Research question

Do endometriotic lesions undergo endothelial–mesenchymal transition (EndoMT)?

Design

Lesion samples from 30 patients with ovarian endometriomas and deep endometriosis, and control endometrial tissue samples from 30 women without endometriosis, were analysed. In-vitro experimentation using the human umbilical vein endothelial cell (HUVEC) line were conducted. Immunofluorescence staining and immunohistochemistry analysis using antibodies against endothelial cell and mesenchymal cell markers were conducted. The HUVEC cells were co-cultured with activated platelets or control medium with and without neutralization of TGF-β1 PDGFR, or both. Their morphology, proliferation and expression levels of genes and proteins known to be involved in EndoMT were evaluated, along with their migratory and invasive propensity, contractility and collagen production capability.

Results

The proportion of CD31 and FSP-1 dual-positive cells in FSP-1+ fibroblasts was 74.7% (±5.4%) in ovarian endometrioma lesions, significantly higher than that in deep endometriosis lesions (26.8% ± 26.0%; P = 5.7 × 10⁻⁵), and was zero in normal endometrium. The extent of lesional fibrosis correlated positively with staining levels of the lesional mesenchymal markers FSP-1 and α-SMA (r = 0.91; P < 2.2 × 10⁻¹⁶, r = 0.81; P = 5.8 × 10⁻¹⁵, respectively). Human endothelial cells co-cultured with activated platelets acquire a morphology suggestive of EndoMT, concomitant with increased proliferation, loss of CD31 but marked increase in expression of mesenchymal markers. Morphological and gene and protein expression changes are accompanied by functional differentiation reflected by increased migratory and invasive capacity, contractility and collagen production. Neutralization of TGF-β1 and PDGFR signalling abolished platelet-induced EndoMT in human endothelial cells.

Conclusions

Multiple sources of myofibroblasts exist in endometriotic lesions, and implicates platelets, EndoMT, or both, as potential therapeutic targets for treating endometriosis.

中文翻译：

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血小板在子宫内膜异位症中诱导内皮间质转化和随后的纤维化。

研究问题

子宫内膜异位病变会发生内皮间质转化 (EndoMT) 吗？

设计

分析了来自 30 名患有卵巢子宫内膜异位症和深部子宫内膜异位症的患者的病变样本，以及来自 30 名没有子宫内膜异位症的女性的对照子宫内膜组织样本。进行了使用人脐静脉内皮细胞 (HUVEC) 系的体外实验。使用针对内皮细胞和间充质细胞标记物的抗体进行免疫荧光染色和免疫组织化学分析。HUVEC 细胞与活化的血小板或对照培养基共培养，有或没有中和 TGF-β1 PDGFR，或两者兼有。评估了它们的形态、增殖和已知参与 EndoMT 的基因和蛋白质的表达水平，以及它们的迁移和侵入倾向、收缩性和胶原蛋白生产能力。

结果

卵巢子宫内膜异位症病变中FSP-1+成纤维细胞中CD31和FSP-1双阳性细胞的比例为74.7%（±5.4%），显着高于深部子宫内膜异位病变（26.8%±26.0%；P  =5.7×） 10 ^-5 )，在正常子宫内膜中为零。病变纤维化的程度与病变间充质标志物 FSP-1 和 α-SMA 的染色水平呈正相关（r = 0.91；P < 2.2 × 10 ^-16，r = 0.81；P  = 5.8 × 10 ^-15， 分别）。与活化的血小板共培养的人内皮细胞获得提示 EndoMT 的形态，伴随增殖增加、CD31 丢失但间充质标记物的表达显着增加。形态、基因和蛋白质表达变化伴随着功能分化，表现为迁移和侵袭能力、收缩力和胶原蛋白生成的增加。TGF-β1 和 PDGFR 信号的中和消除了人内皮细胞中血小板诱导的 EndoMT。

结论

子宫内膜异位症病变中存在多种肌成纤维细胞来源，并暗示血小板、EndoMT 或两者都是治疗子宫内膜异位症的潜在治疗靶点。