Interceed combined with bone marrow mesenchymal stem cells improves endometrial receptivity of intrauterine adhesion

Background

This study aimed to investigate the impact of intrauterine adhesions (IUA) therapy and endometrial receptivity by implanting autologous bone marrow mesenchymal stem cells (BMSCs) into the Interceed and subsequently placing them in the uterine cavity of rats.

Methods

Fifty rats were divided into 5 groups according to the random number table method (10 rats in each group). Following the development of the IUA model through mechanical injury, the animals were categorized into different treatment groups: the IUA model (intrauterine perfusion of saline), Interceed therapy (intrauterine placement of Interceed), BMSCs therapy (intrauterine perfusion of BMSCs), BMSCs + Interceed therapy (intrauterine placement of BMSCs + Interceed), and a control group (intrauterine perfusion of saline). The Hematoxylin-eosin (HE) staining technique was employed to identify and assess the pathological alterations in the endometrium. Additionally, it facilitated the quantification of endometrial glands and the determination of endometrial thickness. Masson staining was used to detect fibrosis in rat uterus. The number of microvascular density (MVD) was detected by immunohistochemistry (IHC). Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot were used to detect the levels of leukemia inhibitory factor (LIF), integrin ανβ3, and vascular endothelial growth factor (VEGF) in uterine tissue. Male and female rats were combined in cages for reproductive and conception evaluation.

Results

In comparison to the control, the number of endometrial glands in the IUA model was significantly reduced, and the degree of endometrial thinning and fibrosis was significantly increased (p < 0.05). Compared with the IUA model, the number of endometrial glands did not exhibit any significant alterations in endometrial thickness and MVD number. The expressions of LIF, integrin ανβ3, and VEGF in the uterine tissue were not significantly improved with Interceed therapy, resulting in no significant improvement in the pregnancy rate (p > 0.05). The number of endometrial glands, endometrial thickness, and MVD in the BMSCs therapy group were significantly increased. Moreover, the expressions of LIF, integrin ανβ3, and VEGF in uterine tissue exhibited a significant increase, leading to a comparatively higher pregnancy rate (p < 0.05). In the BMSCs + Interceed therapy group, the number of endometrial glands, endometrial thickness, and MVD were significantly increased, and the expressions of LIF, integrin ανβ3, and VEGF in uterine tissue were significantly increased as well, along with a corresponding rise in the pregnancy rate (p < 0.05).

Conclusion

The intrauterine placement of Interceed combined with BMSCs in IUA rats can thicken the damaged endometrium, increase the number of glands, promote endometrial angiogenesis, improve endometrial receptivity, and increase the rate of pregnancy in IUA rats.

Transplantation of human umbilical cord blood mononuclear cells promotes functional endometrium reconstruction via downregulating EMT in damaged endometrium

Introduction

Cell transplantation is an emerging and effective therapeutic approach for enhancing uterine adhesions caused by endometrial damage. Currently, human umbilical cord blood mononuclear cells (HUCBMCs) have been extensively for tissue and organ regeneration. However, their application in endometrial repair remains unexplored. Our investigation focuses on the utilization of HUCBMCs for treating endometrial injury.

Methods

The HUCBMCs were isolated from health umbilical cord blood, and co-cultured with the injured endometrial stromal cells and injured endometrial organoids. The cell proliferation and apoptosis were measured by cck8 assays and flow cytometry. Western blotting was used to detect the expression of PTEN, AKT and p-AKT. Immunofluorescence assay revealed expression levels of epithelial-mesenchymal transition (EMT) -related markers such as E-cadherin, N-cadherin, and TGF-β1. The endometrial thickness, fibrosis level, and glandular number were examined after the intravenous injection of HUCBMCs in mouse endometrial models. Immunohistochemistry was employed to assess changes in growth factors vascular endothelial growth factor (VEGF) and insulin-like growth factor 1 (IGF-1) as well as fibrosis markers α-SMA and COL1A1. Additionally, expressions of EMT-related proteins E-cadherin and N-cadherin were evaluated.

Results

HUCBMCs significantly improved the proliferation and reduced the apoptosis of damaged endometrial stromal cells (ESCs), accompanied by up-regulation of phospho-AKT expression. HUCBMCs increased endometrial thickness and glandular count while decreasing fibrosis and EMT-related markers in mouse endometrial models. Furthermore, EMT-related markers of ESCs and endometrial organoids were significantly decreased.

Conclusions

Our findings suggest that HUCBMCs plays a pivotal role in mitigating endometrial injury through the attenuation of fibrosis. HUCBMCs may exert a reverse effect on the EMT process during the endometrium reconstruction.

Locationally activated PRP via an injectable dual-network hydrogel for endometrial regeneration

Enhancing the effectiveness of platelet-rich plasma (PRP) for endometrial regeneration is challenging, due to its limited mechanical properties and burst release of growth factors. Here, we proposed an injectable interpenetrating dual-network hydrogel that can locationally activate PRP within the uterine cavity, sustained release growth factors and further address the insufficient therapeutic efficacy. Locational activation of PRP is achieved using the dual-network hydrogel. The phenylboronic acid (PBA) modified methacrylated hyaluronic acid (HAMA) dispersion chelates Ca2+ by carboxy groups and polyphenol groups, and in situ crosslinked with PRP-loaded polyvinyl alcohol (PVA) dispersion by dynamic borate ester bonds thus establishing the soft hydrogel. Subsequently, in situ photo-crosslinking technology is employed to enhance the mechanical performance of hydrogels by initiating free radical polymerization of carbon-carbon double bonds to form a dense network. The PRP-hydrogel significantly promoted the endometrial cell proliferation, exhibited strong pro-angiogenic effects, and down-regulated the expression of collagen deposition genes by inhibiting the TGF-β1-SMAD2/3 pathway in vitro. In vivo experiments using a rat intrauterine adhesion (IUA) model showed that the PRP-hydrogel significantly promoted endometrial regeneration and restored uterine functionality. Furthermore, rats treated with the PRP-hydrogel displayed an increase in the number of embryos, litter size, and birth rate, which was similar to normal rats. Overall, this injectable interpenetrating dual-network hydrogel, capable of locational activation of PRP, suggests a new therapeutic approach for endometrial repair.

Intrauterine interventions options for preventing recurrence after hysteroscopic adhesiolysis: a systematic review and network meta-analysis of randomized controlled trials

PURPOSE

Recurrence of adhesions after hysteroscopic adhesiolysis is a challenging clinical problem without a unified management approach. Therefore, we conducted a network meta-analysis that considered both direct and indirect comparisons between interventions to identify optimal strategies for preventing recurrence.

METHODS

We searched for research trials published up to July 2023 from PubMed, Embase and the Cochrane Database. We selected randomized controlled trials comparing the use of different interventions for the prevention of adhesion recurrence, with no language or regional restrictions. We used random-effects models to assess odds ratios (OR) and mean difference (MD) with 95% confidence intervals (CI). Adverse events associated with the interventions were also assessed. This study was registered on PROSPERO, CRD42023449068.

RESULTS

Data from 21 randomized controlled trials involving 2406 patients were synthesized, including interventions with balloon, amnion, platelet-rich plasma (PRP), intrauterine device (IUD), hyaluronic acid (HA), platelet-rich fibrin (PRF), and granulocyte colony-stimulating factor (G-CSF). The top 5 interventions for change in AFS scores were: PRP + Balloon (MD = 5.44; 95% CI, 2.63-8.25), Amnion + Balloon (MD = 5.08; 95% CI, 2.71-7.44), IUD + Balloon (MD = 4.89; 95% CI, 2.49-7.30), HA + Balloon (MD = 3.80; 95% CI, 1.78-5.82), and G-CSF + Balloon (MD = 3.84; 95% CI, 1.05-6.63). There were no statistically significant differences between interventions in the recurrence rate of moderate-to-severe uterine adhesions and the clinical pregnancy rate. Most interventions were safe.

CONCLUSIONS

To our knowledge, this is the most comprehensive network meta-analysis to date of interventions for preventing postoperative intrauterine adhesion recurrence. Our results indicate that PRP + Balloon seems to be the most effective approach.

Comparing the efficacy and pregnancy outcome of intrauterine balloon and intrauterine contraceptive device in the prevention of adhesion reformation after hysteroscopic adhesiolysis in infertile women: a prospective, randomized, controlled trial study

STUDY OBJECTIVE

To evaluate the efficacy and pregnancy outcomes of intrauterine balloon and intrauterine contraceptive devices in the prevention of adhesion reformation following hysteroscopic adhesiolysis in infertile women with moderate to severe intrauterine adhesion.

DESIGN

A prospective, randomized, controlled trial study.

SETTING

A tertiary university hospital.

PATIENTS

A total of 130 patients with moderate (American Fertility Society [AFS] score of 5-8) and severe (AFS score of 9-12) intrauterine adhesions were recruited.

INTERVENTIONS

86 patients were evenly allocated to group treated with an IUD for 1 month and group treated with an IUD for 2 months. 44 patients were allocated to group treated with a Foley catheter balloon.(IUD: Yuangong IUD).

MEASUREMENTS AND MAIN RESULTS

The primary outcome measures were the AFS score, endometrial thickness, and pregnancy outcome. After hysteroscopy, the AFS score was significantly decreased(P<0.05), whereas endometrial thickness was significantly increased across the three groups(P<0.001). Notably, the decline in the AFS score in the balloon group was greater than that in the IUD-1-month group and IUD-2-month group(P<0.01), with no significant difference between the IUD groups(P = 0.298). Lastly, In addition, the extent of the increase in endometrial thickness(P = 0.502) and the pregnancy outcomes(P = 0.803) in the three groups were not significantly different.

CONCLUSION

Inserting a balloon or placing an IUD for one or two months can effectively lower the risk of adhesion recurrence and restore the shape of the uterine cavity. While the therapeutic effect of the balloon was superior to that of the IUD, no significant differences were observed in the one-month and two-month IUD groups.

