WGS of intrauterine E. coli from cows with early postpartum uterine infection reveals a non-uterine specific genotype and virulence factors.

Escherichia coli has been attributed to playing a major role in a cascade of events that affect the prevalence and severity of uterine disease in cattle. The objectives of this project were to (i) define the association between the prevalence of specific antimicrobial resistance and virulence factor genes in E. coli with the clinical status related to uterine infection, (ii) identify the genetic relationship between E. coli isolates from cows with diarrhea, with mastitis, and with and without metritis, and (iii) determine the association between the phenotypic and genotypic antimicrobial resistance identified on the E. coli isolated from postpartum cattle. Bacterial isolates (n = 148) were obtained from a larger cross-sectional study. Cows were categorized into one of three clinical groups before enrollment: metritis, cows with purulent discharge, and control cows. For genomic comparison, public genomes (n = 130) from cows with diarrhea, mastitis, and metritis were included in a genome-wide association study, to evaluate differences between the drug classes or the virulence factor category among clinical groups. A distinct E. coli genotype associated with metritis could not be identified. Instead, a high genetic diversity among the isolates from uterine sources was present. A virulence factor previously associated with metritis (fimH) using PCR was not associated with metritis. There was moderate accuracy for whole-genome sequencing to predict phenotypic resistance, which varied depending on the antimicrobial tested. Findings from this study contradict the traditional pathotype classification and the unique intrauterine E. coli genotype associated with metritis in dairy cows.IMPORTANCEMetritis is a common infectious disease in dairy cattle and the second most common reason for treating a cow with antimicrobials. The pathophysiology of the disease is complex and is not completely understood. Specific endometrial pathogenic Escherichia coli have been reported to be adapted to the endometrium and sometimes lead to uterine disease. Unfortunately, the specific genomic details of the endometrial-adapted isolates have not been investigated using enough genomes to represent the genomic diversity of this organism to identify specific virulence genes that are consistently associated with disease development and severity. Results from this study provide key microbial ecological advances by elucidating and challenging accepted concepts for the role of Intrauterine E. coli in metritis in dairy cattle, especially contradicting the existence of a unique intrauterine E. coli genotype associated with metritis in dairy cows, which was not found in our study.

Molecular Mechanisms Associated with the Development of the Metritis Complex in Dairy Cattle.

The metritis complex (MC), a group of post-partum uterine diseases, is associated with increased treatment costs and reduced milk yield and fertility. The goal of this study was to identify genetic variants, genes, or genomic regions that modulate MC disease. A genome-wide association study was performed using a single-locus mixed linear model of 1967 genotypes (624,460 SNPs) and metritis complex records. Then, in-silico functional analyses were performed to detect biological mechanisms and pathways associated with the development of MC. The ATP8A2, COX16, AMN, and TRAF3 genes, located on chromosomes 12, 10, and 21, were associated with MC at p ≤ 0.0001. These genes are involved in the regulation of cholesterol metabolism in the stromal tissue of the uterus, which can be directly associated with the mode of transmission for pathogens causing the metritis complex. The modulation of cholesterol abundance alters the efficiency of virulence factors and may affect the susceptibility of the host to infection. The SIPA1L1, DEPDC5, and RNF122 genes were also significantly associated with MC at p ≤ 0.0001 and are involved in the PI3k-Akt pathway, responsible for activating the autophagic processes. Thus, the dysregulation of these genes allows for unhindered bacterial invasion, replication, and survival within the endometrium.

Synergistic effects of electroacupuncture and bone marrow mesenchymal stem cell transplantation on rat intrauterine adhesion： an observation. / 电针联合骨髓间å è´¨å¹²ç»†èƒžç§»æ¤æ²»ç–—å¤§é¼ å®«è ”ç²˜è¿žçš„ååŒæ•ˆåº”è§‚å¯Ÿ.

