Mechanisms of Regeneration and Fibrosis in the Endometrium.

The uterine lining (endometrium) regenerates repeatedly over the life span as part of its normal physiology. Substantial portions of the endometrium are shed during childbirth (parturition) and, in some species, menstruation, but the tissue is rapidly rebuilt without scarring, rendering it a powerful model of regeneration in mammals. Nonetheless, following some assaults, including medical procedures and infections, the endometrium fails to regenerate and instead forms scars that may interfere with normal endometrial function and contribute to infertility. Thus, the endometrium provides an exceptional platform to answer a central question of regenerative medicine: Why do some systems regenerate while others scar? Here, we review our current understanding of diverse endometrial disruption events in humans, nonhuman primates, and rodents, and the associated mechanisms of regenerative success and failure. Elucidating the determinants of these disparate repair processes promises insights into fundamental mechanisms of mammalian regeneration with substantial implications for reproductive health.

CTRP6 alleviates endometrial fibrosis by regulating Smad3 pathway in intrauterine adhesion†.

Intrauterine adhesion (IUA) is manifestations of endometrial fibrosis and excessive extracellular matrix deposition. C1q/tumor necrosis factor-related protein-6 (CTRP6) is a newly identified adiponectin paralog which has been reported to modulate the fibrosis process of several diseases; however, the endometrial fibrosis function of CTRP6 remains unknown. Our study aimed to assess the role of CTRP6 in endometrial fibrosis and further explore the underlying mechanism. Here, we found that the expression of CTRP6 was downregulated in the endometrial tissues of IUA. In vitro experiments demonstrated the reduced level of CTRP6 in facilitated transforming growth factor-ß1 (TGF-ß1)-induced human endometrial stromal cells (HESCs). In addition, CTRP6 inhibited the expression of α-smooth muscle actin (α-SMA) and collagen I in TGF-ß1-treated HESCs. Mechanistically, CTRP6 activated the AMP-activated protein kinase (AMPK) and protein kinase B (AKT) pathway in HESCs, and AMPK inhibitor (AraA) or PI3K inhibitor (LY294002) pretreatment abolished the protective effect of CTRP6 on TGF-ß1-induced fibrosis. CTRP6 markedly decreased TGF-ß1-induced Smad3 phosphorylation and nuclear translocation, and AMPK or AKT inhibition reversed these effects. Notably, CTRP6-overexpressing treatment alleviated the fibrosis of endometrium in vivo. Therefore, CTRP6 ameliorates endometrial fibrosis, among which AMPK and AKT are essential for the anti-fibrotic effect of CTRP6 via the Smad3 pathway. Taken together, CTRP6 may be a potential therapeutic target for the treatment of intrauterine adhesion.

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.

Human amnion mesenchymal stem cells promote endometrial repair via paracrine, preferentially than transdifferentiation.

