Focus on the Primary Prevention of Intrauterine Adhesions: Current Concept and Vision

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.

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.

The efficacy of early office hysteroscopy in preventing intrauterine adhesions after abortion: a randomized controlled trial

BACKGROUND

Intrauterine adhesions (IUA) are a challenging clinical problem in reproductive infertility. The most common causes are intrauterine surgery and abortions. We aimed to investigate whether early second-look office hysteroscopy can prevent IUA.

METHODS

A single-center, prospective, two-armed, randomized controlled trial was designed to explore the efficacy of early office hysteroscopy after first-trimester induced abortion (suction dilatation and curettage [D&C]) and to further analyze fertility outcomes. Women aged 20-45 years undergoing suction D&C and desiring to conceive were recruited. Between October 2019 and September 2022, 66 women were enrolled, of whom 33 were allocated to group A (early hysteroscopy intervention). The women in intervention group A were planned to receive 2 times of hysteroscopies (early and late). In group B, women only underwent late (6 months post suction D&C) hysteroscopy.

RESULTS

The primary outcome was the IUA rate assessed using office hysteroscopy 6 months after artificial abortion. Secondary outcomes included menstrual amount/durations and fertility outcomes. In intervention group A, 31 women underwent the first hysteroscopy examination, and 15 completed the second. In group B (late hysteroscopy intervention, 33 patients), 16 completed the hysteroscopic exam 6 months after an artificial abortion. Twenty-one women did not receive late hysteroscopy due to pregnancy. The IUA rate was 16.1% (5/31) at the first hysteroscopy in group A, and no IUA was detected during late hysteroscopy. Neither group showed statistically significant differences in the follow-up pregnancy and live birth rates.

CONCLUSIONS

Early hysteroscopy following suction D&C can detect intrauterine lesions. IUA detected early by hysteroscopy can disappear on late examination and become insignificant for future pregnancies. Notably, the pregnancy outcomes showed a favorable trend in the early hysteroscopy group, but there were no statistically significant differences.

TRIAL REGISTRATION

ClinicalTrials.gov , ID: NCT04166500. Registered on 2019-11-10. https://clinicaltrials.gov/ct2/show/NCT04166500 .

The Endometrial Stem/Progenitor Cells and Their Niches

Endometrial stem/progenitor cells are a type of stem cells with the ability to self-renew and differentiate into multiple cell types. They exist in the endometrium and form niches with their neighbor cells and extracellular matrix. The interaction between endometrial stem/progenitor cells and niches plays an important role in maintaining, repairing, and regenerating the endometrial structure and function. This review will discuss the characteristics and functions of endometrial stem/progenitor cells and their niches, the mechanisms of their interaction, and their roles in endometrial regeneration and diseases. Finally, the prospects for their applications will also be explored.

Injectable alginate-based zwitterionic hydrogels promoting endometrial repair and restoring fertility

The development of novel therapeutic approaches to facilitate endometrial repair and regeneration while preventing adhesion recurrence is a crucial research objective aimed at enhancing clinical outcomes for women with intrauterine adhesions (IUA). In this study, we introduced an injectable Alg-GMA/PTSB zwitterionic hydrogel, characterized by excellent biocompatibility, anti-protein adsorption properties, and biodegradability. In a rat model, the hydrogel significantly promoted the regeneration and angiogenesis of damaged endometrial tissue, leading to improved recovery of epithelial cells, glands, proliferation, and vascularization. Furthermore, it exhibited the ability to suppress cellular apoptosis and collagen deposition, thereby mitigating fibrosis. Additionally, the hydrogel restored the expression of estrogen/progesterone receptors and endometrial receptivity markers, contributing to enhanced embryo implantation and fertility. These findings underscore the potential of the hydrogel as a promising therapeutic strategy for addressing endometrial injury, reducing fibrosis, restoring fertility, and ultimately improving outcomes for women with IUA.

Secretion of WNT7A by UC-MSCs assist in promoting the endometrial epithelial regeneration

Stem cell therapy for intrauterine adhesions (IUAs) has been widely used in clinical treatment. However, intravenous injection lacks sufficient targeting capabilities, while in situ injection poses challenges in ensuring the effective survival of stem cells. Furthermore, the mechanism underlying the interaction between stem cells and endometrial cells in vivo remains poorly understood, and there is a lack of suitable in vitro models for studying these problems. Here, we designed an extracellular matrix (ECM)-adhesion mimic hydrogel for intrauterine administration, which was more effective than direct injection in treating IUAs. Additionally, we analyzed the epithelial-mesenchymal transition (EMT) and confirmed that the activation of endometrial epithelial stem cells is pivotal. Our findings demonstrated that umbilical cord mesenchymal stem cells (UC-MSCs) secrete WNT7A to activate endometrial epithelial stem cells, thereby accelerating regeneration of the endometrial epithelium. Concurrently, under transforming growth factor alpha (TGFA) stimulation secreted by the EMT epithelium, UC-MSCs upregulate E-cadherin while partially implanting into the endometrial epithelium.

Semaglutide May Ameliorate Fibrosis and Inhibit Epithelial-Mesenchymal Transition in Intrauterine Adhesion Models

The purpose of this study was to explore the effect of Semaglutide on intrauterine adhesions and discover new drugs for such adhesions. In this study, the cell model was simulated by TGF-β1-induced human endometrial epithelial cells, and the animal model was established through mechanical curettage and inflammatory stimulation. After co-culturing with TGF-β1 with or without different concentrations of Semaglutide for 48 h, cells were collected for RT-qPCR and Western blotting analyses. Three doses were subcutaneously injected into experimental mice once a day for two weeks, while the control group received sterile ddH2O. The serum and uterine tissues of the mice were collected. HE and Masson staining were used for the uterine histomorphological and pathological analyses. RT-qPCR and Western blotting were used for mRNA and protein expression analyses. Serum indicators were detected using ELISA kits. The results showed that Semaglutide significantly reduced the mRNA levels of fibrosis indicators ACTA2, COL1A1, and FN and inflammatory indicators TNF-α, IL-6, and NF-κB in the two models. Semaglutide improved endometrium morphology, increased the number of endometrial glands, and reduced collagen deposition in IUA mice. The results also showed that Semaglutide could inhibit vimentin, E-Cadherin, and N-Cadherin in the two models. In summary, Semaglutide can ameliorate fibrosis and inflammation of intrauterine adhesions as well as inhibit epithelial-mesenchymal transition in IUA models.

Injectable "Homing-Like" Bioactive Short-Fibers for Endometrial Repair and Efficient Live Births

The prevalence of infertility caused by endometrial defects is steadily increasing, posing a significant challenge to women's reproductive health. In this study, injectable "homing-like" bioactive decellularized extracellular matrix short-fibers (DEFs) of porcine skin origin are innovatively designed for endometrial and fertility restoration. The DEFs can effectively bind to endometrial cells through noncovalent dipole interactions and release bioactive growth factors in situ. In vitro, the DEFs effectively attracted endometrial cells through the "homing-like" effect, enabling cell adhesion, spreading, and proliferation on their surface. Furthermore, the DEFs effectively facilitated the proliferation and angiogenesis of human primary endometrial stromal cells (HESCs) and human umbilical vein endothelial cells (HUVECs), and inhibited fibrosis of pretreated HESCs. In vivo, the DEFs significantly accelerated endometrial restoration, angiogenesis, and receptivity. Notably, the deposition of endometrial collagen decreased from 41.19 ± 2.16% to 14.15 ± 1.70% with DEFs treatment. Most importantly, in endometrium-injured rats, the use of DEFs increased the live birth rate from 30% to an impressive 90%, and the number and development of live births close to normal rats. The injectable "homing-like" bioactive DEFs system can achieve efficient live births and intrauterine injection of DEFs provides a new promising clinical strategy for endometrial factor infertility.

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.