TRIAL REGISTRATION

This research was registered in the Chinese Clinical Trial Registry ( http://www.chictr.org.cn/enIndex.aspx ); Clinical trial registry identification number: ChiCTR-IOR-17,011,943 ( http://www.chictr.org.cn/showprojen.aspx?proj=17979 ). Date of trial registration: July 11, 2017.

Intrauterine infusion of platelet-rich plasma improves fibrosis by transforming growth factor beta 1/Smad pathway in a rat intrauterine adhesion model

This study aims to elucidate the effects of Platelet-rich plasma (PRP) in fibrosis development in intrauterine adhesion (IUA), and the associated underlying mechanisms are also explored, which are expected to be a potential therapeutic scheme for IUA. In this research, PRP was obtained and prepared from the peripheral venous blood of rats. A rat model was induced by mechanical injury. Further, PRP was directly injected into the uterus for treatment. The appearance and shape of the uterus were assessed based on the tissues harvested. The fibrosis biomarker levels were analyzed. The transforming growth factor beta 1 (TGF-β1) and Mothers against decapentaplegic homolog 7 (Smad7) levels, the phosphorylation of Smad2 (p-Smad2), and the phosphorylation of Smad3 (p-Smad3) were analyzed, and the molecular mechanism was investigated by rescue experiments. It was found that PRP improved the appearance and shape of the uterus in IUA and increased endometrial thickness and gland numbers. The administration of PRP resulted in a decrease in the expressions of fibrosis markers including collagen I, α-SMA, and fibronectin. Furthermore, PRP increased Smad7 levels and decreased TGF-β1 levels, p-Smad2, and p-Smad3. Meanwhile, administration of TGF-β1 activator reversed the therapeutic effects of PRP in IUA. Collectively, the intrauterine infusion of PRP can promote endometrial damage recovery and improve endometrial fibrosis via the TGF-β1/Smad pathway. Hence, PRP can be a potential therapeutic strategy for IUA.

in the treatment of intrauterine adhesions based on network pharmacology, molecular docking and experimental validation

BACKGROUND

Smilax china L. (SCL) is a traditional herbal medicine for the potential treatment of intrauterine adhesion (IUA). However, the mechanisms of action have not yet been determined. In this study, we explored the effects and mechanisms of SCL in IUA by network pharmacology, molecular docking and molecular biology experiments.

METHODS

Active ingredients and targets of SCL were acquired from TCMSP and SwissTargetPrediction. IUA-related targets were collected from the GeneCards, DisGeNET, OMIM and TTD databases. A protein‒protein interaction (PPI) network was constructed by Cytoscape 3.9.1 and analysed with CytoHubba and CytoNCA to identify the core targets. The DAVID tool was used for GO and KEGG enrichment analyses. Furthermore, molecular docking was employed to assess the interaction between the compounds and key targets. Finally, the mechanisms and targets of SCL in IUA were verified by cellular experiments and western blot.

RESULTS

A total of 196 targets of SCL were identified, among which 93 were related to IUA. Topological and KEGG analyses results identified 15 core targets that were involved in multiple pathways, such as inflammation, apoptosis, and PI3K/AKT signalling pathways. Molecular docking results showed that the active compounds had good binding to the core targets. In vitro experiments showed that astilbin (AST), a major component of SCL, significantly reduced TGF-β-induced overexpression of fibronectin (FN), activation of the PI3K/AKT signalling pathway and the expression of downstream factors (NF-κB and BCL2) in human endometrial stromal cells, suggesting that AST ameliorates IUA by mediating the PI3K/AKT/NF-κB and BCL2 proteins.

CONCLUSIONS

AST, a major component of SCL, may be a potential therapeutic agent for IUA. Moreover, its mechanism is strongly associated with regulation of the PI3K/AKT signalling pathway and the downstream NF-κB and BCL2 proteins. This study will provide new strategies that utilize AST for the treatment of IUA.

Glutaminolysis regulates endometrial fibrosis in intrauterine adhesion via modulating mitochondrial function

BACKGROUND

Endometrial fibrosis, a significant characteristic of intrauterine adhesion (IUA), is caused by the excessive differentiation and activation of endometrial stromal cells (ESCs). Glutaminolysis is the metabolic process of glutamine (Gln), which has been implicated in multiple types of organ fibrosis. So far, little is known about whether glutaminolysis plays a role in endometrial fibrosis.

METHODS

The activation model of ESCs was constructed by TGF-β1, followed by RNA-sequencing analysis. Changes in glutaminase1 (GLS1) expression at RNA and protein levels in activated ESCs were verified experimentally. Human IUA samples were collected to verify GLS1 expression in endometrial fibrosis. GLS1 inhibitor and glutamine deprivation were applied to ESCs models to investigate the biological functions and mechanisms of glutaminolysis in ESCs activation. The IUA mice model was established to explore the effect of glutaminolysis inhibition on endometrial fibrosis.

RESULTS

We found that GLS1 expression was significantly increased in activated ESCs models and fibrotic endometrium. Glutaminolysis inhibition by GLS1 inhibitor bis-2-(5-phenylacetamido-1,2,4-thiadiazol-2-yl) ethyl sulfide (BPTES or glutamine deprivation treatment suppressed the expression of two fibrotic markers, α-SMA and collagen I, as well as the mitochondrial function and mTORC1 signaling in ESCs. Furthermore, inhibition of the mTORC1 signaling pathway by rapamycin suppressed ESCs activation. In IUA mice models, BPTES treatment significantly ameliorated endometrial fibrosis and improved pregnancy outcomes.

CONCLUSION

Glutaminolysis and glutaminolysis-associated mTOR signaling play a role in the activation of ESCs and the pathogenesis of endometrial fibrosis through regulating mitochondrial function. Glutaminolysis inhibition suppresses the activation of ESCs, which might be a novel therapeutic strategy for IUA.

Analysis of factors affecting the prognosis of patients with intrauterine adhesions after transcervical resection of adhesions

OBJECTIVES

To study the factors affecting the prognosis of patients with intrauterine adhesions (IUAs) after transcervical resection of adhesions (TCRA), analyze the reproductive outcome, and guide prognostic improvements.

DESIGN

Prospective study.

PATIENTS

Our study included 292 patients diagnosed with IUAs who underwent follow-up office hysteroscopy at Shenyang Women's and Children's Hospital between June 2018 and June 2022.

INTERVENTIONS

Patients were divided into case (52 patients whose hysteroscopy results indicated the presence of IUAs) and nocase (240 patients whose uterine cavity had returned to normal shape without obvious adhesion) groups on the basis of the results of a 2-month follow-up hysteroscopy following TCRA. Clinical data were collected and compared with various influencing factors, and the combined effect of these factors was assessed using multifactorial logistic regression analysis. A nomogram prediction model was constructed and internally validated on the basis of multifactorial analysis.

MAIN OUTCOME MEASURES

Intrauterine re-adhesion was observed at a 2-month follow-up after TCRA.

RESULTS

Postoperative re-adhesion occurred in 52 of 292 patients with IUAs. Multifactorial binary logistic regression analysis showed that IUA barrier gel reapplication 5 days after TCRA was a protective factor. In contrast, the preoperative American Fertility Society scores demonstrated that severe IUAs and chronic endometritis were risk factors. The results of the multifactorial analysis were used to build a nomogram model, and the area under the curve value of the nomogram model for predicting postoperative recurrence was 0.914 (95% confidence interval: 0.864-0.956). The bootstrap method was subsequently used to resample 1,000 times for internal validation. The results showed that the internal validation C-index was 0.9135, and the calibration and ideal curves were well-matched.

CONCLUSION

The prognosis of patients with IUAs after TCRA is related to the severity of preoperative IUAs, presence of chronic endometritis, and IUA barrier gel reapplication 5 days after TCRA. Therefore, clinicians should monitor patients using targeted data to reduce recurrence risk after TCRA and improve the prognosis of patients with IUAs.

Combination Therapy of Bone Marrow Mesenchymal Stem Cell Transplantation and Electroacupuncture for the Repair of Intrauterine Adhesions in Rats: Mechanisms and Functional Recovery

Transplantation of bone marrow mesenchymal stem cells (BMSCs) has demonstrated promising clinical utility in the treatment of endometrial injury and the restoration of fertility. However, since the efficacy of BMSCs after transplantation is not stable, it is very important to find effective ways to enhance the utilisation of BMSCs. Electroacupuncture (EA) has some positive effects on the chemotaxis of stem cells and diseases related to uterine injury. In this study, we established the intrauterine adhesion (IUA) model of the Sprague-Dawley rat using lipopolysaccharide infection and mechanical scratching. Phosphate-buffered saline, BMSCs alone, and BMSCs combined with EA were randomly administered to the rats. Fluorescent cell labelling showed the migration of transplanted BMSCs. H&E staining, Masson staining, Western blot, immunohistochemistry, ELISA, and qRT-PCR were utilised to detect changes in endometrial morphology and expressions of endometrial receptivity-related factors, endometrial pro-inflammatory factors, and fibrosis factors. Finally, we conducted a fertility test to measure the recovery of uterine function. The results showed that EA promoted transplanted BMSCs to migrate into the injured uterus by activating the SDF-1/CXCR4 axis. Endometrial morphology showed the most significant improvement in the BMSC + EA group. The expressions of endometrial pro-inflammatory factors and fibrosis indexes in the BMSC + EA group were lower than those in the model and BMSC groups. Further studies revealed that the expression of endometrial receptivity-related factors and the number of embryos implanted on day 8 of gestation increased in the BMSC + EA group compared with the model group and the BMSC group.

