OBJECTIVE To investigate PGRMC1-precipitating proteins in human endometrial stromal cells (ESC) to understand its role during in vitro decidualization. DESIGN Prospective observational study. SETTING Academic fertility center. PATIENT(S) Fifteen fertile oocyte donors. INTERVENTION(S) Isolated ESCs decidualized in vitro and used in pulldown assays. MAIN OUTCOME MEASURE(S) GST-PGRMC1-precipitated proteins identified in nondecidualized ESC (ndESC) and ESC decidualized via a long (8 days) or short (4 days) decidualization protocol (dESC). RESULT(S) Using pulldown assays and mass spectrometry, decidualization was evaluated by prolactin secretion (ELISA) and cytoskeleton morphology (F-actin staining). The protein interactions were validated by colocalization and coimmunoprecipitation. The pulldown and mass spectrometry analysis identified 21, 24, and 24 new significant GST-PGRMC1-precipitated proteins in ndESC, long dESC, and short dESC, respectively, compared with controls. The functional annotation analysis categorized these proteins mainly into endomembrane system and mitochondria cellular components, both related to adenosine triphosphate (ATP) generation and transport activity, protein biosynthesis and posttranslational processing, vesicle trafficking, and protection against oxidative stress activities. Monoamine oxidase B (MAOB) and B-cell receptor-associated protein 31 (BAP31) were identified in dESC from both decidualization protocols. PGRMC1-MAOB/BAP31 interactions were confirmed by immunofluorescence and coimmunoprecipitation in dESC. CONCLUSION(S) Novel GST-PGRMC1-precipitated proteins discovered in ESC suggest that this protein is implicated in deep remodeling of ESC during decidualization and aggregates mainly with proteins involved in biosynthesis, intracellular transport, and mitochondrial activity.

中文翻译：

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新型非经典孕激素受体 PGRMC1 下拉沉淀蛋白揭示了人类蜕膜化过程中的关键作用

目的 研究人子宫内膜基质细胞 (ESC) 中的 PGRMC1 沉淀蛋白，以了解其在体外蜕膜化过程中的作用。设计前瞻性观察研究。设置学术生育中心。患者 15 个可育卵母细胞供体。干预 分离的 ESC 在体外蜕膜并用于下拉分析。主要结果测量在非蜕膜化 ESC (ndESC) 和通过长 (8 天) 或短 (4 天) 蜕膜化方案 (dESC) 蜕膜化的 ESC 中鉴定的 GST-PGRMC1 沉淀蛋白。结果 使用下拉测定法和质谱法，通过催乳素分泌 (ELISA) 和细胞骨架形态学（F-肌动蛋白染色）评估蜕膜化。通过共定位和共免疫沉淀验证蛋白质相互作用。下拉和质谱分析确定了 21、24、与对照相比，ndESC、长 dESC 和短 dESC 中分别有 24 种新的显着 GST-PGRMC1 沉淀蛋白。功能注释分析将这些蛋白质主要分为内膜系统和线粒体细胞成分，两者都与三磷酸腺苷 (ATP) 生成和运输活动、蛋白质生物合成和翻译后加工、囊泡运输和抗氧化应激活动有关。单胺氧化酶 B (MAOB) 和 B 细胞受体相关蛋白 31 (BAP31) 在 dESC 中从两种蜕膜化方案中得到鉴定。PGRMC1-MAOB/BAP31 相互作用通过 dESC 中的免疫荧光和共免疫沉淀得到证实。