Microbiome dysbiosis in patients with chronic endometritis and Clostridium tyrobutyricum ameliorates chronic endometritis in mice.

Chronic endometritis is associated with the imbalance of female reproductive tract microbiota and pathogenic microbial infection. This study aimed to identify the specific changes in the endometrial microbiome in patients with endometritis and to explore how Clostridium tyrobutyricum (C.t) influences the progression of endometritis in mice for further elucidating endometritis pathogenesis. For this purpose, endometrial tissues from 100 participants were collected and divided into positive, weakly positive, and negative groups based on CD138 levels, while endometrial microbiome differences were detected and analyzed using 16S rRNA gene sequencing. Staphylococcus aureus (S. aureus)-induced endometritis mouse model was established, followed by treatment with C.t, and inflammatory response, epithelial barrier, and TLR4/NF-κB pathway were evaluated. Results showed that α- and ß-diversity was significantly lower in the positive group compared with the weakly positive or negative groups, where the negative group had more unique operational taxonomic units. The abundance of Proteobacteria was found to be increased, while that of Actinobacteria, Firmicutes, and Bacteroidetes was found to be reduced in the positive group, while the area under the curve value was found to be 0.664. Furthermore, C.t treatment resulted in the alleviation of S. aureus-induced inflammatory response, epithelial barrier damage, and activation of the TLR4/NF-κB pathway in mice. Clinical samples analysis revealed that the diversity and abundance of microbiota were altered in patients with endometritis having positive CD138 levels, while mechanistic investigations revealed C.t alleviated S. aureus-induced endometritis by inactivating TLR4/NF-κB pathway. The findings of this study are envisaged to provide a diagnostic and therapeutic potential of microbiota in endometritis.

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.

Up-regulation of inflammatory, oxidative stress, and apoptotic mediators via inflammatory, oxidative stress, and apoptosis-associated pathways in bovine endometritis.

Endometritis is the inflammation of the endothelial lining of the uterine lumen and is multifactorial in etiology. Escherichia (E.) coli is a Gram-negative bacteria, generally considered as a primary causative agent for bovine endometritis. Bovine endometritis is characterized by the activation of Toll-like receptors (TLRs) by E. coli, which in turn triggers inflammation, oxidative stress, and apoptosis. The objective of this study was to investigate the gene expression of inflammatory, oxidative stress, and apoptotic markers related to endometritis in the uteri of cows. Twenty uterine tissues were collected from the abattoir. Histologically, congestion, edema, hyperemia, and hemorrhagic lesions with massive infiltration of neutrophil and cell necrosis were detected markedly (P < 0.05) in infected uterine samples. Additionally, we identify E. coli using the ybbW gene (177 base pairs; E. coli-specific gene) from infected uterine samples. Moreover, qPCR and western blot results indicated that TLR2, TLR4, proinflammatory mediators, and apoptosis-mediated genes upregulated except Bcl-2, which is antiapoptotic, and there were downregulations of oxidative stress-related genes in the infected uterine tissue. The results of our study suggested that different gene expression regimes related to the immune system reflex were activated in infected uteri. This research gives a novel understanding of active immunological response in bovine endometritis.

Endometrial expression of antimicrobial peptides as markers of subclinical endometritis in mares.