Establishment and comparison of different procedures for modeling intrauterine adhesion in rats: A preliminary study

The establishment of a stable animal model for intrauterine adhesion (IUA) can significantly enhance research on the pathogenesis and pathological changes of this disease, as well as on the development of innovative therapeutic approaches. In this study, three different modeling methods, including phenol mucilage combined mechanical scraping, ethanol combined mechanical scraping and ethanol modeling alone were designed. The morphological characteristics of the models were evaluated. The underlying mechanisms and fertility capacity of the ethanol modeling group were analyzed and compared to those of the sham surgery group. All three methods resulted in severe intrauterine adhesions, with ethanol being identified as a reliable modeling agent and was subsequently subjected to further evaluation. Immunohistochemistry and RT-PCR results indicated that the ethanol modeling group exhibited an increase in the degree of fibrosis and inflammation, as well as a significant reduction in endometrial thickness, gland number, vascularization, and endometrial receptivity, ultimately resulting in the loss of fertility capacity. The aforementioned findings indicate that the intrauterine perfusion of 95 % ethanol is efficacious in inducing the development of intrauterine adhesions in rats. Given its cost-effectiveness, efficacy, and stability in IUA formation, the use of 95 % ethanol intrauterine perfusion may serve as a novel platform for evaluating innovative anti-adhesion materials and bioengineered therapies.

Long noncoding RNAs regulate intrauterine adhesion and cervical cancer development and progression

Intrauterine adhesion, one of reproductive system diseases in females, is developed due to endometrial injury, such as infection, trauma, uterine congenital abnormalities and uterine curettage. Intrauterine adhesion affects female infertility and causes several complications, including amenorrhoea, hypomenorrhoea, and recurrent abortion. Cervical cancer is one of the common gynecological tumors and the fourth leading cancer-related death in women worldwide. Although the treatments of cervical cancer have been improved, the advanced cervical cancer patients have a low survival rate due to tumor recurrence and metastasis. The molecular mechanisms of intrauterine adhesion and cervical tumorigenesis have not been fully elucidated. In recent years, long noncoding RNAs (lncRNAs) have been known to participate in intrauterine adhesion and cervical carcinogenesis. Therefore, in this review, we will summarize the role of lncRNAs in regulation of intrauterine adhesion development and progression. Moreover, we will discuss the several lncRNAs in control of cervical oncogenesis and progression. Furthermore, we highlight that targeting lncRNAs could be used for treatment of intrauterine adhesion and cervical cancer.

Intrauterine adhesion in ultrasound-guided manual vacuum aspiration (USG-MVA) versus electric vacuum aspiration (EVA): a randomised controlled trial

BACKGROUND

Intrauterine adhesion (IUA) can arise as a potential complication following uterine surgery, as the surgical procedure may damage the endometrial stratum basalis. The objective of this study was to assess and compare the occurrence of IUA in women who underwent ultrasound-guided manual vacuum aspiration (USG-MVA) versus electric vacuum aspiration (EVA) for managing first-trimester miscarriage.

METHODS

This was a prospective, single-centre, randomised controlled trial conducted at a university-affiliated tertiary hospital. Chinese women aged 18 years and above who had a delayed or incomplete miscarriage of ≤ 12 weeks of gestation were recruited in the Department of Obstetrics and Gynaecology at the Prince of Wales. Recruited participants received either USG-MVA or EVA for the management of their miscarriage and were invited for a hysteroscopic assessment to evaluate the incidence of IUA between 6 and 20 weeks after the surgery. Patients were contacted by phone at 6 months to assess their menstrual and reproductive outcomes.

RESULTS

303 patients underwent USG-MVA or EVA, of whom 152 were randomised to 'USG-MVA' and 151 patients to the 'EVA' group. Out of the USG-MVA group, 126 patients returned and completed the hysteroscopic assessment, while in the EVA group, 125 patients did the same. The incidence of intrauterine adhesion (IUA) was 19.0% (24/126) in the USG-MVA group and 32.0% (40/125) in the EVA group, showing a significant difference (p < 0.02) between the two groups. No significant difference in the menstrual outcomes at 6 months postoperatively between the two groups but more patients had miscarriages in the EVA group with IUA.

CONCLUSIONS

IUAs are a possible complication of USG-MVA. However, USG-MVA is associated with a lower incidence of IUA postoperatively at 6-20 weeks. USG-MVA is a feasible, effective, and safe alternative surgical treatment with less IUA for the management of first-trimester miscarriage.

TRIAL REGISTRATION

The study was registered with the Centre for Clinical Research and Biostatics- Clinical Trials Registry (CCRBCTR), which is a partner registry of the WHO Primary Registry-Chinese Clinical Trials Registry (ChiCTR) (Unique Trial Number: ChiCTR1900023198 with the first trial registration date on 16/05/2019).

Incidence of intrauterine adhesion after ultrasound-guided manual vacuum aspiration (USG-MVA) for first-trimester miscarriages: a prospective cohort study

PURPOSE

Ultrasound-guided manual vacuum aspiration (USG-MVA) is a feasible and effective outpatient treatment to treat early pregnancy loss.

METHODS

This was a prospective observational study at a university-affiliated hospital. All women undergoing either a USG-MVA or electric vacuum aspiration (EVA) were invited to return 3-6 months later for follow-up at which women completed a questionnaire to document their post-evacuation menstrual and reproductive history, and underwent a hysteroscopy if they were not pregnant. The severity of intrauterine adhesion (IUA), if present, was graded (Stage I-III) according to the American fertility society classification.

RESULTS

A total of 292 women had a hysteroscopy after their initial surgical evacuation, USG-MVA 169(57.9%) versus EVA 123(42.1%). Women undergoing EVA as opposed to a USG-MVA had a 12.9% higher incidence of IUA (24.1% vs. 37.0%, p = 0.042) equivalent to 1.84 times higher risk (95% CI 1.01-3.34; p = 0.048). Women having EVA continued to show an increased but not statistically significant trend towards an increased risk of IUA after adjusting for the type of miscarriage (aOR = 1.3; 95% CI 0.66-2.50; p = 0.46).

CONCLUSION

There were no significant differences in their reproductive outcomes and fewer women post-USG-MVA complained of hypomenorrhea. IUA may still occur in women undergoing USG-MVA but it is lower than the rate in women undergoing EVA. Clinical trials registry The trial was registered with the Centre for Clinical Research and Biostatistics - Clinical Trials Registry (CCRBCTR), a partner registry of the WHO Primary Registry-Chinese Clinical Trials Registry (ChiCTR) with a Unique Trial Number: CUHK_CCRB00541 on 22 Dec 2016.

Comparison of clinical outcomes and second-look hysteroscopy of the complete and incomplete septate uterus after hysteroscopic septoplasty

PURPOSE

Septate uterus is the most common congenital uterine malformation. This retrospective cohort study compared clinical outcomes and second-look hysteroscopy findings in patients with complete and incomplete septate uteri after septoplasty.

METHODS

We reviewed the medical records of patients with a septate uterus who underwent hysteroscopic septoplasty and second-look hysteroscopy at the West China Second University Hospital between September 2013 and September 2021. Information regarding pregnancy outcomes was collected through telephone interviews. The independent samples t-test, Mann-Whitney U test, Pearson's chi-square test, and Fisher's exact test were used to explore the differences between the complete and incomplete septate uterus groups.

RESULTS

A total of 64 patients were enrolled in this study. There was no significant difference in intrauterine adhesion (IUA) rates (16.7% and 32.1%), pregnancy rates (44.1% and 42.9%), term delivery rates (35.3% and 32.1%), premature delivery rates (2.9% and 0), placenta previa rates (2.9% and 3.6%), placenta implantation/adhesion rates (5.9% and 3.6%), and premature rupture of membranes rates (2.9% and 0) between the complete and the incomplete group after hysteroscopic septoplasty (P > 0.05). Endometrial polyps in the septate uterus were common, with an incidence of 33.3% and 25% in the complete and incomplete groups, respectively (P > 0.05).

CONCLUSION

The pregnancy outcomes of complete and incomplete septate uteri after hysteroscopic septoplasty were similar. There was no statistical difference in IUAs after surgery. Different treatment strategies may not be required for complete or incomplete septate uteri.

Synergistic effects of electroacupuncture and bone marrow mesenchymal stem cell transplantation on rat intrauterine adhesion： an observation

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.

Effects of treatment with stem cell-derived extracellular vesicles in preclinical rodent models of intrauterine adhesion: A meta-analysis

Background

Intrauterine adhesion (IUA) results from serious complications of intrauterine surgery or infection and mostly remains incurable. Small extracellular vesicles (sEVs) derived from mesenchymal stem cells (MSCs) have emerged as a potential new approach for the treatment of IUA; however, their impact is not fully understood. Here, we performed a meta-analysis summarizing the effects of sEVs on IUA in preclinical rodent models.

Methods

This meta-analysis included searches of PubMed, EMBASE, Cochrane, and the Web of Science databases from January 1, 1997, to April 1, 2022, to identify studies reporting the therapeutic effect of sEVs on rodent preclinical animal models of IUA. We compared improvements in endometrial thickness, endometrial gland number, fibrosis area, embryo number, vascular endothelial growth factor (VEGF), transforming growth factor β1 (TGFβ1), and leukemia inhibitory factor (LIF) levels after treatment.

Results

Our search included 100 citations, of which 7 met the inclusion criteria, representing 231 animals. Compared with that in the control group, the fibrosis area in the sEV-treated group was significantly reduced (standardized mean difference (SMD) = -6.87，95 % confidence interval (CI) = -9.67 to -4.07). The number of glands increased after the intervention (95 % CI, 3.72-7.68; P = 0.000). Endometrial thickness was significantly improved in the sEV-treated group (SMD = 2.57, 95 % CI, 1.62-3.52).

Conclusions

This meta-analysis is highlighting that sEV treatment can improve the area of endometrial fibrosis, as well as VEGF, and LIF level, in a mouse IUA model. This knowledge of these findings will provide new insights into future preclinical research.

