BACKGROUND: The sirtuin family is well recognized for its crucial involvement in various cellular processes. Nevertheless, studies on its role in the human endometrium are limited. This study aimed to explore the expression and localization of the sirtuin family in the human endometrium, focusing on sirtuin 3 (SIRT3) and its potential role in the oxidative imbalance of the endometrium in polycystic ovary syndrome (PCOS). METHODS: Endometrial specimens were collected from both patients with PCOS and controls undergoing hysteroscopy at the Center for Reproductive Medicine, Peking University Third Hospital, from July to August 2015 and used for cell culture. The protective effects of SIRT3 were investigated, and the mechanism of SIRT3 in improving endometrial receptivity of patients with PCOS was determined using various techniques, including cellular bioenergetic analysis, small interfering ribonucleic acid (siRNA) silencing, real-time quantitative polymerase chain reaction, Western blot, immunofluorescence, immunohistochemistry, and flow cytometry analysis. RESULTS: The sirtuin family was widely expressed in the human endometrium, with SIRT3 showing a significant increase in expression in patients with PCOS compared with controls ( P <0.05), as confirmed by protein and gene assays. Concurrently, endometrial antioxidant levels were elevated, while mitochondrial respiratory capacity was reduced, in patients with PCOS ( P <0.05). An endometrial oxidative stress (OS) model revealed that the downregulation of SIRT3 impaired the growth and proliferation status of endometrial cells and reduced their receptivity to day 4 mouse embryos. The results suggested that SIRT3 might be crucial in maintaining normal cellular state by regulating antioxidants, cell proliferation, and apoptosis, thereby contributing to enhanced endometrial receptivity. CONCLUSIONS Our findings proposed a significant role of SIRT3 in improving endometrial receptivity in patients with PCOS by alleviating OS and regulating the balance between cell proliferation and apoptosis. Therefore, SIRT3 could be a promising target for predicting and improving endometrial receptivity in this patient population.
Humans ; Female ; Polycystic Ovary Syndrome/metabolism* ; Endometrium/metabolism* ; Sirtuin 3/genetics* ; Oxidative Stress/genetics* ; Adult ; Animals ; Mice ; Apoptosis/physiology* ; Immunohistochemistry ; Cell Proliferation/physiology*

Intrauterine adhesion(IUA) is a common gynecological disease that is difficult to treat, and there is a lack of specific effective drugs and measures to prevent endometrial fibrosis. In this study, the mechanism of endometrial oxidative stress and fibrosis regulation was studied in an IUA rat model constructed by Bushen Huoxue Formula intervention of mechanical injury combined with infection. A total of 72 SPF SD female rats aged 8-10 weeks were randomly divided into blank control group, model control group, low-dose, medium-dose, and high-dose groups of Bushen Huoxue Formula, and estrogen groups. The rats in the estrous cycle of the model control group and the positive control group were simulated with surgical injury and infection, and the sham operation group was treated with on-off abdominal treatment. After successful modeling, the model control group was administered intragastrically with purified water of 15 μL·g~(-1) every day. The low-dose group was administered intragastrically with Bushen Huoxue Formula of 7.8 g·kg~(-1); the medium-dose group was administered intragastrically with Bushen Huoxue Formula of 15.6 g·kg~(-1), and the high-dose group was administered intragastrically with Bushen Huoxue Formula of 31.2 g·kg~(-1). The estrogen group was administered intragastrically with estradiol valerate of 4.2 mg·kg~(-1). After continuous intervention for 28 days, all rats were deprived of water and killed to collect blood and tissue. Hematoxylin-eosin(HE) staining calculated the number of uterine glands; Masson staining calculated the area of uterine collagen fibers. Combined with HE and Masson staining, semi-quantitative scores were performed on the degree of endometrial fibrosis. Immunohistochemistry was performed to detect the vascular endothelial growth factor(VEGF), stromal cell-derived factor-1(SDF-1), and transforming growth factor-β1(TGF-β1) expression in rats' uterine tissue. Enzyme-linked immunosorbent assay(ELISA) dected angiopoietin 1(IFN-γ), interleukin-1α(IL-1α), TGF-β1, tumor necrosis factor-α(TNF-α), collagen type Ⅳ(Ⅳ-Col), leukemia inhibitory factor(LIF), superoxide dismutase(SOD)、glutathione peroxidase(GSH-Px);The mRNA expressions of Smad2, Smad3, adisintegrin and metalloproteinase(ADAM17) and TGF-β1 were determined by qPCR. Notch and ADAM17 protein expression in rat uterus were determined by Western blot. The results showed that the area of uterine fibrosis was significantly reduced and the conditions of edema and adhesion were effectively alleviated after high-dose intervention of Bushen Huoxue Formula. The levels of inflammatory factors and Ⅳ-Col were significantly decreased, and the levels of LIF and antioxidant enzymes were significantly increased. The mRNA expressions of Smad2, Smad3, ADAM17 and TGF-β1 were significantly down-regulated. Immunohistochemical results showed that Bushen Huoxu Formula could effectively increase the positive expression of SDF-1 and reduce the positive expression of VEGF and TGF-β1. Western blot results showed that the protein expressions of Notch and ADAM17 in high-dose, medium-dose and low-dose of Bushen Huoxu Formula groups were significantly down-regulated in a dose-dependent manner. These results suggest that Bushen Huoxue Formula may inhibit fibrosis process through ADAM17/Notch signaling pathway, suggesting that Bushen Huoxuet Formula is one of the potential therapeutic methods for IUA.
Animals ; Female ; Drugs, Chinese Herbal/administration & dosage* ; Rats, Sprague-Dawley ; Endometrium/pathology* ; Rats ; Fibrosis/metabolism* ; Oxidative Stress/drug effects* ; Humans ; Uterine Diseases/genetics* ; Vascular Endothelial Growth Factor A/genetics*