BACKGROUND: Endometritis is a major cause of subfertility in mares. Multiparous old mares are more susceptible to developing endometritis given that ageing is associated with an altered immune response and with inadequate physiological uterine clearance after breeding, which can lead to degenerative changes in the endometrium. Molecules such as antimicrobial peptides (AMPs) have been proposed as endometritis markers in the equine species. STUDY DESIGN: Cross-sectional. OBJECTIVES: To investigate the endometrial expression of defensin-beta 4B (DEFB4B), lysozyme (LYZ) and secretory leukocyte peptidase inhibitor (SLPI) genes in mares either affected or not by subclinical endometritis, due to the role of these AMPs in the immune response to bacteria and inflammatory reactions. METHODS: Endometrial biopsy for histopathological and gene expression examinations was performed on 26 mares. The inclusion criteria for the normal mare group (NM, N = 7) were 2-4 years of age, maiden status, no clinical signs of endometritis and a uterine biopsy score of I, while for mares affected by subclinical endometritis (EM, N = 19) the inclusion criteria were 10-22 years of age, barren status for 1-3 years, no clinical signs of endometritis and a uterine biopsy score between IIA and III. RESULTS: A significantly higher expression of LYZ (NM: 0.76 [1.84-0.37] vs. EM: 2.78 [5.53-1.44], p = 0.0255) and DEFB4B (NM: 0.06 [0.11-0.01] vs. EM: 0.15 [0.99-0.08], p = 0.0457) genes was found in endometritis mares versus normal mares. Statistically significant moderate positive correlations were found between the level of expression of LYZ gene and both the age (r = 0.4071, p = 0.039) and the biopsy grade (r = 0.4831, p = 0.0124) of the mares. MAIN LIMITATIONS: The study investigated a limited number of genes and mares, and the presence/location of the proteins coded by these genes was not confirmed within the endometrium by IHC. CONCLUSIONS: If the results of this study are confirmed, LYZ and DEFB4B genes can be used as markers to identify mares that are affected by subclinical endometritis.

Therapeutic effect of human umbilical cord mesenchymal stem cells and their conditioned medium on LPS-induced endometritis in mice.

AIM: To explore the effect of human umbilical cord mesenchymal stem cells (hUC-MSCs) and their conditioned medium (MSC-CM) in repairing the endometritis mouse model in vivo. METHODS: Lipopolysaccharide (LPS) was used to induce acute inflammation in endometritis mouse model. Mice were treated in six groups: control group (PBS), model group (LPS), LPS+MSC-CM (6 h) group, LPS+MSC-CM (12 h) group, LPS+MSCs (6 h) group and LPS+MSCs (12 h) group. Morphological and histological changes of mouse uterus were observed, and mouse uterine inflammation index myeloperoxidase (MPO) and related immune index TNF-α, IL-6 and IL-1ß levels were detected by ELISA. RESULTS: There exist remarkable inflammatory response and an obvious increase in the value of MPO, TNF-α, IL-1ß and IL-6 in the endometritis mouse model compared with the control group. Morphological and histological appearances were relieved after treated with hUC-MSCs and MSC-CM. Besides, the value of MPO, TNF-α, IL-1ß and IL-6 showed different degrees of decline. In comparison with LPS+MSC-CM (12 h) and LPS+MSCs (12 h) group, there was significant decrease in inflammatory indicators in LPS+MSC-CM (6 h) and LPS+MSCs (6 h) group. CONCLUSIONS: Intrauterine infusion of hUC-MSCs and MSC-CM can alleviate LPS induced endometritis.

Microbial responses and changes in metabolic products in bovine uteri infected with Staphylococcus aureus.

There is mounting evidence that the uterine microbiota has an important role in the pathogenesis of endometritis, with invasion of pathogenic bacteria being a main cause of uterine microbial imbalance. However, mechanisms of uterine microbiota resistance to pathogen invasion remain unclear. In this study, an intrauterine infusion of Staphylococcus aureus was used as a bovine endometritis model; it significantly increased abundance of pathogenic bacteria (Streptococcus, Helccoccus, Fusobacterium, and Escherichia-Shigella) and significantly decreased abundance of probiotics (Allstipes, Bacteroides, Phascolarctobacterium, Romboutsia, and Prevotella). In addition, the metabolite aloe-emodin was positively correlated with Prevotella and based on combined analyses of omics and probiotics, the presence of its metabolite aloe-emodin in the uterus at least partially resisted Staphylococcus aureus invasion. Therefore, Aloe-emodin has potential for regulating microbial structure and preventing endometritis.

Evaluation of Lipopolysaccharide and Interleukin-6 as Useful Screening Tool for Chronic Endometritis.