Granulocyte-macrophage colony-stimulating factor promotes endometrial repair after injury by regulating macrophages in mice

Intrauterine adhesion (IUA) caused by endometrial injury is a common cause of female infertility and is challenging to treat. Macrophages play a critical role in tissue repair and cyclical endometrial regeneration. Granulocyte-macrophage colony-stimulating factor (GM-CSF) has significant reparative and anti-fibrotic effects in various tissues. However, there is limited research on the role of GM-CSF in the repair of endometrial injury and the involvement of macrophages in GM-CSF-mediated endometrial repair. In this study, using a mouse model of endometrial scratching injury, we found that GM-CSF treatment accelerated the repair of endometrial injury and improved fertility. At the molecular level, we observed that GM-CSF can downregulate the transcript levels of tumor necrosis factor (TNF) in mouse bone marrow-derived macrophages (BMDMs) stimulated by lipopolysaccharide (LPS) and upregulate the expression of Arginase-1 (Arg-1) and mannose receptor C-type 1 (MRC1). Importantly, during the early and middle stages of injury, GM-CSF increased the proportion of M1-like, M2-like, and M1/M2 mixed macrophages, while in the late stage of injury, GM-CSF facilitated a decline in the number of M2-like macrophages. These findings suggest that GM-CSF may promote endometrial repair by recruiting macrophages and modulating the LPS-induced M1-like macrophages into a less inflammatory phenotype. These insights have the potential to contribute to the development of novel therapeutic approaches for the treatment of intrauterine adhesion and related infertility.

Adjuvants to prevent reformation of adhesions following adhesiolysis for Asherman syndrome: a systematic review and meta-analysis

Two international guidelines published on the management of Asherman syndrome (AS) have made recommendations on various adjuvant methods to prevent intrauterine reformation. Nevertheless, the effectiveness of these methods when used in primary or secondary prevention settings is different. Our aim is to assess the effectiveness of various adjuvant methods for the secondary prevention of intrauterine adhesions (IUAs). Articles were considered eligible if they included subjects with AS before surgery and compared a chosen method with either a control or a comparison group (using another method). The primary outcome was the IUA reformation rate at follow-up hysteroscopy. A total of 29 studies [15 randomised controlled trials (RCTs) and 14 cohort studies] were included. Adhesion reformation with various methods to prevented IUA reformation when compared with controls were: second-look hysteroscopy: [risk ratio (RR): 0.21, 95% confidence interval (CI): 0.05-0.90 (p = 0.02)]; intrauterine contraceptive device: RR: 0.64, 95% CI: 0.36-1.12 (p = 0.12); continuous intrauterine balloon: RR: 0.18, 95% CI: 0.05-0.68 (p = 0.01); intermittent intrauterine balloon: RR: 0.50, 95% CI: 0.31-0.80 (p = 0.004); anti-adhesion gel: RR: 0.80, 95% CI: 0.58-1.10 (p = 0.17); amnion graft: RR: 0.63, 95% CI: 0.44-0.91 (p = 0.01).

Epigenetic alternations and targeted therapy in intrauterine adhesion: A comparative study

Although intrauterine adhesion (IUA) has been well recognized as a critical factor in infertility, little information is available regarding the molecular mechanisms. We performed a high-throughput RNA sequencing in the endometrium of three IUA patients and three normal controls. And another two gene expression profiles (PMID34968168 and GSE160365) were analyzed together. A total of 252 DEGs were identified. Cell cycle, E2F target, G2M checkpoint, integrin3 pathway and H1F1 signaling were aberrantly regulated in the IUA endometrium. 10 hub genes (CCL2, TFRC, THY1, IGF1, CTGF, SELL, SERPINE1, HBB, HBA1, LYZ) were exhibited in PPI analysis. FOXM1, IKBKB and MYC were three common transcription factors of DEGs. Five chemicals (MK-1775, PAC-1, TW-37, BIX-01294, 3-matida) were identified as putative therapeutic agents for IUA. Collectively, a series of DEGs associated with IUA were disclosed. Five chemicals and ten hub genes may be further explored as potential drugs and targets for IUA treatment.

Extracellular Vesicles Derived from Mesenchymal Stem Cells as Cell-Free Therapy for Intrauterine Adhesion

Intrauterine adhesion (IUA) can occur after trauma to the basal layer of the endometrium, contributing to severe complications in females, such as infertility and amenorrhea. To date, the proposed therapeutic strategies are targeted to relieve IUA, such as hysteroscopic adhesiolysis, Foley catheter balloon, and hyaluronic acid injection have been applied in the clinic. However, these approaches showed limited effects in alleviating endometrial fibrosis and thin endometrium. Mesenchymal stem cells (MSCs) can offer the potential for endometrium regeneration owing to reduce inflammation and release growth factors. On this basis, MSCs have been proposed as promising methods to treat intrauterine adhesion. However, due to the drawbacks of cell therapy, the possible therapeutic use of extracellular vesicles released by stem cells is raising increasing interest. The paracrine effect, mediated by MSCs derived extracellular vehicles (MSC-EVs), has recently been suggested as a mechanism for their therapeutic properties. Here, we summarizes the main pathological mechanisms involved in intrauterine adhesion, the biogenesis and characteristics of extracellular vesicles, explaining how these vesicles could provide new opportunities for MSCs.

[Observation on the effect of electroacupuncture on the regeneration of endometrium in rats with intrauterine adhesion]

OBJECTIVE

To observe the effect of electroacupuncture (EA) on the degree of endometrial fibrosis and inflammatory response in the rat model of intrauterine adhesion (IUA), so as to explore the possible mechanism of EA underlying improving IUA and promoting endometrium regeneration.

METHODS

Forty-five female SD rats were randomly divided into blank, model and EA groups, with 15 rats in each group. The IUA model was established by mechanical scratching combined with lipopolysaccharide infection. EA was applied to bilateral "Zigong" (EX-CA1) and "Sanyinjiao" (SP6), with acupuncture applied to "Guanyuan" (CV4) for rats in the EA group, started from the 2nd day after modeling, 15 minutes every time, once a day for 2 consecutive estrous cycles. Samples from 5 rats in each group were collected during estrus period. Changes of endometrial histopathology and number of glands were observed after HE staining. The area of endometrial fibrosis was observed and calculated after Masson staining. The positive expressions of collagen type I (Col-I) and transforming growth factor β1 (TGF-β1) proteins in endometrial tissue were detected by immunohistochemistry method. The protein expression of integrin αγβ3 in uterine tissue was detected by Western blot. The contents of interleukin (IL)-1β and tumor necrosis factor α (TNF-α) in uterine tissue were detected by ELISA. Samples from remaining 10 rats in each group were collected on the 8th day of gestation for calculation of the embryo implantation numbers of the rats.

RESULTS

HE staining showed complete uterine tissue structure of the rats in the blank group during estrus period, with clear endometrial layer, unobstructed and regular uterine cavity, and dense glands. Destroyed endometrial layer, narrowed and adhered uterine cavity, and sparse glands of the rats were seen in the model group, which was relatively milder in the EA group. Following modeling, the number of endometrial glands, the protein expression of Integrin αγβ3, the number of implanted uterine embryos on the injured side of the model group were significantly decreased (P<0.01), while the area of endometrial fibrosis, the positive expressions of Col-I and TGF-β1 proteins, and the contents of IL-1β and TNF-α in the uterine tissue were significantly increased (P<0.01) in comparison with those in the blank group. After intervention, the number of endometrial glands, the protein expression of Integrin αγβ3, the number of implanted uterine embryos on the injured side of the EA group were significantly increased (P<0.01，P<0.05), while the area of endometrial fibrosis, the positive expressions of Col-I and TGF-β1 proteins, and the contents of IL-1β and TNF-α in the uterine tissue were significantly decreased (P<0.01,P<0.05) compared with the model group.

CONCLUSION

EA can enhance endometrial receptivity, and promote endometrial regeneration, be conducive to embryo implantation in IUA model rats, which may be related to its effect in alleviating endometrial fibrosis and reducing inflammatory response.

Mesenchymal stem cell-derived exosomes ameliorate TGF-β1-induced endometrial fibrosis by altering their miRNA profile

OBJECTIVE

Mesenchymal stem cell (MSC)-derived exosomes (MSC-exo) can treat reproductive disorders. However, the action of microRNAs (miRNAs) in this mechanism has yet to be systematically investigated. This study aimed to explore the effect of MSC-exo on TGF-β1-induced endometrial fibrosis in intrauterine adhesions and elucidate the regulatory mechanisms involved in key genes by comparing miRNA expression profiles.

METHODS

MSC-exo were isolated and identified based on particle size and protein marker detection. Cell counting kit-8, flow cytometry, and western blotting were used to determine the effects of MSC-exo on cell function and fibrosis in human endometrial epithelial cells (hEECs). Subsequently, we sequenced and annotated the small RNA in MSC-exo and TGF-β1-induced MSC-exo to screen for differentially expressed (DE) miRNAs. After the prediction and functional enrichment of target genes of DE miRNAs, key genes were selected for functional experiments.

RESULTS

TGF-β1 inhibited the proliferation of hEECs and promoted apoptosis and fibrosis. However, these effects were significantly reversed by the addition of MSC and MSC-exo. Fifteen DE miRNAs were identified by comparing the miRNA profiles of MSC-exo and TGF-β1-induced MSC-exo. Among these, miR-145-5p was found to be significantly upregulated in TGF-β1-induced MSC-exo. Furthermore, the addition of miR-145-5p mimic was found to reverse fibrosis in hEECs while promoting the expression of key autophagy protein P62.

CONCLUSION

MSC-exo ameliorated TGF-β1-induced endometrial fibrosis. RNA sequencing, bioinformatic analysis, and functional experiments revealed that miR-145-5p may exert its action through the P62-dependent autophagy pathway.

Ellagic acid increases implantation rates with its antifibrotic effect in the rat model of intrauterine adhesion

Intrauterine adhesions (IUA) are defined as the adhesion of opposing endometrial tissue with dense fibrous adhesive bands within the uterine cavity. With the increase in cesarean sections and endometrial surgical procedures, intrauterine adhesions have become a problem with increasing incidence and decreasing implantation. The purpose of the study was to investigate the effect of ellagic acid (EA), a phenolic compound, on fibrosis in IUA model rats. Another goal of the study was to increase endometrial receptivity with EA. The groups in the study were planned as control, DMSO, EA, IUA, IUA+DMSO, and IUA+EA, with 8 Sprague Dawley rats in each group. EA was administered at a dose of 100 mg/kg/day for 35 days. At the end of the experiment, the uterine tissues of the rats were removed. Histochemical staining was used to validate the IUA model and determine the degree of fibrosis. The levels of some fibrosis-related genes and proteins in the obtained uterine tissues were evaluated. In addition, implantation rates were determined. In our findings, it was observed that the fibrotic structure was decreased in the treated IUA+EA group compared to the IUA group, while fibrotic improvement was supported by down-regulation of TGFβ1 activity and up-regulation of BMP7 activity. The increase in the expression of the endometrial marker LIF with EA treatment was consistent with the increase in implantation rates with treatment. As a result of the study, it can be said that EA applied as a treatment against IUA causes healing in uterine tissue by reducing fibrosis and increases implantation rates by increasing endometrial receptivity.