Objective To explore the mechanism of ubiquitin specific peptidase 21 (USP21) increasing the stability of forkhead box protein M1 (FOXM1) and promoting M2 polarization of macrophages in endometriosis (EM). Methods Eutopic endometrial stromal cells (EESC) collected from patients and normal endometrial stromal cells (NESC) from routine health examiners were cultured in vitro, and the expression levels of USP21 and FOXM1 were detected using RT-qPCR and Western blot. EESCs were co-cultured with macrophages. M1 polarization markers of interleukin 6 (IL-6) and CXC chemokine ligand 10 (CXCL10) and M2 polarization markers of CD206 and fibronectin 1 (FN1) were tested using RT-qPCR. M2 marker CD206 was further detected by flow cytometry. IL-6, tumor necrosis factor-alpha (TNF-α), IL-10, and transforming growth factor-beta (TGF-β) levels in cell supernatant were detected by ELISA. Co-immunoprecipitation was used to assess the interaction between USP21 and FOXM1, and the ubiquitination level of FOXM1. FOXM1 protein stability was detected through cycloheximide (CHX) assay. Results USP21 and FOXM1 expression levels in the EESC group were significantly increased compared with those in the NESC group; compared with the NESC + M0 group, the EESC + M0 group showed no significant difference in the expression of M1 polarization markers (IL-6 and CXCL10), but increased expression of M2 polarization markers (CD206 and FN1), along with notably increased number of M2 macrophages; there was no significant difference in IL-6 and TNF-α levels, but increased levels of IL-10 and TGF-β in the cell supernatant. The above findings indicated that the deubiquitinase USP21 was highly expressed in EM, promoting M2 polarization of macrophages. Knocking down USP21 or FOXM1 can inhibit M2 polarization of EM macrophages. USP21 interacted with FOXM1 in EESC, leading to a decrease in FOXM1 ubiquitination level and an increase in FOXM1 protein stability. Overexpression of FOXM1 reversed the inhibitory effect of knocking down USP21 on M2 polarization of EM macrophages. Conclusion The deubiquitinase USP21 interacts with FOXM1 to increase the stability of FOXM1 and promote M2 polarization of EM macrophages.
Humans ; Forkhead Box Protein M1/genetics* ; Female ; Macrophages/cytology* ; Endometriosis/genetics* ; Ubiquitin Thiolesterase/genetics* ; Cells, Cultured ; Endometrium/metabolism* ; Ubiquitination ; Adult ; Interleukin-10/metabolism* ; Interleukin-6/metabolism* ; Protein Stability ; Stromal Cells/metabolism*

