Abstract：
Endometrium fibrosis is the leading cause of uterine infertility. Macrophages participated in the occurrence and development of endometrial fibrosis. We previously reported that human umbilical cord multipotent stromal cells (hUC-MSCs) exerted their therapeutic effect in a macrophage-dependent manner in endometrial fibrosis. However precise mechanisms by which hUC-MSCs may influence macrophages in endometrial fibrosis remain largely unexplored. Here, we demonstrated that abnormal iron and lipid metabolism occurred in patients with intrauterine adhesions (IUA) and murine models. Ferroptosis has been proven to contribute to the progression of fibrotic diseases. Our results revealed that pharmacological activation of ferroptosis by Erastin aggravated endometrial fibrosis, while inhibition of ferroptosis by Ferrostatin-1 ameliorated endometrial fibrosis in vivo. Moreover, ferroptosis of macrophages was significantly upregulated in endometria of IUA murine models. Of note, transcriptome profiles revealed that CD36 gene expression was significantly increased in patients with IUA and immunofluorescence analysis showed CD36 protein was mainly located in macrophages. Silencing CD36 in macrophages could reverse cell ferroptosis. Dual luciferase reporter assay revealed that CD36 was the direct target of activation transcription factor 3 (ATF3). Furthermore, through establishing coculture system and IUA murine models, we found that hUC-MSCs had a protective role against macrophage ferroptosis and alleviated endometrial fibrosis related to decreased CD36 and ATF3. The effect of hUC-MSCs on macrophage ferroptosis was attributed to the upregulation of amphiregulin (AREG). Our data highlighted that macrophage ferroptosis occurred in endometrial fibrosis via the ATF3-CD36 pathway and hUC-MSCs protected against macrophage ferroptosis to alleviate endometrial fibrosis via secreting AREG. These findings provided a potential target for therapeutic implications of endometrial fibrosis.
摘要：
子宫内膜纤维化是导致子宫不孕的主要原因。巨噬细胞参与了子宫内膜纤维化的发生和发展。我们先前报道了人脐带多能基质细胞（hUC-MSCs）在子宫内膜纤维化中以巨噬细胞依赖性方式发挥其治疗作用。然而，hUC-MSC可能影响子宫内膜纤维化中巨噬细胞的精确机制仍未被探索。这里,我们证明在宫腔粘连(IUA)患者和小鼠模型中发生铁和脂质代谢异常.铁性凋亡已被证明有助于纤维化疾病的进展。我们的结果表明，Erastin对铁凋亡的药理激活加重了子宫内膜纤维化，而Ferrostatin-1抑制铁凋亡可改善体内子宫内膜纤维化。此外，在IUA小鼠模型的子宫内膜中，巨噬细胞的铁蛋白显着上调。值得注意的是，转录组谱显示IUA患者CD36基因表达显著增加，免疫荧光分析显示CD36蛋白主要位于巨噬细胞中。沉默巨噬细胞中的CD36可以逆转细胞铁凋亡。双荧光素酶报告基因分析显示CD36是激活转录因子3(ATF3)的直接靶标。此外，通过建立共培养系统和IUA小鼠模型，我们发现,hUC-MSCs对巨噬细胞铁凋亡具有保护作用,并减轻与CD36和ATF3降低相关的子宫内膜纤维化.hUC-MSC对巨噬细胞铁凋亡的影响归因于双调蛋白(AREG)的上调。我们的数据强调，子宫内膜纤维化通过ATF3-CD36途径发生巨噬细胞铁凋亡，hUC-MSCs通过分泌AREG保护免受巨噬细胞铁凋亡以减轻子宫内膜纤维化。这些发现为子宫内膜纤维化的治疗意义提供了潜在的靶点。