OBJECTIVES: To investigate the effects of electroacupuncture(EA) combined with bone marrow mesen-chymal stem cells(BMSCs) transplantation on the endometrium of rats with intrauterine adhesions(IUA), so as to explore the possible mechanisms underlying their combined therapeutic effects. METHODS: Forty adult female SD rats were randomly divided into control, model, cell, and combined groups. The IUA rat model was established using a dual injury method of mechanical scratching and lipopolysaccharide infection. After successful modeling, on days 1, 3, and 7, rats in the model group received tail vein injection of phosphate buffered solution, while rats in the cell group received tail vein injection of BMSCs suspension for BMSCs transplantation；and rats in the combined group received BMSCs transplantation combined with EA treatment (2 Hz/15 Hz, 1-2 mA), targeting the "Guanyuan"(CV4), bilateral "Zusanli"(ST36) and "Sanyinjiao"(SP6) for 20 min daily for 3 consecutive estrous cycles. After intervention, uterine tissue was collected from 5 rats in each group. Histological analysis was performed using hematoxylin and eosin staining to evaluate endometrial thickness and glandular number. Masson staining was used to assess endometrial fibrosis area. Immunohistochemistry was performed to detect the positive expressions of vascular endothelial growth factor(VEGF), proliferating cell nuclear antigen(PCNA), and estrogen receptor(ER). Western blot analysis was conducted to determine the protein expressions of homeobox A10(HoxA10) and leukemia inhibitory factor(LIF), both key regulators of endometrial receptivity. The remaining 5 rats in each group were co-housed with male rats, and the uterine function recovery was evaluated by assessing the number of embryo implantations. RESULTS: Compared with the control group, the model group showed thinning endometrium(P<0.001), decreased glandular number(P<0.001), increased endometrial fibrosis area(P<0.001), reduced positive expressions of VEGF, PCNA, ER, expressions of HoxA10 and LIF, and decreased embryo implantation number (P<0.001) on the injured side of the uterus. Compared with the model group, the combined group showed a reversal of the aforementioned indicators(P<0.001, P<0.01)；the cell group exhibited thicker endometrium(P<0.001) and reduced endometrial fibrosis area(P<0.001). Compared with the cell group, the combined group showed increased endometrial thickness(P<0.01), elevated glandular number(P<0.05), significantly decreased endometrial fibrosis area(P<0.05), enhanced positive expressions of VEGF, PCNA and ER, expressions of HoxA10 and LIF in the endometrium, and a significant increase in embryo implantation number (P<0.001, P<0.05, P<0.01) on the injured side of the uterus, indicating better results than the cell group. CONCLUSIONS: The combination of EA and BMSCs synergistically promotes the repair of damaged endometrium, improves endometrial morphology, reduces fibrosis levels, enhances vascular regeneration and matrix cell proliferation, improves endometrial receptivity, which ultimately facilitates embryo implantation.

MicroRNA-122-5p alleviates endometrial fibrosis via inhibiting the TGF-ß/SMAD pathway in Asherman's syndrome.

RESEARCH QUESTION: What is the effect of miR-122 on the progression and recovery of fibrosis in Asherman's syndrome? DESIGN: Endometrial tissue was collected from 21 patients, 11 with intrauterine adhesion (IUA) and 10 without IUA. Quantitative real-time polymerase chain reaction, immunofluorescence and Western blot were applied to observe the expression of mRNAs/miRNAs and protein, respectively. The endometrial physical injury was carried out in C57BL/6 mice to create an endometrial fibrosis model, with intrauterine injection of adenovirus to compare the antifibrosis and repair function of miR-122 on endometrium. The morphology of the uterus was observed using haematoxylin and eosin staining, and fibrosis markers were detected by immunohistochemistry. RESULTS: miR-122 expression was reduced in patients with IUAs, accompanied by fibrosis. MiR-122 overexpression reduced the degree of fibrosis in endometrial stromal cells. Further molecular analyses demonstrated that miR-122 inhibited fibrosis through the TGF-ß/SMAD pathway by directly targeting the 3' untranslated region of SMAD family member 3, suppressing its expression. Notably, miR-122 promoted endometrial regeneration and recovery of pregnancy capacity in a mouse endometrial injury model. CONCLUSIONS: miR-122 is a critical regulator for repair of endometrial fibrosis and provided new insight for the clinical treatment of intrauterine adhesions.