OBJECTIVES: Transcervical resection of adhesions (TCRA) under hysteroscopy is the mainstay treatment for intrauterine adhesions (IUA), but its effectiveness varies depending on the surgical approach. This study aims to investigate the impact of different surgical techniques on endometrial repair and pregnancy outcomes in patients with secondary infertility and moderate-to-severe IUA. METHODS: A retrospective analysis was conducted on 225 patients who underwent TCRA followed by in vitro fertilization and embryo transfer between January 2021 and December 2022. Patients were grouped based on the surgical method: A cold knife group (n=127) and an electrosurgical group (n=98). Adhesions were separated using either cold knife or electrosurgical instruments. Postoperative visualization of uterine angle and tubal ostia, endometrial restoration, vascular endothelial growth factor (VEGF) expression in adhesion tissues, and clinical pregnancy outcomes were compared. Univariate and multivariate Logistic regression analyses were performed to identify factors influencing pregnancy outcomes. A LightGBM model was constructed to predict pregnancy outcomes. RESULTS: Compared with the electrosurgical group, patients in the cold knife group had significantly greater postoperative endometrial thickness [(8.86±0.53) mm vs (8.10±0.87) mm, P<0.05], higher live birth rates (64.57% vs 30.61%, P<0.05), and lower VEGF expression (1.31±0.09 vs 1.53±0.16, P<0.05). Logistic regression analyses identified age, number of visible tubal ostia postoperatively, and surgical method as significant factors affecting pregnancy outcomes (P<0.05). The LightGBM model based on surgical method had an area under the curve (AUC) of 0.882 (0.838-0.926), with internal validation AUC of 0.817 (0.790-0.840). CONCLUSIONS Cold knife surgery promotes faster recovery of the endometrial microenvironment and earlier improvement of fertility in patients with secondary infertility and IUA Surgical method is a key factor influencing pregnancy outcomes, and the LightGBM model based on surgical approach shows good predictive performance for pregnancy outcomes in patients with moderate-to-severe IUA.
Humans ; Female ; Pregnancy ; Tissue Adhesions/surgery* ; Retrospective Studies ; Adult ; Pregnancy Outcome ; Uterine Diseases/surgery* ; Hysteroscopy/methods* ; Infertility, Female/etiology* ; Electrosurgery/methods* ; Fertilization in Vitro ; Endometrium/surgery* ; Embryo Transfer ; Vascular Endothelial Growth Factor A/metabolism*

The onset of pregnancy is marked by the formation of a zygote, while the culmination of gestation is manifested by the delivery of a fetus. Meanwhile, a successful pregnancy entails a meticulously coordinated sequence of events from embryo implantation to sustained decidualization of the uterus to placental development and childbirth. The decidual reaction, a pivotal process occurring within the endometrium during pregnancy, is finely regulated by sex steroids and cytokines. Notably, fibroblast growth factors (FGFs), particularly FGF2, play a critical role in this physiological cascade. Dysregulated FGF expression may trigger inadequate decidualization, precipitating a spectrum of adverse pregnancy outcomes, including preeclampsia, recurrent implantation failure, and miscarriage. Furthermore, the human decidua, distinct from most mammalian species and similar to great apes, undergoes regular cycles of formation and shedding, independent of the presence of the embryo in the endometrium. This process is also tightly controlled by various FGFs. In this review, we comprehensively compare diverse research decidualization models, delineate the trend of endometrial FGFs during the menstrual cycle, and provide a synopsis of endometrial diseases triggered by FGF dysregulation.
Humans ; Female ; Pregnancy ; Decidua/physiology* ; Animals ; Endometrium/physiology* ; Fibroblast Growth Factors/metabolism* ; Embryo Implantation ; Menstrual Cycle/physiology*

