Umbilical cord mesenchymal stem cell-derived exosomes reverse endometrial fibrosis by the miR-145-5p/ZEB2 axis in intrauterine adhesions.

RESEARCH QUESTION: What is the specific mechanism of umbilical cord mesenchymal stem cell-derived exosomes (UCMSC-exos) in regulating endometrial repair and regeneration? DESIGN: In this study, UCMSC-exos were harvested by differential ultracentrifugation from umbilical cord mesenchymal stem cell culture supernatant and identified with western blotting, transmission electron microscopy and nanoparticle tracking analysis. Transforming growth factor-ß1 (TGFß1) at different concentrations was used to construct the intrauterine adhesions cell model. The fibrotic markers were assessed by quantitative reverse transcription-polymerase chain reaction and western blotting. The effects of miR-145-5p over-expression on endometrial fibrosis were assessed. Dual luciferase assay was performed to verify the relationship between miR-145-5p and zinc finger E-box binding homeobox 2 (ZEB2). RESULTS: The isolated UCMSC-exos had a typical cup-shaped morphology, expressed the specific exosomal markers Alix, CD63 and TSG101, and were approximately 50-150 nm in diameter. TGFß1 at 10 ng/ml significantly promoted endometrial fibrosis, which was reversed by 20 µg/ml UCMSC-exos. Exosomal miR-145-5p ameliorated TGFß1-induced endometrial fibrosis. ZEB2 was inversely regulated by exosomal miR-145-5p as a direct target. CONCLUSIONS: UCMSC-exos might reverse endometrial stromal cell fibrosis by regulating the miR-145-5p/ZEB2 axis, representing a potential novel strategy to promote endometrial repair.

Evaluation of different rat models intrauterine adhesion models and improvement of the technique for their establishment.

Intrauterine adhesion (IUA), a leading cause of uterine infertility, is characterized by endometrial fibrosis. Implementing an appropriate animal model is essential for the research on the mechanisms of IUA. In the present study, we established and evaluated different intrauterine adhesion modeling procedures in rats to provide a reference for researchers. Rat IUA models were established by mechanical injury, 95% ethanol injection, and dual (mechanical injury with infection) injury. After two estrus cycles, the female rats were mated with sexually mature male rats, and uterine tissues were obtained on the 5th day of pregnancy. Hematoxylin and eosin staining and immunohistochemical detection of cytokeratin 19 and vimentin were performed to assess the morphology of the endometrium. Masson's trichrome staining and the expression of transforming growth factor-ß1 and collagen I were used to assess the endometrium fibrosis. The expression of integrin avß3, leukemia inhibitory factor, and homeobox gene A10 in the rat endometrium was used to evaluate the endometrial receptivity. In addition, the efficiency of embryo implantation was examined in the uterus on the 8th day of pregnancy. Our study found that mechanical injury caused by a curette can be completely repaired after two estrus cycles. However, dual injury and 95% ethanol injection can be used to establish an IUA rat model, and the dual injury is closer to the clinicpathological characteristics of IUA.

Postoperative reproductive results of infertile patients with intrauterine adhesions: A retrospective analysis.

OBJECTIVE: To explore the reproductive outcomes after hysteroscopic separation of intrauterine adhesions (IUA) in infertile patients due to IUA. METHODS: This retrospective study enrolled patients with fertility requirements and infertility due to IUA. Data were collected from the hospital medical records and by follow-up by telephone. The impact on pregnancy and pregnancy outcome of preoperative adhesion, menstrual conditions before and after surgery and postoperative re-adhesion was analysed. RESULTS: A total of 106 patients (median age, 28 years) were enrolled in the study. There was a significant correlation between preoperative menstrual patterns and pregnancy rate. There were 56 pregnancies (pregnancy rate 52.83%) after the operation. Patients with improved menstruation after the operation had a significantly higher pregnancy rate (pregnancy rate 56.25%; 45 of 80 patients) compared with the patients that did not experience any improvement in their postoperative menstrual status (pregnancy rate 21.43%; three of 14 patients). Of the 56 pregnancies, 40 (71.43%) resulted in live births and six (10.71%) patients had miscarriages. A total of 54 of 56 patients (96.43%) became pregnant within 2 years. CONCLUSION: Pregnancy after intrauterine adhesion separation has a high rate of miscarriage and obstetric complications, so close monitoring of the patient is required.