Ferroptosis contributes to endometrial fibrosis in intrauterine adhesions.

Intrauterine adhesions (IUA), characterized by endometrial fibrosis, is a challenging clinical issue in reproductive medicine. We previously demonstrated that epithelial-mesenchymal transition (EMT) and fibrosis of endometrial stromal cells (HESCs) played a vital role in the development of IUA, but the precise pathogenesis remains elucidated. Ferroptosis has now been recognized as a unique form of oxidative cell death, but whether it is involved in endometrial fibrosis remains unknown. In the present study, we performed an RNA-seq of the endometria from 4 severe IUA patients and 4 normal controls. Enrichment analysis and protein-protein interactions (PPIs) network analysis of differentially expressed genes (DEGs) were conducted. Immunohistochemistry was used to assess ferroptosis levels and cellular localization. The potential role of ferroptosis for IUA was investigated by in vitro and in vivo experiments. Here, we demonstrated that ferroptosis load is increased in IUA endometria. In vitro experiments showed that erastin-induced ferroptosis promoted EMT and fibrosis in endometrial epithelial cells (P < 0.05), but did not lead to pro-fibrotic differentiation in endometrial stromal cells (HESCs). Cell co-culture experiments showed that erastin-stimulated epithelial cell supernatants promoted fibrosis in HESCs (P < 0.05). In vivo experiments suggested that elevation of ferroptosis level in mice by erastin led to mild endometrial EMT and fibrosis. Meanwhile, the ferroptosis inhibitor Fer-1 significantly ameliorated endometrial fibrosis in a dual-injury IUA murine model. Overall, our findings revealed that ferroptosis may serve as a potential therapeutic target for endometrial fibrosis in IUA.

Pathogenesis of endometrium-related diseases based on genomic alterations in normal uterine endometrium.

The human endometrium is a dynamically remodeling tissue that undergoes more than 400 cycles of regeneration, differentiation, shedding, and rapid healing during a woman's reproductive years. The endometrium is also the origin of various gynecologic diseases, such as endometriosis, adenomyosis, and uterine corpus cancer. Cancer-associated gene mutations are detected in endometriosis, adenomyosis, and normal endometrium. Some reports have demonstrated that the accumulation of genomic alterations is a critical carcinogenic mechanism in the progression from normal endometrium to ovarian clear cell carcinoma via endometriosis. In this review, we discuss the clinical importance of genomic alterations in the normal endometrium, contributing to the elucidation of the pathogenesis of endometrium-related diseases.

Umbilical cord mesenchymal stem cell-derived exosomes reverse endometrial fibrosis by the miR-145-5p/ZEB2 axis in intrauterine adhesions.

RESEARCH QUESTION: What is the specific mechanism of umbilical cord mesenchymal stem cell-derived exosomes (UCMSC-exos) in regulating endometrial repair and regeneration? DESIGN: In this study, UCMSC-exos were harvested by differential ultracentrifugation from umbilical cord mesenchymal stem cell culture supernatant and identified with western blotting, transmission electron microscopy and nanoparticle tracking analysis. Transforming growth factor-ß1 (TGFß1) at different concentrations was used to construct the intrauterine adhesions cell model. The fibrotic markers were assessed by quantitative reverse transcription-polymerase chain reaction and western blotting. The effects of miR-145-5p over-expression on endometrial fibrosis were assessed. Dual luciferase assay was performed to verify the relationship between miR-145-5p and zinc finger E-box binding homeobox 2 (ZEB2). RESULTS: The isolated UCMSC-exos had a typical cup-shaped morphology, expressed the specific exosomal markers Alix, CD63 and TSG101, and were approximately 50-150 nm in diameter. TGFß1 at 10 ng/ml significantly promoted endometrial fibrosis, which was reversed by 20 µg/ml UCMSC-exos. Exosomal miR-145-5p ameliorated TGFß1-induced endometrial fibrosis. ZEB2 was inversely regulated by exosomal miR-145-5p as a direct target. CONCLUSIONS: UCMSC-exos might reverse endometrial stromal cell fibrosis by regulating the miR-145-5p/ZEB2 axis, representing a potential novel strategy to promote endometrial repair.

cfDNA Methylation Profiles and T-Cell Differentiation in Women with Endometrial Polyps.