Universal diagnostic criteria for chronic endometritis (CE) have not been established due to differences in study design among researchers and a lack of typical clinical cases. Lipopolysaccharides (LPSs) have been reported to cause inflammation in the reproductive systems of several animals. This study aimed to elucidate the influence of LPS in the pathogenesis of CE in humans. We investigated whether LPS affected cytokine production and cell proliferation in the endometrium using in vivo and in vitro experiments. LPS concentrations were analyzed between control and CE patients using endometrial tissues. LPS administration stimulated the proliferation of EM-E6/E7 cells derived from human endometrial cells. High LPS concentrations were detected in CE patients. LPS concentration was found to correlate with IL-6 gene expression in the endometrium. Inflammation signaling evoked by LPS led to the onset of CE, since LPS stimulates inflammatory responses and cell cycles in the endometrium. We identified LPS and IL-6 as suitable candidate markers for the diagnosis of CE.

Luteolin attenuates Staphylococcus aureus-induced endometritis through inhibiting ferroptosis and inflammation via activating the Nrf2/GPX4 signaling pathway.

Endometritis, a local inflammatory disease, has been known as the most common cause of infertility in mares. In this study, we investigated the protective effects of luteolin on endometritis induced by Staphylococcus aureus (S. aureus) and further clarified the possible molecular mechanisms. An S. aureus-induced endometritis model was established by the infusion of S. aureus into the uterus. Luteolin was intraperitoneally administered to mice 1 h before S. aureus treatment. The results showed that the mice of the S. aureus group showed severe histological changes of uterine tissues, increased myeloperoxidase (MPO) activity, and elevated TNF-α, IL-1ß, and IL-6 levels. These changes induced by S. aureus were dose-dependently inhibited by luteolin. Furthermore, luteolin inhibited MDA and Fe2+ production and increased the production of GSH decreased by S. aureus. Luteolin prevented S. aureus-induced endometrial barrier disruption through up-regulating ZO-1 and occludin expression. Luteolin dramatically inhibited S. aureus-induced NF-κB activation. The expression of Nrf2 and HO-1 was increased by luteolin. In addition, the inhibitory effects of luteolin on S. aureus-induced endometritis were reversed in Nrf2 knockdown mice. In conclusion, these data indicated that luteolin protected mice against S. aureus-induced endometritis through inhibiting inflammation and ferroptosis via regulating the Nrf2 signaling pathway.IMPORTANCEEndometritis is an inflammatory disease of the endometrium, which is a common gynecological disease. Up to now, there is no evidence for the protective effects of luteolin on endometritis. The purpose of this study was to investigate whether luteolin has protective effects against S. aureus-induced endometritis and attempts to clarify the mechanism.

Lack of Annexin A1 Exacerbates Inflammatory Response in Acute Endometritis Model.

Annexin A1 (AnxA1) is a glucocorticoid-inducible protein and an important endogenous modulator of inflammation. However, its effect in the endometrial microenvironment is poorly explained. This study aimed to evaluate the role of endogenous AnxA1 in an endometritis mouse model induced by lipopolysaccharide (LPS). Female C57BL/6 wild-type (WT) and AnxA1-/- mice were divided into two groups: SHAM and LPS. To induce endometritis, mice received a vaginal infusion of 50 µL of LPS (1 mg/mL) dissolved in phosphate-buffered saline. After 24 h, the mice were euthanized, and blood and uteri samples were collected. The endometrium inflammatory scores were significantly increased in the LPS-treated group. AnxA1-/- mice from the LPS group demonstrated a significant increase in the number of degranulated mast cell levels compared to AnxA1-/- SHAM mice. The Western blotting analysis revealed that a lack of AnxA1 promoted the upregulation of NLRP3 and pro-IL-1ß in the acute endometritis animal model compared to WT LPS animals. LPS-induced endometritis increased the number of blood peripheral leukocytes in both WT and AnxA1-/- mice compared with SHAM group mice (p < 0.001). AnxA1-/- mice also showed increased plasma levels of IL-1ß (p < 0.01), IL-6, IL-10, IL-17, and TNF-α (p < 0.05) following LPS-induced endometritis. In conclusion, a lack of endogenous AnxA1 exacerbated the inflammatory response in an endometritis model via NLRP3 dysregulation, increased uterine mast cell activation, and plasma pro-inflammatory cytokine release.

