Interleukin-33 promotes intrauterine adhesion formation in mice through the mitogen-activated protein kinase signaling pathway.

IL-33 belongs to the inflammatory factor family and is closely associated with the inflammatory response. However, its role in the development of intrauterine adhesions (IUAs) remains unclear. In this study, the role of IL-33 in the formation of IUAs after endometrial injury was identified via RNA sequencing after mouse endometrial organoids were transplanted into an IUA mouse model. Major pathological changes in the mouse uterus, consistent with the expression of fibrotic markers, such as TGF-ß, were observed in response to treatment with IL-33. This finding may be attributed to activation of the phosphorylation of downstream MAPK signaling pathway components, which are activated by the release of IL-33 in macrophages. Our study provides a novel mechanism for elucidating IUA formation, suggesting a new therapeutic strategy for the prevention and clinical treatment of IUAs.

Reproductive factors and subsequent pregnancy outcomes in patients with prior pregnancy loss.

BACKGROUND: At present, individualized interventions can be given to patients with a clear etiology of pregnancy loss to improve the subsequent pregnancy outcomes, but the current reproductive status of the patient cannot be changed. The aim of this study was to investigate the association between female reproductive status and subsequence pregnancy outcome in patients with prior pregnancy loss (PL). METHODS: A prospective, dynamic population cohort study was carried out at the Second Hospital of Lanzhou University. From September 2019 to February 2022, a total of 1955 women with at least one previous PL were enrolled. Maternal reproductive status and subsequent reproductive outcomes were recorded through an electronic medical record system and follow-up. Logistic regression was used to evaluate the association between reproductive status and the risk of subsequent reproductive outcomes. RESULTS: Among all patients, the rates of subsequent infertility, early PL, late PL, and live birth were 20.82%, 24.33%, 1.69% and 50.77% respectively. In logistic regression, we found that age (OR 1.08, 95% CI 1.04-1.13) and previous cesarean delivery history (OR 2.46, 95% CI 1.27-4.76) were risk factors for subsequent infertility in patients with PL. Age (OR 1.06, 95% CI 1.03-1.10), age at first pregnancy (OR 1.06, 95% CI 1.03-1.10), BMI (OR 1.06, 95% CI 1.02-1.11), previous PL numbers (OR 1.18, 95% CI 1.04-1.57) and without pre-pregnancy intervention (OR 1.77, 95% CI 1.35-2.24) were risk factors for non-live birth. Age (OR 1.06, 95% CI 1.03-1.09), age at first pregnancy (OR 1.06, 95% CI 1.02-1.09), BMI (OR 1.07, 95% CI 1.02-1.11), previous PL numbers (OR 1.15, 95% CI 1.02-1.31) and without pre-pregnancy intervention (OR 2.16, 95% CI 1.65-2.84) were risk factors for PL. CONCLUSIONS: The reproductive status of people with PL is strongly correlated with the outcome of subsequent pregnancies. Active pre-pregnancy intervention can improve the subsequent pregnancy outcome. TRIAL REGISTRATION: This study was registered in the Chinese Clinical Trial Registry with the registration number of ChiCTR2000039414 (27/10/2020).

Estrogen attenuates TGF-ß1-induced EMT in intrauterine adhesion by activating Wnt/ß-catenin signaling pathway

Although estrogen has crucial functions for endometrium growth, the specific dose and underlying molecular mechanism in intrauterine adhesion (IUA) remain unclear. In this study, we aimed to investigate the effects of estrogen on epithelial-mesenchymal transition (EMT) in normal and fibrotic endometrium, and the role of estrogen and Wnt/β-catenin signaling in the formation of endometrial fibrosis. CCK-8 and immunofluorescence assay were performed to access the proliferation of different concentrations of estrogen on normal human endometrial epithelial cells (hEECs). qRT-PCR and western blot assay were utilized to explore the effect of estrogen on EMT in normal and fibrotic endometrium, and main components of Wnt/β-catenin signaling pathway in vitro. Hematoxylin and eosin and Masson staining were used to evaluate the effect of estrogen on endometrial morphology and fibrosis in vivo. Our results indicated that the proliferation of normal hEECs was inhibited by estrogen at a concentration of 30 nM accompanied by upregulation of mesenchymal markers and downregulation of epithelial markers. Interestingly, in the model of transforming growth factor β1 (TGF-β1)-induced endometrial fibrosis, the same concentration of estrogen inhibited the process of EMT, which might be partially mediated by regulation of the Wnt/β-catenin pathway. In addition, relatively high doses of estrogen efficiently increased the number of endometrial glands and reduced the area of fibrosis as determined by the reduction of EMT in IUA animal models. Taken together, our results demonstrated that an appropriate concentration of estrogen may prevent the occurrence and development of IUA by inhibiting the TGF-β1-induced EMT and activating the Wnt/β-catenin pathway.