Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountainous Region, Ministry of Education, College of Animal Science, Guizhou University, Guiyang, China.
College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.
Front Immunol. 2023 Jan 25;14:1024706. doi: 10.3389/fimmu.2023.1024706. eCollection 2023.
High-mobility group box 1 (HMGB1) is a non-histone nuclear protein and can be extracellularly secreted to induce sterile inflammation. Although uterine deletion of HMGB1 causes implantation and decidualization defects, how secreted HMGB1 is involved in mouse early pregnancy is still unknown.
Mouse models, mouse primary endometrial cells and human endometrial cell lines were used in this study. Both immunofluorescence and Western blot were performed to show the localization and relative level of HMGB1 and acetylated HMGB1, respectively. Relative mRNA levels were analyzed by real time RT-PCR.
The secreted HMGB1 was detected in uterine lumen fluid in mouse periimplantation uterus. There is an obvious difference for secreted HMGB1 levels in uterine fluid between day 4 of pregnancy and day 4 of pseudopregnancy, suggesting the involvement of blastocysts during HMGB1 secretion. Trypsin is clearly detected in mouse blastocyst cavity and in the supernatant of cultured blastocysts. Trypsin significantly stimulates HB-EGF production through activating PAR2 and ADAM17. Uterine injection of PAR2 inhibitor into day 4 pregnant mice significantly reduces the number of implantation sites. HB-EGF released from luminal epithelium can induce mouse in vitro decidualization. The conditioned medium collected from trypsin-treated luminal epithelium is able to induce in vitro decidualization, which is suppressed by EGFR inhibitor. Intrauterine injection of glycyrrhizin (HMGB1 inhibitor) can significantly inhibit mouse embryo implantation. We also showed that exogenous HMGB1 released from human epithelial cells are able to induce human in vitro decidualization.
Trypsin can induce decidualization of stromal cells via PAR2-HMGB1-ADAM17-HB-EGF from luminal epithelium.
高迁移率族蛋白 B1（HMGB1）是一种非组蛋白核蛋白，可被细胞外分泌以诱导无菌性炎症。虽然子宫中 HMGB1 的缺失会导致着床和蜕膜化缺陷，但分泌的 HMGB1 如何参与小鼠早期妊娠仍不清楚。
本研究使用了小鼠模型、小鼠原代子宫内膜细胞和人子宫内膜细胞系。通过免疫荧光和 Western blot 分别显示 HMGB1 和乙酰化 HMGB1 的定位和相对水平。通过实时 RT-PCR 分析相对 mRNA 水平。
在小鼠着床期子宫的子宫腔液中检测到分泌的 HMGB1。妊娠第 4 天和假孕第 4 天的子宫液中分泌的 HMGB1 水平存在明显差异，提示在 HMGB1 分泌过程中存在胚泡的参与。胰蛋白酶在小鼠胚泡腔和培养的胚泡上清液中明显被检测到。胰蛋白酶通过激活 PAR2 和 ADAM17 显著刺激 HB-EGF 的产生。在妊娠第 4 天的小鼠子宫内注射 PAR2 抑制剂可显著减少着床点的数量。腔上皮细胞释放的 HB-EGF 可诱导小鼠体外蜕膜化。从胰蛋白酶处理的腔上皮细胞收集的条件培养基能够诱导体外蜕膜化，而 EGFR 抑制剂可抑制其诱导作用。子宫内注射甘草酸（HMGB1 抑制剂）可显著抑制小鼠胚胎着床。我们还表明，人上皮细胞释放的外源性 HMGB1 能够诱导人体外蜕膜化。
胰蛋白酶可通过腔上皮细胞中的 PAR2-HMGB1-ADAM17-HB-EGF 诱导基质细胞的蜕膜化。
Zotero 插件
