Recurrent spontaneous miscarriage refers to the repeated loss of two or more clinically detected pregnancies occurring within 24 weeks of gestation. No identifiable cause has been identified for nearly 50% of these cases. This group is referred to as idiopathic recurrent spontaneous miscarriage (IRSM) or miscarriage of unknown origin. Due to lack of robust scientific evidence, guidelines on the diagnosis and management of IRSM are not well defined and often contradictory. This motivates us to explore the vibrational fingerprints of endometrial tissue in these women. Endometrial tissues were collected from women undergoing IRSM (n = 20) and controls (n = 20) corresponding to the window of implantation. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectra were obtained within the range of 400-4000 cm-1 using Agilent Cary 630 FTIR spectrometer. Raman spectra were also generated within the spectral window of 400-4000 cm-1 using Thermo Fisher Scientific, DXR Raman spectrophotometer. Based on the limited molecular information provided by a single spectroscopic tool, fusion strategy combining Raman and ATR-FTIR spectroscopic data of IRSM is proposed. The significant features were extracted applying principal component analysis (PCA) and wavelet threshold denoising (WTD) and fused spectral data used as input into support vector machine (SVM), adaptive boosting (AdaBoost) and decision tree (DT) models. Altered molecular vibrations associated with proteins, glutamate, and lipid metabolism were observed in IRSM using Raman spectroscopy. FTIR analysis indicated changes in the molecular vibrations of lipids and proteins, collagen dysregulation and impaired glucose metabolism. Combination of both spectroscopic data using mid-level fusion (MLF: 92% using AdaBoost and DT models) and high-level fusion (HLF: 92% using SVM models) methods showed improved IRSM classification accuracy as compared to individual spectral models. Our results indicate that spectral fusion technology hold promise in enhancing diagnostic accuracy of IRSM in clinical settings. Validation of these findings in a larger patient population is underway.

UNASSIGNED: This study aimed to determine the effect and mechanism of the Decoction of Yougui Wan combined with Wuzi Yanzong Wan (DYWWYW), a traditional Chinese herbal formula, in a mouse model with thin endometrium induced by 95% ethanol.
UNASSIGNED: Thin endometrium mice were treated with progynova (0.002 mg) as well as a low and high dose of DYWWYW (0.05 and 0.5 mL DYWWYW, respectively, diluted in 2 mL normal saline). Western blotting and qRT-PCR analyses were performed to determine the protein and mRNA expression levels, respectively, of integrin αγβ3 and leukaemia inhibitor factor (LIF) in uterus tissues. Serum oestradiol and progesterone concentrations were determined via ELISA. The remaining thin endometrium mice were mated with male mice, and the number of embryos implanted in the different groups was calculated.
UNASSIGNED: A high dose of DYWWYW effectively ameliorated the injury of endometrium caused by 95% ethanol. The levels of oestradiol, progesterone, αγβ3 and LIF in thin endometrium mice treated with a high dose of DYWWYW were also significantly elevated. Additionally, a high dose of DYWWYW remarkably increased the number of embryo implantations in mice with thin endometrium.
UNASSIGNED: DYWWYW has improvement effects on thin endometrium by elevating the levels of endogenous oestradiol, progesterone, αγβ3, and LIF in a mouse model.
During the reproductive cycle, endometrium thickness of more than 7 mm is considered as a cut-off value for successful embryo implantation. Currently, although therapies for the improvement of endometrium thickness such as sildenafil, endometrial scraping, granulocyte colony-stimulating factor and low dose of aspirin have been tried, the effects on patients are not consistent. Consequently, it is necessary to seek novel therapies to increase endometrium thickness effectively. A 95% ethanol-induced thin endometrium female ICR mouse model was established in this study. High dose of Decoction of Yougui Wan combined with Wuzi Yanzong Wan (DYWWYW) effectively ameliorated the injury of endometrium and remarkably increased the number of embryo implantations in thin endometrium mice. Additionally, the levels of some key indicators including oestradiol, progesterone, αγβ3, and LIF were also increased in thin endometrium mice treated with high dose of DYWWYW. Therefore, DYWWYW was feasible in increasing endometrium thickness in a mouse model.