Estimating risk of endometrial malignancy and other intracavitary uterine pathology in women without abnormal uterine bleeding using IETA-1 multinomial regression model: validation study.

OBJECTIVES: To assess the ability of the International Endometrial Tumor Analysis (IETA)-1 polynomial regression model to estimate the risk of endometrial cancer (EC) and other intracavitary uterine pathology in women without abnormal uterine bleeding. METHODS: This was a retrospective study, in which we validated the IETA-1 model on the IETA-3 study cohort (n = 1745). The IETA-3 study is a prospective observational multicenter study. It includes women without vaginal bleeding who underwent a standardized transvaginal ultrasound examination in one of seven ultrasound centers between January 2011 and December 2018. The ultrasonography was performed either as part of a routine gynecological examination, during follow-up of non-endometrial pathology, in the work-up before fertility treatment or before treatment for uterine prolapse or ovarian pathology. Ultrasonographic findings were described using IETA terminology and were compared with histology, or with results of clinical and ultrasound follow-up of at least 1 year if endometrial sampling was not performed. The IETA-1 model, which was created using data from patients with abnormal uterine bleeding, predicts four histological outcomes: (1) EC or endometrial intraepithelial neoplasia (EIN); (2) endometrial polyp or intracavitary myoma; (3) proliferative or secretory endometrium, endometritis, or endometrial hyperplasia without atypia; and (4) endometrial atrophy. The predictors in the model are age, body mass index and seven ultrasound variables (visibility of the endometrium, endometrial thickness, color score, cysts in the endometrium, non-uniform echogenicity of the endometrium, presence of a bright edge, presence of a single dominant vessel). We analyzed the discriminative ability of the model (area under the receiver-operating-characteristics curve (AUC); polytomous discrimination index (PDI)) and evaluated calibration of its risk estimates (observed/expected ratio). RESULTS: The median age of the women in the IETA-3 cohort was 51 (range, 20-85) years and 51% (887/1745) of the women were postmenopausal. Histology showed EC or EIN in 29 (2%) women, endometrial polyps or intracavitary myomas in 1094 (63%), proliferative or secretory endometrium, endometritis, or hyperplasia without atypia in 144 (8%) and endometrial atrophy in 265 (15%) women. The endometrial sample had insufficient material in five (0.3%) cases. In 208 (12%) women who did not undergo endometrial sampling but were followed up for at least 1 year without clinical or ultrasound signs of endometrial malignancy, the outcome was classified as benign. The IETA-1 model had an AUC of 0.81 (95% CI, 0.73-0.89, n = 1745) for discrimination between malignant (EC or EIN) and benign endometrium, and the observed/expected ratio for EC or EIN was 0.51 (95% CI, 0.32-0.82). The model was able to categorize the four histological outcomes with considerable accuracy: the PDI of the model was 0.68 (95% CI, 0.62-0.73) (n = 1532). The IETA-1 model discriminated very well between endometrial atrophy and all other intracavitary uterine conditions, with an AUC of 0.96 (95% CI, 0.95-0.98). Including only patients in whom the endometrium was measurable (n = 1689), the model's AUC was 0.83 (95% CI, 0.75-0.91), compared with 0.62 (95% CI, 0.52-0.73) when using endometrial thickness alone to predict malignancy (difference in AUC, 0.21; 95% CI, 0.08-0.32). In postmenopausal women with measurable endometrial thickness (n = 848), the IETA-1 model gave an AUC of 0.81 (95% CI, 0.71-0.91), while endometrial thickness alone gave an AUC of 0.70 (95% CI, 0.60-0.81) (difference in AUC, 0.11; 95% CI, 0.01-0.20). CONCLUSION: The IETA-1 model discriminates well between benign and malignant conditions in the uterine cavity in patients without abnormal bleeding, but it overestimates the risk of malignancy. It also discriminates well between the four histological outcome categories. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

The association between endometrial polyps, chronic endometritis, and IVF outcomes.