DNA methylation is a part of the regulatory mechanisms of gene expression, including chromatin remodeling and the activity of microRNAs, which are involved in the regulation of T-cell differentiation and function. However, the role of cfDNA methylation in T-cell differentiation is entirely unknown. In patients with endometrial polyps (EPs), we have found an imbalance of T-cell differentiation and an aberrant cfDNA methylation profile, respectively. In this study, we investigated the relationship between cfDNA methylation profiles and T-cell differentiation in 14 people with EPs and 27 healthy controls. We found that several differentially methylated genes (DMGs) were associated with T-cell differentiation in people with EPs (ITGA2-Naïve CD4, r = -0.560, p = 0.037; CST9-EMRA CD4, r = -0.626, p = 0.017; and ZIM2-CM CD8, r = 0.576, p = 0.031), but not in healthy controls (all p > 0.05). When we combined the patients' characteristics, we found a significant association between ITGA2 methylation and polyp diameter (r = 0.562, p = 0.036), but this effect was lost when adjusting the level of Naïve CD4 T-cells (r = 0.038, p = 0.903). Moreover, the circulating sex hormone levels were associated with T-cell differentiation (estradiol-Naïve CD4, r = -0.589, p = 0.027), and the cfDNA methylation profile (testosterone-ZIM2, r = -0.656, p = 0.011). In conclusion, this study has established a link between cfDNA methylation profiles and T-cell differentiation among people with EPs, which may contribute to the etiology of EPs. Further functional studies are warranted.

ß-Klotho Promotes the Development of Intrauterine Adhesions via the PI3K/AKT Signaling Pathway.

Intrauterine adhesion (IUA) refers to injury to the basal layer of the endometrium, which can be caused by various factors. It is often accompanied by clinical symptoms such as abnormal menstruation, infertility, recurrent abortion, and periodic abdominal pain. In recent years, a number of studies have reported the effects of ß-Klotho (KLB) on the occurrence and development of human tumors and fibrotic diseases, but its relationship with endometrial fibroblasts and endometrial fibrosis has not been elucidated. In this study, we compared the expression of KLB in endometrial stromal cells (ESCs) from patients with IUA and normal controls. We constructed animal and cell models of IUA and conducted expression verification and functional experiments on KLB. We found that the expression of KLB was significantly increased in the ESCs of IUA patients and rat models compared with the controls. The overexpression of KLB could promote the proliferation and fibrosis of ESCs. In addition, the overexpression of KLB activated the PI3K/AKT signaling pathway in ESCs. Our study shows that KLB protein is highly expressed in the ESCs of patients with IUA and can enhance stromal cell proliferation and cell fibrosis by activating the PI3K/AKT pathway, thus promoting the development of IUA.

A LIGHT-HVEM/LTßR axis contributes to the fibrosis of intrauterine adhesion.

Intrauterine adhesion (IUA) is a fibrotic disease, with complex and multifactorial process, causing menstrual disorders, pregnancy loss or infertility. LIGHT (also named TNFSF14), mainly expressed by immune cells, has been reported to be associated with tissue fibrosis. However, the features of immunocyte subsets, the expression and roles of LIGHT and its receptor HVEM (herpes virus entry mediator) and LTßR (lymphotoxin beta receptor) in IUA remain largely unknown. Compared with the control group, we observed increased ratios of CD45+ cells, neutrophils, T cells, macrophages and decreased natural killer cells proportion, and high LIGHT expression on CD4+ T cells and macrophages in IUA endometrium. Further analysis showed there was a positive correlation between upregulated profibrotic factors (e.g., ɑ-smooth muscle actin, transforming growth factor ß1) and HVEM in IUA endometrial tissue. More importantly, recombinant human LIGHT protein directly up-regulated the expression of HVEM, LTßR, profibrotic and proinflammatory factors expression in human endometrial stromal cells. These findings reveal abnormal changes of immune cell subsets proportion and the overexpression of LIGHT-HVEM/LTßR axis in IUA endometrium, should contribute to inflammation and fibrosis formation of IUA.