Intrauterine adhesion

Intrauterine adhesions (IUA) occurred in the reproductive-age women are a big economic and health problem, resulting in severe impairment of social, psychological and physical function of the female genital organs. IUA-related symptoms or signs are varied greatly from free of symptoms or ambiguous symptoms (an incidental finding during the intervention) to ceased menstruation and loss of fecundability. The underlying pathophysiology is not completely understood, but intrauterine damage with broken basal layers of the endometrium formatting scar tissues or fibrosis in the endometrium with subsequently causing partial or complete occlusion of the uterine cavity may be a well-accepted hypothesis. Previously, infection is the most common cause to develop IUA, but now, intrauterine surgery may be a critical cause contributing to the majority of cases of IUA. In the current review, update information about the etiology, epidemiology, pathophysiology, sequelae and prevention of IUA will be renewed. We emphasize the importance of awareness of IUA, and primary prevention should be considered in the routine clinical practice if intrauterine surgery has been applied, based on uncertainty of ideal treatment for the established IUA and unpredictable outcomes after IUA treatment. So far, evidence supports that hyaluronic acid with/without other strategy is the most valuable and effective method to reduce the formation and re-formation of IUA as well as to achieve the best fertility outcome.

Short-term reproductive outcomes analysis and prediction of the modified uterine stent treatment for mild to moderate intrauterine adhesions: experience at a single institution

BACKGROUND

To evaluate the efficacy of modified uterine stent in the treatment of mild-to-moderate intrauterine adhesions and explore the relative indicators affecting prognosis prediction.

METHODS

A total of 115 patients with mild-to-moderate intrauterine adhesions received a modified uterine stent placement after hysteroscopy adhesiolysis. The second-look hysteroscopy operated after 3 months surgery, and the third-look hysteroscopy operated after 6 months surgery if necessary. The stent was removed when the cavity shape was repaired, then the reproductive outcomes were followed up one year.

RESULTS

Menstrual blood volume, endometrial thickness and volume had increased significantly after 3 months surgery. The rates of cavity repaired were 86.96% (100/115) after 3 months surgery and 100% (115/115) after 6 months surgery cumulatively. Endometrial thickness after 3-months surgery was positively associated with uterine cavity shape repaired (P<0.01). The receive operating characteristic (ROC) curve showed the rate of uterine cavity shape repaired predicted by the model was 0.92, based on the endometrial thickness after 3-months surgery. The rate of pregnancy was 86.09% (99/115) in one year, while the rate of miscarriage accounted for 26.26% (26/99). The median time interval between stent removal and subsequent conception was 3 months. It showed adhesion recurrence was the risk factor for subsequent pregnancy (P<0.01).

CONCLUSIONS

A modified uterine stent placement under hysteroscopy was an effective approach for mild-to-moderate intrauterine adhesions, which is easy to operate and worthy for clinical promotion. Endometrial thickness measured by ultrasonography probably has predictive value in adhesion recurrence and subsequent pregnancy.

TRIAL REGISTRATION

ChiCTR2100051524. Date of registration (retrospectively registered): 26/09/2021.

Human umbilical cord-derived mesenchymal stem cells and auto-crosslinked hyaluronic acid gel complex for treatment of intrauterine adhesion

OBJECTIVE

The purpose of this study was to explore the therapeutic characteristics of mesenchymal stem cells generated from human umbilical cord (hUC-MSCs) when utilized in conjunction with auto-crosslinked hyaluronic acid gel (HA-gel) for the management of intrauterine adhesion (IUA). The goal was to see how this novel therapy could enhance healing and improve outcomes for IUA patients.

METHODS

In this study, models of intrauterine adhesion (IUA) were established in Sprague-Dawley (SD) rats, which were then organized and divided into hUC-MSCs groups. The groups involved: hUC-MSCs/HA-gel group, control group, and HA-gel group. Following treatment, the researchers examined the uterine cavities and performed detailed analyses of the endometrial tissues to determine the effectiveness of the interventions.

RESULTS

The results indicated that in comparison with to the control group, both HA-gel, hUC-MSCs, and hUC-MSCs/HA-gel groups showed partial repair of IUA. However, in a more notable fashion transplantation of hUC-MSCs/HA-gel complex demonstrated significant dual repair effects. Significant outcomes were observed in the group treated with hUC-MSCs and HA-gel, they showed thicker endometrial layers, less fibrotic tissue, and a higher number of endometrial glands. This treatment strategy also resulted in a significant improvement in fertility restoration, indicating a profound therapeutic effect.

CONCLUSIONS

The findings of this study suggest that both HA-gel, hUC-MSCs, and hUC-MSCs/HA-gel complexes have the potential for partial repair of IUA and fertility restoration caused by endometrium mechanical injury. Nonetheless, the transplantation of the hUC-MSCs/HA-gel complex displayed exceptional dual healing effects, combining effective anti-adhesive properties with endometrial regeneration stimuli.

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.

Reproductive outcomes following copper‑containing intrauterine device after hysteroscopic lysis for intrauterine adhesions

The present study aimed to investigate the reproductive outcomes of copper-containing intrauterine devices (IUDs) after hysteroscopic lysis in patients with mild to severe intrauterine adhesions (IUAs), according to the American Fertility Society (AFS) classification. Therefore, a prospective randomized controlled study was conducted at the Affiliated Jinhua Hospital of Wenzhou Medical University (Jinhua, China). A total of 173 women with IUAs were initially recruited between January 2020 and June 2021 and were then randomized to the copper-containing IUD group or the no barrier device group. Following hysteroscopic procedure, the fertility and obstetric outcomes were analyzed. Among the 173 patients enrolled, a total of 109 participants completed the study protocol. The results showed that AFS scores were not significantly different between the two groups prior to hysteroscopy. In addition, no statistically significant differences were recorded in pregnancy and live birth rates between the copper-containing IUD and no barrier device groups. Overall, the results of the current study indicated that the copper-containing IUDs had no positive effect on pregnancy and live birth rates in patients with mild to severe IUAs after hysteroscopic adhesiolysis. The present trial was retrospectively registered in the Chinese Clinical Trial Registry on 28th December 2023 (registration no. ChiCTR2300079233).

Integrating Network Pharmacology and In Vitro Experimental Verification Revealing Bushenhuoxue Recipe Against Intrauterine Adhesions via PI3K-AKT Signaling Pathway

We aimed to investigate therapeutic effect of Bushenhuoxue recipe in intrauterine adhesions (IUA) and explore the underlying molecular mechanism via integrating network pharmacology and in vitro experimental verification. The active compounds and gene targets of Bushenhuoxue recipe were screened in the TCMSP database and the IUA-related genes were identified using GeneCards database by the keyword "Intrauterine adhesions". Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were conducted to reveal the underlying molecular mechanism of Bushenhuoxue recipe treating IUA. T-HESC cells were inducted to fibrotic state using TGF-β1 of 10 ng/ml concentration treating for 24 h. RT-qPCR or western blot was used to demonstrate the expression levels of fibrosis markers (COL1A1 and α-SMA) and KEGG pathway markers. Cell counting kit-8 (CCK8) assay was performed to illustrate the cell viability of endometrial stromal cell. The treatment of Bushenhuoxue recipe could significantly inhibit the proliferation and fibrosis of endometrial stromal cells. We obtained a total of 169 no-repeat ingredients of Bushenhuoxue recipe and 3044 corresponding targets. After taking intersection with 4230 no-repeat IUA-related genes, a total of 83 target genes related to both Bushenhuoxue recipe and IUA were finally identified. KEGG analysis found that PI3K-AKT signaling pathway might be the key pathway. Further experiment revealed that PI3K-AKT signaling pathway was significantly activated in endometrial stromal cells of fibrotic state and the treatment of Bushenhuoxue recipe could inhibit the PI3K-AKT signaling pathway. Further rescue assay demonstrated that Bushenhuoxue recipe suppressed the proliferation and fibrosis of endometrial stromal cells via PI3K-AKT signaling pathway. Bushenhuoxue recipe suppresses the proliferation and fibrosis of endometrial stromal cells via PI3K-AKT signaling pathway, eventually inhibiting the progression of IUA.

Hypoxic bone marrow mesenchymal stem cell exosomes promote angiogenesis and enhance endometrial injury repair through the miR-424-5p-mediated DLL4/Notch signaling pathway

Background

Currently, bone marrow mesenchymal stem cells (BMSCs) have been reported to promote endometrial regeneration in rat models of mechanically injury-induced uterine adhesions (IUAs), but the therapeutic effects and mechanisms of hypoxic BMSC-derived exosomes on IUAs have not been elucidated.

