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Abstract Background Endometriosis-related infertility is a common worldwide reproductive health concern. Despite ongoing research, the causes of infertility remain unclear. Evidence suggests that epigenetic regulation is crucial in reproduction. However, the role of N6-methyladenosine (m6A) modification of RNA in endometriosis-related infertility requires further investigation. Methods We examined the expression of m6A and methyltransferase-like 3 (METTL3) in endometrial samples taken from normal fertile women in the proliferative phase (the NP group) or the mid-secretory phase (the NS group) or from women with endometriosis-related infertility at the mid-secretory phase (the ES group). We treated primary endometrial stromal cells (ESCs) with medroxyprogesterone acetate and 8-Bromo-cyclic adenosine monophosphate for in vitro decidualization and detected the expression of m6A, METTL3, and decidual markers. We analyzed the expression of m6A, METTL3, and forkhead box O1 (FOXO1) in ESCs from normal fertile women (the ND group) or women with endometriosis-related infertility (the ED group). We also assessed the expression of m6A, METTL3, and decidual markers, as well as the embryo adhesion rate, upon METTL3 overexpression or knockdown. Additionally, we investigated the role of METTL3 in embryo implantation in vivo by applying mice with endometriosis. Furthermore, we performed RNA stability assays, RNA immunoprecipitation (RIP), and methylated RIP assays to explore the mechanisms underlying the regulation of FOXO1 by METTL3-mediated m6A. Results The expression of m6A and METTL3 was reduced only in the NS group; the NP and ES groups demonstrated increased m6A and METTL3 levels. m6A and METTL3 levels decreased in ESCs with prolonged decidual treatment. Compared to the ND group, m6A and METTL3 levels in the ED group increased after decidual treatment, whereas the expression of FOXO1 decreased. METTL3 overexpression suppressed the expression of decidual markers and embryo implantation in vitro; METTL3 knockdown exhibited the opposite effect. Inhibition of METTL3 promoted embryo implantation in vivo. Furthermore, we observed that METTL3-mediated m6A regulated the degradation of FOXO1 mRNA through YTHDF2, a m6A binding protein. Conclusions METTL3-regulated m6A promotes YTHDF2-mediated decay of FOXO1 mRNA, thereby affecting cellular decidualization and embryo implantation. These findings provide novel insights into the development of therapies for women with endometriosis-related infertility.

Background: Hysteroscopic adhesiolysis effectively restores the anatomical integrity of the uterine cavity in cases of intrauterine adhesions (IUA). However, there is ongoing debate regarding the factors influencing the reproductive outcomes of hysteroscopic adhesiolysis in women with IUA. Methods: One-hundred and thirty-seven patients with IUAs who wanted to become pregnant were enrolled. All patients underwent hysteroscopic adhesiolysis performed by a single experienced surgeon at a tertiary University-affiliated hospital between February 2019 and July 2021. Subsequently, these patients attempted to conceive within the following two years. Patients with concurrent intrauterine diseases such as polyps, submucosal myoma, or IUAs attributed to tuberculosis were excluded from the study. General clinical data were collected and analyzed using univariate and multivariable logistic regression analyses. Results: The clinical pregnancy rate for patients with IUA was 60.6% (83/137), and the live birth rate was 51.8% (71/137). The clinical pregnancy and live birth rates were similar between the in vitro fertilization (IVF) group and the spontaneous conception group. Multivariable logistic regression analysis revealed that patients aged 37 years or older (Odds ratio (OR) 3.928, 95% confidence interval (CI) 1.214–12.710, p = 0.022) or with severe IUA (OR 4.579, 95% CI 1.811–11.578, p = 0.002) were significantly more likely to have a lower clinical pregnancy rate. Similarly, patients aged 37 years or older (OR 3.919, 95% CI 1.147–13.388, p = 0.029) or with severe IUA (OR 5.8, 95% CI 2.129–15.806, p = 0.001) were more likely to have a lower birth rate. Conclusions: Patients’ age and severity of IUA can potentially predict the reproductive outcomes of IUA treatment.

Background Polycystic ovary syndrome (PCOS) is the most common endocrine disorder with complex pathophysiological mechanism. It is reported that even a modest weight loss of 5–10% substantially may improve the reproductive and metabolic profile. This study aims to assess the efficacy of the low dose of liraglutide (0.6 mg QD) combined with metformin (0.85 mg BID) in weight loss in Chinese Han women with PCOS.Methods We included clinical data of 102 obese/overweight (≥18 years, body mass index ≥28 kg/m2 or ≥24 kg/m2) women who were diagnosed with PCOS from October 2016 to March 2018 in Wuhan Union Hospital initially. They were treated with dinae-35, low dose of liraglutide (0.6 mg QD) and metformin (0.85 mg BID) for 12 weeks. The demographic and clinical data were retrieved retrospectively, and weight loss was the main outcome measure. Student’s paired t-test and Wilcoxon rank sum test were used to compare the differences before and after therapy, p