LIN28B Polymorphisms Confer a Higher Postoperative Recurrence Risk in Reproductive-Age Women with Endometrial Polyps.

The RNA-binding protein LIN28B is an important factor for cell proliferation. Because LIN28B polymorphisms have been shown to be relative with the recurrence of some hyperplastic diseases, we hypothesized that genetic variants of LIN28B gene were associated with postoperative recurrence risk in reproductive-age women with endometrial polyps (EP). In a hospital-based cohort of 351 reproductive female patients underwent hysteroscopic polypectomies between May 2018 and Jan 2020, we genotyped two common polymorphisms in LIN28B gene (rs369065 C > T and rs314280 A > G) and analyzed their associations with the risk of postoperative recurrence in multiple Cox regression model. When followed up to Jun 2021, carries of rs369065 TT genotype had an increased risk of polyp recurrence (adjusting hazard ratio [HR] = 1.883, 95% confidence interval [CI] = 1.033 - 3.434) and had a shorter time to recurrence (median time 352 vs. 342 days, log-rank P < 0.01), compared to the CC/CT genotype. Further stratification analysis showed that the increased risk of rs369065 TT genotype was more evident in patients who were older than 33 years (adjusted HR = 2.597, 95%CI = 1.037 - 6.505), had a single polyp (adjusted HR = 2.545, 95%CI = 1.059 - 6.113), and had smaller polyps (<1.2 cm, adjusted HR = 2.708, 95%CI = 1.042 - 7.043). However, no significant association between rs314280 A > G polymorphism and the risk of polyp recurrence was found. Our study suggests that rs369065 TT genotype of LIN28B gene is associated with an increased postoperative recurrence risk in EP patients, especially in those with fewer and smaller polyps. These findings implicate a precise choice of clinical counseling and decision making. Larger studies in different ethnic populations are warranted.

Loss of MIG-6 results in endometrial progesterone resistance via ERBB2.

Female subfertility is highly associated with endometriosis. Endometrial progesterone resistance is suggested as a crucial element in the development of endometrial diseases. We report that MIG-6 is downregulated in the endometrium of infertile women with endometriosis and in a non-human primate model of endometriosis. We find ERBB2 overexpression in the endometrium of uterine-specific Mig-6 knockout mice (Pgrcre/+Mig-6f/f; Mig-6d/d). To investigate the effect of ERBB2 targeting on endometrial progesterone resistance, fertility, and endometriosis, we introduce Erbb2 ablation in Mig-6d/d mice (Mig-6d/dErbb2d/d mice). The additional knockout of Erbb2 rescues all phenotypes seen in Mig-6d/d mice. Transcriptomic analysis shows that genes differentially expressed in Mig-6d/d mice revert to their normal expression in Mig-6d/dErbb2d/d mice. Together, our results demonstrate that ERBB2 overexpression in endometrium with MIG-6 deficiency causes endometrial progesterone resistance and a nonreceptive endometrium in endometriosis-related infertility, and ERBB2 targeting reverses these effects.

Single-cell transcriptome analysis uncovers the molecular and cellular characteristics of thin endometrium.

Infertility is a social and medical problem around the world and the incidence continues to rise. Thin endometrium (TE) is a great challenge of infertility treatment, even by in vitro fertilization and embryo transfer. It is widely believed that TE impairs endometrium receptivity. However, only a few studies have explained the molecular mechanism. Herein, in order to reveal the possible mechanism, we sampled endometrium from a TE patient and a control volunteer and got a transcriptomic atlas of 18 775 individual cells which was constructed using single-cell RNA sequencing, and seven cell types have been identified. The cells were acquired during proliferative and secretory phases, respectively. The proportion of epithelial cells and stromal cells showed a significant difference between the TE group and the control group. In addition, differential expressed genes (DEGs) in diverse cell types were revealed, the enriched pathways of DEGs were found closely related to the protein synthesis in TE of both proliferative and secretory phases. Some DEGs can influence cell-type ratio and impaired endometrial receptivity in TE. Furthermore, divergent expression of estrogen receptors 1 and progesterone receptors in stromal and epithelial cells were compared in the TE sample from the control. The cellular and molecular heterogeneity found in this study provided valuable information for disclosing the mechanisms of impaired receptivity in TE.