Objective

To investigate the potential mechanism by which the BMSCS-derived exosomal miR-424-5p regulates IUA angiogenesis through the DLL4/Notch signaling pathway under hypoxic conditions and promotes endometrial injury repair.

Methods

The morphology of the exosomes was observed via transmission electron microscopy, and the expression of exosome markers (CD9, CD63, CD81, and HSP70) was detected via flow cytometry and Western blotting. The expression of angiogenesis-related genes (Ang1, Flk1, Vash1, and TSP1) was detected via RT‒qPCR, and the expression of DLL4/Notch signaling pathway-related proteins (DLL4, Notch1, and Notch2) was detected via Western blotting. Cell proliferation was detected by a CCK-8 assay, and angiogenesis was assessed via an angiogenesis assay. The expression of CD3 was detected by immunofluorescence. The endometrial lesions of IUA rats were observed via HE staining, and the expression of CD3 and VEGFA was detected via immunohistochemistry.

Results

Compared with those in exosomes from normoxic conditions, miR-424-5p was more highly expressed in the exosomes from hypoxic BMSCs. Compared with those in normoxic BMSC-derived exosomes, the proliferation and angiogenesis of HUVECs were significantly enhanced after treatment with hypoxic BMSC-derived exosomes, and these effects were weakened after inhibition of miR-424-5p. miR-424-5p can target and negatively regulate the expression of DLL4, promote the expression of the proangiogenic genes Ang1 and Flk1, and inhibit the expression of the antiangiogenic genes Vash1 and TSP1. The effect of miR-424-5p can be reversed by overexpression of DLL4. In IUA rats, treatment with hypoxic BMSC exosomes and the miR-424-5p mimic promoted angiogenesis and improved endometrial damage.

Conclusion

The hypoxic BMSC-derived exosomal miR-424-5p promoted angiogenesis and improved endometrial injury repair by regulating the DLL4/Notch signaling pathway, which provides a new idea for the treatment of IUAs.

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.

Preventive effects of sodium hyaluronate combined with pelvic floor neuromuscular electrical stimulation on the intrauterine adhesions in women after abortion

The aim of this study was to investigate the clinical efficacy of combining pelvic floor neuromuscular stimulation treatment (NMES) with sodium hyaluronate in preventing intrauterine adhesions (IUA) following abortion. A total of 140 women who underwent artificial abortion were enrolled. The control group received only an intrauterine injection of sodium hyaluronate post-surgery, while the observation group received both the injection and daily pelvic floor NMES treatments, beginning on the day after the abortion. Monthly follow-ups on menstrual conditions were conducted for six months post-surgery. Fasting venous blood samples from both groups were collected on the second day post-abortion and the day after treatment. Transvaginal color Doppler ultrasound was used on the second day post-abortion and the 15th day post the first menstrual cycle to measure endometrial thickness, and the pulsatility and resistance indices of the endometrial spiral arteries. Over the six-month follow-up, the combination therapy group exhibited a notably lower IUA incidence compared to the control group (2.8% vs. 15.7%). Furthermore, combined treatment significantly expedited post-abortion menstrual recovery, reduced vaginal bleeding volume and duration (P < 0.001). It also increased endometrial thickness and reduced the endometrial spiral artery's pulsatility and resistance indices (P < 0.05). In addition, lower serum tumor necrosis factor alpha (TNF-α) and higher interleukin-10 (IL-10) were found in the observation group compared to the control group (P < 0.05). The combination therapy offers significant advantages in preventing and reducing IUA after abortion, resulting in a substantial reduction in IUA occurrence.

Study on the Mechanism of Estrogen Regulating Endometrial Fibrosis After Mechanical Injury Via MIR-21-5P/PPARΑ/FAO Axis

BACKGROUND

Intrauterine adhesion (IUA) caused by endometrial mechanical injury has been found as a substantial risk factor for female infertility (e.g., induced abortion). Estrogen is a classic drug for the repair of endometrial injury, but its action mechanism in the clinical application of endometrial fibrosis is still unclear.

OBJECTIVE

To explore the specific action mechanism of estrogen treatment on IUA.

METHODS

The IUA model in vivo and the isolated endometrial stromal cells (ESCs) model in vitro were built. Then CCK8 assay, Real-Time PCR, Western Blot and Dual- Luciferase Reporter Gene assay were applied to determine the targeting action of estrogen on ESCs.

RESULTS

It was found that 17β-estradiol inhibited fibrosis of ESCs by down-regulating miR-21-5p level and activating PPARα signaling. Mechanistically, miR-21-5p significantly reduced the inhibitory effect of 17β-estradiol on fibrotic ESCs (ESCs-F) and its maker protein (e.g., α-SMA, collagen I, and fibronectin), where targeting to PPARα 3'- UTR and blocked its activation and transcription, thus lowering expressions of fatty acid oxidation (FAO) associated key enzyme, provoking fatty accumulation and reactive oxygen species (ROS) production, resulting in endometrial fibrosis. Nevertheless, the PPARα agonist caffeic acid counteracted the facilitation action of miR-21-5p on ESCs-F, which is consistent with the efficacy of estrogen intervention.

CONCLUSION

In brief, the above findings revealed that the miR-21-5p/PPARα signal axis played an important role in the fibrosis of endometrial mechanical injury and suggested that estrogen might be a promising agent for its progression.

Association of intrauterine synechiae with pituitary gonadotrophin pulse patterns: A pilot study

BACKGROUND

Intrauterine synechiae (IS) is an acquired uterine condition that occurs when scar tissues (adhesions) form within the uterus and/or cervix, causing menstrual disturbance. However, approximately 50% of patients with IS are refractory to treatment. Therefore, other endocrine disturbances, such as gonadotropin disturbance, may affect treatment success.

STUDY AIM

To analyze gonadotropin levels in women with and without IS.

METHODS

Ten women with refractory IS experiencing amenorrhea since at least 6 months and nine with normal menstrual cycles (control group) were included in this study. Blood sample were collected every 10 minutes during a 4-h period. The serial ultrasound was performed in both groups for evaluating the cycle phase. Blood was collected when the follicles size was between 5-10 mm. Serum LH, FSH, progesterone and estradiol concentrations were measured. To detect LH and FSH pulses, the technique proposed by Santen and Bardin was adopted; therefore, one pulse was defined as a 20% increase in the concentrations as to the preceding point, followed by an important decrease.

RESULTS

No differences were observed between the study groups at baseline. Estradiol levels were lower in the IS group than in the control group, but the difference was not statistically significant. During the first hour of monitoring, cumulative FSH pulsatile frequency of IS group was lower than one of control.

CONCLUSION

Our data suggest that the estradiol levels of IS participants are lower than those of women with normal menstrual cycle. The role of this finding in the physiology of uterine synechiae requires further investigation.

Melatonin-pretreated human umbilical cord mesenchymal stem cells improved endometrium regeneration and fertility recovery through macrophage immunomodulation in rats with intrauterine adhesions†

Intrauterine adhesions (IUA) are a common gynecological problem. Stem cell therapy has been widely used in the treatment of IUA. However, due to the complex and harsh microenvironment of the uterine cavity, the effectiveness of such therapy is greatly inhibited. This study aimed to investigate whether melatonin pretreatment enhances the efficacy of human umbilical cord mesenchymal stem cells (HucMSCs) in IUA treatment in rats. First, we explored the effect of melatonin on the biological activity of HucMSCs in vitro through a macrophage co-culture system, Cell Counting Kit 8 (CCK-8), 5-Ethynyl-2'-deoxyuridine (EdU), flow cytometry, immunofluorescence staining, and qRT-PCR. Subsequently, we established the IUA rat model and tracked the distribution of HucMSCs in this model. In addition, we observed the number of M1 and M2 macrophages through immunofluorescence staining and detected the levels of inflammatory cytokines. Four weeks after cell transplantation, HE, Masson, and immunohistochemical staining were performed. In vitro experiments showed that melatonin pretreatment of HucMSCs promoted proliferation, reduced apoptosis, up-regulated the stemness gene, and regulated macrophage polarization. In vivo, melatonin pretreatment caused more HucMSCs to remain in the uterine cavity. Melatonin-pretreated HucMSCs recruited more macrophages, regulated macrophage polarization, and reduced inflammation. Melatonin-pretreated HucMSCs relieved fibrosis, increased endometrium thickness, and up-regulated CD34, vimentin, proliferating cell nuclear antigen (PCNA), and alpha small muscle antigen (α-SMA) expression. Fertility tests showed that melatonin-pretreated HucMSCs increased the number of embryos. In summary, pretreatment with melatonin was beneficial for HucMSC treatment because it enhanced the cell's ability to recruit macrophages and regulate macrophage polarization, which led to the regeneration of the endometrium and improved pregnancy outcomes.

