CBLL1 promotes endometrial stromal cell senescence via inhibiting PTEN in recurrent spontaneous abortion.

Recurrent spontaneous abortion (RSA) is a common pregnancy-related disorder. Cbl proto-oncogene like 1 (CBLL1) is an E3 ubiquitin ligase, which has been reported to vary with the menstrual cycle in the endometrium. However, whether CBLL1 is involved in the occurrence and development of RSA remains unclear. This study aimed to investigate the effects of CBLL1 on RSA. We analyzed the expression of CBLL1 in the decidua of RSA patients, as well as its functional effects on cellular senescence, oxidative stress, and proliferation of human endometrial stromal cells (HESCs). RNA sequencing was employed to identify a key downstream target gene regulated by CBLL1. We found that CBLL1 was upregulated in the decidua of RSA patients. Additionally, overexpression of CBLL1 promoted HESC senescence, increased oxidative stress levels, and inhibited proliferation. Phosphatase and tensin homolog located on chromosome 10 (PTEN) was identified as one of the important downstream target genes of CBLL1. In vivo experiments demonstrated that CBLL1 overexpression in the endometrium caused higher embryo absorption rate in mice. Consequently, elevated CBLL1 expression is a potential cause of RSA, representing a novel therapeutic target for RSA.

Extracellular vesicles secreted by human uterine stromal cells regulate decidualization, angiogenesis, and trophoblast differentiation.

In humans, the uterus undergoes a dramatic transformation to form an endometrial stroma-derived secretory tissue, termed decidua, during early pregnancy. The decidua secretes various factors that act in an autocrine/paracrine manner to promote stromal differentiation, facilitate maternal angiogenesis, and influence trophoblast differentiation and development, which are critical for the formation of a functional placenta. Here, we investigated the mechanisms by which decidual cells communicate with each other and with other cell types within the uterine milieu. We discovered that primary human endometrial stromal cells (HESCs) secrete extracellular vesicles (EVs) during decidualization and that this process is controlled by a conserved HIF2α-RAB27B pathway. Mass spectrometry revealed that the decidual EVs harbor a variety of protein cargo, including cell signaling molecules, growth modulators, metabolic regulators, and factors controlling endothelial cell expansion and remodeling. We tested the hypothesis that EVs secreted by the decidual cells mediate functional communications between various cell types within the uterus. We demonstrated that the internalization of EVs, specifically those carrying the glucose transporter 1 (GLUT1), promotes glucose uptake in recipient HESCs, supporting and advancing the decidualization program. Additionally, delivery of HESC-derived EVs into human endothelial cells stimulated their proliferation and led to enhanced vascular network formation. Strikingly, stromal EVs also promoted the differentiation of trophoblast stem cells into the extravillous trophoblast lineage. Collectively, these findings provide a deeper understanding of the pleiotropic roles played by EVs secreted by the decidual cells to ensure coordination of endometrial differentiation and angiogenesis with trophoblast function during the progressive phases of decidualization and placentation.

Resveratrol protected against the development of endometriosis by promoting ferroptosis through miR-21-3p/p53/SLC7A11 signaling pathway.

Resveratrol is involved in regulating ferroptosis, but its role in Endometriosis (EMS) is not clear. In this study, we aim to investigate the effect of ferroptosis and resveratrol intervention in the pathogenesis of EMS cyst. Cell proliferation, migration, and oxidative stress level were analyzed. The interaction of miR-21-3p and p53 was analyzed by dual luciferase assay. The interaction between p53 and SLC7A11 were analyzed by chromatin immunoprecipitation (CHIP). The miR-21-3p, GPX4, ACSL4, FTH1, p53, SLC7A11, Ptgs2 and Chac1 expression were analyzed by RT-qPCR or Western blot. The Fe3+ deposition and miR-21-3p, GPX4, FTH1 and SLC7A11 expressions were increased, and ACSL4, p53, Ptgs2 and Chac1 expression were decreased in EMS patients. Resveratrol inhibited migration, induced Ptgs2 and Chac1 expression in EESCs. Overexpression of miR-21-3p inhibited p53, Ptgs2 and Chac1 expression, and promoted SLC7A11 expression, which was reversed by resveratrol. miR-21-3p bound to p53, which interacted with SLC7A11. Resveratrol promoted Ptgs2 and Chac1 expression in the sh-p53 EESCs. Resveratrol reduced miR-21-3p and SLC7A11 expressions, and increased p53, Ptgs2 and Chac1 expressions, and Fe3+ deposition in the lesion tissues of EMS mice, which were reversed by miR-21-3p mimics. Resveratrol activated p53/SLC7A11 pathway by down-regulating miR-21-3p to promote ferroptosis and prevent the development of EMS.

Deciphering the role of PGRMC2 in the human endometrium during the menstrual cycle and in vitro decidualization using an in vitro approach.