OBJECTIVES: To explore the mechanism through which moxibustion promotes endometrial repair in rats with in thin endometrium (TE). METHODS: Female SD rats were randomized into control group, 95% anhydrous ethanol-induced TE model group and moxibustion (at "Guan Yuan") group. High-throughput sequencing was used to identify the target genes of TE, and the targeting relationship between miR-223-3p and NLRP3 was verified using a dual luciferase assay. Histopathological of rat uterus was observed with HE staining, and expressions of miR-223-3p and NLRP3 were detected using RT-qPCR; serum levels of IL-1β and IL-18 of the rats were detected using ELISA, and protein expressions of NLRP3, ASC, caspase-1 and GSDMD in the uterus were detected with Western blotting. The pregnancies of the rats after treatment were counted. RESULTS: Enrichment analysis of the differential genes suggested up-regulated inflammatory response in TE, and dual luciferase assay verified targeted inhibition of NLRP3 expression by miR-223-3p. The rat models of TE had significantly decreased endometrial thickness and reduced endometrial glands and blood vessels with enhanced mRNA expression of NLRP3, increased serum levels of IL-1β and IL-18, up-regulated protein expressions of NLRP3, ASC, caspase-1 and GSDMD, lowered pregnancy rates on both the affected and unaffected sides and the overall number of pregnancies. Treatment of the rat models with mo-xibustion obviously increased the endometrial thickness and the density of glands and blood vessels, up-regulated miR-223-3p expression, lowered serum IL-1β and IL-18 levels and the protein expressions of NLRP3, ASC, caspase-1 and GSDMD, and significantly increased the number of pregnancies. CONCLUSIONS Moxibustion at "Guan Yuan" acupoint up-regulates the expression of miR-223-3p, which results in targeted inhibition of NLRP3 to suppress pyroptosis and promote endometrial repair in rat models of TE.
Animals ; Female ; MicroRNAs/genetics* ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Endometrium/pathology* ; Rats, Sprague-Dawley ; Rats ; Moxibustion ; Pyroptosis ; Up-Regulation ; Interleukin-1beta/metabolism* ; Interleukin-18 ; Caspase 1/metabolism*

Embryo implantation involves a complex interaction between the embryo and the endometrium of the mother, the study of which faces a variety of problems. The modeling of endometrial epithelial organoids and endometrial assembloids provides a new way to study the process of embryo implantation in vitro. This paper summarized the latest research progress in embryo implantation, the regulation mechanism of endometrial receptivity by estrogen- progesterone coordination and embryo-derived signals, the establishment of endometrial organoids, and the development and application of endometrial assembloids in the research on mother-embryo interaction, providing new strategies for studying the communication between embryo and maternal uterus during implantation.
Endometrium/physiology* ; Organoids/cytology* ; Embryo Implantation/physiology* ; Female ; Animals ; Progesterone/pharmacology* ; Pregnancy ; Estrogens/metabolism* ; Humans

OBJECTIVE: To analyze the difference in the gene expression, amino acid and carnitine levels in the cervical secretions between the endometria of pre-receptive and receptive stages, with an aim to provide clues for identifying new molecular markers for endometrial receptivity. METHODS: Fifty nine infertile women treated at the Department of Reproductive Medicine of Linyi People's Hospital from January 6, 2020 to January 31, 2022 were selected as as the study subjects, which were matched with 3 pairs (6 cases) of infertile women preparing for embryo transfer based on factors such as age, body mass index, and length of infertility. Endometrial tissue samples were collected for gene transcription and expression analysis. Twenty five women who had become pregnant through assisted reproductive technology were selected as the control group, and 28 non-pregnant women receiving ovulation monitoring at the Outpatient Department were enrolled as the case group. Status of endometrial receptivity was determined by ultrasonography. In the former group, endometrial tissues were sampled for sequencing, and GO and KEGG database enrichment analysis of differentially expressed genes was carried out. In the latter group, cervical secretions were collected, and amino acid and carnitine levels were measured by mass spectrometry. Statistical analysis was carried out using rank sum test, t test and chi-square test with SPSS v25.0 software. RESULTS: No difference was found in the clinical data of the patients with regard to age, body mass index, infertility years, AMH, FSH, LH, E2, and type of infertility. Compared with the receptive endometrial tissues, there were 100 significantly up-regulated genes and 191 significantly down-regulated genes in the pre-receptive endometrial tissue, with the most significantly altered ones being HLA-DRB5 and MMP10. The biological processes, molecular functions and pathways enriched by more differentially expressed genes in GO and KEGG were mainly immune regulation, cell adhesion and tryptophan metabolism. Analysis of secretion metabolism also revealed a significant difference in the levels of amino acids and carnitine metabolites between the two groups (P < 0.05), in particular those of Alanine, Valine, 3-hydroxybutyrylcarnitine (C4OH) + malonylcarnitine (C3DC)/captoylcarnitine (C10). CONCLUSION A significant difference has been discovered in the levels of gene transcription and protein expression in the endometrial tissues from the pre-receptive and receptive stages. The levels of amino acids and carnitine, such as Alanine, Valine, 3-hydroxybutyryl carnitine (C4OH)+malonyl carnitine (C3DC)/caproyl carnitine (C10), may be associated with the receptive status of the endometrium, though this need to be verified with larger samples.
Pregnancy ; Humans ; Female ; Infertility, Female/genetics* ; Endometrium/metabolism* ; Amino Acids/metabolism* ; Gene Expression ; Carnitine ; Alanine/metabolism* ; Valine/metabolism*