Objective: To construct a repetitive implantation failure (RIF)-related competitive endogenous RNA (ceRNA) regulatory network and validate with clinical samples. Methods: RIF-related long non-coding RNA (lncRNA), microRNA (miRNA) and messenger RNA (mRNA) from the high-throughput gene expression omnibus (GEO) database Expression profile data set were obtained to construct a ceRNA regulatory network of lncRNA-miRNA-mRNA. At the same time, weighted gene co-expression network analysis (WGCNA) was used to explore hub genes in the network. This retrospective study collected RIF patients and controls (at least one pregnancy history after assisted conception) who underwent in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) for assisted pregnancy from 2020 to 2021 at the Reproductive Medicine Center of the First Affiliated Hospital of Zhengzhou University. In the endometrial tissue of patients with 1 pregnancy history, real-time fluorescence quantitative polymerase chain reaction (qRT-PCR) was used to verify the mRNA expression levels of RIF-related hub genes, and Western blotting and immunohistochemistry were used to verify protein expression levels of vascular cell adhesion molecule-1 (VCAM1). Results: A RIF-related ceRNA regulatory network consisting of 32 lncRNAs, 31 miRNAs and 88 mRNAs was constructed, and 7 RIF-related hub genes were identified using WGCNA. By intersecting 88 mRNAs and hub genes in the ceRNA network, two RIF-related key genes were obtained, i.e., VCAM1 and interleukin-2 receptor α (interleukin-2 receptor α, IL-2RA). In clinical verification, the ages of the control group and RIF group [M (Q1, Q3)] were 26.50 (25.00, 34.00) and 30.50 (25.75, 35.25) years old, respectively (P>0.05). Compared with the control group, the mRNA [0.30 (0.15, 0.42) vs 0.99 (0.69, 1.34), P=0.001] and protein expression [0.44 (0.16, 1.27) vs 2.39 (1.58, 2.58), P<0.001] of VCAM1 in the endometrium of the RIF group were both reduced. Conclusions: This study uses bioinformatics analysis methods to construct a RIF-related ceRNA regulatory network, and it is confirmed through clinical samples that the expression level of VCAM1 in the endometrial tissue of RIF patients is significantly reduced.
目的： 构建反复种植失败（RIF）相关竞争性内源RNA（ceRNA）调控网络并进行临床样本验证。 方法： 从高通量基因表达数据库（GEO）得到RIF相关的长链非编码RNA（lncRNA）、微小RNA（miRNA）和信使RNA（mRNA）表达谱数据集，构建lncRNA-miRNA-mRNA的ceRNA调控网络。同时利用加权基因共表达网络分析（WGCNA）探索网络中的枢纽基因。回顾性收集2020—2021年于郑州大学第一附属医院生殖医学中心行体外受精（IVF）/卵胞浆内单精子显微注射（ICSI）助孕的RIF患者和对照组（助孕后至少有1次妊娠史）患者的子宫内膜组织，应用实时荧光定量聚合酶链反应（qRT-PCR）验证RIF相关枢纽基因的mRNA表达水平，并应用Western印迹和免疫组化技术验证血管细胞黏附分子-1（VCAM1）的蛋白表达水平。 结果： 构建了由32个lncRNA、31个miRNA和88个mRNA组成的RIF相关ceRNA调控网络，并利用WGCNA鉴定出7个RIF相关枢纽基因。将ceRNA网络中的88个mRNA与枢纽基因取交集得到2个RIF相关关键基因：VCAM1和白细胞介素2受体α（IL-2RA）。临床验证中，对照组和RIF组的年龄［M（Q1，Q3）］分别为26.50（25.00，34.00）和30.50（25.75，35.25）岁（P>0.05）。与对照组相比，RIF组子宫内膜中VCAM1的mRNA［M（Q1，Q3）］［0.30（0.15，0.42）比0.99（0.69，1.34），P=0.001］和蛋白表达水平［M（Q1，Q3）］［0.44（0.16，1.27）比2.39（1.58，2.58），P<0.001］均降低。 结论： 本研究成功构建了RIF相关ceRNA调控网络，并通过临床样本证实RIF患者子宫内膜组织中VCAM1的表达水平降低。.

The cytokine context present in the reproductive tract of cows is closely involved in normal uterine functions, including the estrous cycle and the establishment and maintenance of pregnancy. However, the roles of some cytokines in the uterus, and their relation with reproductive performance remain to be elucidated. Thus, this study aimed to examine the protein expression of several cytokines such as TNFα, IL-6, IL-8, IFNγ, IL-4, and TGF-β3 in endometrial biopsies previous to conception, to evaluate the possible association with delayed conception in dairy cows. Protein expression levels were evaluated by immunohistochemistry. Results showed that the protein expression levels of TNFα, IL-6, IL-4 and TGF-β3 were not associated with the parturition-conception interval, whereas the high protein expression levels of IFNγ were associated with the parturition-conception interval. Finally, the low protein expression of IL-8 showed a statistical tendency to be associated with delayed conception. This is the first report about the protein expression of IFN-γ in the endometrium of dairy cows and also, this cytokine could enhance the favorable conditions to achieve an early pregnancy.