The humanin analogue (HNG) alleviates intrauterine adhesions by inhibiting endometrial epithelial cells ferroptosis: a rat model-based study

STUDY QUESTION

Does a humanin analogue (HNG) have a therapeutic effect on intrauterine adhesions (IUAs) caused by uterine cavity surgery in a rat model?

SUMMARY ANSWER

HNG supplementation attenuated the development of endometrial fibrosis and IUAs, improved fertility, and contributed to the regulation of endometrial fibrosis by inhibiting endometrial ferroptosis in rats with IUAs.

WHAT IS KNOWN ALREADY

IUAs, which are characterized by endometrial fibrosis, are a common cause of female infertility. Humanin (rattin in rats) is a mitochondrial-derived peptide that is widely expressed in multiple tissues. S14G-humanin (HNG) is an HNG that has been reported to have a protective effect against myocardial fibrosis.

STUDY DESIGN, SIZE, DURATION

Endometrial tissues from three patients with IUAs and three controls were tested for humanin expression. Two animal models were used to evaluate the modelling effect of IUAs and the preventive effect of HNG against IUAs. In the first model, 40 rats were equally randomized to control and Day 7, 14, and 21 groups to establish the IUA model. In the second model, 66 rats were equally randomized to the control, IUA, and IUA + humanin analogue (HNG) groups. Erastin was used to induce ferroptosis in the Ishikawa cell line.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The endometrium was scraped with a surgical spatula, combined with lipopolysaccharide treatment, to establish the rat model of IUAs. Rats were intraperitoneally injected with 5 mg/kg/day HNG for 21 consecutive days beginning from the day of operation to evaluate the therapeutic effect on IUAs. Haematoxylin-eosin and Masson's trichrome staining were used to assess endometrial morphology and evaluate fibrosis. Ferroptosis-related markers, namely nuclear factor E2-related factor 2 (Nrf2), acyl-CoA synthetase long-chain family member 4 (ACSL4), haeme oxygenase-1 (HO-1), solute carrier family 7 member 11 (SLC7A11), glutathione peroxidase 4 (GPX4), and ferritin, were measured by immunohistochemistry and western blotting to determine whether ferroptosis was involved in the development of IUAs and to assess the attenuative effect of HNG on ferroptosis. Additionally, the female rats were mated with male rats with normal fertility to assess fertility.

MAIN RESULTS AND THE ROLE OF CHANCE

Humanin was widely expressed in endometrial cells, including epithelial and stromal cells, in both humans and rats. Humanin expression levels were downregulated in the endometria of patients and rats with IUAs relative to the endometria of controls. Endometrial thickness and the number of glands were significantly decreased on Day 7, 14, and 21 after endometrial scraping when compared with the controls (all P < 0.05), whereas the fibrotic area was significantly increased (P < 0.05). Among the tested ferroptosis markers, the expression levels of Nrf2, SLC7A11, and GPX4 were significantly downregulated and those of ACSL4, HO-1, and ferritin were significantly upregulated after endometrial scraping relative to their expression levels in controls (all P < 0.05). The mating rates in the control, IUA, and IUA + HNG groups were 100% (10/10), 40% (4/10), and 80% (8/10), respectively. The number of embryos in rats with IUAs (mean ± SD: 1.6 ± 2.1) was significantly less than the number in the controls (11.8 ± 1.5). HNG supplementation significantly attenuated this decrease in the number of implanted embryos (6.3 ± 4.5) (P < 0.01). Further results showed that HNG significantly attenuated the altered expression levels of proteins involved in ferroptosis in the endometria of rats with IUAs. Moreover, in vitro experiments showed that HNG significantly attenuated the erastin-induced decrease in the viability of the Ishikawa cell line and also attenuated the increase in reactive oxygen species production and the downregulation of GPX4.

LARGE SCALE DATA

None.

LIMITATIONS, REASONS FOR CAUTION

The findings of this study showed that HNG inhibited ferroptosis and reduced fibrosis in a rat model of IUAs. However, we could not establish a causal relationship between ferroptosis and the development of IUAs.

WIDER IMPLICATIONS OF THE FINDINGS

HNG may be effective at alleviating fibrosis during the development of IUAs, and the inhibition of ferroptosis is a promising new strategy for IUA therapy.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the National Natural Science Foundation of China (No. 82171647); the '1000 Talent Plan' of Yunnan Province (No. RLQN20200001); and the Basic Research Project of the Yunnan Province-Outstanding Youth Foundation (No. 202101AW070018). The authors declare no competing financial interests.

HPV infection and vaginal microecological disorders in women with intrauterine adhesion: cross-sectional study in a Chinese population

BACKGROUND

The purpose of this study was to evaluate the vaginal microecology and the distribution of human papillomavirus (HPV) subtypes in patients with uterine adhesions and explore the correlation between HPV infection and vaginal microecology imbalance and the occurrence of intrauterine adhesion (IUA).

METHODS

A total of 479 women were enrolled in the study, including 259 in the normal group and 220 in the IUA group. Vaginal microecological and HPV analyses were performed on all participants. Significant differences between the two groups were analyzed, and Spearman correlation analysis was performed.

RESULTS

The incidence of IUA in patients between 31 and 40 years of age was high. The I-II degree of vaginal cleanliness in the IUA group was significantly lower than that in the normal group, and the number of III-IV degree was significantly higher than that in the normal group. Moreover, the incidences of VVC (vulvovaginal candidiasis) and vaginal disorders and infections with HPV 16 and HPV 52 subtypes were significantly higher in the IUA group than in the normal group. The incidence of high-risk HPV infection combined with vaginal disorders in the IUA group was higher than that in the normal group. Correlation analysis showed that the occurrence of IUAs was positively correlated with HPV infection and negatively correlated with PH and vaginal microecological imbalance.

CONCLUSION

The HPV infection rate and vaginal microecology disorders affect the occurrence of IUAs. For patients with IUAs, control of the HPV infection rate and the prevention of vaginal microecological disorders should be improved.

The use of intrauterine balloon therapy in reproductive medicine and surgery: a guidance for practice

The use of balloon therapy in obstetric practice especially in postpartum haemorrhage (PPH) is well established and has recently been reviewed. However, little attention has been drawn regarding the use of intrauterine balloon (IUB) in gynaecological practice. This study focuses on the various usage of IUB in gynaecological practice. An electronic literature search through Medline, EMBASE and Clinicaltrial.gov from inception to August 2022 was conducted. The study focuses on the three following areas: (1) Indications: prevention and removal of intrauterine adhesions, management of ectopic pregnancy, facilitation of endoscopic surgery and other clinical usages; (2) Practical aspects of balloon therapy including ultrasound guidance, choice of balloon, inflation volume, duration of balloon therapy; and (3) Potential complications including pain, infection, uterine rupture and how they can be avoided. IUB therapy is a simple, inexpensive and effective method that can be applied in various gynaecological conditions ranging from IUA to intrauterine haemorrhage. Complications are rare, but in most cases can be avoided with correct use.

Clinical efficacy of hysteroscopic adhesiolysis combined with periodic balloon dilation for intrauterine adhesion in IVF treatment

Background

Intrauterine adhesions (IUA), arising from diverse etiological factors, pose a significant threat to female fertility, particularly during in vitro fertilization (IVF) treatment.

Objective

To assess the effectiveness of hysteroscopic adhesiolysis (HA) combined with periodic balloon dilation in treating IUA and its impact on reproductive outcomes in women undergoing IVF treatment.

