Intrauterine adhesions (IUAs) are manifestations of endometrial fibrosis characterized by inflammation and fibrinogen aggregation in the extracellular matrix (ECM). The available therapeutic interventions for IUA are insufficiently effective in the clinical setting for postoperative adhesion recurrence and infertility problems. In this study, we investigated whether si-SNHG5-FOXF2 can serve as a molecular mechanism for the inhibition of IUA fibrosis ex vivo. FOXF2, TGF-β1 and collagen expression levels were measured by microarray sequencing analysis in three normal endometrium groups and six IUA patients. We induced primary human endometrial stromal cells (HESCs) into myofibroblasts (MFs) to develop an IUA cell model with various concentrations of TGF-β1 at various times. Downstream target genes of FOXF2 were screened by chromatin immunoprecipitation combined with whole-genome high-throughput sequencing (ChIP-seq). We investigated ECM formation, cell proliferation and Wnt/β-catenin signalling pathway-related proteins in primary HESCs with FOXF2 downregulation by quantitative reverse transcription-polymerase chain reaction (qRT-PCR), western blotting (WB), immunohistochemistry (IHC), flow cytometry, ethylenediurea (EdU) and CCK8 assays. We identified long noncoding RNAs (lncRNA) SNHG5 as the upstream regulatory gene of FOXF2 through RNA immunoprecipitation (RIP), RNA pulldown and fluorescence in situ hybridization (FISH). Finally, we examined FOXF2 expression, ECM formation, cell proliferation and Wnt/β-catenin signalling pathway-related proteins in primary HESCs upon FOXF2 downregulation. FOXF2 was highly expressed in the endometrium of patients with IUA. Treatment of primary HESCs with 10 ng/ml TGF-β1 for 72 h was found to be most effective for developing an IUA cell model. FOXF2 regulated multiple downstream target genes, including collagen, vimentin (VIM) and cyclin D2/DK4, by ChIP-seq and ChIP-PCR. FOXF2 downregulation inhibited TGF-β1-mediated primary HESC fibrosis, including ECM formation, cell proliferation and Wnt/β-catenin signalling pathway-related protein expression. We identified lncRNA SNHG5 as an upstream gene that directly regulates FOXF2 by RIP-seq, qRT-PCR, WB and FISH. SNHG5 downregulation suppressed FOXF2 expression in the IUA cell model, resulting in synergistic repression of the Wnt/β-catenin pathway, thereby altering TGF-β1-mediated ECM aggregation in endometrial stromal cells ex vivo. Regulation of the Wnt/β-catenin signalling pathway and ECM formation by si-SNHG5-FOXF2 effectively inhibited the profibrotic effect of TGF-β1 on primary HESCs. This finding can provide a molecular basis for antagonizing TGF-β1-mediated fibrosis in primary HESCs.

中文翻译：

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si-SNHG5-FOXF2 通过 Wnt/β-catenin 信号通路抑制 TGF-β1 诱导的人原发性子宫内膜基质细胞纤维化

宫腔粘连 (IUAs) 是子宫内膜纤维化的表现，其特征是细胞外基质 (ECM) 中的炎症和纤维蛋白原聚集。IUA 可用的治疗干预措施在临床环境中对术后粘连复发和不孕问题的有效性不足。在这项研究中，我们研究了 si-SNHG5-FOXF2 是否可以作为体外抑制 IUA 纤维化的分子机制。通过微阵列测序分析在三个正常子宫内膜组和六个 IUA 患者中测量 FOXF2、TGF-β1 和胶原蛋白表达水平。我们将原代人子宫内膜基质细胞 (HESCs) 诱导成肌成纤维细胞 (MFs)，以开发在不同时间具有不同浓度 TGF-β1 的 IUA 细胞模型。通过染色质免疫沉淀结合全基因组高通量测序（ChIP-seq）筛选FOXF2的下游靶基因。我们通过定量逆转录聚合酶链反应 (qRT-PCR)、蛋白质印迹 (WB)、免疫组织化学 (IHC)、流流式细胞术、乙二脲 (EdU) 和 CCK8 测定。我们通过 RNA 免疫沉淀 (RIP)、RNA pulldown 和荧光原位杂交 (FISH) 将长非编码 RNA (lncRNA) SNHG5 鉴定为 FOXF2 的上游调控基因。最后，我们检测了 FOXF2 下调后原代 HESC 中的 FOXF2 表达、ECM 形成、细胞增殖和 Wnt/β-catenin 信号通路相关蛋白。FOXF2 在 IUA 患者的子宫内膜中高表达。发现用 10 ng/ml TGF-β1 处理原代 HESC 72 小时对于开发 IUA 细胞模型最有效。FOXF2 通过 ChIP-seq 和 ChIP-PCR 调节多个下游靶基因，包括胶原蛋白、波形蛋白 (VIM) 和细胞周期蛋白 D2/DK4。FOXF2 下调抑制 TGF-β1 介导的原发性 HESC 纤维化，包括 ECM 形成、细胞增殖和 Wnt/β-catenin 信号通路相关蛋白表达。我们通过 RIP-seq、qRT-PCR、WB 和 FISH 将 lncRNA SNHG5 鉴定为直接调节 FOXF2 的上游基因。SNHG5 下调抑制 IUA 细胞模型中 FOXF2 的表达，导致 Wnt/β-连环蛋白途径的协同抑制，从而改变 TGF-β1 介导的 ECM 离体在子宫内膜基质细胞中的聚集。si-SNHG5-FOXF2 对 Wnt/β-catenin 信号通路和 ECM 形成的调节有效抑制了 TGF-β1 对原代 HESCs 的促纤维化作用。这一发现可为拮抗原发性 HESC 中 TGF-β1 介导的纤维化提供分子基础。