Endometriosis is a common condition that affects 5% to 10% of women during their reproductive years, although the aetiology and pathophysiology are still unknown. This study aimed to create an endometriosis model in rats to investigate the efficacy of natural and synthetic medications in treating endometriosis. An in vivo endometriotic model was established using a surgical induction method and the endocrine-disrupting drug diethylstilbestrol (DES). In brief, the experiment is categorised into three different groups. Each group contains five rats. The first group had no surgery, while in the in the second group of rats (n = 5), two small tissue grafts were fixed at the right and left walls of the abdomen. But in the in the third group of rats (n = 5), two small pieces of tissue have been grafted on the right and left abdomen walls by surgically along with DES treatments. Noninvasive photoacoustic imaging (PAI) was employed in the study to measure factors such as haemoglobin levels, oxygen saturation, and the size of endometriotic lesions. Histopathological analysis was carried out utilising staining techniques such as Hematoxylin and Eosin, Masson\'s Trichrome, and Periodic Acid Schiff, as well as immunohistochemistry with marker antibodies. Molecular markers in uterine tissue were examined using Western blots and real-time PCR. The developed endometriosis rat model showed a significant increase in the expression of anti-apoptotic Bcl-2, angiogenic marker VEGF and pro-inflammatory (COX-2 and IL-6) protein markers. In contrast to the control group, the treatment group had considerably lower Caspase-3 expression levels. Photoacoustic imaging (PAI) data demonstrated a constant increase in lesion size, as well as a decrease in oxygen saturation levels. The findings suggest that the in vivo endometriosis rat model may accurately assess the efficacy of natural or synthetic endometriosis treatments. This model may help in the improvement of disease understanding and the development of targeted therapeutic drugs.

In patients with endometriosis, refluxed endometrial fragments evade host immunosurveillance, developing into endometriotic lesions. However, the mechanisms underlying this evasion have not been fully elucidated. N-Myc and STAT Interactor (NMI) have been identified as key players in host immunosurveillance, including interferon (IFN)-induced cell death signaling pathways. NMI levels are markedly reduced in the stromal cells of human endometriotic lesions due to modulation by the Estrogen Receptor beta/Histone Deacetylase 8 axis. Knocking down NMI in immortalized human endometrial stromal cells (IHESCs) led to elevated RNA levels of genes involved in cell-to-cell adhesion and extracellular matrix signaling following IFNA treatment. Furthermore, NMI knockdown inhibited IFN-regulated canonical signaling pathways, such as apoptosis mediated by Interferon Stimulated Gene Factor 3 and necroptosis upon IFNA treatment. In contrast, NMI knockdown with IFNA treatment activated non-canonical IFN-regulated signaling pathways that promote proliferation, including β-Catenin and AKT signaling. Moreover, NMI knockdown in IHESCs stimulated ectopic lesions\' growth in mouse endometriosis models. Therefore, NMI is a novel endometriosis suppressor, enhancing apoptosis and inhibiting proliferation and cell adhesion of endometrial cells upon IFN exposure.

Not discounting the important foetal or placental contribution, the endometrium is a key determinant of pregnancy outcomes. Given the inherently linked processes of menstruation, pregnancy and parturition with the endometrium, further understanding of menstruation will help to elucidate the maternal contribution to pregnancy. Endometrial health can be assessed via menstrual history and menstrual fluid, a cyclically shed, easily and non-invasively accessible biological sample that represents the distinct, heterogeneous composition of the endometrial environment. Menstrual fluid has been applied to the study of endometriosis, unexplained infertility and early pregnancy loss; however, it is yet to be examined regarding adverse pregnancy outcomes. These adverse outcomes, including preeclampsia, foetal growth restriction (FGR), spontaneous preterm birth and perinatal death (stillbirth and neonatal death), lay on a spectrum of severity and are often attributed to placental dysfunction. The source of this placental dysfunction is largely unknown and may be due to underlying endometrial abnormalities or endometrial interactions during placentation. We present existing evidence for the endometrial contribution to adverse pregnancy outcomes and propose that a more comprehensive understanding of menstruation can provide insight into the endometrial environment, offering great potential value as a diagnostic tool to assess pregnancy risk. As yet, this concept has hardly been explored.