Methods

A total of 234 patients diagnosed with IUA were included in this study. The IUA women were categorized into three subgroups based on the severity of adhesion. All IUA patients underwent HA separation followed by periodic balloon dilation along with hormone replacement therapy (HRT). Frozen embryo transfer was performed post-treatment, and a comparative analysis of the general characteristics and clinical outcomes among the subgroups was conducted. The control group consisted of patients who underwent their first embryo transfer of HRT cycle without any uterine abnormalities, as assessed by the propensity score matching (PSM). The clinical outcomes of IUA group and control group were compared. Multivariate logistic regression analyses were employed to investigate the risk factors associated with live birth.

Results

① The endometrial thickness was significantly increased post-operation compared to pre-operation in all three IUA subgroups (all P <0.001), with the most pronounced change observed in the severe IUA group. After treatment, normal uterine cavity was restored in 218 women (93.16%). ② The overall clinical pregnancy rate was 49.57% (116/234) and live birth rate was 29.91% (70/234). The clinical outcomes were similar among the three subgroups after first embryo transfer (all P>0.05). Multivariate logistic regression analyses revealed that age (aOR 0.878, 95% CI 0.817~0.944, P=0.001) and endometrial thickness after treatment (aOR 1.292, 95% CI 1.046~1.597, P=0.018) were the two significant risk factors for live birth rate. ③ Following the process of matching, a total of 114 patients were successfully enrolled in the control group. The baselines and the clinical outcomes were all comparable between the IUA group and control group (all P>0.05).

Conclusion

The combination of HA and periodic balloon dilation is beneficial for improving endometrial receptivity and has a significant clinical impact on patients with IUA undergoing IVF.

Yangmo decoction versus hyaluronic acid gel in women with intrauterine re-adhesion after hysteroscopic adhesiolysis: a retrospective efficacy and safety analysis

BACKGROUND

Hysteroscopic adhesiolysis is the preferred primary method for intrauterine adhesion. However, there is about a 60% of chance of re-adhesion after surgery. The objectives of the study were to evaluate the efficacy and safety of Yangmo decoction as a secondary treatment in preventing intrauterine re-adhesion against those of hyaluronic acid gel.

METHODS

Women received oral Yangmo decoction (YD cohort, n = 105) or intrauterine hyaluronic acid gel (HA cohort, n = 125) or did not receive secondary re-adhesion prevention treatments (EP cohort, n = 165) after hysteroscopic adhesiolysis for 6 months. In addition, all women have received 3 mg of oral estrogen and 20 mg oral progesterone combination after hysteroscopic adhesiolysis for 3 months. Intrauterine re-adhesion after hysteroscopic adhesiolysis after 6 months with or without secondary treatment(s) was detected using hysteroscopy. The extent of the cavity, type of adhesion, and the menstrual pattern were included to define the American Fertility Society classification of intrauterine re-adhesions (AFS) score.

RESULTS

Fewer numbers of women suffered from intrauterine re-adhesion after hysteroscopic adhesiolysis in the YD cohort than those of the HA (15(14%) vs. 40(32%), p = 0.0019) and the EP (15(14%) vs. 58(35%). p = 0.0001) cohorts. Among women who developed intrauterine re-adhesion, AFS score was fewer for women of the YD cohort than those of HA (2(2-1) vs. 4(4-3), p < 0.001) and the EP (2(2-1) vs. 4(4-4), p < 0.001) cohorts. AFS score after surgery was fewer for women of the HA cohort than those of the EP cohort (p < 0.05). Higher numbers of women of the YD cohort retained pregnancies after 6-months of treatment than those of the HA (55(52%) vs. 45(36%), p = 0.0161) and EP (55(52%) vs. 35(21%), p < 0.0001) cohorts. Among women who develop re-adhesion, 10(10%) women of the YD cohort only had successful pregnancies.

CONCLUSIONS

Yangmo decoction for 6 months after hysteroscopic adhesiolysis can reduce AFS score, prevent intrauterine re-adhesion, and increases the chances of successful pregnancies of women.

LEVEL OF EVIDENCE

IV.

TECHNICAL EFFICACY

Stage 5.

A construct of adipose-derived mesenchymal stem cells-laden collagen scaffold for fertility restoration by inhibiting fibrosis in a rat model of endometrial injury

Severe endometrium damage causes pathological conditions such as thin endometrium and intrauterine adhesion, resulting in uterine factor infertility. Mesenchymal stem cell (MSC) therapy is a promising strategy in endometrial repair; yet, exogenous MSCs still raise concerns for safety and ethical issues. Human adipose-derived mesenchymal stem cells (ADMSCs) residing in adipose tissue have high translational potentials due to their autologous origin. To harness the high translation potentials of ADMSC in clinical endometrium regeneration, here we constructed an ADMSCs composited porous scaffold (CS/ADMSC) and evaluated its effectiveness on endometrial regeneration in a rat endometrium-injury model. We found that CS/ADMSC intrauterine implantation (i) promoted endometrial thickness and gland number, (ii) enhanced tissue angiogenesis, (iii) reduced fibrosis and (iv) restored fertility. We ascertained the pro-proliferation, pro-angiogenesis, immunomodulating and anti-fibrotic effects of CS/ADMSC in vitro and revealed that the CS/ADMSC influenced extracellular matrix composition and organization by a transcriptomic analysis. Our results demonstrated the effectiveness of CS/ADMSC for endometrial regeneration and provided solid proof for our future clinical study.

Mucosal adhesion phenomenon after maxillary sinus floor elevation: A preclinical study

AIM

To describe the histological events that occur after maxillary sinus floor elevation when the elevated and undetached sinus mucosa are in close proximity or in contact with each other.

MATERIALS AND METHODS

From 76 rabbits, 152 elevated maxillary sinuses were analyzed histologically. Sites without adhesions were classified as "No proximity," whereas the adhesion stages were divided into "Proximity," "Fusion," and "Synechia stages." The width of the pseudostratified columnar epithelium and the distance between the two layers of the elevated and undetached sinus mucosae were measured at various standardized positions.

RESULTS

Thirty-one sites presenting with adhesions were found. Twelve sites were in the proximity stage," presenting cilia of the two epithelial layers that were shortened and interlinked within the mucous context. Hyperactivity of the goblet cells was also observed. In the other cases, the hyperplastic epithelium showed attempts to reach the contralateral mucosa. The 15 "fusion stage" sites presented regions with epithelial cells of the two mucosal layers that penetrated each other. Four sites presented "synechiae stages," represented by bridges of connective tissue connecting the two lamina propria.

CONCLUSIONS

Close proximity or tight contact between the elevated and undetached mucosa adhering to the bone walls might occur after maxillary sinus floor elevation. This induced hyperplasia of the epithelial cells and adhesion of the two layers until synechiae formation.

Integrative analysis links autophagy to intrauterine adhesion and establishes autophagy-related circRNA-miRNA-mRNA regulatory network

BACKGROUND

Intrauterine adhesion (IUA) is a troublesome complication characterized with endometrial fibrosis after endometrial trauma. Increasing number of investigations focused on autophagy and non-coding RNA in the pathogenesis of uterine adhesion, but the underlying mechanism needs to be further studied.

METHODS

mRNA expression profile and miRNA expression profile were obtained from Gene Expression Omnibus database. The autophagy related genes were low. Venn diagram was used to set the intersection of autophagy genes and DEGs to obtain ARDEGs. Circbank was used to select hub autophagy-related circRNAs based on ARDEMs. Then, the differentially expressed autophagy-related genes, miRNAs and circRNAs were analyzed by functional enrichment analysis, and protein-protein interaction network analysis. Finally, the expression levels of hub circRNAs and hub miRNAs were validated through RT-PCR of clinical intrauterine adhesion samples. In vitro experiments were investigated to explore the effect of hub ARCs on cell autophagy, myofibroblast transformation and collagen deposition.

RESULTS

11 autophagy-related differentially expressed genes (ARDEGs) and 41 differentially expressed miRNA (ARDEMs) compared between normal tissues and IUA were identified. Subsequently, the autophagy-related miRNA-mRNA network was constructed and hub ARDEMs were selected. Furthermore, the autophagy-related circRNA-miRNA-mRNA network was established. According to the ranking of number of regulated ARDEMs, hsa-circ-0047959, hsa-circ-0032438, hsa-circ-0047301 were regarded as the hub ARCs. In comparison of normal endometrial tissue, all three hub ARCs were upregulated in IUA tissue. All hub ARDEMs were downregulated except has-miR-320c.