BACKGROUND: Intrauterine adhesion (IUA) is one of the most severe causes of infertility in women of childbearing age with injured endometrium secondary to uterine performance. Stem cell therapy is effective in treating damaged endometrium. The current reports mainly focus on the therapeutic effects of stem cells through paracrine or transdifferentiation, respectively. This study investigates whether paracrine or transdifferentiation occurs preferentially in treating IUA. METHODS: Human amniotic mesenchymal stem cells (hAMSCs) and transformed human endometrial stromal cells (THESCs) induced by transforming growth factor beta (TGF-ß1) were co-cultured in vitro. The mRNA and protein expression levels of Fibronectin (FN), Collagen I, Cytokeratin19 (CK19), E-cadherin (E-cad) and Vimentin were detected by Quantitative real-time polymerase chain reaction (qPCR), Western blotting (WB) and Immunohistochemical staining (IHC). The Sprague-Dawley (SD) rats were used to establish the IUA model. hAMSCs, hAMSCs-conditional medium (hAMSCs-CM), and GFP-labeled hAMSCs were injected into intrauterine, respectively. The fibrotic area of the endometrium was evaluated by Masson staining. The number of endometrium glands was detected by hematoxylin and eosin (H&E). GFP-labeled hAMSCs were traced by immunofluorescence (IF). hAMSCs, combined with PPCNg (hAMSCs/PPCNg), were injected into the vagina, which was compared with intrauterine injection. RESULTS: qPCR and WB revealed that FN and Collagen I levels in IUA-THESCs decreased significantly after co-culturing with hAMSCs. Moreover, CK19, E-cad, and Vimentin expressions in hAMSCs showed no significant difference after co-culture for 2 days. 6 days after co-culture, CK19, E-cad and Vimentin expressions in hAMSCs were significantly changed. Histological assays showed increased endometrial glands and a remarkable decrease in the fibrotic area in the hAMSCs and hAMSCs-CM groups. However, these changes were not statistically different between the two groups. In vivo, fluorescence imaging revealed that GFP-hAMSCs were localized in the endometrial stroma and gradually underwent apoptosis. The effect of hAMSCs by vaginal injection was comparable to that by intrauterine injection assessed by H&E staining, MASSON staining and IHC. CONCLUSIONS: Our data demonstrated that hAMSCs promoted endometrial repair via paracrine, preferentially than transdifferentiation.

IUA is the crucial cause of infertility in women of childbearing age, and no satisfactory treatment measures have been found in the clinic. hAMSCs can effectively treat intrauterine adhesions through paracrine and transdifferentiation mechanisms. This study confirmed in vitro and in vivo that amniotic mesenchymal stem cells preferentially inhibited endometrial fibrosis and promoted epithelial repair through paracrine, thus effectively treating intrauterine adhesions. The level of fibrosis marker proteins in IUA-THESCs decreased significantly after co-culturing with hAMSCs for 2 days in vitro. However, the level of epithelial marker proteins in hAMSCs increased significantly, requiring at least 6 days of co-culture. hAMSCs-CM had the same efficacy as hAMSCs in inhibiting fibrosis and promoting endometrial repair in IUA rats, supporting the idea that hAMSCs promoted endometrial remodeling through paracrine in vivo. In addition, GFP-labeled hAMSCs continuously colonized the endometrial stroma instead of the epithelium and gradually underwent apoptosis. These findings prove that hAMSCs ameliorate endometrial fibrosis of IUA via paracrine, preferentially than transdifferentiation, providing the latest insights into the precision treatment of IUA with hAMSCs and a theoretical basis for promoting the "cell-free therapy" of MSCs.

Extended balloon stent placement for reducing intrauterine adhesion recurrence: a retrospective cohort study.

RESEARCH QUESTION: What are the efficacy, safety and reproductive outcomes of intrauterine balloon stent placement for 4 or 6 weeks after hysteroscopic adhesiolysis? DESIGN: This retrospective cohort study was conducted at a university-affiliated hospital, and included 155 women with moderate to severe intrauterine adhesions who underwent hysteroscopic adhesiolysis between March 2016 and December 2019. Participants were divided according to whether the heart-shaped balloon stent was left in place for 4 (group 1) or 6 (group 2) weeks after surgery. Stents removed at the second-look hysteroscopy 4 or 6 weeks after surgery were sent for culturing of common bacteria. The incidence of adhesion reformation, adhesion score reduction, bacterial colonization of the intrauterine balloon stent, live birth rate and time to live birth were analysed. RESULTS: Group 2 had a significantly lower adhesion reformation rate (45.7% versus 28.2%, P = 0.024) and a more significant reduction in adhesion score (5.2 ± 2.1 versus 6.3 ± 2.2, P = 0.003) compared with group 1. However, no statistical difference was observed in the percentage of bacterial colonization of the intrauterine balloon stent (55.9% versus 66.7%, P = 0.174), live birth rate (52.4% versus 42.3%, P = 0.331) or time to live birth (hazard ratio 1.09, 95% confidence interval 0.60-1.96, P = 0.778) between the two groups. CONCLUSIONS: Extending intrauterine balloon stent use from 4 to 6 weeks further reduces the adhesion reformation rate after hysteroscopic adhesiolysis in patients with moderate to severe intrauterine adhesion. No increase in bacterial colonization of the balloon stent was observed. Extending the duration of intrauterine balloon stent placement did not significantly affect live birth rates.

