Department of Endocrine Pharmacology, Tokyo University of Pharmacy and Life Sciences, Tokyo 192-0392, Japan.
Department of Obstetrics and Gynecology, Tokyo Medical University, Tokyo 160-0023, Japan.
Mol Hum Reprod. 2021 May 29;27(6). doi: 10.1093/molehr/gaab036.
Endometriosis is characterised by inflammation and fibrotic changes. Our previous study using a mouse model showed that proinflammatory factors present in peritoneal haemorrhage exacerbated inflammation in endometriosis-like grafts, at least in part through the activation of prostaglandin (PG) E2 receptor and protease-activated receptor (PAR). In addition, hypoxia is a well-known inducer of fibrosis that may be associated with epithelial-mesenchymal transition (EMT). However, the complex molecular interactions between hypoxia and proinflammatory menstruation-related factors, PGE2 and thrombin, a PAR1 agonist, on EMT in endometriosis have not been fully characterised. To explore the effects of hypoxia and proinflammatory factors on EMT-like changes in endometrial cells, we determined the effects of PGE2 and thrombin (P/T) on EMT marker expression and cell migration in three dimensional cultured human endometrial epithelial cells (EECs) and endometrial stromal cells (ESCs). Treatment of EECs with P/T under hypoxia stimulated cell migration, increased the expression of mesenchymal N-cadherin, vimentin and C-X-C chemokine receptor type 4 (CXCR4), and reduced the expression of epithelial E-cadherin. Furthermore, treatment with C-X-C motif chemokine ligand 12 (CXCL12), a ligand for CXCR4, increased EMT marker expression and cell migration. In ESCs, P/T or oestrogen treatment under hypoxic conditions increased the expression and secretion of CXCL12. Taken together, our data show that hypoxic and proinflammatory stimuli induce EMT, cell migration and inflammation in EECs, which was increased by CXCL12 derived from ESCs. These data imply that inflammatory mediators in retrograde menstrual fluid contribute to ectopic endometrial EMT and migration in the presence of peritoneal hypoxia.
子宫内膜异位症的特征是炎症和纤维化改变。我们之前的研究使用小鼠模型表明，腹腔出血中的促炎因子加剧了子宫内膜异位样移植物中的炎症，至少部分是通过激活前列腺素（PG）E2 受体和蛋白酶激活受体（PAR）。此外，缺氧是纤维化的已知诱导剂，可能与上皮-间充质转化（EMT）有关。然而，缺氧与促炎月经相关因子（PGE2 和凝血酶，PAR1 激动剂）之间的复杂分子相互作用，以及它们对子宫内膜异位症中 EMT 的影响尚未得到充分描述。为了探讨缺氧和促炎因子对子宫内膜细胞 EMT 样变化的影响，我们确定了 PGE2 和凝血酶（P/T）对三维培养的人子宫内膜上皮细胞（EEC）和子宫内膜基质细胞（ESC）中 EMT 标志物表达和细胞迁移的影响。缺氧下 P/T 处理刺激 EEC 细胞迁移，增加间充质 N-钙粘蛋白、波形蛋白和 C-X-C 趋化因子受体 4（CXCR4）的表达，降低上皮 E-钙粘蛋白的表达。此外，CXCR4 的配体 C-X-C 基序趋化因子配体 12（CXCL12）的处理增加了 EMT 标志物的表达和细胞迁移。在 ESC 中，缺氧条件下 P/T 或雌激素处理增加了 CXCL12 的表达和分泌。总之，我们的数据表明，缺氧和促炎刺激诱导 EEC 中的 EMT、细胞迁移和炎症，而来源于 ESC 的 CXCL12 增加了这种作用。这些数据表明，逆行月经液中的炎症介质有助于在腹膜缺氧存在的情况下异位子宫内膜 EMT 和迁移。