STUDY QUESTION: What is the human endometrial non-classical progesterone receptor (PGR) membrane component 2 (PGRMC2) expression pattern throughout the menstrual cycle and what role does it play during decidualization? SUMMARY ANSWER: Endometrial PGRMC2 expression fluctuates during the human menstrual cycle and is abundantly expressed in human endometrial stromal cells (hEnSCs) during in vitro decidualization, process where PGRMC2 is involved in embryo implantation-related pathways. WHAT IS KNOWN ALREADY: The endometrial response to progesterone is mediated by the classical and non-classical PGRs. We previously demonstrated that PGR membrane component 1 (PGRMC1) is critical for endometrial function, embryo implantation, and future placentation, however, the role(s) of PGRMC2, which is structurally similar to PGRMC1, have not been studied in the human endometrium. STUDY DESIGN, SIZE, DURATION: This prospective study comprehensively evaluated the endometrial expression of PGRMC2 throughout the human menstrual cycle and during in vitro decidualization of hEnSCs (isolated from 77 endometrial biopsies that were collected from 66 oocyte donors), using immunohistochemistry, RT-qPCR, western blot, transcriptomic, and proteomic analyses. In addition, functional analysis was carried out to validate the implication of PGRMC2 in hEnSCs during embryo invasion using an in vitro outgrowth model. PARTICIPANTS/MATERIALS, SETTING, METHODS: In vitro decidualization of hEnSCs was induced using co-treatment with cAMP and medroxyprogesterone 17-acetate progestin, and evaluated by measuring prolactin by ELISA and F-actin immunostaining. RT-qPCR was employed to compare expression with other PGRs. To reveal the function of PGRMC2 during the decidualization process, we specifically knocked down PGRMC2 with siRNAs and performed RNA-seq and quantitative proteomics techniques (SWATH-MS). The common differentially expressed genes (DEGs) and proteins (DEPs) were considered for downstream functional enrichment analysis. Finally, to verify its implication in the trophoblast invasion, an outgrowth model was carried out where hEnSCs with silenced PGRMC2 were co-cultured with human trophoblastic spheroids (JEG-3) following in vitro decidualization. MAIN RESULTS AND THE ROLE OF CHANCE: In contrast to PGRMC1 and classical PGRs, endometrial PGRMC2 gene expression was significantly lower during the late- versus mid-secretory phase (P < 0.05). Accordingly, the elevated PGRMC2 protein abundance observed in the endometrial epithelial glands throughout the menstrual cycle dropped in the late secretory phase, when abundance decreased in all endometrial compartments. Nevertheless, PGRMC2 protein increased during the mid-secretory phase in stromal and glandular cells, and PGRMC2 mRNA (P < 0.0001) and protein (P < 0.001) levels were significantly enhanced in the membranes/organelles of decidualized hEnSCs, compared to non-decidualized hEnSCs. Notably, PGRMC1 and PGRMC2 mRNA were significantly more abundant than classical PGRs throughout menstrual cycle phases and in decidualized and non-decidualized hEnSCs (P < 0.05). RNA-seq and proteomics data revealed 4687 DEGs and 28 DEPs, respectively, in decidualized hEnSCs after PGRMC2 silencing. While functional enrichment analysis showed that the 2420 upregulated genes were mainly associated with endoplasmic reticulum function, vesicular transport, morphogenesis, angiogenesis, cell migration, and cell adhesion, the 2267 downregulated genes were associated with aerobic respiration and protein biosynthesis. The protein enrichment analysis showed that 4 upregulated and 24 downregulated proteins were related to aerobic respiration, cellular response, metabolism, localization of endoplasmic reticulum proteins, and ribonucleoside biosynthesis routes. Finally, PGRMC2 knockdown significantly compromised the ability of the decidualized hEnSCs to support trophoblast expansion in an outgrowth model (P < 0.05). LARGE-SCALE DATA: Transcriptomic data are available via NCBI's Gene Expression Omnibus (GEO) under GEO Series accession number GSE251843 and proteomic data via ProteomeXchange with identifier PXD048494. LIMITATIONS, REASONS FOR CAUTION: The functional analyses were limited by the discrete number of human endometrial biopsies. A larger sample size is required to further investigate the potential role(s) of PGRMC2 during embryo implantation and maintenance of pregnancy. Further, the results obtained in the present work should be taken with caution, as the use of a pure primary endometrial stromal population differentiated in vitro does not fully represent the heterogeneity of the endometrium in vivo, nor the paracrine communications occurring between the distinct endometrial cell types. WIDER IMPLICATIONS OF THE FINDINGS: The repression of endometrial PGRMC2 during the late- versus mid-secretory phase, together with its overexpression during decidualization and multiple implications with embryo implantation not only highlighted the unknown roles of PGRMC2 in female reproduction but also the potential to exploit PGRMC2 signaling pathways to improve assisted reproduction treatments in the future. STUDY FUNDING/COMPETING INTEREST(S): This research was funded by Instituto de Salud Carlos III (ISCIII) granted to F.D. (PI20/00405 and PI23/00860), co-funded by the European Union. Y.M.-L. was supported by a predoctoral research grant from Generalitat Valenciana (ACIF/2019/262). R.G.-M. was supported by Generalitat Valenciana (CIAPOT/2022/15). P.d.C. was supported by a predoctoral grant for training in research into health (PFIS FI20/00086) from the Instituto de Salud Carlos III. I.D.-H. was supported by the Spanish Ministry of Science, Innovation and Universities (FPU18/01550). A.P. was supported by the Instituto de Salud Carlos III (PFIS FI18/00009). This research was also supported by IVI Foundation-RMA Global (1911-FIVI-103-FD). The authors declare no conflict of interest.

Progesterone-induced progesterone receptor membrane component 1 rise-to-decline changes are essential for decidualization.