PDGFBB improved the biological function of menstrual blood-derived stromal cells and the anti-fibrotic properties of exosomes

BACKGROUND

Intrauterine adhesion (IUA) is a reproductive dysfunction disease characterized by endometrial fibrosis, with limited therapeutic options and poor prognosis. Our previous studies confirmed that menstrual blood-derived stromal cells (MenSCs) effectively attenuated endometrial fibrosis in an animal model of IUA mainly through exosomes. This therapeutic effect can be enhanced by platelet-rich plasma (PRP), in which PDGFBB is an abundant growth factor. Therefore, we aimed to compare the effects of PRP and PDGFBB on the biological activities of MenSCs in vitro, and to further investigate the molecular mechanism of MenSCs-derived exosomes in alleviating endometrial fibrosis.

METHODS

MenSCs were isolated for in vitro functional assays to examine the viability, migration, and stemness of MenSCs. Endometrial stromal cells (EndoSCs) were treated with 50 ug/ml of MenSCs-derived exosomes, obtained by differential ultracentrifugation extraction. The molecular mechanisms by which PDGFBB improves MenSCs and exosomes alleviate EndoSCs fibrosis were then explored using immunofluorescence, western blot, and co-immunoprecipitation.

RESULTS

Both 100 ng/ml PDGFBB and 10% activated PRP promoted the proliferation, increased the S phase of cell cycle, and inhibited apoptosis of MenSCs in vitro. Compared with PRP, PDGFBB significantly promoted MenSCs migration. All of these effects were inhibited by sorafenib, a PDGFR-β inhibitor. PRP and PDGFBB activated AKT/NF-κB signaling pathway in MenSCs and increased the expression of P65 and OCT4. Moreover, pretreatment of PDGFBB did not increase the secretion of MenSCs but significantly increased the anti-fibrosis effects of MenSCs-derived exosomes on IUA-EndoSCs. MenSCs-derived exosomes attenuated SMAD3 phosphorylation and increased YAP ubiquitination, which reduced the binding of YAP/SMAD3. Pretreatment with PDGFBB amplified this effect.

CONCLUSIONS

In summary, PDGFBB could improve the biological functions of MenSCs via AKT/NF-κB signaling pathway, including viability, migration, and stemness. Our results indicated that PDGFBB amplified MenSCs-derived exosomes to attenuate endometrial fibrosis by inhibiting YAP activity, revealing a novel mechanism by which PRP enhanced the ability of MenSCs to repair tissue injury and providing a potential option for improving stem cell efficacy in IUA.

Label-free proteomic analysis and functional analysis in patients with intrauterine adhesion

Intrauterine adhesion (IUA) is one of the principal causes of secondary infertility in women of reproductive age, which seriously affects female reproductive function and quality of life. In recent years, the incidence of IUA has been increasing year by year, but its pathological mechanism has not yet been clarified. This study intended to reveal the pathogenesis of IUA and find new therapeutic targets by analyzing the proteomic differences between intrauterine adhesion tissues and normal human endometrial tissues. In the label-free quantitative proteomics, we identified 789 up-regulated differentially expressed proteins (DEPs) and 539 down-regulated DEPs. These DEPs were further analyzed by Gene Ontology (GO) annotation and enrichment analysis, Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis to preliminarily clarify the biomarkers involved in the pathogenesis of the IUA. The DEPs were further verified by parallel reaction monitoring (PRM) to confirm the results of proteomics. Finally, 7 target proteins may be candidates for treatment and elucidating the pathophysiology of IUA. SIGNIFICANCE: IUA is a fertility complication, which has increasing incidence recently. Until now, only a little research paid attention to the proteomic changes of IUA. This is the first study focused on the comparative analysis of endometrial tissue between IUA patients and normal women. We found 7 key proteins that may become the potential biomarkers of IUA.

Improvement of vaginal probiotics Lactobacillus crispatus on intrauterine adhesion in mice model and in clinical practice

BACKGROUND

Intrauterine adhesion (IUA) is a frequent acquired endometrial condition, for which there is no effective preventive or treatment. Previous studies have found that vaginal microbiota dysregulation is closely related to endometrial fibrosis and IUA. Therefore, we wondered whether restoration of vaginal microbiota by vaginal administration of L. crispatus could prevent endometrial fibrosis and ameliorate IUA.

RESULTS

First, we created a mechanically injured mouse model of IUA and restored the mice's vaginal microbiota by the addition of L. crispatus convolvulus. The observations suggested that intrauterine injections of L. crispatus significantly decreased the degree of uterine fibrosis, the levels of IL-1β and TNF-α in blood, and downregulated the TGF-β1/SMADs signaling pathway in IUA mice. A therapy with L. crispatus considerably raised the abundance of the helpful bacteria Lactobacillus and Oscillospira and restored the balance of the vaginal microbiota in IUA mice, according to high-throughput sequencing. Then we conducted a randomized controlled trial to compare the therapeutic effect of L. crispatus with estrogen after transcervical resection of adhesion (TCRA). And the results showed that vaginal probiotics had a better potential to prevent intrauterine adhesion than estrogen.

CONCLUSIONS

This study confirmed that L. crispatus could restore vaginal microbiota after intrauterine surgery, inhibit endometrial fibrosis, and finally play a preventive and therapeutic role in IUA. At the same time, it is a new exploration for the treatment of gynecological diseases with vaginal probiotics.

CLINICAL TRIAL REGISTRATION

http://www.chictr.org.cn/ , identifier (ChiCTR1900022522), registration time: 15/04/2019.

Oroxylin A relieves intrauterine adhesion in mice through inhibiting macrophage pyroptosis via SIRT3-SOD2-ROS pathway

Intrauterine adhesion (IUA) is manifested by endometrial fibrosis and inflammation, which seriously affects female reproductive health. Macrophages are mainly inflammatory cells and have been reported to participate in the fibrosis of IUA. Oroxylin A (OA), a kind of flavonoid compounds, was showed to possess the inhibitory effects on inflammation and fibrosis. However, the role of OA in IUA remains unclear. In the present study, we found that OA effectively alleviated the level of inflammation and uterine fibrosis in IUA mice. OA also decreased the macrophage pyroptosis which increased in uteri of IUA mice. Pyroptosis is a programmed cell death accompanied by an inflammatory response. Moreover, OA repressed the mediators of pyroptosis including the expression of NOD-like receptor family pyrin domain containing 3 (NLRP3), caspase-1 and Gasdermin D (GSDMD) and the release of IL-1β, IL-18 and cleaved-caspase-1 in J774A.1 cells induced by LPS/ATP in vitro. Mechanistically, the alleviation of OA on uterine fibrosis is achieved by inhibiting macrophage pyroptosis via SIRT3-SOD2-ROS pathway. Our data indicate that OA may serve as an effective agent for the treatment of the endometrial fibrosis with IUA.

Exosomal miR-543 derived from umbilical cord mesenchymal stem cells ameliorates endometrial fibrosis in intrauterine adhesion via downregulating N-cadherin

INTRODUCTION

Human umbilical cord mesenchymal stem cells (UCMSCs) play an important role in repairing the damaged endometrium of intrauterine adhesion (IUA). Meanwhile, exosomes released by UCMSCs can mediate intercellular communication by delivering miRNAs. It has been shown that miR-543 level was reduced in IUA tissues. However, the role of miR-543 in the progression of IUA remains largely unknown. Therefore, we investigated the role of UCMSCs-derived exosomal miR-543 in IUA.

METHODS

In this study, human endometrial epithelial cells (hEECs) were treated with TGF-β1 for mimicking endometrial fibrosis in vitro. In addition, the IUA-like mouse model in vivo was established by a dual damage method of curettage and LPS infection.

RESULTS

The level of miR-543 was markedly reduced in hEECs exposed to TGF-β1 and in endometrium tissues of IUA mice. Additionally, miR-543 could be transferred from UCMSCs to hEECs via exosomes. Meanwhile, exosomal miR-543-derived from UCMSCs significantly reduced the expressions of N-cadherin, α-SMA, fibronectin 1 and elevated the expression of E-cadherin in TGF-β1-treated hEECs. Furthermore, UCMSCs-derived exosomal miR-543 attenuated IUA-induced endometrial fibrosis in vivo, as shown by the decreased N-cadherin, α-SMA and fibronectin 1 protein expressions.

DISCUSSION

Collectively, UCMSCs-derived exosomal miR-543 was able to prevent endometrial fibrosis both in vitro and in vivo via downregulating N-cadherin. These results may provide an insight into the clinical treatment for IUA.

Evaluation of pharmacokinetics and safety of a long-term estradiol-releasing stent in rat uterine

Purpose

Intrauterine adhesion (IUA), often leading to gynecological complications including amenorrhea, abdominal pain and infertility, is frequently induced by injuries to the endometrium. Hence it would be of great benefit to take efforts to prevent adhesion after intrauterine operations. Orally administration of 17β-estradiol (E2) is commonly used to promote endometrium regeneration, but is limited by low concentrations at the injured sites. We aim at preparing an E2-releasing uterine stent, which could improve the efficiency of E2 therapy and be utilized for IUA prevention.

Methods

We designed a silicone rubber stent, which could be implanted in the uterine cavity and continuously release E2 in long term. Stents were placed in rodent uterine, and removed at different time points. Remaining E2 in stent was measured by high performance liquid chromatography (HPLC), and organ E2 concentrations were detected by enzyme-linked immuno sorbent assay (ELISA). Endometrium morphology was examined by histological staining of paraffin sections.