Identification and validation of long non-coding RNA associated ceRNAs in intrauterine adhesion.

Intrauterine adhesion (IUA) is an endometrial fibrotic disease with unclear pathogenesis. Increasing evidence suggested the important role of competitive endogenous RNA (ceRNA) in diseases. This study aimed to identify and verify the key long non-coding RNA (lncRNA) associated-ceRNAs in IUA. The lncRNA/mRNA expression file was obtained by transcriptome sequencing of IUA and normal samples. The microRNAs expression date was downloaded from the Gene Expression Omnibus database. Differential expressions of mRNAs, lncRNAs and miRNAs were analyzed using the DESeq2 (2010) R package. Protein interaction network was constructed to explore hub genes. TargetScan and miRanda databases were used to predicate the interaction. Enrichment analysis in Gene Ontology and Kyoto Encyclopedia of Genes and Genomes were performed to identify the biological functions of ceRNAs. Regression analysis of ceRNAs' expression level was performed. There were 915 mRNAs and 418 lncRNAs differentially expressed. AURKA, CDC20, IL6, ASPM, CDCA8, BIRC5, UBE2C, H2AFX, RRM2 and CENPE were identified as hub genes. The ceRNAs network, including 28 lncRNAs, 28 miRNAs, and 299 mRNAs, was constructed. Regression analysis showed a good positive correlation between ceRNAs expression levels (r > 0.700, p < 0.001). The enriched functions include ion transmembrane transport, focal adhesion, cAMP signaling pathway and cGMP-PKG signaling pathway. The novel lncRNA-miRNA-mRNA network in IUA was excavated. Crucial lncRNAs such as ADIRF-AS1, LINC00632, DIO3OS, MBNL1-AS1, MIR1-1HG-AS1, AC100803.2 was involved in the development of IUA. cGMP-PKG signaling pathway and ion transport might be new directions for IUA pathogenesis research.

Atypical uterine polyps show morphologic and molecular overlap with mullerian adenosarcoma but follow a benign clinical course.

A subset of clinically benign uterine polyps shows atypical morphologic features worrisome for, but not diagnostic of, Mullerian adenosarcoma. We report clinicopathologic data for 63 polyps from 58 women with atypical morphologic features including abnormal architecture, abnormal periglandular stroma, stromal atypia, and mitoses >2 per 10 hpf. Four (11%) of 36 women with follow-up tissue sampling had residual/recurrent atypical polyp. Twelve (27%) of 44 women underwent hysterectomy subsequent to a diagnosis of atypical polyp. No patient developed adenosarcoma over median follow-up of 150 months. Twenty-one primary atypical polyps underwent molecular profiling. Five (24%) harbored chr 12q13-15 gain or amplification, 9/20 (45%) harbored chr 6q25.1 gain, and 7/21 (33%) had no significant copy number alterations. Gains of chr 1q, chr 8p12, and chr 10q11.21-23, amplifications of chr 12q24.12-13, chr 15p24.1-26.1, and chr 18q21.33, and loss of chr 7 and chr 11q21 were each seen in a single polyp. Mean tumor mutational burden was 3.1 (range, 0.76-8.365) mutations/Mb. Pathogenic point mutations were identified in 12/20 (60%) primary atypical polyps. We propose the term "atypical uterine polyps" for these lesions, which show biologic overlap with early Mullerian adenosarcoma but lack molecular alterations characteristic of clinically aggressive adenosarcoma and appear to follow a benign clinical course. Conservative management with close clinical follow-up and repeat sampling can be considered for these lesions, when clinically appropriate.

Role of SIRT1 and Progesterone Resistance in Normal and Abnormal Endometrium.