BACKGROUND: Decidualization of endometrial cells is the prerequisite for embryo implantation and subsequent placenta formation and is induced by rising progesterone levels following ovulation. One of the hormone receptors contributing to endometrial homeostasis is Progesterone Receptor Membrane Component 1 (PGRMC1), a non-classical membrane-bound progesterone receptor with yet unclear function. In this study, we aimed to investigate how PGRMC1 contributes to human decidualization. METHODS: We first analyzed PGRMC1 expression profile during a regular menstrual cycle in RNA-sequencing datasets. To further explore the function of PGRMC1 in human decidualization, we implemented an inducible decidualization system, which is achieved by culturing two human endometrial stromal cell lines in decidualization-inducing medium containing medroxyprogesterone acetate and 8-Br-cAMP. In our system, we measured PGRMC1 expression during hormone induction as well as decidualization status upon PGRMC1 knockdown at different time points. We further conferred proximity ligation assay to identify PGRMC1 interaction partners. RESULTS: In a regular menstrual cycle, PGRMC1 mRNA expression is gradually decreased from the proliferative phase to the secretory phase. In in vitro experiments, we observed that PGRMC1 expression follows a rise-to-decline pattern, in which its expression level initially increased during the first 6 days after induction (PGRMC1 increasing phase) and decreased in the following days (PGRMC1 decreasing phase). Knockdown of PGRMC1 expression before the induction led to a failed decidualization, while its knockdown after induction did not inhibit decidualization, suggesting that the progestin-induced 'PGRMC1 increasing phase' is essential for normal decidualization. Furthermore, we found that the interactions of prohibitin 1 and prohibitin 2 with PGRMC1 were induced upon progestin treatment. Knocking down each of the prohibitins slowed down the decidualization process compared to the control, suggesting that PGRMC1 cooperates with prohibitins to regulate decidualization. CONCLUSIONS: According to our findings, PGRMC1 expression followed a progestin-induced rise-to-decline expression pattern during human endometrial decidualization process; and the correct execution of this expression program was crucial for successful decidualization. Thereby, the results of our in vitro model explained how PGRMC1 dysregulation during decidualization may present a new perspective on infertility-related diseases.

Extracellular succinate derived from ectopic milieu drives adhesion and implantation growth of ectopic endometrial stromal cells via the SUCNR1 signal in endometriosis.

BACKGROUND: As a dual-function metabolite, succinate has emerged in cell function and plays a key signaling role in linking mitochondrial function to other cellular functions. Succinate accumulation in the cytoplasm is commonly associated with hypoxia in the microenvironment and immune cell activation. Extracellular succinate released into the microenvironment is considered an inflammatory alarm that can be sensed by its membrane receptor SUCNR1, which boosts proinflammatory responses and acts akin to classical hormones and cytokines. Succinate plays an important role in the development of inflammatory diseases. Whether succinate facilitates the progression of endometriosis (EMs), characterized by chronic inflammation and peritoneal adhesion, is worth exploring. OBJECTIVE: We mimicked the ectopic milieu in vitro and in vivo to evaluate the main source and potential role of succinate in endometriosis. We assessed the molecular and functional effects of succinate on macrophages and peritoneal mesothelial cells in peritoneal cavity. The effect of succinate/SUCNR1 signaling on ectopic endometrial stromal cells (ESCs) was further explored in this study. METHODS: In this study, we used targeted organic acid metabolomics analysis and in vitro assays to assess the potential accumulation of succinate in the peritoneal fluid of EMs patients. We examined its correlation with disease severity, Visual Analogue Scale, and the Endometriosis Fertility Index. Flow cytometry, enzyme linked immunosorbent assay, western blot assay, quantitative real-time PCR, and other molecular biology techniques were used to explore the potential mechanisms. RESULTS: By mimicking the ectopic milieu, we constructed an in vitro co-culture system and found that M1 polarized macrophages and that the peritoneal mesothelial cell line (HMrSV5) mainly released succinate into their microenvironment and activated the succinate receptor (SUCNR1) signal, which further polarized the macrophages and significantly enhanced the invasive survival of ESCs, and the adhesion to the peritoneum. We further investigated the pathological effects of extracellular succinate in vivo using a xenograft mouse models of endometriosis. CONCLUSIONS: Succinate-SUCNR1 signaling facilitates the creation of inflammatory cells and plays a vital role in EMs progression and peritoneal adhesion. Our work on the molecular mechanisms underlying succinate accumulation and function will help elucidate the phenotypic mysteries of pain and infertility in EMs. Video Abstract.

Inhibitory effects of estetrol on the invasion and migration of immortalized human endometrial stromal cells.

Endometriosis, a common gynecological disorder characterized by the growth of endometrial gland and stroma outside the uterus, causes several symptoms such as dysmenorrhea, hypermenorrhea, and chronic abdominal pain. 17ß estradiol (E2) stimulates the growth of endometriotic lesions. Although estetrol (E4), produced by human fetal liver, is also a natural estrogen, it may have the opposite effects on endometriotic cells. We investigated different effects of E4 and E2 on the invasion and migration of immortalized human endometrial stromal cells (HESCs) and evaluated whether E4 affects the expression of Wiskott-Aldrich syndrome protein (WASP) family member 1 (WASF-1). We measured the invasion of HESCs by a Matrigel chamber assay. Cell migration was measured by wound healing assay and cell tracking analysis. The expression of WASF-1 was confirmed by independent real-time PCR analysis. Transfection of cells with siRNAs was carried out to knock down the expression of WASF-1 in HESCs. E4 significantly inhibited E2-induced invasion and migration of HESCs. WASF-1 was found to be a potential mediator based on metastasis PCR array. WASF-1 was upregulated by E2 and downregulated by E4. Knockdown of WASF-1 inhibited migration. Our results suggest that E4 may inhibit E2-induced growth of endometriotic lesions. Downregulation of WASF-1 is involved in the inhibitory effects of E4 on migration. The use of E4 combined with progestins as combined oral contraceptives may cause endometriotic lesions to regress in women with endometriosis.