OBJECTIVE: Endometrial polyps (EPs) are one of the most common pathologies detected during the examination of the uterine cavity of infertile women. We aimed to demonstrate the relationship between EPs, chronic endometritis (CE) and in vitro fertilization (IVF) outcomes. PATIENTS AND METHODS: This retrospective study was performed on 394 hysteroscopically examined infertility cases. We performed polyp resections (PR) and extensive biopsies of the endometrium to demonstrate the association with clinical pregnancy (CP) by IVF. We performed statistical analysis to compare these associations. RESULTS: The incidence of CE was twice as high in the presence of EPs as in the absence of EPs. The associations between EPs and PR were found to be significant for positive CP outcomes. A significant difference in IVF outcome was found between the group with EPs and the group without EPs. All these associations were statistically significant (p < 0.05). CONCLUSIONS: We found a frequent association between EPs and CE. The pregnancy rate obtained after IVF was negatively affected by the presence of EPs. Treatment of these pathologies improved IVF outcomes.

Hysteroscopic features suggestive of chronic endometritis: a systematic review.

The purpose of this systematic review is to identify common hysteroscopic findings suggestive of endometritis, chronic or subclinical, based on current scientific evidence. Data sources were MEDLINE, Embase, PubMed and other sources of grey literature. Four (4) authors independently selected studies addressing hysteroscopic detection of CE based on specific and clearly stated hysteroscopic criteria. The diagnosis was confirmed by histologic assessment, as stated in the materials and methods of these studies included. The initial search identified 599 studies, of which 21 met the inclusion criteria. Significant heterogeneity among published studies on Chronic endometritis (CE) remains the main limitation in performing a metanalysis and further analysis of diagnostic accuracy on the subject. Hysteroscopy is an important diagnostic tool in cases of chronic endometritis when accompanied by endometrial biopsies. Clinicians relate hyperaemia and endometrial oedema with chronic endometritis while more than half include micropolyposis as a pathognomonic feature of this subclinical condition. Micropolyps, stromal oedema, haemorrhagic spots, strawberry aspect, and hyperaemia are proposed as adequate indicators of hysteroscopic evidence of CE according to the literature. The impact of CE in long-term reproductive outcomes remain unclear, thus clinicians ought to communicate this to the patients and provide treatment where clinically appropriate. In addition, we present hysteroscopic images of histologically confirmed CE cases that could play the role of a hysteroscopic atlas.

Hysteroscopic versus histopathological agreement in the diagnosis of chronic endometritis: results from a retrospective observational study.

PURPOSE: To evaluate the agreement rate between hysteroscopy and pathological examination in case of chronic endometritis. METHODS: A retrospective observational study carried out at Gynecology and Obstetrics Department, Puerta de Hierro Hospital, Autónoma University of Madrid, Spain, from January 2021 to June 2022 was performed by obtaining data from 115 medical records of women who underwent office hysteroscopies that was compared with the findings of final histological examination of endometrial biopsy. Cohen's kappa index was used to evaluate this agreement rate. In addition, sensitivity, specificity, positive and negative predictive value and diagnostic accuracy were obtained. RESULTS: The agreement between hysteroscopic findings and histological examination showed a modest result with a Cohen's kappa index of 34%. In addition, we obtained a specificity of 70% and a sensitivity of 64%. The positive and negative predictive value were 60.8% and 73.4%, respectively. An excellent agreement rate (100%) between histological and hysteroscopic results was observed in presence of hyperemia and micropolyps. CONCLUSION: Although the sample size is not as large as that of other studies published so far, the first glance of our experience is that hysteroscopic signs are not yet sufficient to make an accurate diagnosis of chronic endometritis, thus requiring a histopathological confirmation to make it.