CONTEXT: Progesterone resistance, a known pathologic condition associated with a reduced cellular response to progesterone and heightened estrogen responses, appears to have a normal physiologic role in mammalian reproduction. The molecular mechanism responsible for progesterone resistance in normal and abnormal endometrium remains unclear. OBJECTIVE: To examine the roles of sirtuin-1 (SIRT1) in normal endometrium as well as endometrium associated with infertility and endometriosis, as an epigenetic modulator associated with progesterone resistance. METHODS: SIRT1 expression was examined by Western blot, quantitative real-time polymerase chain reaction, and immunohistochemistry in mouse uterus and human endometrium. Mice with uterine specific Sirt1 overexpression were developed to examine SIRT1's role in endometrial function and endometriosis development. EX-527, a SIRT1 inhibitor, and SRT1720, a SIRT1 agonist, were also used to evaluate SIRT1 effect on endometriosis. RESULTS: In normal healthy women, endometrial SIRT1 is expressed only during menses. SIRT1 was dramatically overexpressed in the endometrium from women with endometriosis in both the epithelium and stroma. In mice, SIRT1 is expressed at the time of implantation between day 4.5 and 5.5 of pregnancy. Overexpression of SIRT1 in the mouse uterus leads to subfertility due to implantation failure, decidualization defects and progesterone resistance. SIRT1 overexpression in endometriotic lesions promotes worsening endometriosis development. EX-527 significantly reduced the number of endometriotic lesions in the mouse endometriosis model. CONCLUSIONS: SIRT1 expression and progesterone resistance appears to play roles in normal endometrial functions. Aberrant SIRT1 expression contributes to progesterone resistance and may participate in the pathophysiology of endometriosis. SIRT1 is a novel and targetable protein for the diagnosis as well as treatment of endometriosis and the associated infertility seen in this disease.

Tumor necrosis factor-α-primed mesenchymal stem cell-derived exosomes promote M2 macrophage polarization via Galectin-1 and modify intrauterine adhesion on a novel murine model.

Background: Intrauterine adhesion (IUA) is a condition caused due to damage or infection of the endometrium. It is characterized by continuous inflammation and following fibrosis and dysfunction. However, the current animal IUA models have several disadvantages, including complex operation, high mortality, and many extra distractions owing to opening of the abdominal cavity to expose the uterus. Mesenchymal stem cells (MSCs), which have been used in treatment of IUA, are heterogeneous and immunosuppressive. However, their therapeutic effect is not as good as expected. Methods: Here, we successfully built a new murine IUA model, called electric tool-scratching IUA model, and applied it in our experiments to investigate the efficacy of tumor necrosis factor-α (TNF-α) primed MSCs (T-MSCs). In the new model, we used a self-made electric tool that can cause mechanical damage to the endometrium without opening the abdominal cavity. ELISA and histological staining analysis were performed to evaluate pathological features of IUA. qRT-PCR, flow cytometry and immunofluoresence staining were performed to detect the phenotypes of macrophages. TMT proteomics quantification and western blotting assay were performed to analyze the differentially expressed proteins of MSC exosomes. Results: Based on the new IUA model, we found TNF-α pretreatment could enhance the ability of MSCs to relieve inflammation and reduce endometrium fibrosis. Mechanistically, T-MSC promoted macrophage polarization to M2 phenotype through exosomes. Subsequently, we found the expression of Galectin-1 was increased in T-MSC exosomes. Finally, we analyzed the gene expression pattern of Galectin-1 treated macrophages and found Galectin-1 promoted macrophage polarization to M2 phenotype mainly through the Jak-STAT signaling pathway. Conclusions: Our studies proposed an innovative mouse model and a better MSC treatment strategy for IUA.

Down-Regulation of Casein Kinase 1α Contributes to Endometriosis through Phosphatase and Tensin Homolog/Autophagy-Related 7-Mediated Autophagy.