[Quercetin Alleviates H2O2-Induced Oxidative Stress Damage to Human Endometrial Stromal Cells by Inhibiting the p38 MAPK/NOX4 Signaling Pathway]. / æ§²çš®ç´ é€šè¿‡æŠ‘åˆ¶p38 MAPK/NOX4信号通路减轻H2O2è¯±å¯¼çš„äººå­å®«å† è†œåŸºè´¨ç»†èƒžæ°§åŒ–åº”æ¿€æŸä¼¤.

Objective: This study aims to systematically evaluate the protective role of quercetin (QCT), a naturally occurring flavonoid, against oxidative damage in human endometrial stromal cells (HESCs) induced by hydrogen peroxide (H2O2). Oxidative stress, such as that induced by H2O2, is known to contribute significantly to cellular damage and has been implicated in various reproductive health issues. The study is focused on investigating how QCT interacts with specific molecular pathways to mitigate this damage. Special attention was given to the p38 MAPK/NOX4 signaling pathway, which is crucial to the regulation of oxidative stress responses in cellular systems. By elucidating these mechanisms, the study seeks to confirm the potential of QCT not only as a protective agent against oxidative stress but also as a therapeutic agent that could be integrated in treatments of conditions characterized by heightened oxidative stress in endometrial cells. Methods: I n vitro cultures of HESCs were treated with QCT at different concentrations (0, 10, 20, and 40 µmol/L) for 24 h to verify the non-toxic effects of QCT on normal endometrial cells. Subsequently, 250 µmol/L H2O2 was used to incubate the cells for 12 h to establish an H2O2-induced HESCs injury model. HESCs were pretreated with QCT for 24 h, which was followed by stimulation with H2O2. Then, CCK-8 assay was performed to examine the cell viability and to screen for the effective intervention concentration. HESCs were divided into 3 groups, the control group, the H2O2 model group, and the H2O2+QCT group. Intracellular levels of reactive oxygen species (ROS) were precisely quantified using the DCFH-DA fluorescence assay, a method known for its accuracy in detecting and quantifying oxidative changes within the cell. The mitochondrial membrane potential was determined by JC-1 staining. Annexin Ⅴ/PI double staining and flow cytometry were performed to determine the effect of QCT on H2O2-induced apoptosis of HESCs. Furthermore, to delve deeper into the cellular mechanisms underlying the observed effects, Western blot analysis was conducted to measure the expression levels of the critical proteins involved in oxidative stress response, including NADPH oxidase 4 (NOX4), p38 mitogen-activated protein kinase (p38 MAPK), and phosphorylated p38 MAPK (p-p38 MAPK). This analysis helps increase understanding of the specific intracellular signaling pathways affected by QCT treatment, giving special attention to its potential for modulation of the p38 MAPK/NOX4 pathway, which plays a significant role in cellular defense mechanisms against oxidative stress. Results: In this study, we started off by assessing the toxicity of QCT on normal endometrial cells. Our findings revealed that QCT at various concentrations (0, 10, 20, and 40 µmol/L) did not exhibit any cytotoxic effects, which laid the foundation for further investigation into its protective roles. In the H2O2-induced HESCs injury model, a significant reduction in cell viability was observed, which was linked to the generation of ROS and the resultant oxidative damage. However, pretreatment with QCT (10 µmol/L and 20 µmol/L) significantly enhanced cell viability after 24 h (P<0.05), with the 20 µmol/L concentration showing the most substantial effect. This suggests that QCT can effectively reverse the cellular damage caused by H2O2. Furthermore, the apoptosis assays demonstrated a significant increase in the apoptosis rates in the H2O2 model group compared to those in the control group (P<0.01). However, co-treatment with QCT significantly reversed this trend (P<0.05), indicating QCT's potential protective role in mitigating cell apoptosis. ROS assays showed that, compared to that in the control group, the average fluorescence intensity of ROS in the H2O2 model group significantly increased (P<0.01). QCT treatment significantly reduced the ROS fluorescence intensity in the H2O2+QCT group compared to the that in the H2O2 model group, suggesting an effective alleviation of oxidative damage (P<0.05). JC-1 staining for mitochondrial membrane potential changes revealed that compared to that in the control, the proportion of cells with decreased mitochondrial membrane potential significantly increased in the H2O2 model group (P<0.01). However, this proportion was significantly reduced in the QCT-treated group compared to that of the H2O2 model group (P<0.05). Finally, Western blot analysis indicated that the expression levels of NOX4 and p-p38 MAPK proteins were elevated in the H2O2 model group compared to those of the control group (P<0.05). Following QCT treatment, these protein levels significantly decreased compared to those of the H2O2 model group (P<0.05). These results suggest that QCT may exert its protective effects against oxidative stress by modulating the p38 MAPK/NOX4 signaling pathway. Conclusion: QCT has demonstrated significant protective effects against H2O2-induced oxidative damage in HESCs. This protection is primarily achieved through the effective reduction of ROS accumulation and the inhibition of critical signaling pathways involved in the oxidative stress response, notably the p38 MAPK/NOX4 pathway. The results of this study reveal that QCT's ability to modulate these pathways plays a key role in alleviating cellular damage associated with oxidative stress conditions. This indicates not only its potential as a protective agent against cellular oxidative stress, but also highlights its potential for therapeutic applications in treating conditions characterized by increased oxidative stress in the endometrium, thereby offering the prospect of enhancing reproductive health. Future studies should explore the long-term effects of QCT and its clinical efficacy in vivo, thereby providing a clear path toward its integration into therapeutic protocols.

