Wu Rong-Feng, Huang Zhi-Xiong, Ran Jing, Dai Song-Juan, Lin Dian-Chao, Ng Tai-Wei, Chen Qing-Xi, Chen Qiong-Hua
1 Reproductive Medical Center, The First Affiliated Hospital of Xiamen University, Xiamen, Fujian, People's Republic of China.
2 State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, China.
Reprod Sci. 2018 Apr;25(4):566-578. doi: 10.1177/1933719117718271. Epub 2017 Jul 10.
Epithelial-mesenchymal transition (EMT) is essential for embryogenesis, fibrosis, and tumor metastasis. Aberrant EMT phenomenon has been reported in endometriotic tissues of patients with endometriosis (EM). In this study, we further investigated the molecular mechanism of which lipoxin A (LXA) suppresses estrogen (E)-induced EMT in EM.
The EMT markers were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot in eutopic endometrial epithelial cells (EECs) or investigated by immunohistochemistry and qRT-PCR in endometriotic lesion of EM mice. The invasion and migration under different treatments were assessed by transwell assays with or without Matrigel. The messenger RNA (mRNA) and activities of matrix metalloproteinase 2 (MMP-2) and MMP-9 were determined by qRT-PCR and gelatin zymography, respectively. Luciferase reporter assay was used to measure the activity of zinc finger E-box binding homeobox 1(ZEB1) promoter. The level of E in endometriotic tissues was assessed by enzyme-linked immunosorbent assay.
In eutopic EECs, stimulatory effects of E on EMT progress, migration, and invasion were all diminished by LXA. Lipoxin A reduced E-induced ZEB1 promoter activity. Lipoxin A also attenuated the phosphorylation of extracellular signal-regulated kinase and p38 mitogen-activated protein kinase induced by E. Co-incubation with Boc-2 rather than DMF antagonized the influence of LXA. Animal experiments showed that LXA inhibited the EMT progress, MMP expression, and proteinase activities of endometriotic lesion in an LXA receptor (ALXR) manner, which suppressed the progression of EM. ZEB1 mRNA expression was upregulated and well correlated with E level in human endometrium.
Lipoxin A suppresses E-induced EMT via ALXR-dependent manner in eutopic EECs, which reveals a novel biological effect of LXA in EM.
上皮-间质转化（EMT）对于胚胎发育、纤维化和肿瘤转移至关重要。子宫内膜异位症（EM）患者的异位内膜组织中已报道存在异常的EMT现象。在本研究中，我们进一步探究了脂氧素A（LXA）抑制EM中雌激素（E）诱导的EMT的分子机制。
通过定量实时聚合酶链反应（qRT-PCR）和蛋白质免疫印迹法分析在位子宫内膜上皮细胞（EECs）中的EMT标志物，或通过免疫组织化学和qRT-PCR在EM小鼠的异位内膜病变中进行研究。采用有或无基质胶的Transwell实验评估不同处理下的侵袭和迁移能力。分别通过qRT-PCR和明胶酶谱法测定基质金属蛋白酶2（MMP-2）和MMP-9的信使核糖核酸（mRNA）及活性。采用荧光素酶报告基因检测法测定锌指E盒结合同源框1（ZEB1）启动子的活性。通过酶联免疫吸附测定法评估异位内膜组织中的E水平。
在位EECs中，LXA减弱了E对EMT进程、迁移和侵袭的促进作用。脂氧素A降低了E诱导的ZEB1启动子活性。脂氧素A还减弱了E诱导的细胞外信号调节激酶和p38丝裂原活化蛋白激酶的磷酸化。与Boc-2而非二甲基甲酰胺共同孵育可拮抗LXA的影响。动物实验表明，LXA以脂氧素A受体（ALXR）依赖的方式抑制异位内膜病变的EMT进程、MMP表达和蛋白酶活性，从而抑制EM的进展。ZEB1 mRNA表达上调，且与人子宫内膜中的E水平密切相关。
脂氧素A在位EECs中通过ALXR依赖的方式抑制E诱导的EMT，这揭示了LXA在EM中的一种新的生物学效应。
