作用。它是一个充满活力的器官，在妊娠的不同阶段会经历生长发育的巨大变化。在孕早期，孕体在低氧环境中发育，有利于胚胎中的器官发生和胎盘中的细胞增殖和血管生成；在怀孕后期，需要更高的氧气浓度来支持胎儿的快速生长。这种氧转变似乎是人类胎盘独有的，必须通过连续几轮的蛋白质特征改变进行微调。本研究比较了正常妊娠早期 (FT) 和足月人类胎盘 (TP) 中的胎盘蛋白质组。收集正常人类妊娠早期和足月胎盘样本，并使用二维液相色谱-串联质谱法鉴定差异表达的蛋白质。尽管总体相似，但有 120 种蛋白质在第一胎和足月胎盘中表达不同。其中，与足月胎盘相比，72 个上调，48 个下调。对 120 种不同表达的蛋白质中的 20 种进行了测序，其中 7 种显示增加（GRP78、PDIA3、ENOA、ECH1、PRDX4、ERP29、ECHM），11 种减少（TRFE、ALBU、K2C1、ACTG、CSH2、PRDX2、FABP5、HBG1、 FABP4、K2C8、K1C9）在妊娠早期的表达与足月胎盘相比，以及在妊娠早期胎盘中专门表达的两种蛋白质（MESD、MYDGF）。根据 Reactome 和 PANTHER 软件，这些蛋白质主要参与对化学刺激和压力的反应、生物质量的调节、程序性细胞死亡、止血和分解代谢过程、蛋白质折叠、细胞氧化剂解毒、凝血和视网膜稳态。阐明胎盘发育过程中蛋白质特征的改变将使研究人员更好地了解胎盘发生的关键生物学过程，并描述发育过程中参与胎盘功能调节的蛋白质。