Results

Our stent showed a controlled release of E2 in rodent uterine for over 60 days, and significantly increased E2 concentration in serum and in situ uterine. After the stent was removed from uterine, E2 rapidly reverted to a normal level. Also, the stent did not induce pathological changes in endometrium.

Conclusions

The uterine stent provided abundant local E2 in uterine cavity with satisfactory safety. The silicone rubber based E2-releasing uterine stent could be further advanced by adjusting its shape and E2 load for its clinical application, and might promisingly help lowering the incidence of IUA.

•

The silicone rubber uterine stent continuously released E2 in long term.

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The E2-releasing uterine stent revealed more efficient E2 delivery capacity than orally administrated E2.

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The E2-releasing uterine stent is safe for endometrium and remote organs.

Long-term maintenance of human endometrial epithelial stem cells and their therapeutic effects on intrauterine adhesion

Background

The human endometrium is a highly regenerative tissue that is believed to have two main types of stem cells: endometrial mesenchymal/stromal stem cells (eMSCs) and endometrial epithelial stem cells (eESCs). So far, eMSCs have been extensively studied, whereas the studies of eESCs are constrained by the inability to culture and expand them in vitro. The aim of this study is to establish an efficient method for the production of eESCs from human endometrium for potential clinical application in intrauterine adhesion (IUA).

Results

Here we developed a culture condition with a combination of some small molecules for in vitro culturing and expansion of human SSEA-1⁺ cells. The SSEA-1⁺ cells exhibited stem/progenitor cell activity in vitro, including clonogenicity and differentiation capacity into endometrial epithelial cell-like cells. In addition, the SSEA-1⁺ cells, embedded in extracellular matrix, swiftly self-organized into organoid structures with long-term expansion capacity and histological phenotype of the human endometrial epithelium. Specifically, we found that the SSEA-1⁺ cells showed stronger therapeutic potential than eMSCs for IUA in vitro. In a rat model of IUA, in situ injection of the SSEA-1⁺ cells-laden chitosan could efficiently reduce fibrosis and facilitate endometrial regeneration.

Conclusions

Our work demonstrates an approach for isolation and expansion of human eESCs in vitro, and an appropriate marker, SSEA-1, to identify eESCs. Furthermore, the SSEA-1⁺ cells-laden chitosan might provide a novel cell-based approach for IUA treatment. These findings will advance the understanding of pathophysiology during endometrial restoration which may ultimately lead to more rational clinical practice.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13578-022-00905-4.

Animal models in intrauterine adhesion research

Intrauterine adhesion (IUA) is a gynaecological disease caused by uterine cavity surgeries and infections that leads to partial or total occlusion of the uterine cavity. However, the underlying mechanism(s) and progression of the disease have not yet been identified. IUA has a high recurrence rate and poor prognosis, and effective drugs to prevent adhesion are lacking. Therefore, establishing an effective animal model of IUA is of great significance for revealing the pathogenesis of IUA and the mechanism(s) governing drug effects. Rats, mice, rabbits, and other animals are currently used to establish intrauterine adhesion models. The IUA induction methods include chemical, thermal, or mechanical damage and mechanical damage combined with an infective method. We analysed the advantages and disadvantages of various models and their clinical simulations in order to provide a precise animal model for exploring the pathogenesis, treatment strategies, and prevention of IUA.

Bone marrow mesenchymal stem cells combined with estrogen synergistically promote endometrial regeneration and reverse EMT via Wnt/β-catenin signaling pathway

BACKGROUND

Intrauterine adhesion (IUA) is a clinical disease characterized by the uterine cavity occlusion caused by the damage of the endometrial basal layer. Bone marrow mesenchymal stem cells (BMSCs) transplantation have the potential to promote endometrial regeneration mainly through paracrine ability. Estrogen is an indispensable and important factor in the repair of endometrial damage, which has been reported as a promising and adjunctive therapeutic application for stem cell transplantation therapy. This study aims to investigate the synergistic effect of BMSCs and estrogen on improving the endometrial regeneration and restoring the endometrium morphology in a dual damage model of IUA in rabbits and the underlying molecular mechanisms.

METHODS

BMSCs were isolated and identified by adipogenic and osteogenic differentiation and flow cytometry assays. The rabbit IUA animal model was established by a dual damage method of mechanical curettage and lipopolysaccharide infection. Additionally, we investigated the therapeutic impact of both BMSCs and estrogen either separately or in combination in a rabbit model. The retention of PKH26-labeled BMSCs was observed by vivo fluorescence imaging.The number of endometrial glands and the degree of fibrosis were observed by H&E and Masson staining respectively. Western blotting, Immunohistochemistry and immunofluorescence staining were performed to detect biomarkers related to endometrial epithelium, endometrial fibrosis and EMT. Finally, the protein expression of core molecules of Wnt/β-catenin pathway was detected by Western blotting.

RESULTS

PKH26-labeled fluorescence results revealed that BMSCs appeared and located in the endometrial glands and extracellular matrix area when orthotopic transplanted into the uterine cavity. Histological assays showed that remarkably increasing the number of endometrial glands and decreasing the area of endometrial fibrosis in the BMSCs combined with estrogen treatment group. Moreover, downregulated expression of fibrosis markers (fibronectin, CollagenI, a-SMA) and interstitial markers (ZEB1, Vimentin, N-cadherin), as well as upregulated E-cadherin expression were found in the combined group. Further study of in vivo staining revealed that fluorescence intensity of CK7 was stronger in the combined group than that of direct BMSCs intrauterine transplantation, while vimentin showed the opposite results. Moreover, the protein levels of β-catenin, Axin2, C-myc, CycinE of Wnt/β-catenin signaling pathway increased in the BMSCs combined with estrogen group than in the other treatment groups.

CONCLUSION

BMSCs combined with estrogen can promote the differentiation of stem cells into endometrial epithelial cells to facilitate the regeneration of damaged endometrium. The potential mechanism of the synergistic effect may inhibit the occurrence of EMT by activating the Wnt/β-catenin signaling pathway.

A LIGHT-HVEM/LTβR 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 LTβR (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 β1) and HVEM in IUA endometrial tissue. More importantly, recombinant human LIGHT protein directly up-regulated the expression of HVEM, LTβR, 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/LTβR axis in IUA endometrium, should contribute to inflammation and fibrosis formation of IUA.

A review of the effects of estrogen and epithelial-mesenchymal transformation on intrauterine adhesion and endometriosis

Uterus transplantation has become an option for women suffering from some form of infertility. Current review discusses key physiological functions of the endometrium requiring the transition of tissue cells between the mesenchyme and epithelial cell phenotype, a process known as epithelial-mesenchymal transition (EMT). Estrogen and EMT play a key role in the pathogenesis and treatment of intrauterine adhesion and endometriosis. There is also a close regulatory relationship between estrogen and EMT, and investigation of this relationship is of great significance for the treatment of endometrial disorders. The present review discusses the effects of estrogen on endometrial dysfunction, with a focus on the relationship between estrogen and EMT in endometrial disorders, taking into consideration the mechanisms by which receptors that regulate their functions and proteins that regulate their local biological functions interact with the factors involved in EMT. In addition, the review summarizes emerging drugs targeting receptors or proteins and provides information on the direction of new therapies for endometrial disorders.

Melatonin-primed MSCs alleviate intrauterine adhesions by affecting MSC-expressed galectin-3 on macrophage polarization

Intrauterine adhesion (IUA) is characterized by the presence of fibrosis on the uterine cavity. It is mainly caused by infection or trauma to the endometrium, and it imposes a great challenge to female reproductive health. Mesenchymal stem cells (MSCs) have been used to regenerate the human endometrium in patients with IUA, but stem cell therapy is not curative in some patients. Melatonin (MT) was reported as a potential modulator of MSCs. However, it remains unclear whether MSCs pretreated with MT exert an improved therapeutic effect on IUA. In this study, an IUA model was established using our invented electric scratching tool. Our results illustrated that MT-pretreated MSCs significantly attenuated the development of IUA. Moreover, MT-pretreated MSCs highly expressed galectin-3 (Gal-3), which enhanced MSC proliferation and migration and influenced macrophage polarization. Of note, IUA mice exhibited colonic injury, and MT-pretreated MSCs alleviated this injury by normalizing colonic microbial communities and recruiting macrophages. Furthermore, inhibition of sympathetic nerves had no effect on IUA progression but delayed colonic injury, and Gal-3 combined with norepinephrine better promoted M2-like macrophage polarization and inhibited M1-like macrophage polarization. Together, these data indicated that MT-primed MSCs can ameliorate injury of both the uterus and colon in an IUA model through high Gal-3 expression to influence sympathetic nerves and in turn affect the polarization and recruitment of macrophages.

Effect of new biological patch in repairing intrauterine adhesion and improving clinical pregnancy outcome in infertile women: study protocol for a randomized controlled trial

Background

Endometrial fibrosis caused by intrauterine adhesion (IUA) can lead to hypomenorrhea, amenorrhea, and even infertility and abortion. The postoperative recurrence rate of severe IUA remains high, giving rise to low pregnancy rates. An extracellular matrix (ECM) scaffold, a new biological material that can promote cell proliferation and differentiation at lesions, has been widely used in general surgery and neurosurgery. The present study applied ECM scaffolds in obstetrics and gynecology for the first time to improve endometrial fibrosis, repair severe IUA, and improve pregnancy outcomes for infertile patients.