Effects and safety of hyaluronic acid gel on intrauterine adhesion and fertility after intrauterine surgery: a systematic review and meta-analysis with trial sequential analysis of randomized controlled trials.

OBJECTIVE: This study aimed to determine the efficacy and safety of hyaluronic acid gel for the prevention of intrauterine adhesions and improved fertility after intrauterine surgery. DATA SOURCES: PubMed, EMBASE, Cochrane Library, Web of science, and ClinicalTrials.gov were searched up to November 1, 2023. STUDY ELIGIBILITY CRITERIA: Randomized controlled trials that reported intrauterine adhesion and fertility outcomes among women who used hyaluronic acid after intrauterine surgery. METHODS: The risk of bias was assessed using criteria of the Cochrane Handbook, and the quality of the evidence was evaluated using the Grades of Recommendation, Assessment, Development, and Evaluation system. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. A trial sequential analysis was conducted to assess the outcomes, and Stata 14 was used for sensitivity analyses and publication bias analyses. RESULTS: Data from 16 randomized controlled trials involving 2359 patients were extracted and analyzed. The analysis revealed that hyaluronic acid reduced the incidence of intrauterine adhesion (risk ratio, 0.53; 95% confidence interval, 0.42-0.67; I2=48%) and improve pregnancy rates (risk ratio, 1.24; 95% confidence interval, 1.02-1.50; I2=0%). A subgroup analysis was conducted to evaluate factors that influence the effect of hyaluronic acid on the incidence of intrauterine adhesion. It was found that a small volume of hyaluronic acid reduced the incidence of intrauterine adhesions. Hyaluronic acid exhibited a protective effect among patients who underwent various intrauterine surgeries and who had different gynecologic medical histories. The protective effect was statistically significant after a follow-up of 6 to 12 weeks. The results of the trial sequential analysis indicated that the effect of hyaluronic acid on the incidence of mild intrauterine adhesions, pregnancy rates, live birth rates, and miscarriage rates after intrauterine surgery may be inconclusive and thus further evaluation is required in the form of additional clinical trials. However, the remaining effects were found to be verifiable and did not require more clinical trials for confirmation. CONCLUSION: Hyaluronic acid can safely and effectively reduce the incidence of intrauterine adhesions and may improve fertility outcomes.

Histological study of telocytes in mice intrauterine adhesion model and their positive effect on mesenchymal stem cells in vitro.

Intrauterine adhesions (IUA), the main cause of secondary infertility in women, result from irreversible fibrotic repair of the endometrium due to inflammation or human factors, accompanied by disruptions in the repair function of endometrial stem cells. This significantly impacts the physical and mental health of women in their childbearing years. Telocytes (TCs), a distinctive type of interstitial cells found in various tissues and organs, play diverse repair functions due to their unique spatial structure. In this study, we conduct the inaugural exploration of the changes in TCs in IUA disease and their potential impact on the function of stem cells. Our results show that in vivo, through double immunofluorescence staining (CD34+/Vimentin+; CD34+/CD31-), as endometrial fibrosis deepens, the number of TCs gradually decreases, telopodes shorten, and the three-dimensional structure becomes disrupted in the mouse IUA mode. In vitro, TCs can promote the proliferation and cycle of bone mesenchymal stem cells (BMSCs) by promoting the Wnt/ß-catenin signaling pathway, which were inhibited using XAV939. TCs can promote the migrated ability of BMSCs and contribute to the repair of stem cells during endometrial injury. In addition, TCs can inhibit the apoptosis of BMSCs through the Bcl-2/Bax pathway. In conclusion, our study demonstrates, for the first time, the resistance role of TCs in IUA disease, shedding light on their potential involvement in endometrial repair through the modulation of stem cell function.