The microbiota of uterine biopsies, cytobrush and vaginal swabs at artificial insemination in Norwegian red cows.

The individual resistance or tolerance against uterine disease in dairy cattle might be related to variations in the uterine tract microbiota. The uterine tract microbiota in dairy cattle is a field of increasing interest. However, its specific taxonomy and functional aspects is under-explored, and information about the microbiota in the endometrium at artificial insemination (AI) is still missing. Although uterine bacteria are likely to be introduced via the vaginal route, it has also been suggested that pathogens can be transferred to the uterus via a hematogenous route. Thus, the microbiota in different layers of the uterine wall may differ. Norwegian Red (NR) is a high fertility breed that also has a high prevalence of subclinical endometritis (SCE), an inflammation of the uterus that has a negative effect on dairy cattle fertility. However, in this breed the negative effect is only moderate, raising the question of whether this may be due to a favorable microbiota. In the present study we investigated the endometrial microbiota in NR at AI by biopsy and cytobrush samples, and comparing this to the vaginal microflora. The second objective was to describe potential differences at both distinct depths of the endometrium, in healthy vs SCE positive NR cows. We sampled 24 lactating and clinically healthy Norwegian red cows in their second heat or more after calving, presented for first AI. First, we obtained a vaginal swab and a cytobrush sample, in addition to a cytotape to investigate the animal's uterine health status with respect to SCE. Secondly, we acquired a biopsy sample from the uterine endometrium. Bacterial DNA from the 16S rRNA gene was extracted and sequenced with Illumina sequencing of the V3-V4 region. Alpha and beta diversity and taxonomic composition was investigated. Our results showed that the microbiota of endometrial biopsies was qualitatively different and more even than that of cytobrush and vaginal swab samples. The cytobrush samples and the vaginal swabs shared a similar taxonomic composition, suggesting that vaginal swabs may suffice to sample the surface-layer uterine microbiota at estrus. The current study gave a description of the microbiota in the healthy and SCE positive NR cows at AI. Our results are valuable as we continue to explore the mechanisms for high fertility in NR, and possible further improvements.

Establishment and verification of hysteroscopic scoring system for chronic endometritis in infertile patients. / ä¸å­•æ‚£è€ æ ¢æ€§å­å®«å† è†œç‚Žå®«è ”é•œè¯„åˆ†ç³»ç»Ÿçš„æž„å»ºåŠéªŒè¯.

OBJECTIVES: To establish and verify a hysteroscopic scoring system for the diagnosis of chronic endometritis (CE) in infertile patients. METHODS: A total of 238 infertile patients who underwent hysteroscopy and endometrial biopsy in the Reproductive Medicine Center, Shijiazhuang Obstetrics and Gynecology Hospital Affiliated to Hebei Medical University from October 1 to December 31, 2019 were enrolled in the study. According to the results of CD138 immunohistochemistry, the patients were divided into CE group (n=73) and non-CE group (n=165). Univariate and binary logistic regression analyses were used to screen the risk factors of CE and a nomogram was establish for hysteroscopic scoring. Receiver operating characteristic (ROC) curve, calibration curve and Bootstrap resampling method were used to evaluate and verify the system. RESULTS: Univariate and binary logistic regression analyses showed that hyperemia area (HA) degree ≥2, micropolyps, polypoid hyperplasia of endometrium and history of ectopic pregnancy were independent risk factors for CE (all P<0.05). A nomogram was generated to establish a hysteroscopy scoring system based on the above four factors. The area under ROC curve of the hysteroscopy scoring system for predicting CE was 0.801 (95%CI:0.742-0.861), the sensitivity was 74.0% and the specificity was 73.9%. The calibration curve showed that the predicting value of the scoring system was highly consistent with the actual value. In the internal verification, the C-index was 0.7811. The predicting value of the verification group in the calibration curve was basically consistent with the actual value, indicating that the scoring system had good stability. CONCLUSIONS: The hysteroscopic scoring system composed of HA, micropolyp, polypoid hyperplasia of endometrium and history of ectopic pregnancy can effectively and intuitively predict CE, which is conducive to improving the diagnosis of CE.