Methods

This paper presents a prospective randomized single-blind controlled superiority study of infertile women aged ≤40 years with IUA. According to the scoring criteria for IUA established by the American Fertility Society, patients with moderate or severe IUA were randomized into two groups at a ratio of 1:1; patients in the experimental group were treated with an ECM scaffold (small intestinal submucosa [SIS]) + intrauterine balloon, while patients in the control group were treated with an intrauterine balloon only. A hysteroscopic examination of adhesion repair was performed again after 2 months of postoperative hormone replacement therapy. Endometrial tissue was sampled during the two operations, and immunohistochemistry was used to observe endometrial and microvascular proliferation. After thawing and resuscitation, a postoperative frozen embryo transfer was performed on the participants in both groups, and their endometrial thickness, intrauterine volume, endometrial vascularization flow index, endometrial flow index, and uterine artery blood flow resistance were evaluated by 3D ultrasonography. The rates of embryo implantation, clinical pregnancy, and early spontaneous abortion were observed.

Discussion

The ECM scaffold (SIS) + intrauterine balloon method was able to repair endometrial fibrosis and improve IUA. This new technique represents a novel treatment method for improving the pregnancy outcome of infertile patients with moderate/severe IUA.

Trial registration

Chinese Clinical Trial Register ChiCTR2100052027. Registered on October 14, 2021.

Post-surgical Intrauterine Adhesions After Hysteroscopic Myomectomy Using the Myoma Pseudocapsule Preservation Technique Evaluated bv Second-look Hysteroscopy: A Retrospective Comparative Study

STUDY OBJECTIVE

To analyze the frequency and risk factors of post-surgical intrauterine adhesions (IUA) using second-look hysteroscopy (SLH) in patients undergoing hysteroscopic myomectomy carried out by the myoma pseudocapsule preservation technique for submucosal myoma.

DESIGN

Retrospective cohort study.

SETTING

University hospital from January 2017 to December 2019.

PATIENTS

A total of 124 patients underwent hysteroscopic myomectomy and SLH.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Surgical duration, intraoperative blood loss, number of enucleated myomas, volume of specimen, post-surgical IUA evaluated by SLH. Post-surgical IUA were found in 5/124 cases (4.0%) at SLH. There were no cases of intrauterine adhesion formation in cases in which a single myomas was resected (0/83 cases, 0%), all cases were multiple myomas (5/41 cases, 12.2%), and significantly occurred more frequently in cases of multiple myoma (p = 0.003). Univariate analyses showed that the IUA group contained a significantly larger number of enucleated uterine myoma (p < 0.001), required a longer operation (p = 0.003), displayed an increased volume of intraoperative bleeding (p = 0.007), and the heavier the specimen, the greater the number of patients that had inserted an IUD than the group that did not display post-surgical IUA. Multivariate logistic regression analysis of the risk factors of post-surgical IUA showed that the number of enucleated myomas was strongly associated with IUA (odds ratio 1.45,95% confidence interval 1.06-1.97).

CONCLUSION

The frequency of post-surgical IUA after hysteroscopic myomectomy was high in cases of multiple myoma and may be a risk factor. SLH should be actively pursued in cases where the patient desires to bear children, and informed consent should be attained before carrying out surgery.

Local renin-angiotensin system molecular mechanisms in intrauterine adhesions formation following gynecological operations, new strategy for novel treatment

It has recently been proposed that local tissue renin-angiotensin system activation has a role in post-surgical adhesion. Intrauterine adhesions are scar tissues that form in the endometrial cavity causing the walls of the uterine to adhere together. Women, undergoing major gynecological surgery, are exposed to a high risk of adhesion formation. Post-operative uterine adhesion is associated with chronic pain and infertility that are important problems following post-operation uterine adhesion. A local renin-angiotensin system has been found in the organs of the female reproductive system, for example in the endometrium. Data about the physiological roles of local RAS in the gynecological tract are largely unknown, but dysfunctional local RAS in the endometrium may contribute to this pathological condition. Local AngII/AT1R may be over-activated after surgical injury or hypoxia leading to an up-regulation of the molecular mechanisms that may lead to a chronic immune response, oxidative stress, and increase the expression of fibrotic molecules like TGF-β to induce the risk of connective fibrotic tissues. Based on AngII/AT1R pathological potential to induce pelvic and uterine adhesions, using angiotensin receptor blockers could be a therapeutic strategy for the prevention and treatment of post-surgical adhesions.IMPACT STATEMENTWhat is already known on this subject? Intrauterine adhesions are described as fibrotic scar tissues following gynecological surgeries. It's reported that 55-100% of women are at risk of intrauterine adhesion after gynecological surgeries. Injury to tissues and hypoxia during the surgery, promote molecular mechanisms to contribute post-surgical adhesion. Recently evidence supports the existence of renin-angiotensin system components in the gynecological tract. Abnormal expression of local angiotensin II and AT1R in uterus tissue following gynecological surgeries up-regulate molecular mechanisms to induce post-operative adhesions.What do the results of this study add? Recently there has been an increased focus on the role of the local renin-angiotensin system in organ fibrosis. The results of this Mini-review article refer to the pathological roles of the local renin-angiotensin system in fibrotic bands formation after gynecological operations. Over-activation of local renin-angiotensin systems up-regulate molecular mechanisms such as inflammation and the TGF-β1 signalling pathway. TGF-β as a profibrotic molecule strongly induces the expression of some fibrotic molecules such as PAI and TIMP to increase the risk of intrauterine adhesions.What are the implications of these findings for clinical practice and/or further research? According to the biological roles of local renin-angiotensin system and AT1R following injuries to develop post-operative adhesion, the administration of ARBs may be considered as a new therapeutic strategy for the prevention of IUA.

EndMT: New findings on the origin of myofibroblasts in endometrial fibrosis of intrauterine adhesions

BACKGROUND

Intrauterine adhesion (IUA) is one of the leading causes of infertility and the main clinical challenge is the high recurrence rate. The key to solving this dilemma lies in elucidating the mechanisms of endometrial fibrosis. The aim of our team is to study the mechanism underlying intrauterine adhesion fibrosis and the origin of fibroblasts in the repair of endometrial fibrosis.

METHODS

Our experimental study involving an animal model of intrauterine adhesion and detection of fibrosis-related molecules. The levels of molecular factors related to the endothelial-to-mesenchymal transition (EndMT) were examined in a rat model of intrauterine adhesion using immunofluorescence, immunohistochemistry, qPCR and Western blot analyses. Main outcome measures are levels of the endothelial marker CD31 and the mesenchymal markers alpha-smooth muscle actin (α-SMA) and vimentin.

RESULTS

Immunofluorescence co-localization of CD31 and a-SMA showed that 14 days after moulding, double positive cells for CD31 and a-SMA could be clearly observed in the endometrium. Decreased CD31 levels and increased α-SMA and vimentin levels indicate that EndMT is involved in intrauterine adhesion fibrosis.

CONCLUSIONS

Endothelial cells promote the emergence of fibroblasts via the EndMT during the endometrial fibrosis of intrauterine adhesions.

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.

Clinical application of three-dimensional transvaginal ultrasonography in the diagnosis of intrauterine adhesions

Objective

The present study aimed to evaluate the diagnostic accuracy of three-dimensional transvaginal ultrasonography (3D-TVS) for intrauterine adhesions (IUA).

Methods

We performed a retrospective cohort study. A total of 500 women aged 19 to 46 years with uterine lesions who received treatment from the Department of Obstetrics and Gynecology were enrolled. Endometrial 3D imaging was conducted to obtain the display plane and 3D-TVS parameters. Patients also underwent hysteroscopy for a definitive diagnosis.

Results

For diagnosing IUA, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy of 3D-TVS were 98.8%, 90.8%, 91.4%, 98.7%, and 94.8%, respectively. For diagnosing a submucosal myoma, the sensitivity, specificity, PPV, NPV, and overall accuracy of 3D-TVS were 88.2%, 97.9%, 88.2%, 97.9%, and 96.4%, respectively. For diagnosing endometrial polyps, the sensitivity, specificity, PPV, NPV, and overall accuracy of 3D-TVS were 94.7%, 96.8%, 92.9%, 97.7%, and 96.2%, respectively.

Conclusions

Before hysteroscopy, 3D-TVS, as a method of screening, has great value for comparing differences before and after treatment, and for evaluating therapeutic effects.

Recent trends in therapeutic strategies for repairing endometrial tissue in intrauterine adhesion

Intrauterine adhesion (IUA) is a common gynaecological disease that develops from infection or trauma. IUA disease may seriously affect the physical and mental health of women of childbearing age, which may lead to symptoms such as hypomenorrhea or infertility. Presently, hysteroscopic transcervical resection of adhesion (TCRA) is the principal therapy for IUAs, although its function in preventing the recurrence of adhesion and preserving fertility is limited. Pharmaceuticals such as hormones and vasoactive agents and the placement of nondegradable stents are the most common postoperative adjuvant therapy methods. However, the repair of injured endometrium is relatively restricted due to the different anatomical structures of the endometrium. Recently, the treatment outcome of IUAs has improved with the advancement of hysteroscopic techniques. In particular, the application of bioactive scaffolds combined with tissue engineering technology has proven to have high therapeutic potential or endometrial repair in IUA treatment. Herein, this review has summarized past therapeutic strategies, including postoperative adjuvant therapy, cell or therapeutic molecular delivery therapy methods and bioactive scaffold-based tissue engineering methods. Therefore, this review presented the recent therapeutic strategies for repairing endometrium treatment and pointed out the issues of clinical concern to provide alternative methods for the management of IUAs.

The Top 100 Most Cited Articles on Intrauterine Adhesion: a Bibliometric Analysis

Bibliometric analysis is a statistical method that attempts to assess articles by their citations, analyzing their frequency and citation pattern, which subsequently gleans direction and guidance for future research. Over the past few years, articles focused on intrauterine adhesions have been published with increasing frequency. Nevertheless, little is known about the properties and qualities of this research, and no current analysis exists that has examined the progress in intrauterine adhesion research. Web of Science Core Collection, BIOSIS Citation Index, and MEDLINE database were searched to identify articles on intrauterine adhesion published from 1950 to October 2020. The 100 most cited articles were chosen to analyze citation count, citation density, authorship, theme, geographic distribution, time-related flux, level of evidence, and network analysis. An overwhelming majority of these 100 articles were published in the 2010s (35%). Citations per article ranged from 30 to 253. Chinese authors published the most papers in the top 100, followed by the USA, France, Israel, and Italy. The most salient study themes included operative hysteroscopy and adjunctive treatments for improving reproductive outcomes. The most common level of evidence was level II, and there was no statistical difference in the number of citations between the levels. The network analysis indicated that hysteroscopy, hysteroscopic adhesiolysis, infertility, and the reproductive outcome had a great degree of centrality in the 2000s and 2010s. In comparison, placental implantation had a great degree of centrality in the 2000s, and stem cell and fibrosis had a great degree of centrality in the 2010s. The value of IUA investigation has been gradually appreciated recently. Hysteroscopic adhesiolysis was continuously explored to achieve better reproductive outcome. Over time, the main focus of research has gradually shifted from complications to postoperative adjuvant treatment. Moreover, breakthrough progress is needed in underlying mechanism and early prevention of IUA.