CONCLUSIONS

In the current study, we firstly constructed autophagy-related circRNA-miRNA-mRNA regulatory network and identified hub ARCs and ARDEMs had not been reported in IUA.

Clinical evaluation of autologous platelet-rich plasma therapy for intrauterine adhesions: a systematic review and meta-analysis

Objective

This meta-analysis aims to evaluate the efficacy and safety of autologous platelet-rich plasma (PRP) administration in reducing adhesion recurrence and improving pregnancy outcomes in patients with intrauterine adhesion (IUA).

Methods

We conducted a comprehensive search of Pubmed, Embase, the Cochrane Library, Web of Science, Scopus, and China National Knowledge Internet (CNKI) from inception to February 10, 2023, without any language or regional restrictions. We used random-effects models to assess odds ratios (OR) and weight mean differences (WMD) with 95% confidence intervals (CI).

Results

Our meta-analysis included a total of 730 patients from 10 clinical studies (6 RCTs and 4 non-RCTs). The results showed that PRP administration significantly increased endometrial thickness (WMD = 0.79, 95% CI: 0.40-1.19; P < 0.001; I² = 0.0%), menstrual volume (WMD = 2.96, 95% CI = 2.30-3.61; P < 0.001; I² = 0.0%), and days of menstruation (WMD = 1.13, 95% CI = 0.86-1.41; P < 0.001; I² = 0.0%). Additionally, the clinical pregnancy rate was also improved (OR = 1.82, 95% CI: 1.19-2.78; P = 0.006; I² = 0.0%). However, there was insufficient evidence to reach a conclusion regarding the effects of PRP on the recurrence rate of moderate to severe IUA, changes in AFS scores, miscarriage rate, and live birth rate.

Conclusions

Our analysis confirms that autologous PRP is an effective treatment for IUA. However, the limited sample size suggests that the results should be interpreted with caution. Therefore, larger and well-designed studies are necessary in the future to confirm these findings and explore the optimal PRP dosing regimens further.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO, identifier CRD42023391115.

Dulaglutide Ameliorates Intrauterine Adhesion by Suppressing Inflammation and Epithelial-Mesenchymal Transition via Inhibiting the TGF-β/Smad2 Signaling Pathway

Intrauterine adhesion (IUA) is a common gynecological disease with limited therapeutic options. Dulaglutide is a long-acting glucagon-like peptide-1 (GLP-1) analog with some anti-fibrotic and anti-inflammatory properties; however, its action on IUA remains uncertain. The purpose of the experiments in this study was to explore the effect of dulaglutide on IUA and to elucidate its mechanism to provide new ideas for the clinical treatment of IUA. An IUA mouse model was established via mechanical curettage and inflammation induction; mice received subcutaneous injection with three doses of dulaglutide once a day for two weeks (treatment) or equal amounts of sterile ddH₂O (control), and sham-operated mice were treated similarly to the control mice. Mice were sacrificed, and uterine tissues were subjected to hematoxylin and eosin (H&E) and Masson's trichrome staining for histomorphological and pathological analyses and real-time quantitative polymerase chain reaction (RT-qPCR) and Western blotting (WB) for gene and protein expression analyses. Dulaglutide improved the shape of the uterine cavity, increased endometrial thickness and the number of glands, and significantly reduced the area of collagen fiber deposition in the endometrium. It significantly reduced collagen type I A 1 (COL1A1), interleukin-1beta (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), C-C motif chemokine ligand 2 (CCL2), F4/80 (macrophage), vimentin and transforming growth factor-beta (TGF-β) mRNA levels and COL1A1, IL-1β, IL-6, TNF-α, F4/80, vimentin, E-cadherin, TGF-β, and p-Smad2 protein expression levels. This study demonstrates that dulaglutide reduces inflammatory responses by inhibiting M1 macrophage polarization and inflammatory factor release and may ameliorate fibrosis by inhibiting epithelial-mesenchymal transition (EMT) via TGF-β/Smad2 signaling.

A Case Report of Asherman's Syndrome With Abnormal Placenta Implantation (Intrauterine Adhesion)

We report the case of a 28-year-old patient with a partial placental insertion on an intrauterine adhesion diagnosed at 20 weeks' gestation. The increasing incidence of intrauterine adhesions during the last decade has been attributed to the rising number of uterine surgeries in the fertile population and better imaging studies facilitating diagnosis. Although uterine adhesions during pregnancy are generally considered benign, the existing evidence is conflicting. The obstetric risks in these patients are unclear, but higher numbers of placental abruption, preterm premature rupture of membranes (PPROM), and cord prolapse have been reported. Thus, a prenatal diagnosis should prompt close feto-maternal observation. Surgical resection should be offered to patients with adhesions found prior to pregnancy.

Bioactive Injectable and Self-Healing Hydrogel Via Cell-Free Fat Extract for Endometrial Regeneration

The damaged endometrium and the formation of fibrosis are key barriers to pregnancy and further lead to infertility. However, how to promote endometrium repair is always a challenge. Here, a bioactive injectable and self-healing hydrogel is developed by physically combination of thiolated polyethylene (PEG), Cu²⁺ and cell-free fat extract (CEFFE, CF) for endometrial regeneration and fertility. By inheriting the advantages of various active proteins contained in CEFFE, it could induce the overall repair of endometrial microenvironment for intrauterine adhesion (IUA). In vitro, CF@Cu-PEG reduces endometrial cell apoptosis by more than 50%, and increases angiogenesis by 92.8%. In the IUA mouse, injection of CF@Cu-PEG significantly reduces the rate of uterine hydrometra and prevents the formation of endometrial fibrosis. Remarkably, CF@Cu-PEG contributes to the repair of endometrial microstructure, especially increases the number of endometrial pinopodes, significantly improves endometrial receptivity, and increases the pregnancy rate of IUA mice from 7.14% to 66.67%. In summary, through the physically combination of CEFFE and Cu-PEG, the construction of loaded bioactive injectable hydrogel not only inhibits the IUA, but also induces the self-repair of endometrial cells in situ and improves fertility, providing a new strategy for IUA repair in clinical application.

Hyaluronic acid encapsulated silver metal organic framework for the construction of a slow-controlled bifunctional nanostructure: Antibacterial and anti-inflammatory in intrauterine adhesion repair

Intrauterine adhesion (IUA) is a common gynecological disease caused by endometrial injury, which might result in abnormal menstruation, miscarriage, and even fetal deaths. Nevertheless, existing treatment strategies such as intrauterine device and uterine cavity balloons only provide a physical barrier, and not circumvent inflammation of endometrial microenvironment and retrograde infection. In this study, a slow-controlled bifunctional nanostructure was developed via encapsulating hyaluronic acid (HA) on surface of silver-metal organic framework (Ag-MOF), and then loaded in poly lactic-co-glycolic acid scaffold to prevent IUA. In therapy, macro-molecule of HA provided anti-inflammatory function by the adjustment of signal transduction pathways of macrophage surface receptors, whereas Ag-MOF inactivated bacteria by destroying bacterial membrane and producing reactive oxygen. Significantly, the coated HA effectively avoided burst release of Ag⁺, thus achieving long-term antibacterial property and good biocompatibility. Antibacterial results showed antibacterial rate of the scaffold reached 87.8 % against staphylococcus aureus. Anti-inflammatory assays showed that the scaffold inhibited the release of inflammatory cytokines and promoted the release of anti-inflammatory cytokines. Moreover, in vitro cell tests revealed that the scaffold effectively inhibited fibroblast growth, indicating its good ability to prevent IUA. Taken together, the scaffold may be a promising candidate for IUA treatment.

Chronic endometritis positively correlates with the aggravation of intrauterine adhesions but has limited effects on reproductive prognosis with antibiotic application

OBJECTIVE

To assess the effect of chronic endometritis (CE) diagnosed by CD138 staining on the aggravation of intrauterine adhesions (IUAs), and the reproductive prognosis after transcervical resection of adhesions (TCRA).

