Adequate endometrial stromal cell (ESC) decidualization is vital for endometrial health. Given the importance of extracellular vesicles (EVs) in intercellular communication, we investigated how their protein landscape is reprogrammed and dysregulated during decidual response. Small EVs (sEVs) from human ESC-conditioned media at Day-2 and -14 following decidual stimuli were grouped as well- (WD) or poorly decidualized (PD) based on their prolactin secretion and subjected to mass spectrometry-based quantitative proteomics. On Day 2, in PD- versus WD-ESC-sEVs, 17 sEV- proteins were down-regulated (C5, C6; complement/coagulation cascades, and SERPING1, HRG; platelet degranulation and fibrinolysis) and 39 up-regulated (FLNA, COL1A1; focal adhesion, ENO1, PKM; glycolysis/gluconeogenesis, and RAP1B, MSN; leukocyte transendothelial migration). On Day 14, in PD- versus WD-ESC-sEVs, FLNA was down-regulated while 21 proteins were up-regulated involved in complement/coagulation cascades (C3, C6), platelet degranulation (SERPINA4, ITIH4), B-cell receptor signalling and innate immune response (immunoglobulins). Changes from Days 2 to 14 suggested a subsequent response in PD-ESC-sEVs with 89 differentially expressed proteins mostly involved in complement and coagulation cascades (C3, C6, C5), but no change in WD-ESC-sEVs ESC. Poor decidualization was also associated with loss of crucial sEV-proteins for cell adhesion and invasion (ITGA5, PFN1), glycolysis (ALDOA, PGK1) and cytoskeletal reorganization (VCL, RAC1). Overall, this study indicates varied ESC response even prior to decidualization and provides insight into sEVs-proteomes as a benchmark of well-decidualized ESC. It shows distinct variation in sEV-protein composition depending on the ESC decidual response that is critical for embryo implantation, enabling and limiting trophoblast invasion during placentation and sensing a healthy embryo.

中文翻译：

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蜕膜刺激后子宫内膜基质细胞衍生的细胞外囊泡的蛋白质组定义了细胞成功蜕膜的潜力

充分的子宫内膜基质细胞 (ESC) 蜕膜化对子宫内膜健康至关重要。鉴于细胞外囊泡 (EV) 在细胞间通讯中的重要性，我们研究了它们的蛋白质景观在蜕膜反应期间是如何重新编程和失调的。在蜕膜刺激后的第 2 天和第 -14 天，来自人类 ESC 条件培养基的小型 EV (sEV) 根据其催乳素分泌分为良好 (WD) 或蜕膜不良 (PD)，并进行基于质谱的定量蛋白质组学。第 2 天，在 PD- 与 WD-ESC-sEV 中，17 个 sEV- 蛋白下调（C5、C6；补体/凝血级联和 SERPING1、HRG；血小板脱粒和纤维蛋白溶解）和 39 个上调（FLNA、 COL1A1；粘着斑，ENO1，PKM；糖酵解/糖异生，和 RAP1B，MSN；白细胞跨内皮迁移）。第 14 天，在 PD-与 WD-ESC-sEVs 中，FLNA 下调，而 21 种蛋白质上调，参与补体/凝血级联反应（C3、C6）、血小板脱粒（SERPINA4、ITIH4）、B 细胞受体信号传导和先天免疫反应（免疫球蛋白）。从第 2 天到第 14 天的变化表明 PD-ESC-sEVs 有随后的反应，其中 89 种差异表达的蛋白质主要参与补体和凝血级联反应（C3、C6、C5），但 WD-ESC-sEVs ESC 没有变化。蜕膜不良还与细胞粘附和侵袭（ITGA5、PFN1）、糖酵解（ALDOA、PGK1）和细胞骨架重组（VCL、RAC1）的关键sEV蛋白丢失有关。总体而言，这项研究表明，即使在蜕膜化之前，ESC 也会有不同的反应，并提供了对 sEV 蛋白质组作为良好蜕膜化 ESC 基准的洞察。