Stem cell-based therapy for ameliorating intrauterine adhesion and endometrium injury

Intrauterine adhesion refers to endometrial repair disorders which are usually caused by uterine injury and may lead to a series of complications such as abnormal menstrual bleeding, recurrent abortion and secondary infertility. At present, therapeutic approaches to intrauterine adhesion are limited due to the lack of effective methods to promote regeneration following severe endometrial injury. Therefore, to develop new methods to prevent endometrial injury and intrauterine adhesion has become an urgent need. For severely damaged endometrium, the loss of stem cells in the endometrium may affect its regeneration. This article aimed to discuss the characteristics of various stem cells and their applications for uterine tissue regeneration.

Hierarchical cluster analysis in the study of the effect of cytokine expression patterns on endometrial repair and receptivity after hysteroscopic adhesiolysis

Background

In a previous study, we reported that amnion promotes endometrial cell growth by regulating cytokines. In this study, hierarchical cluster analysis enabled the evaluation of cytokine expression changes after amnion treatment to be explored by cluster patterns. The role of IL1B on endometrial repair and receptivity was revealed.

Methods

A total of 30 patients were recruited in this clinical trial (NCT02496052) of hysteroscopic adhesiolysis. They were randomly allocated into an amnion grafts group (amnion group) and a control group. After hysteroscopic adhesiolysis, a Foley catheter covered with a sterilized freeze-dried amnion graft was inserted into the uterine cavity of the participants in the amnion group, whereas for the control group, a Foley catheter without amnion graft was inserted. After surgery, patient follow-up was done for a year. Uterine exudates were collected every day for seven days after surgery, and analyzed by enzyme-linked immunosorbent assays. Hierarchical cluster analysis was performed to compare expression patterns of each cytokine. Single-gene gene set enrichment analysis and differentially expressed genes enrichment analysis of IL1B were performed using NCBI GEO (N=151) to evaluate its potential mechanisms and impact on endometrial receptivity.

Results

Compared to the control group, cytokine expression patterns of the amnion group revealed significant stratifications, which were highly correlated with the expression levels of IL1B on the sixth to seventh day after surgery, improving the pregnant rate. Wilcoxon test revealed significantly low expression levels of IL1B in the reduced endometrial receptivity group compared to the normal group. Moreover, gene set enrichment analysis showed that lysosomes, cell cycle, and calcium signaling pathways were associated with the biological processes in which IL1B plays a role. Screening and enrichment analyses of differentially expressed genes further verified the mechanisms of action of IL1B on endometrial repair and receptivity recovery.

Conclusions

Amnion promotes endometrial repair and receptivity by altering the expression levels and patterns of IL1B. Furthermore, by affecting lysosomal, cell cycle, and calcium signaling pathways, IL1B may be one of the factors involved in endometrial repair and receptivity recovery.

Repair abilities of mouse autologous adipose-derived stem cells and ShakeGel™3D complex local injection with intrauterine adhesion by BMP7-Smad5 signaling pathway activation

BACKGROUND

The objective was to explore the therapeutic effect of autologous adipose-derived stem cells (ADSCs) combined with ShakeGel™3D transplantation to activate the BMP7-Smad5 signaling pathway to treat intrauterine adhesions (IUA).

METHODS

Autologous ADSCs were isolated and then merged with ShakeGel™3D. The IUA model was established by mechanical injury. The third generation of autologous ADSCs was injected directly into the uterus in combination with ShakeGel™3D. After 7 days of treatment, endometrial morphology, number of endometrial glands, endometrial fibrosis area, and fibrosis biomarker analysis by RT-PCR and IHC were examined. BMP7 and phosphorylation of Smad5 were also detected, and the recovery of infertility function in treated mice was evaluated.

RESULTS

Fluorescence-activated cell sorting (FACS) showed that autologous ADSCs expressed CD105 (99.1%), CD29 (99.6%), and CD73 (98.9%). Autologous ADSCs could still maintain a good growth state in ShakeGel™3D. Histological examination revealed that the number of endometrial glands increased significantly, and the area of fibrosis decreased. At the same time, the expression of BMP7 and Smad5 in the ADSCs + Gel group was significantly upregulated, and the final reproductive function of this group was partly recovered.

CONCLUSIONS

Autologous ADSCs can be used in combination with ShakeGel™3D to maintain functionality and create a viable three-dimensional growth environment. The combined transplantation of autologous ADSCs and ShakeGel™3D promotes the recovery of damaged endometrial tissue by increasing BMP7-Smad5 signal transduction, resulting in endometrium thickening, increased number of glands, and decreased fibrosis, leading to restoration of partial fertility.

Construction and Optimization of an Endometrial Injury Model in Mice by Transcervical Ethanol Perfusion

This study aimed to establish a stable animal model of intrauterine adhesion (IUA) using a minimally invasive method that recapitulates the clinicopathologic characteristics of IUA. Mice were randomly divided into groups based on the ethanol treatment time (the EtOH-10 s, EtOH-20 s, EtOH-40 s, EtOH-1 min, and sham operation groups), and after the cervix was relaxed with phloroglucinol, the uterine horn was perfused with 95% ethanol through the cervix to induce endometrial injury. Eight days after the procedure, routine biochemical assays were performed to assess liver and kidney function; HE and Masson staining were used to assess uterine morphology and fibrosis; and immunohistochemistry was performed to evaluate the expression of CD31 and F4/80 in the endometrium. Furthermore, the fertility of mice in the EtOH-40 s group and the sham operation group was compared. As expected, the ethanol treatment time was positively correlated with the degree of uterine damage and kidney dysfunction in mice. In particular, the endometria of mice in the EtOH-40 s group were significantly thinner than those of mice in the sham operation group and exhibited severe necrosis, glandular loss, incomplete epithelial and glandular epithelial cell structure, severe tissue fibrosis, an activated inflammatory response, and a significant decrease in the number of fetuses, consistent with the clinical characteristics of severe IUA. In conclusion, this study resulted in successful establishment, by a minimally invasive transcervical ethanol perfusion technique, of a mouse model of endometrial injury, which could support an in-depth study of IUA pathogenesis and further promote the development of IUA therapies.

Predictive value of live birth rate based on different intrauterine adhesion evaluation systems following TCRA

OBJECTIVE

The aim of this study was to assess the predictive value of five different intrauterine adhesion (IUA) evaluation systems for live birth rate following transcervical resection of adhesion (TCRA).

METHOD

This retrospective study included 128 women with IUA who desired for spontaneous conception after TCRA. All the patients were retrospectively scored by the American Fertility Society (AFS) classification, European Society of Gynecological Endoscopy (ESGE) classification, March's classification (March), Nasr classification (Nasr) and Chinese IUA diagnosis classification criteria (Chinese). The predictive value of these evaluation systems was determined by receiver operating characteristic (ROC) curves and area under a ROC curve (AUC).

RESULTS

The correlation coefficients of AFS, ESGE, March, Nasr and Chinese classification and the live birth rate were 0.313, 0.313, 0.288, 0.380, and 0.336, respectively. Among women with hypomenorrhea and amenorrhea, as well as women with no infertility, the severities determined by all five evaluation systems were correlated with live birth rate (P <  0.001). All five scoring systems were efficient to predict live birth rate. Among them, Nasr classification showed the highest AUC (0.748) with the best predictive value. Multivariate logistic regression analyses showed that Nasr classification had the highest OR (OR, 6.523; 95% CI, 2.612, 18.263). And, Nasr's classification system also showed highest sensitivity (81.8%) and negative predictive value (96.7%) when divide the system into mild IUA vs. moderate and severe IUA.

CONCLUSION

AFS, ESGE, March, Nasr and Chinese classification were demonstrated to be capable of predicting live birth following TCRA although the predictive capacities might be limited, and Nasr classification showed the highest predictive value of live birth.

Intrauterine adhesion prevention with Malecot catheter after hysteroscopic myomectomy: A novel approach

OBJECTIVE

Intrauterine adhesion after hysteroscopic myomectomy contributes to infertility, recurrent miscarriages, menstrual irregularities, and hinders pregnancy outcomes. The aim of this study was to apply the indwelling Malecot catheter in prevention of intrauterine adhesion after hysteroscopic myomectomy and to further evaluate the effectiveness of this approach with reported live birth rates in infertile patients who underwent subsequent infertility treatment.

MATERIALS AND METHODS

Seventeen patients with FIGO Classification System PALM-COIEN Type 0 or 1 submucous myoma that received hysteroscopic myomectomy were recruited in this retrospective analysis. Post-operative insertion of the Malecot catheter via the aid of the uterine sound was performed and the catheter was left in place for seven days.

RESULTS

The mean duration of TTP (time to pregnancy) was 15.6 months after hysteroscopy. Within three years after the operation, 10 out of 17 infertility patients achieved ongoing pregnancy over 12 weeks. Ongoing pregnancy rate was 58.8% (10/17). Eight patients achieved live birth (seven singletons, one twin pregnancy) with mean gestational age of 38 weeks. Live birth rate was 47.1% (8/17).

CONCLUSION

The Malecot catheter is an inexpensive, easy-to-operate, and effective physical barrier method for preventing IUA in infertile patients undergoing hysteroscopic myomectomy with high live birth rate and no obvious visible post-operative adhesions.