The endometrium is crucial for the perpetuation of human species. It is a complex and dynamic tissue lining the inner wall of the uterus, regulated throughout a woman\'s life based on estrogen and progesterone fluctuations. During each menstrual cycle, this multicellular tissue undergoes cyclical changes, including regeneration, differentiation in order to allow egg implantation and embryo development, or shedding of the functional layer in the absence of pregnancy. The biology of the endometrium relies on paracrine interactions between epithelial and stromal cells involving complex signaling pathways that are modulated by the variations of estrogen and progesterone levels across the menstrual cycle. Understanding the complexity of estrogen and progesterone receptor signaling will help elucidate the mechanisms underlying normal reproductive physiology and provide fundamental knowledge contributing to a better understanding of the consequences of hormonal imbalances on gynecological conditions and tumorigenesis. In this narrative review, we delve into the physiology of the endometrium, encompassing the complex signaling pathways of estrogen and progesterone.

BACKGROUND: Patients with endometriosis suffer with chronic pelvic pain and infertility, and from the lack of pharmacologic therapies that consistently halt disease progression. Differences in the endometrium of patients with endometriosis vs. unaffected controls are well-documented. Specifically, shed endometrial tissues (delivered to the pelvic cavity via retrograde menstruation) reveal that a subset of stromal cells exhibiting pro-inflammatory, pro-fibrotic, and pro-senescence-like phenotypes is enhanced in endometriosis patients compared to controls. Additionally, cultured biopsy-derived endometrial stromal cells from endometriosis patients exhibit impaired decidualization, a defined differentiation process required for human embryo implantation and pregnancy. Quercetin, a senolytic agent, shows therapeutic potential for pulmonary fibrosis, a disorder attributed to senescent pulmonary fibroblasts. In rodent models of endometriosis, quercetin shows promise, and quercetin improves decidualization in vitro. However, the exact mechanisms are not completely understood. Therefore, we investigated the effects of quercetin on menstrual effluent-derived endometrial stromal cells from endometriosis patients and unaffected controls to define the signaling pathways underlying quercetin\'s effects on endometrial stromal cells.
METHODS: Menstrual effluent-derived endometrial stromal cells were collected and cultured from unaffected controls and endometriosis patients and then, low passage cells were treated with quercetin (25 µM) under basal or standard decidualization conditions. Decidualization responses were analyzed by measuring the production of IGFBP1 and PRL. Also, the effects of quercetin on intracellular cAMP levels and cellular oxidative stress responses were measured. Phosphokinase arrays, western blotting, and flow cytometry methods were performed to define the effects of quercetin on various signaling pathways and the potential mechanistic roles of quercetin.
RESULTS: Quercetin significantly promotes decidualization of control- and endometriosis-endometrial stromal cells. Quercetin substantially reduces the phosphorylation of multiple signaling molecules in the AKT and ERK1/2 pathways, while enhancing the phosphorylation of p53 and total p53 levels. Furthermore, p53 inhibition blocks decidualization while p53 activation promotes decidualization. Finally, we provide evidence that quercetin increases apoptosis of endometrial stromal cells with a senescent-like phenotype.
CONCLUSIONS: These data provide insight into the mechanisms of action of quercetin on endometrial stromal cells and warrant future clinical trials to test quercetin and other senolytics for treating endometriosis.

BACKGROUND: Monoamine oxidases (MAOs) is an enzyme that catalyzes the deamination of monoamines. The current research on this enzyme is focused on its role in neuropsychiatric, neurodevelopmental, and neurodegenerative diseases. Indeed, MAOs with two isoforms, namely, A and B, are located on the outer mitochondrial membrane and are widely distributed in the central nervous system and peripheral tissues. Several reports have described periodic changes in the levels of this enzyme in the human endometrial tissue.
RESULTS: The novel role of MAOs in endometrial receptivity establishment and embryonic development by maintaining monoamine homeostasis was investigated in this study. MAOs activity was observed to be enhanced during the first trimester in both humans and mice under normal conditions. However, under pathological conditions, MAOs activity was reduced and was linked to early pregnancy failure. During the secretory phase, the endometrial stromal cells differentiated into decidual cells with a stronger metabolism of monoamines by MAOs. Excessive monoamine levels cause monoamine imbalance in decidual cells, which results in the activation of the AKT signal, decreased FOXO1 expression, and decidual dysfunction.
CONCLUSIONS: The findings suggest that endometrial receptivity depends on the maintenance of monoamine homeostasis via MAOs activity and that this enzyme participates in embryo implantation and development.