Endometriosis, a heterogeneous, inflammatory, and estrogen-dependent gynecological disease defined by the presence and growth of endometrial tissues outside the lining of the uterus, affects approximately 5-10% of reproductive-age women, causing chronic pelvic pain and reduced fertility. Although the etiology of endometriosis is still elusive, emerging evidence supports the idea that immune dysregulation can promote the survival and growth of retrograde endometrial debris. Peritoneal macrophages and natural killer (NK) cells exhibit deficient cytotoxicity in the endometriotic microenvironment, leading to inefficient eradication of refluxed endometrial fragments. In addition, the imbalance of T-cell subtypes results in aberrant cytokine production and chronic inflammation, which contribute to endometriosis development. Although it remains uncertain whether immune dysregulation represents an initial cause or merely a secondary enhancer of endometriosis, therapies targeting altered immune pathways exhibit satisfactory effects in preventing disease onset and progression. Here, we summarize the phenotypic and functional alterations of immune cells in the endometriotic microenvironment, focusing on their interactions with microbiota and endocrine and nervous systems, and how these interactions contribute to the etiology and symptomology of endometriosis.
Female ; Humans ; Endometriosis/metabolism* ; Killer Cells, Natural/metabolism* ; T-Lymphocytes/metabolism* ; Estrogens ; Endometrium/metabolism*

Corded and hyalinized endometrioid carcinoma (CHEC) is a morphologic variant of endo-metrioid adenocarcinoma. The tumor exhibits a biphasic appearance with areas of traditional low-grade adenocarcinoma merging directly with areas of diffuse growth composed of epithelioid or spindled tumor cells forming cords, small clusters, or dispersed single cells. It is crucial to distinguish CHEC from its morphological mimics, such as malignant mixed mullerian tumor (MMMT), because CHECs are usually low stage, and are associated with a good post-hysterectomy prognosis in most cases while the latter portends a poor prognosis. The patient reported in this article was a 54-year-old woman who presented with postmenopausal vaginal bleeding for 2 months. The ultrasound image showed a thickened uneven echo endometrium of approximately 12.2 mm and a detectable blood flow signal. Magnetic resonance imaging revealed an abnormal endometrial signal, considered endometrial carcinoma (Stage Ⅰ B). On hysterectomy specimen, there was an exophytic mass in the uterine cavity with myometrium infiltrating. Microscopically, most component of the tumor was well to moderately differentiated endometrioid carcinoma. Some oval and spindle stromal cells proliferated on the superficial surface of the tumor with a bundle or sheet like growth pattern. In the endometrial curettage specimen, the proliferation of these stromal cells was more obvious, and some of the surrounding stroma was hyalinized and chondromyxoid, which made the stromal cells form a cord-like arrangement. Immunostains were done and both the endometrioid carcinoma and the proliferating stroma cells showed loss of expression of DNA mismatch repair protein MLH1/PMS2 and wild-type p53 protein. Molecular testing demonstrated that this patient had a microsatellite unstable (MSI) endometrial carcinoma. The patient was followed up for 6 months, and there was no recurrence. We diagnosed this case as CHEC, a variant of endometrioid carcinoma, although this case did not show specific β-catenin nuclear expression that was reported in previous researches. The striking low-grade biphasic appearance without TP53 mutation confirmed by immunohistochemistry and molecular testing supported the diagnosis of CHEC. This special morphology, which is usually distributed in the superficial part of the tumor, may result in differences between curettage and surgical specimens. Recent studies have documented an aggressive clinical course in a significant proportion of cases. More cases are needed to establish the clinical behaviors, pathologic features, and molecular profiles of CHECs. Recognition of the relevant characteristics is the prerequisite for pathologists to make correct diagnoses and acquire comprehensive interpretation.
Female ; Humans ; Middle Aged ; Carcinoma, Endometrioid/surgery* ; Endometrial Neoplasms/pathology* ; Endometrium/metabolism* ; Adenocarcinoma/pathology* ; Stromal Cells/pathology*