METHODS

Sixty-three patients with severe IUAs (group A) and 119 patients with moderate IUAs (group B) were included in this retrospective study. TCRA and endometrial biopsy with CD138 staining were performed. Participants in each group were classified into two subgroups: CE group and NCE group (without CE). Patients were treated with a course of oral antibiotics for 2 weeks after TCRA. Embryo transfer would be performed if patients had embryos after operations.

RESULTS

Increased incidence of CE was found in group A (18/63, 28.57%) compared with group B (18/119, 15.13%) (P = 0.030). No significant differences were found in the comparisons of chemical pregnancy rate, early miscarriage rate, or full-term pregnancy rate between the CE group and NCE group (P > 0.05), in either the subgroup analysis of group A and group B, or the total analysis.

CONCLUSION

CE has a positive correlation with the aggravation of IUAs. CE did not have a negative impact on the reproductive prognosis of patients with moderate or severe IUAs after TCRA followed by antibiotic administration.

Intrauterine adhesion after hysteroscopic myomectomy of submucous myomas

PURPOSE

To evaluate the frequency of intrauterine adhesion (IUA) after hysteroscopic myomectomy, and to analyze the association of IUA and the location of submucous myomas and the use of postoperative barrier (POB).

METHODS

Hysteroscopic myomectomy was performed in 217 patients with submucous myomas. The retrospective investigation was performed, and the cases were divided into three groups: cases with solitary submucous myoma (SSM; group 1), cases with apposing submucous myomas (ASMs; group 2) and cases with submucous myomas that were far from each other or not in apposition to one another (not apposing submucous myomas: NASMs; group 3). As POB, intrauterine device with oxidized regenerated cellulose and silicon sheet was inserted immediately after surgery.

RESULTS

IUA formation after hysteroscopic myomectomy was more frequent in group 2 than groups 1 and 3 (p = 0.03 and 0.01, respectively), despite the higher rates of POB use (p = 0.02). There was no significant difference in IUA formation in cases with POB between each group (p = 0.06 and 0.21, respectively). But in cases without POB, group 2 showed higher rates of IUA formation than group 1 (p = 0.04) and group 3 (p = 0.03). Multivariable analysis for IUA formation demonstrated that ASMs were a risk factor of IUA (hazard ratio [HR] = 27.9, p < 0.01), and the use of POB was a prognostic factor for reduction of IUA formation (HR = 0.08, p < 0.01).

CONCLUSION

ASMs appear to be a risk factor for IUA formation. The use of POB may be associated with preventing IUA formation after hysteroscopic myomectomy.

A short peptide encoded by long non-coding RNA small nucleolar RNA host gene 6 promotes cell migration and epithelial-mesenchymal transition by activating transforming growth factor-beta/SMAD signaling pathway in human endometrial cells

BACKGROUND

Endometrial dysfunction is closely correlated with the development of multiple severe gynecological disorders including intrauterine adhesion. Accumulating evidence supports that some long non-coding RNAs (lncRNAs) have peptide-coding potential. In this text, the peptide-coding ability of lncRNA SNHG6 was examined. Also, the effects of an SNHG6-encoded peptide on the viability and migration of human endometrial stromal cells (hESCs) and human endometrial epithelial cells (hEECs) and related molecular mechanisms were explored.

METHODS

The peptide-encoding potential of SNHG6 was predicted by FuncPEP and getorf databases and validated by western blot assay. Cell viability was tested by cell counting kit-8 assay. Cell migratory ability was examined by wound healing and transwell migration assays. Protein levels of genes were measured by western blot assay.

RESULTS

Prediction analysis suggested that SNHG6 had the potential peptide-coding ability and multiple open-reading frames (ORFs). Western blot validated that SNHG6 ORF#1 and ORF#2 could translate into short peptides. SNHG6 ORF#2 overexpression facilitated cell migration and epithelial-mesenchymal transition (EMT) in hESCs and hEECs, while these effects were abrogated by transforming growth factor-beta (TGF-β)/SMAD signaling inhibitor GW788388. Moreover, GW788388 inhibited the increase of p-SMAD2 and p-SMAD3 levels induced by SNHG6 ORF#2 in hESCs. SNHG6 ORF#2-encoded peptide did not influence endometrial stromal and epithelial cell viability.

CONCLUSIONS

LncRNA SNHG6 ORF#1 and ORF#2 could translate into small peptides and SNHG6 ORF#2 overexpression promoted cell migration and EMT by activating the TGF-β/SMAD pathway in hESCs and hEECs, suggesting the potential roles of SNHG6-encoded peptides in the development of endometrial stromal and epithelial cells and related gynecological diseases.

In Search of an Imaging Classification of Adenomyosis: A Role for Elastography?

Adenomyosis is a complex and poorly understood gynecological disease. It used to be diagnosed exclusively by histology after hysterectomy; today its diagnosis is carried out increasingly by imaging techniques, including transvaginal ultrasound (TVUS) and magnetic resonance imaging (MRI). However, the lack of a consensus on a classification system hampers relating imaging findings with disease severity or with the histopathological features of the disease, making it difficult to properly inform patients and clinicians regarding prognosis and appropriate management, as well as to compare different studies. Capitalizing on our grasp of key features of lesional natural history, here we propose adding elastographic findings into a new imaging classification of adenomyosis, incorporating affected area, pattern, the stiffest value of adenomyotic lesions as well as the neighboring tissues, and other pathologies. We argue that the tissue stiffness as measured by elastography, which has a wider dynamic detection range, quantitates a fundamental biologic property that directs cell function and fate in tissues, and correlates with the extent of lesional fibrosis, a proxy for lesional "age" known to correlate with vascularity and hormonal receptor activity. With this new addition, we believe that the resulting classification system could better inform patients and clinicians regarding prognosis and the most appropriate treatment modality, thus filling a void.

Characteristics and transcriptomic analysis of scar tissues on the inner uterine cavity wall in patients with intrauterine adhesions

Introduction: It has been previously reported that intrauterine adhesions (IUAs) are the main cause of uterine infertility. However, the histological origin of scar tissue present on the inner wall of the uterine cavity with IUAs has not been previously studied, which is particularly necessary for follow-up research and prevention and treatment. Methods: In this study, myometrium with normal uterus were assigned to the control group and scar tissues with IUAs were assigned to the experimental group. And pathological characteristics and transcriptomic were analyzed between the two groups. Results: We founded no difference was noted in the histological morphology and the α-SMA expression between the experimental and control groups. A total of 698 differentially expressed genes were identified between the two groups. Gene Ontology (GO) analyses revealed that the DEGs were significantly enriched in cell proliferation, AP-1 complex formation, and angiogenesis. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses revealed that the target genes were significantly enriched in the AGE-RAGE, FOXO and TNF signaling pathway. Discussion: As far as we know, this is the first study to propose that the scar tissues are mainly derived from the myometrium and the first one to report differentially expressed genes in the scar tissues of IUAs.

Efficacy of electrical stimulation combined with ultrasound acupuncture therapy on treatment in patients with intrauterine adhesions: Study protocol for a placebo-controlled, single-blind, single-center, randomized trial

BACKGROUND

Recurrence of postoperative adhesions is one of the most important factors for poor reproductive outcomes after hysteroscopic surgery, particularly in cases diagnosed with severe intrauterine adhesions (IUAs), where the recurrence rate is significantly higher. This study aims to explore the effectiveness of the electrical muscle stimulation combined with ultrasound acupuncture therapy in preventing the recurrence of IUAs and improving reproductive outcomes after operative hysteroscopy.

METHODS

This study is a single-center, randomized controlled trial. A total of 210 patients with IUAs will be randomly assigned into 2 groups according to the ratio of 1:1, as the treatment group and the control group. Participants will receive the electrical muscle stimulation combined with ultrasound acupuncture therapy and oral hormone supplementation or receive oral hormone supplementation only. The primary outcome was the clinical response rate. There were 3 menstrual cycles of treatment and 3 menstrual cycles of follow-up in this study.

ETHICS AND DISSEMINATION

This study protocol was approved by the Ethics Committee of the Reproductive Hospital of Guangxi Zhuang Autonomous Region (approval number: KY-LL-2022-06). This trial will be conducted in accordance with the principles of the Declaration of Helsinki as well as Good Clinical Practice. Study results will be disseminated at academic presentations and publications in peer-reviewed journals.