Deoxycholic acid inhibits Staphylococcus aureus-induced endometritis through regulating TGR5/PKA/NF-κB signaling pathway.

Endometritis, a common gynecological disease, is the most common cause of infertility. As a natural metabolite of gut microbiota, deoxycholic acid (DCA) has been reported to have anti-inflammatory function. In the current study, the protective role of DCA on Staphylococcus aureus (S.aureus)-induced endometritis was tested. In vivo, DCA inhibited uterine histological change, MPO activity, endometrial barrier disruption, and inflammatory cytokine production induced by S.aureus. In vitro, DCA suppressed S.aureus-induced TNF-α and IL-1ß production in mouse endometrial epithelial cells (mEECs). Also, DCA markedly suppressed S.aureus-induced NF-κB activation. Takeda G protein-coupled receptor 5 (TGR5)is a critical bile acid membranereceptor that mainly regulated the cyclic AMP (cAMP)/protein kinase A (PKA)signaling pathway to inhibit NF-κB activation. We found DCA significantly increased TGR5 and PKA expression and S.aureus-induced inflammatory cytokine production and NF-κB activation were prevented by TGR5 inhibitor and PKA inhibitor. In conclusion, DCA protected S.aureus-induced endometritis by regulating TGR5/PKA/NF-κB signaling pathway.

The Impact of Chronic Endometritis on Infertility: Prevalence, Reproductive Outcomes, and the Role of Hysteroscopy as a Screening Tool.

OBJECTIVES: The objective of this study was to examine the prevalence of chronic endometritis (CE) in infertile women, its impact on reproductive outcomes, and the accuracy of hysteroscopy as a screening tool for CE. DESIGN: This was a prospective observational study. PARTICIPANTS: Participants involved in this study were 514 asymptomatic patients with infertility. SETTING: The review was conducted in a tertiary care center. METHODS: The participants underwent a hysteroscopy and endometrial biopsy (EMB). Antibiotics were given for cases of CE. We investigated the prevalence of CE in patients starting assisted reproductive technologies (ART) as a primary outcome. Secondary outcomes were the clinical pregnancy rate (CPR) in the ART cycle after hysteroscopy, EMB, and antibiotic treatment in cases of CE; the cumulative CPR in the subsequent 2 years after hysteroscopy and EMB; the sensitivity and specificity of hysteroscopy as a screening tool compared to EMB as the "gold standard" for diagnosing CE. RESULTS: CE was identified in 2.8% of patients starting ART (11/393). CPRs did not differ significantly between patients with CE and the entire cohort of patients without CE in the subsequent ART cycle (OR: 0.43; 95% CI: 0.09-2.02) or in the 2 years after EMB (OR: 0.56; 95% CI: 0.16-1.97). In a matched control comparison (with matching for age, basal FSH, and cause of infertility), CPR in patients with CE did not differ in the subsequent ART cycle (OR: 0.39; 95% CI: 0.09-1.61); however, their CPR in the 2 years after EMB was significantly lower (OR: 0.22; 95% CI: 0.13-0.38). The sensitivity and specificity of hysteroscopy as a screening tool for diagnosing CE were 8.3% and 90.1%, respectively. LIMITATIONS: Due to our cohort's low CE prevalence, we could not detect significant differences in CPRs. CONCLUSION: CE is rare in our studied population of asymptomatic patients starting ART. Hysteroscopy cannot replace EMB for diagnosing CE.

The Role of NF-κB in Endometrial Diseases in Humans and Animals: A Review.