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).

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-ß1, 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.

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.

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.

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.

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.

Prolonged adhesiolysis to pregnancy interval is associated with placenta accreta spectrum in women with intrauterine adhesion.

BACKGROUND: Both the trauma of endometrium and hysteroscopic adhesiolysis can lead to a high rate of placenta accreta spectrum (PAS) in women with intrauterine adhesion (IUA). This study analysed the impact of time interval from adhesiolysis to pregnancy on PAS in IUA women. METHODS: Patients diagnosed with IUA who underwent adhesiolysis in Anhui Women and Children's Medical Centre between January 2016 and December 2020 were included in this case-series study. Clinical data were obtained from electronic medical records and telephone interviews. RESULTS: Among a total of 102 IUA women with successful pregnancies, 8 (7.8%) suffered from miscarriages with PAS, and 94 (92.2%), 47 with PAS and 47 without PAS, had successful delivery. The total prevalence of PAS in pregnant women with IUA was 53.9% (55/102). The average time from adhesiolysis to pregnancy in the PAS group was significantly longer than in the non-PAS group (14.2 ± 5.7 vs. 10.3 ± 4.4 months, p = 0.000). Regression analysis showed that AFS grade (OR = 7.40, 95% CI 1.38-39.73, p = 0.020) and adhesiolysis to pregnancy interval time between 12 and 24 months (OR = 12.09, 95% CI 3.76-38.83, p = 0.000) were closely related to PAS. A Kaplan-Meier analysis showed the median interval time to PAS was 16.00 months (95% CI 15.11-16.89). CONCLUSIONS: We assume that prolonged adhesiolysis to pregnancy interval may be considered a significant risk factor for PAS in IUA women.

Both the trauma of endometrium and hysteroscopic adhesiolysis can result in a high rate of placenta accreta spectrum in women with intrauterine adhesion. This study analysed the impact of time interval from adhesiolysis to pregnancy on placenta accreta spectrum in intrauterine adhesion women. This case-series study included patients diagnosed with intrauterine adhesion who underwent adhesiolysis in Anhui Women and Children's Medical Centre between January 2016 and December 2020. Clinical data were obtained from electronic medical records and telephone interviews. We assume that prolonged adhesiolysis to pregnancy interval may be considered a significant risk factor for placenta accreta spectrum in intrauterine adhesion women.

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.

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-1ß and TNF-α in blood, and downregulated the TGF-ß1/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.

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 in 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.

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

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

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.

The effect of the combined use of an intrauterine device and a Foley balloon in the prevention of adhesion following hysteroscopic adhesiolysis.

The aim of this study was to determine whether intrauterine device (IUD) combined with Foley balloon could obtain better efficacy in preventing re-adhesion for patients with intrauterine adhesions (IUAs). The data of 89 patients with IUAs, who underwent transcervical resection of adhesion (TCRA) operation, were retrospectively collected. According to the method used for preventing re-adhesion of the uterine cavity after TCRA, the enrolled patients were divided into IUD group, Foley balloon group and the combined group. The second-look hysteroscopy was carried out at 3 months after TCRA surgery. The severity and extent of IUA were scored by American Fertility Society (AFS) scoring system. The endometrial thickness (EMT) was measured by ultrasound. Furthermore, the menstruation and pregnancy outcomes were also assessed. Our results showed that the postoperative decrease in AFS score was significantly greater in the combined group than in the IUD group or in the Foley balloon group. The increase in menstrual score among the 3 groups was not significantly different. The difference between preoperative and postoperative values of EMT was greater in the combined group than in the other 2 groups. In conclusion, the effect of a Foley balloon combined with IUD in preventing re-adhesion after TCRA might be better than that of IUD or Foley balloon alone.