TRIAL REGISTRATION

Registry name: Clinical value of electroultrasonic instrument in the treatment of IUAs and changes of related protein expression; Registry number: ChiCTR2200058901; registration date: April 19th, 2022; http://www.chictr.org.cn/showproj.aspx?proj=166155.

Treatment of septate uterus

Although there is insufficient evidence supporting the link between septate uterus and infertility, there are many studies demonstrated the effect of spetal incision on pregnancy in women diagnosed with septate uterus associated with infertility. Hysteroscopic metroplasty can significantly improve the reproductive performance of those with septate uterus. Some Müllerian malformations can be healed by surgery. The accurate diagnosis and appropriate therapeutic approch are fundamental for successful treatment. Any attempt at surgical correction of uterine abnormalities must be aimed at preserving or improving reproductive function. Among congenital uterine anomalies, septate uterus is the most amenable to simple hysteroscopic treatment. The resection of the septum is performed as standard treatment worldwide.

Value of transvaginal three-dimensional ultrasound in evaluating the curative effect of Yangmo decoction in the treatment of uterine adhesion

OBJECTIVES

Intrauterine adhesions (IUA) is the damage of the basal layer of the endometrium caused by various reasons, resulting in adhesion of the uterine muscle walls to each other, which is manifested as clinical symptoms such as spanomenorrhea, amenorrhea, and infertility. Hysteroscopic adhesiolysis (HA) is the main treatment, for patients with moderate or severe adhesion or angular adhesion, the incidence of postoperative adhesion is high. Traditional Chinese medicine "Yangmo decoction" can promote endometrial growth. Three-dimensional transvaginal ultrasonography (3D-TVUS) can judge IUA and evaluate uterine receptivity through three-dimensional imaging. This study aims to investigate the value of 3D-TVUS in judging the efficacy of Yangmo decoction in the treatment of intrauterine adhesions.

METHODS

The clinical data of patients who underwent HA at two different centers in department of Gynecology of Third Xiangya Hospital of Central South University and Changsha Jiangwan Hospital from January 2021 to August 2021 were retrospectively collected. A total of 275 eligible patients were included. According to the postoperative management measures, the selected patients were divided into two groups. Yangmo decoction group (n=138): the use of Yangmo decoction and uterine-shaped silicon stent post HA; Hormone group (n=137): the use of estrogen, progesterone and uterine-shaped silicon stent post HA. The preoperative general data, preoperative and postoperative 3D-TVUS parameters of the two groups were analyzed.

RESULTS

The endometrial thickness of Yangmo decoction group was thicker than that of hormone group (P<0.001), the intercornual distance was wider (P=0.016), the endometrial echo was more homogeneous (P=0.018), the percentage of bilaterally visible tubal opening was higher (P<0.001), the endometrial morphology was better (P=0.012), and endometrial blood flow, endometrial motility and uterine motion were better in Yangmo decoction group than that in the hormone group (all P<0.001).

CONCLUSIONS

The endometrial thickness, echo, blood flow, and peristalsis, the number of visible tubal opening, uterine motion, and the intercornual distance obtained by 3D-TVUS examination are important factors to evaluate the prognosis of postoperative drug treatment for IUA. 3D-TVUS is of great significance in evaluating the efficacy of Yangmo decoction in the treatment of IUA.

Clinical study on 2 types of intrauterine stents with different thickness and hardness in the treatment of moderate-to-severe intrauterine adhesions

OBJECTIVES

Although hysteroscopic adhesiolysis (HA) is the main treatment for intrauterine adhesion (IUA), postoperative management of IUA remains challenging because there is no consensus on how to mitigate the high rate of postoperative adhesions reformation. This study aims to compare the effectiveness and safety of 2 types of intrauterine stents with different thickness and hardness in treating moderate-to-severe IUA.

METHODS

A retrospective clinical study was conducted in the Third Xiangya Hospital of Central South University from November 2020 to July 2021. A total of 191 patients with moderate-to-severe IUA who received surgical treatment and placed intrauterine stents after HA to prevent recurrence of postoperative adhesions were included. According to the hardness and thickness of the intrauterine stents, the participants were divided into a case group (placed the novel thin intrauterine stent, n=62) and a control group (placed the conventional stent, n=129). After 2-3 menstrual cycles, a second-look hysteroscopy was performed, and the intrauterine stents were removed. The postoperative efficacy [the reduction of American Fertility Society (AFS) scores, the adhesions reformation rate, the changes in menstrual pattern, and the pregnancy rate during the follow-up], safety (the adverse events), and applicability (the difficulty of stent removal) were compared between the 2 groups.

RESULTS

No significant differences in preoperative clinical characteristics were observed between the 2 groups (all P>0.05). The menstrual volume of all patients was increased after the treatment. The reduction of AFS scores and the menstruation recovery rate were not significantly different between the 2 groups (P=0.519 and P=0.272, respectively). Notably, there was no case of displacement in the case group, while the displacement rate of the control group was 2.3% (P=0.552). Moreover, there was no significant difference in abdominal pain or postoperative abnormal vaginal bleeding between the 2 groups (P=0.823 and P=0.851, respectively). However, the difficulty rate of removing the thinner stents was significantly lower than that of removing the traditional stent (21.0% vs 38.8%, P=0.014). During the follow-up for half a year of the postoperative period, the pregnancy rate did not differ significantly in the case and control groups (45.0% vs 34.6%, P=0.173).

CONCLUSIONS

The novel intrauterine stent shows noninferior efficacy and had a good safety profile compared with conventional stents in treating moderate-to-severe IUA. Importantly, it was more convenient to be removed without increasing the rate of displacement and detachment. Therefore, it could reduce the amount of damage to the endometrium and has higher applicability than conventional stents.

Efficacy and safety of auto-cross-linked hyaluronic gel to prevent intrauterine adhesion after hysteroscopic electrosurgical resection: a multi-center randomized controlled trial

Background

The electrothermal effect of hysteroscopic bipolar electrosurgical resection may cause damage to the endometrium, leading to intrauterine adhesion (IUA). Although some studies have demonstrated the efficacy and feasibility of auto-cross-linked hyaluronic (ACP) gel in preventing IUAs, controversy over its use continues. In this randomized controlled multi-center 2-arm parallel trial, we aimed to examine the efficacy and safety of ACP gel in preventing IUA after hysteroscopic electrosurgical resection and facilitate pregnancy in patients.

Methods

Patients from 4 centers in China were randomly assigned (1:1) to receive an intrauterine infusion of ACP gel or nothing after hysteroscopic electrosurgical resection. The randomization assignment was generated by computer and kept in a sealed envelope. A second-look hysteroscopy was performed within 3 months of the surgery.

Results

From June 2018 to May 2021, 200 patients were recruited. Ultimately, 82 patients in both groups were included in the result analysis. The baseline characteristics were comparable. The outcomes were assessed by using per-protocol analysis. The incidence of IUA in the ACP gel group was lower than that in the control group [3.66% vs. 10.98%, risk ratio (RR) =0.333, 95% confidence interval (CI): 0.094-1.187, P=0.072], and the planned pregnancy rate was higher than that of the control group (60.98% vs. 40.54%, RR =1.504, 95% CI: 0.949-2.384, P=0.071), but the difference was not statistically significant. There was no significant difference in menstruation change. Menstrual volume remained unchanged in most cases (86.59% in ACP gel group vs. 89.02% in the control group, RR =0.877, 95% CI: 0.877-1.109, P=0.815). Menstrual volume decreased in 10 women in the ACP gel group and 8 in the control group (12.20% vs. 9.76%, RR =1.250, 95% CI: 0.520-3.007, P=0.617). No adverse effects were observed after the ACP administration.

Conclusions

The present study showed that the use of ACP gel appeared to reduce both the tendency of IUA and American Fertility Society (AFS) scores and improve the subsequent pregnancy rate during hysteroscopic electrosurgical resection when treating polyps, fibroids, and uterine septum. ACP might be recommended to prevent IUA after such surgery. Further studies should be conducted with larger numbers of participants.

Trial Registration

Chinese Clinical Trial Registry ChiCTR2100047165.