The expression of genes of various proinflammatory chemokines and cytokines is controlled, among others, by the signaling pathway of the nuclear factor kappaB (NF-κB) superfamily of proteins, providing an impact on immune system functioning. The present review addresses the influence and role of the NF-κB pathway in the development and progression of most vital endometrial diseases in human and animal species. Immune modulation by NF-κB in endometritis, endometrosis, endometriosis, and carcinoma results in changes in cell migration, proliferation, and inflammation intensity in both the stroma and epithelium. In endometrial cells, the NF-κB signaling pathway may be activated by multiple stimuli, such as bacterial parts, cytokines, or hormones binding to specific receptors. The dysregulation of the immune system in response to NF-κB involves aberrant production of chemokines and cytokines, which plays a role in endometritis, endometriosis, endometrosis, and endometrial carcinoma. However, estrogen and progesterone influence on the reproductive tract always plays a major role in its regulation. Thus, sex hormones cannot be overlooked in endometrial disease physiopathology. While immune system dysregulation seems to be NF-κB-dependent, the hormone-independent and hormone-dependent regulation of NF-κB signaling in the endometrium should be considered in future studies. Future goals in this research should be a step up into clinical trials with compounds affecting NF-κB as treatment for endometrial diseases.

Results of in vitro fertilization after diagnosis and treatment of chronic endometritis.

OBJECTIVE: A significant cause of infertility is the inability of the embryo to implant. Endometritis is one of the major causes affecting embryo implantation. The present study addressed the diagnosis and effects of chronic endometritis (CE) treatment on pregnancy rates after in vitro fertilization (IVF). PATIENTS AND METHODS: We conducted this retrospective study on 578 infertile couples treated with IVF. In 446 couples, we performed a control hysteroscopy with biopsy before IVF. In addition, we examined the visual aspects of the hysteroscopy and the results of the endometrial biopsies, followed by antibiotic therapy if necessary. Finally, the results of IVF were compared. RESULTS: Of the 446 cases studied, we diagnosed 192 (43%) with chronic endometritis, either by direct observation or based on the histopathological result. In addition, the cases diagnosed with CE we treated with a combination of antibiotics. The group diagnosed at CE and subsequently treated with antibiotic therapy had a significantly higher pregnancy rate after IVF (43.2%) than the group without treatment (27.3%). CONCLUSIONS: Hysteroscopic examination of the uterine cavity was particularly important for the success of IVF. The initial CE diagnosis and treatment were an advantage for the cases in which we performed the IVF procedures.

Commonalities and Disparities between Endometriosis and Chronic Endometritis: Therapeutic Potential of Novel Antibiotic Treatment Strategy against Ectopic Endometrium.

Chronic endometritis (CE) is a local mucosal inflammatory disorder of the uterine lining, which is histopathologically recognized as the unusual infiltration of CD138(+) plasmacytes into the endometrial stromal compartment. Accumulating body of research documented that CE is associated with female infertility and several obstetric/neonatal complications. The major cause of CE is thought to be intrauterine infection represented by common bacteria (Escherichia coli, Enterococcus faecalis, Streptococcus, and Staphylococcus), Mycoplasma/Ureaplasma, and Mycobacterium. Additionally, local dysbiosis in the female reproductive tract may be involved in the onset and development of CE. Antibiotic treatments against these microorganisms are effective in the elimination of endometrial stromal plasmacytes in the affected patients. Meanwhile, endometriosis is a common female reproductive tract disease characterized by endometriotic tissues (ectopic endometrium) growing outside the uterus and potentially causes chronic pelvic symptoms (dysmenorrhea, dyspareunia, dyschezia, and dysuria), infertility, and ovarian cancers. Endometriosis involves endocrinological, genetic, and epigenetic factors in its etiology and pathogenesis. Recent studies focus on immunological, inflammatory, and infectious aspects of endometriosis and demonstrate several common characteristics between endometriosis and CE. This review aimed to better understand the immunological and microbial backgrounds underlying endometriosis and CE and look into the therapeutic potential of the novel antibiotic treatment strategy against endometriosis in light of endometrial infectious disease.