Follistatin is a crucial chemoattractant for mouse decidualized endometrial stromal cell migration by JNK signalling.

Follistatin (FST) and activin A as gonadal proteins exhibit opposite effects on follicle-stimulating hormone (FSH) release from pituitary gland, and activin A-FST system is involved in regulation of decidualization in reproductive biology. However, the roles of FST and activin A in migration of decidualized endometrial stromal cells are not well characterized. In this study, transwell chambers and microfluidic devices were used to assess the effects of FST and activin A on migration of decidualized mouse endometrial stromal cells (d-MESCs). We found that compared with activin A, FST exerted more significant effects on adhesion, wound healing and migration of d-MESCs. Similar results were also seen in the primary cultured decidual stromal cells (DSCs) from uterus of pregnant mouse. Simultaneously, the results revealed that FST increased calcium influx and upregulated the expression levels of the migration-related proteins MMP9 and Ezrin in d-MESCs. In addition, FST increased the level of phosphorylation of JNK in d-MESCs, and JNK inhibitor AS601245 significantly attenuated FST action on inducing migration of d-MESCs. These data suggest that FST, not activin A in activin A-FST system, is a crucial chemoattractant for migration of d-MESCs by JNK signalling to facilitate the successful uterine decidualization and tissue remodelling during pregnancy.

TIM-3 regulates the proliferation by BDNF-mediated PI3K/AKT axis in the process of endometriosis.

BACKGROUND: T cell immunoglobulin and mucin domain-containing molecule-3 (TIM-3) initially discovered on the surface of Th1 cells, negatively regulates immune responses and mediates apoptosis of Th1 cells. An increasing number of studies have since shown that TIM-3 is crucial in the genesis and development of immune diseases, cancers, and chronic infectious illnesses. However, the effect of TIM-3 on endometriosis is still unknown. METHODS: Quantitative real-time polymerase chain reaction, western blotting, and immunohistochemistry were used to measure TIM-3 levels in endometriosis. Cell Counting Kit-8, 5-ethynyl-2'-deoxyuridine, colony-forming, Transwell® migration, Matrigel® invasion, and flow cytometry assays were used to explore the function of TIM-3 in vitro, and xenograft experiments in nude mice were used to assess its role in vivo. According to the RNA seq, brain-derived neurotrophic factor (BDNF) was screened. The involvement of specific proliferation-related signaling molecules was determined by transfecting a plasmid and adding an inhibitor in vivo and in vitro. RESULTS: TIM-3 mRNA and protein expression levels were significantly higher in eutopic and ectopic endometrial tissues than in normal endometrial tissues. By examining the effects of TIM-3 overexpression and knockdown on cell proliferation, migration, and invasion in vitro, and lesions formation in vivo, we found that the expression of TIM-3 was positively correlated with cell proliferation and clone formation in vitro, as well as lesions growth in nude mice. By adding the phosphatidylinositol 3 kinase/protein kinase B(PI3K/AKT) pathway inhibitor LY294002 and knocking down PI3K, we further verified that TIM-3 promotes proliferation in vivo and in vitro via the PI3K pathway. By transfecting the plasmid into ESC cells and gave inhibitors to endometriotic rats models, we tested that TIM-3 regulates the proliferation by BDNF-mediated PI3K/AKT axis. CONCLUSION: TIM-3 can promote the proliferation of endometriosis by BDNF-mediated PI3K/AKT axis in vivo and in vitro, which may provide a new therapeutic target for the treatment of endometriosis.

Endometrial stromal cell autophagy-dependent ferroptosis caused by iron overload in ovarian endometriosis is inhibited by the ATF4-xCT pathway.

Ferroptosis is an iron-dependent programmed cell death process characterized by the accumulation of lethal oxidative damage. Localized iron overload is a unique clinical phenomenon in ovarian endometriosis (EM). However, the role and mechanism of ferroptosis in the course of ovarian EM remain unclear. Traditionally, autophagy promotes cell survival. However, a growing body of research suggests that autophagy promotes ferroptosis under certain conditions. This study aimed to clarify the status of ferroptosis in ovarian EM and explore the mechanism(s) by which iron overload causes ferroptosis and ectopic endometrial resistance to ferroptosis in human. The results showed increased levels of iron and reactive oxygen species in ectopic endometrial stromal cells (ESCs). Some ferroptosis and autophagy proteins in the ectopic tissues differed from those in the eutopic endometrium. In vitro, iron overload caused decreased cellular activity, increased lipid peroxidation levels, and mitochondrial morphological changes, whereas ferroptosis inhibitors alleviated these phenomena, illustrating activated ferroptosis. Iron overload increased autophagy, and ferroptosis caused by iron overload was inhibited by autophagy inhibitors, indicating that ferroptosis caused by iron overload was autophagy-dependent. We also confirmed the effect of iron overload and autophagy on lesion growth in vivo by constructing a mouse EM model; the results were consistent with those of the in vitro experiments of human tissue and endometrial stomal cells. However, ectopic lesions in patients can resist ferroptosis caused by iron overload, which can promote cystine/glutamate transporter hyperexpression by highly expressing activating transcription factor 4 (ATF4). In summary, local iron overload in ovarian EM can activate autophagy-related ferroptosis in ESCs, and ectopic lesions grow in a high-iron environment via ATF4-xCT while resisting ferroptosis. The effects of iron overload on other cells in the EM environment require further study. This study deepens our understanding of the role of ferroptosis in ovarian EM.

Genome-wide analysis of histone modifications that underlie the dynamic changes in gene expression during decidualization in human endometrial stromal cells.