Mesenchymal--epithelial transition (MET)-mediated endometrial decidualization is pivotal for achieving endometrial receptivity and successful pregnancy. We observed blockade of MET in the eutopic secretory endometrium of patients with endometriosis, but the underlying mechanism is unknown. In this study, real-time PCR was used to detect PRL and IGFBP1 expression, whereas western blotting was used to detect the expression of MET markers and METTL3. Phalloidin staining was used to identify changes in cell morphology. M6A levels were quantified using a colorimetric method and m6A dot blots, and functional analysis was performed using spheroid adhesion assays. We first found that increased E-cadherin expression was accompanied by decreased vimentin and Slug expression in the eutopic secretory endometrium of individuals with endometriosis. We also detected a significant increase in both the m6A level and the expression of the related methyltransferase METTL3. Finally, METTL3 expression was negatively correlated with PRL, IGFBP1, and MET markers expression. Collectively, our findings suggest that METTL3 mediates m6A modification, thereby inhibiting MET formation within the eutopic secretory endometrium of patients with endometriosis. Increased METTL3-mediated m6A modification plays a crucial role in attenuating MET formation and decidualization impairment in endometrial stromal cells, ultimately contributing to compromised endometrial receptivity in individuals with endometriosis. These insights could lead to the identification of potential therapeutic targets for improving both endometrial receptivity and pregnancy rate among individuals affected by endometriosis. [ABSTRACT FROM AUTHOR]

Oestrogen has been reported to control the invasiveness of endometrial stromal cells in endometriosis. Notch signalling, a master regulator of cell invasion in tumours, is regulated by oestrogen in other diseases and hyperactivated in endometriotic stromal cells. Therefore, we hypothesized that an interaction between Notch signalling and oestrogen may exist in the regulation of endometrial stromal cell invasion, which is essential for the development of endometriosis. Western blot analysis of tissues showed that the expression levels of Notch components (JAG1 and NOTCH1) and Notch activity were markedly higher in ectopic endometria than in their eutopic and normal counterparts. Primary stromal cells obtained from normal endometria cultured with oestrogen presented significant increases in the expression of Notch components and Notch activity, the cytoplasmic and nuclear accumulation of NOTCH1 intracellular domain, the expression of matrix metallopeptidase 9 and vascular endothelial growth factor and cell invasiveness. Knockdown of NOTCH1 markedly alleviated oestrogen-induced matrix metallopeptidase 9 and vascular endothelial growth factor expression and cell invasion. ICI (an oestrogen receptor α antagonist) also blocked these oestrogenic effects. Oestrogen-responsive elements were found in the promoters of NOTCH1 and JAG1. A luciferase reporter analysis revealed that oestrogen regulated the expression of Notch components via oestrogen receptor alpha, which is bound to oestrogen-responsive elements in the JAG1 and NOTCH1 promoters. Collectively, our findings indicate that oestrogen engages in crosstalk with Notch signalling to regulate cell invasion in endometriosis via the activation of oestrogen receptor alpha and the enhancement of Notch activity. Notch signalling blockade may therefore be a novel therapeutic target for endometriosis. [ABSTRACT FROM AUTHOR]

Endometriosis is an estrogen-dependent benign gynecological disease that shares some common features of malignancy. Epithelial- mesenchymal transition (EMT) has been recognized as a core mechanism of endometriosis. MALAT1 is widely known as EMT promoter, while miR200 family members (miR200s) are considered as EMT inhibitors. Previous studies have reported that MALAT1 upregulation and miR200s downregulation are observed in endometriosis. MiR200c has been regarded as the strongest member of miR200s to interact with MALAT1. However, whether MALAT1/miR200c regulates EMT remains largely unclear. In this study, the roles of miR200s and MALAT1 in ectopic endometrium were investigated. Additionally, the effects of E2 on EMT and MALAT1/miR200s were examined in both EECs and Ishikawa cells. Notably, E2 could upregulate MALAT1 and downregulate miR200s expression levels and induce EMT in EECs and Ishikawa cells. PHTPP, an ERß antagonist, could reverse the effect of E2. Overexpression of miR200c and knockdown of MALAT1 significantly inhibited E2-mediated EMT, suggesting that both miR200c and MALAT1 are involved in the E2-induced EMT process in endometriosis. In addition, a reciprocal inhibition was found between miR200s and MALAT1. Therefore, the role of MALAT1/miR200c in EMT is influenced by the presence of estrogen during endometriosis development. [ABSTRACT FROM AUTHOR]

Endometriosis is a benign gynecological disease that shares some characteristics with malignancy like migration and invasion. It has been reported that both hypoxia-inducible factor-1α (HIF-1α) and autophagy were upregulated in ectopic endometrium of patients with ovarian endometriosis. However, the crosstalk between HIF-1α and autophagy in the pathogenesis of endometriosis remains to be clarified. Accordingly, we investigated whether autophagy was regulated by HIF-1α, as well as whether the effect of HIF-1α on cell migration and invasion is mediated through autophagy upregulation. Here, we found that ectopic endometrium from patients with endometriosis highly expressed HIF-1α and autophagy-related protein LC3. In cultured human endometrial stromal cells (HESCs), autophagy was induced by hypoxia in a time-dependent manner and autophagy activation was dependent on HIF-1α. In addition, migration and invasion ability of HESCs were enhanced by hypoxia treatment, whereas knockdown of HIF-1α attenuated this effect. Furthermore, inhibiting autophagy with specific inhibitors and Beclin1 siRNA attenuated hypoxia triggered migration and invasion of HESCs. Taken together, these results suggest that HIF-1α promotes HESCs invasion and metastasis by upregulating autophagy. Thus, autophagy may be involved in the pathogenesis of endometriosis and inhibition of autophagy might be a novel therapeutic approach to the treatment of endometriosis. [ABSTRACT FROM AUTHOR]