The present study aimed to explore the roles of casein kinase 1α (CK1α) in endometriosis and its underlying mechanisms. Endometrial specimen were collected from the patients and healthy volunteers. The expression patterns of CK1α, phosphatase and tensin homolog (PTEN), and autophagy-related proteins were determined using immunohistochemistry staining, Western blot analysis, and quantitative RT-PCR. Besides, the CK1α-overexpressing cells and PTEN knockdown cells were constructed in the endometrial stromal cells isolated from endometriosis patients. In addition, the cells were transfected with pcDNA3.1-CK1α or pcDNA3.1-CK1α plus siRNA- PTEN. The expressions of CK1α, PTEN, and autophagy-related proteins were determined using Western blot and quantitative RT-PCR. The expressions of CK1α and autophagy-related 7 (Atg7) were significantly decreased in the ectopic endometrium compared with the eutopic endometrium. Spearman rank correlation analysis revealed positive correlations between CK1α and PTEN, CK1α and Atg7, and PTEN and Atg7. In addition, CK1α, PTEN, and autophagy-related proteins were down-regulated in ectopic endometrium. Interestingly, overexpression of CK1α significantly increased the expressions of autophagy-related proteins, whereas the protein expression of autophagy-related proteins was decreased with PTEN knock-down. CK1α regulated PTEN/Atg7-mediated autophagy in endometriosis.

circPTPN12/miR-21-5 p/∆Np63α pathway contributes to human endometrial fibrosis.

Emerging evidence demonstrates the important role of circular RNAs (circRNAs) in regulating pathological processes in various diseases including organ fibrosis. Endometrium fibrosis is the leading cause of uterine infertility, but the role of circRNAs in its pathogenesis is largely unknown. Here, we provide the evidence that upregulation of circPTPN12 in endometrial epithelial cells (EECs) of fibrotic endometrium functions as endogenous sponge of miR-21-5 p to inhibit miR-21-5 p expression and activity, which in turn results in upregulation of ΔNp63α to induce the epithelial mesenchymal transition (EMT) of EECs (EEC-EMT). In a mouse model of endometrium fibrosis, circPTPN12 appears to be a cofactor of driving EEC-EMT and administration of miR-21-5 p could reverse this process and improve endometrial fibrosis. Our findings revealed that the dysfunction of circPTPN12/miR-21-5 p/∆Np63α pathway contributed to the pathogenesis of endometrial fibrosis.

The role of epigenetic mechanisms in the regulation of gene expression in the cyclical endometrium.

BACKGROUND: The human endometrium is a highly dynamic tissue whose function is mainly regulated by the ovarian steroid hormones estradiol and progesterone. The serum levels of these and other hormones are associated with three specific phases that compose the endometrial cycle: menstrual, proliferative, and secretory. Throughout this cycle, the endometrium exhibits different transcriptional networks according to the genes expressed in each phase. Epigenetic mechanisms are crucial in the fine-tuning of gene expression to generate such transcriptional networks. The present review aims to provide an overview of current research focused on the epigenetic mechanisms that regulate gene expression in the cyclical endometrium and discuss the technical and clinical perspectives regarding this topic. MAIN BODY: The main epigenetic mechanisms reported are DNA methylation, histone post-translational modifications, and non-coding RNAs. These epigenetic mechanisms induce the expression of genes associated with transcriptional regulation, endometrial epithelial growth, angiogenesis, and stromal cell proliferation during the proliferative phase. During the secretory phase, epigenetic mechanisms promote the expression of genes associated with hormone response, insulin signaling, decidualization, and embryo implantation. Furthermore, the global content of specific epigenetic modifications and the gene expression of non-coding RNAs and epigenetic modifiers vary according to the menstrual cycle phase. In vitro and cell type-specific studies have demonstrated that epithelial and stromal cells undergo particular epigenetic changes that modulate their transcriptional networks to accomplish their function during decidualization and implantation. CONCLUSION AND PERSPECTIVES: Epigenetic mechanisms are emerging as key players in regulating transcriptional networks associated with key processes and functions of the cyclical endometrium. Further studies using next-generation sequencing and single-cell technology are warranted to explore the role of other epigenetic mechanisms in each cell type that composes the endometrium throughout the menstrual cycle. The application of this knowledge will definitively provide essential information to understand the pathological mechanisms of endometrial diseases, such as endometriosis and endometrial cancer, and to identify potential therapeutic targets and improve women's health.