Human endometrial stromal cells (hESCs) undergo a differentiation process with dramatic changes in cell functions during the menstrual cycle, which is called decidualization. This is an important event for implantation of the embryo and successful pregnancy. Defective decidualization can cause implantation failure, miscarriage, and unexplained infertility. A number of genes are upregulated or downregulated during decidualization. Recent studies have shown that epigenetic mechanisms are involved in the regulation of decidualization-related genes and that histone modifications occur throughout the genome during decidualization. The present review focuses on the involvement of genome-wide histone modifications in dramatic changes in gene expression during decidualization. The main histone modifications are the increases of H3K27ac and H3K4me3, which activate transcription. C/EBPß works as a pioneer factor throughout the genome by recruiting p300. This is the main cause of the genome-wide acetylation of H3K27 during decidualization. Histone modifications were observed in both the proximal promoter and distal enhancer regions. Genome editing experiments show that the distal regions have transcriptional activities, which suggests that decidualization induces the interactions between proximal promoter and distal enhancer regions. Taken together, these findings show that gene regulation during decidualization is closely associated with genome-wide changes of histone modifications. This review provides new insights regarding the cases of implantation failure in terms of decidualization insufficiency owing to epigenetic dysregulation, and may lead to novel treatment options for women with implantation failure.

Losartan impairs HTR-8/SVneo trophoblast migration through inhibition of angiotensin II-induced pro-inflammatory profile in human endometrial stromal cells.

A deep interaction between the endometrium and the invading trophoblast occurs during implantation in humans, with the acquisition of uterine receptivity to the invading embryo promoted by an elevation of pro-inflammatory cytokines in the endometrium, and the invasiveness of decidualizing endometrial stromal cells, augmented by trophoblast-derived signals. Considering that usage of angiotensin II type 1 (AT1) receptor blockers, among other renin-angiotensin system (RAS) antagonists, is associated with adverse pregnancy outcomes, here we aim to analyse the involvement of AT1 receptor in the reciprocal dialogue occurring between endometrial stroma and trophoblast cells. In human endometrial stromal cells (T-HESC) pre-incubated with a decidualization cocktail, angiotensin (Ang) II increased protein expression of prolactin and FOXO1, markers of endometrial decidualization, while promoting nuclear translocation of FOXO1. In addition, Ang II treatment increased CXCL8, and matrix metalloprotease (MMP)-2 levels in T-HESC. Incubation with the AT1 receptor blocker losartan or with an NFAT signalling inhibitor, decreased Ang II-induced secretion of prolactin, CXCL8, and MMP-2 in T-HESC. In a wound healing assay, conditioned medium (CM) obtained from Ang II-treated T-HESC, but not CM from losartan-pre-incubated T-HESC, increased migration of HTR-8/SVneo trophoblasts, effect that was inhibited in the presence of a CXCL8-neutralizing antibody. An increased secretion of CXCL8 and MMP-2 was observed after treatment of T-HESC with CM obtained from HTR-8/SVneo cells, which was not observed in T-HESC pre-incubated with losartan or with the NFAT inhibitor. This study evidenced a reciprocal RAS-coded messaging between trophoblast and ESC which is affected by the AT1 receptor blocker losartan.

Influence of the ectopic location on the antigen expression and functional characteristics of endometrioma stromal cells.

RESEARCH QUESTION: Are the alterations observed in the endometriotic cells, such as progesterone resistance, already present in the eutopic endometrium or acquired in the ectopic location? DESIGN: The response to decidualization with progesterone and cyclic AMP for up to 28 days was compared in different endometrial stromal cell (EnSC) lines established from samples of endometriomas (eEnSC), eutopic endometrium from women with endometriosis (eBEnSC), endometrial tissue from healthy women (BEnSC) and menstrual blood from healthy donors (mEnSC). RESULTS: Usual features of decidualized cells, such as changes in cell morphology and expression of prolactin, were similarly observed in the three types of eutopic EnSC studied, but not in the ectopic cells upon decidualization. Among the phenotypic markers analysed, CD105 was down-regulated under decidualization in all cell types (mEnSC, P = 0.005; BEnSC, P = 0.029; eBEnSC, P = 0.022) except eEnSC. mEnSC and BEnSC underwent apoptosis during decidualization, whereas eBEnSC and eEnSC were resistant to the induction of cell death. Lastly, migration studies revealed that mEnSC secreted undetermined factors during decidualization that inhibited cell motility, whereas eEnSC showed a significantly lower ability to produce those migration-regulating factors (P < 0.0001, P  < 0.001 and P = 0.0013 for the migration of mEnSC at 24, 48 and 72 h, respectively; P  < 0.0001 for the migration of eEnSC at all times studied). CONCLUSIONS: This study provides novel insights into the differences between endometriotic and eutopic endometrial cells and reinforces the idea that the microenvironment in the ectopic location plays additional roles in the acquisition of the alterations that characterize the cells of the endometriotic foci.

Progranulin promotes proliferation, migration and invasion via the PI3K/Akt signalling pathway in a model of endometriosis.

RESEARCH QUESTION: What are the levels of progranulin (PGRN) expression in primary endometrial stromal cells (ESC) and endometrial tissue in patients with endometriosis (EMS)? What is the role and mechanism of action of PGRN in EMS? DESIGN: Endometrial tissue was collected from 30 patients, 15 with EMS (EMS group) and 15 without EMS (non-EMS group). PGRN expression in endometrial tissue and ESC was analysed by immunohistochemistry, immunofluorescence, western blotting and quantitative reverse transcription polymerase chain reaction. PGRN overexpression and silencing ESC were established with lentivirus to detect the effect on proliferation, invasion and migration. The relationship between PGRN and the phosphatidylinositol-3-kinase/protein kinase B (PI3K/Akt) signalling pathway was verified by western blotting. A rescue assay was performed with PI3K inhibitor treatment. RESULTS: The PGRN expression was significantly higher in EMS samples. PGRN up-regulation promoted proliferation (P = 0.007), migration (P = 0.002) and invasion (P < 0.001) of eutopic endometrial stromal cells (EUESC). The ratio of p-AKT/AKT was higher in the overexpression PGRN (ovPGRN) group than in the overexpression-NC (ovNC) group (P = 0.004). Silencing PGRN produced the opposite results, and LY2940002 addition reversed the effect of PGRN up-regulation on the proliferation, invasion and migration of EUESC. CONCLUSIONS: PGRN might promote the proliferation, invasion and migration of EUESC via the PI3K/Akt signalling pathway. These preliminary in-vitro findings may present a new perspective and inspire further study of the mechanism of EMS.

Effect of active vitamin D on proliferation, cell cycle and apoptosis in endometriotic stromal cells.

RESEARCH QUESTION: What is the effect of vitamin D3 (1,25(OH)2D3) on proliferation, cell cycle and apoptosis of endometrial stromal cells (ESC) in endometriotic patients? DESIGN: ESC isolated from 10 women with endometriosis and 10 healthy controls were treated with 1,25(OH)2D3. The proliferation of control endometrial stromal cells (CESC), eutopic endometrial stromal cells (EuESC) and ectopic endometrial stromal cells (EESC) was analysed 72 h after the treatment using methyl thiazolyl tetrazolium assay. Propidium iodide staining and flow cytometry were used to determine the cell cycle distribution in ESC. Annexin V/propidium iodide double staining was used to evaluate apoptosis in ESC. RESULTS: In the presence of oestrogen, 1,25(OH)2D3 treatment inhibited the proliferation of ESC from all three origins (P = 0.009 for CESC, P = 0.005 for EuESC and P < 0.001 for EESC). The percentage of S phase cells in EESC was higher than in EuESC and CESC (P = 0.002 and P = 0.001, respectively). The percentage of S phase cells in EuESC was higher than in CESC (P = 0.005). The percentage of G1 phase cells in EESC was lower than that of EuESC and CESC (P = 0.003 and P = 0.002, respectively) and the percentage of G1 phase cells in EuESC was lower than that of CESC (P = 0.007). Moreover, 1,25(OH)2D3 inhibited cell cycle regardless of cell type (P = 0.002 in EESC, P = 0.001 in EuESC and P = 0.014 in CESC), but in the absence of oestrogen, inhibited cell cycle only in EuESC (P = 0.012). CONCLUSIONS: Although 1,25(OH)2D3 increased apoptotic and necrotic cells and decreased live cells in the EuESC and EESC, it did not affect apoptosis in CESC and only increased necrotic cells. These findings indicate that 1,25(OH)2D3 potentially has a growth-inhibiting and pro-apoptotic effect on ESC from endometriotic patients.

In Memory of Ivo Brosens: Reflections on the Pathophysiology of Neonatal Uterine Bleeding.

BACKGROUND: The occurrence of vaginal bleeding in early neonatal life has been observed for centuries and was considered a consequence of the sudden drop in circulating hormones following birth. As such, neonatal uterine bleeding was dismissed as having no clinical significance. Interest in the phenomenon was renewed when a new theory suggested a link between neonatal uterine bleeding (NUB) and accelerated endometrial maturation. This theory was based on the observation of a higher incidence of NUB in babies born post-term or after pregnancies complicated by intrauterine growth restriction, preeclampsia, or blood group incompatibility. OBJECTIVE: The objective of this study was to review of available evidence on the pathogenesis of NUB. METHOD: Review of available literature using Medline search (August 2022, no limit on start date or language) to identify articles that may link NUB with features of the uterus and/or endometrium. OUTCOME: The fetal endometrial responses differ from that of the adult. In the fetus, the endometrium features progestogenic response only in a minority of cases. The endometrium in most newborn girls does not exhibit secretory or decidual changes which indicate lack of progesterone response. Most newborn girls do not have visible bleeding. Animal studies linked exogenous progestogen exposure during the period of organogenesis to poor endometrial gland development, progesterone resistance, and to alterations of reproductive performance. Although the fetal endometrium may not exhibit a full proliferative response, it is clearly sensitive to circulating estrogens. Molecular mechanisms involved in NUB may include "ontogenetic progesterone resistance." CONCLUSION AND OUTLOOK: Endometrial development and its response to withdrawal of hormones at birth varies and may be affected by intrauterine stressors and gestational age. Factors that affect endometrial development during fetal life and in preterm neonates can have implications on future reproductive performance.

Silencing of circ_0007299 suppresses proliferation, migration, and invasiveness and promotes apoptosis of ectopic endometrial stromal cells in endometriosis via miR-424-5p-dependent modulation of CREB1.

BACKGROUND: The abnormality of endometrial stromal cells (ESCs) can contribute to endometriosis pathogenesis. Circular RNAs (circRNAs) possess critical roles in endometriosis pathogenesis. Here, we defined the activity and mechanism of human circ_0007299 in the regulation of ectopic ESCs in vitro. METHODS: Circ_0007299, miR-424-5p and cAMP response element-binding protein 1 (CREB1) were quantified by qRT-PCR or immunoblotting. Cell viability, proliferation, apoptosis, invasion and motility were gauged by CCK-8, 5-Ethynyl-2'-Deoxyuridine (EdU), flow cytometry, transwell, and wound-healing assays, respectively. Dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were used to verify the direct relationship between miR-424-5p and circ_0007299 or CREB1. RESULTS: Our data showed that circ_0007299 was upregulated in human ectopic endometrium tissues and ectopic ESCs. Silencing endogenous circ_0007299 impeded the proliferation, invasiveness, and motility and enhanced apoptosis of ectopic ESCs. Mechanistically, circ_0007299 regulated miR-424-5p expression. Moreover, circ_0007299 silencing impeded the proliferation, invasiveness, and motility and enhanced apoptosis of ectopic ESCs via its regulation on miR-424-5p. CREB1 was identified as a direct miR-424-5p target, and miR-424-5p overexpression suppressed ectopic ESC proliferation, migration, and invasiveness and promoted apoptosis by downregulating CREB1. Furthermore, circ_0007299 positively modulated CREB1 expression through miR-424-5p competition. CONCLUSION: Our findings establish that circ_0007299 silencing impedes the proliferation, invasiveness, and motility and promotes apoptosis of ectopic ESCs at least in part via miR-424-5p-dependent modulation of CREB1.

Oncogene-Induced Senescence Is a Crucial Antitumor Defense Mechanism of Human Endometrial Stromal Cells.

Being the major cellular component of highly dynamic tissue, endometrial stromal cells (EnSCs) are exposed to cycles of proliferation upon hormonal stimulation, which might pose risks for the accumulation of mutations and malignization. However, endometrial stromal tumors are rare and uncommon. The present study uncovered defense mechanisms that might underlie the resistance of EnSCs against oncogenic transformation. All experiments were performed in vitro using the following methods: FACS, WB, RT-PCR, IF, molecular cloning, lentiviral transduction, and CRISPR/Cas9 genome editing. We revealed that the expression of the mutant HRASG12V leads to EnSC senescence. We experimentally confirmed the inability of HRASG12V-expressing EnSCs to bypass senescence and resume proliferation, even upon estrogen stimulation. At the molecular level, the induction of oncogene-induced senescence (OIS) was accompanied by activation of the MEK/ERK, PI3K/AKT, p53/p21WAF/CIP/Rb, and p38/p16INK4a/Rb pathways; however, inhibiting either pathway did not prevent cell cycle arrest. PTEN loss was established as an additional feature of HRASG12V-induced senescence in EnSCs. Using CRISPR-Cas9-mediated PTEN knockout, we identified PTEN loss-induced senescence as a reserve molecular mechanism to prevent the transformation of HRASG12V-expressing EnSCs. The present study highlights oncogene-induced senescence as an antitumor defense mechanism of EnSCs controlled by multiple backup molecular pathways.

Enhanced ZBTB16 Levels by Progestin-Only Contraceptives Induces Decidualization and Inflammation.

Progestin-only long-acting reversible-contraceptive (pLARC)-exposed endometria displays decidualized human endometrial stromal cells (HESCs) and hyperdilated thin-walled fragile microvessels. The combination of fragile microvessels and enhanced tissue factor levels in decidualized HESCs generates excess thrombin, which contributes to abnormal uterine bleeding (AUB) by inducing inflammation, aberrant angiogenesis, and proteolysis. The- zinc finger and BTB domain containing 16 (ZBTB16) has been reported as an essential regulator of decidualization. Microarray studies have demonstrated that ZBTB16 levels are induced by medroxyprogesterone acetate (MPA) and etonogestrel (ETO) in cultured HESCs. We hypothesized that pLARC-induced ZBTB16 expression contributes to HESC decidualization, whereas prolonged enhancement of ZBTB16 levels triggers an inflammatory milieu by inducing pro-inflammatory gene expression and tissue-factor-mediated thrombin generation in decidualized HESCs. Thus, ZBTB16 immunostaining was performed in paired endometria from pre- and post-depo-MPA (DMPA)-administrated women and oophorectomized guinea pigs exposed to the vehicle, estradiol (E2), MPA, or E2 + MPA. The effect of progestins including MPA, ETO, and levonorgestrel (LNG) and estradiol + MPA + cyclic-AMP (E2 + MPA + cAMP) on ZBTB16 levels were measured in HESC cultures by qPCR and immunoblotting. The regulation of ZBTB16 levels by MPA was evaluated in glucocorticoid-receptor-silenced HESC cultures. ZBTB16 was overexpressed in cultured HESCs for 72 h followed by a ± 1 IU/mL thrombin treatment for 6 h. DMPA administration in women and MPA treatment in guinea pigs enhanced ZBTB16 immunostaining in endometrial stromal and glandular epithelial cells. The in vitro findings indicated that: (1) ZBTB16 levels were significantly elevated by all progestin treatments; (2) MPA exerted the greatest effect on ZBTB16 levels; (3) MPA-induced ZBTB16 expression was inhibited in glucocorticoid-receptor-silenced HESCs. Moreover, ZBTB16 overexpression in HESCs significantly enhanced prolactin (PRL), insulin-like growth factor binding protein 1 (IGFBP1), and tissue factor (F3) levels. Thrombin-induced interleukin 8 (IL-8) and prostaglandin-endoperoxide synthase 2 (PTGS2) mRNA levels in control-vector-transfected HESCs were further increased by ZBTB16 overexpression. In conclusion, these results supported that ZBTB16 is enhanced during decidualization, and long-term induction of ZBTB16 expression by pLARCs contributes to thrombin generation through enhancing tissue factor expression and inflammation by enhancing IL-8 and PTGS2 levels in decidualized HESCs.