Correlative study of preoperative three-dimensional transvaginal ultrasound findings and ongoing pregnancy/live birth in patients with intrauterine adhesions following hysteroscopic adhesiolysis: a retrospective study.

Background: Three-dimensional transvaginal ultrasound (3D-TVUS) has recently been adopted in the gynecological sciences as it provides an accurate illustration of adhesions and the extent of cavity damage, and hence, can be used as an essential tool for the prognosis of intrauterine adhesions (IUA). This study aims to demonstrate whether preoperative 3D-TVUS features are relevant to ongoing pregnancy and live births in patients with IUA following hysteroscopic adhesiolysis (HA). Methods: From February 22, 2018, to October 31, 2018, a total of 401 patients with moderate to severe IUA and underwent HA were retrospectively enrolled. Preoperative 3D-TVUS diagnosed data and the patients' basic information were collected, and patients were followed up over 2 years after HA for reproductive outcomes. The correlation between each imaging variable and ongoing pregnancy or live birth was analyzed by binary logistic regression. Results: Among the 401 patients, 143 had live births, 41 patients had abortions, and 217 patients were infertile. Thick endometrium was found to be favorable for ongoing pregnancy (ongoing pregnancy group =5.4±1.95 mm, no-ongoing pregnancy group =4.7±2.24 mm, P=0.0095) and live birth (live birth group=5.6±1.92 mm, no-live birth group =4.7±2.20 mm, P=0.0029). Scar contraction was not conducive for pregnancy, while the lower segmentation was not a risk factor for ongoing pregnancy (P=0.0003). It also was a risk factor for ongoing pregnancy (P<0.0001) and live birth (P<0.0001) when the segmentation of the endometrial absence was mainly in the upper and middle segments of the uterine cavity. The area under the curves (AUCs) of the prediction model for ongoing pregnancy and live birth were 0.9116 and 0.8751, respectively, based on the meaningful variables above combined with other clinical characteristics. Conclusions: Preoperative 3D-TVUS features have a close correlation with ongoing pregnancy and live births in patients with IUA following HA, and can be applied for predicting ongoing pregnancy and live births in IUA patients post-HA.

Mesenchymal stem cells therapy: A promising method for the treatment of uterine scars and premature ovarian failure.

Both intrauterine adhesions (IUA) and premature ovarian failure (POF) have plagued women all over the world for a long time. It is well known that all invasive operations involving the uterus can disrupt its structural and functional integrity to a varying degree, which inevitably lead to abnormal scar formation, such as IUA, also known as Asherman's syndrome with symptoms like hypomenorrhea or infertility. Another reproductive disorder that causes infertility is primary ovarian insufficiency (POI) or POF, which is a degenerative phenomenon in the ovary among women under the age of 40. In recent years, various types of stem cells, especially mesenchymal stem cells (MSCs) have been widely used in reproductive medicine due to their properties, such as immunoregulation, anti-inflammation, angiogenesis, anti-apoptosis, and trophicity. However, the extensive clinical application of cell therapy is impeded by their safety, cost, and manufacturing. In this review, we sought to summarize the recent advances in using different types of MSCs in treating uterine scars and POF. We also describe several biological pathways and molecules involved in animal studies and clinical application; extracellular vesicles secreted by MSCs may be a promising attractive tool to ensure the treatment of infertility by restoring normal reproductive function.

Analysis of endometrial microbiota in intrauterine adhesion by high-throughput sequencing.

BACKGROUND: Intrauterine adhesions (IUA) arise from scar tissue formation between the endometrial surfaces in response to mechanical or infectious injuries. However, the potential role of endometrial microbiota in IUA remains unclear. We aimed to explore the composition of endometrial microbiota and its potential role in IUA. METHODS: We retrospectively enrolled 46 patients diagnosed with IUA and 21 infertility patients without intrauterine lesions, as control subjects. All cases were diagnosed with hysteroscopy and endometrial tissues were taken from the intrauterine cavity using a hysteroscopic cutting ring without electricity study. After endometrial samples were collected, DNA was extracted and amplified for barcoded Illumina high-throughput next-generation sequencing targeted to the 16S rRNA V4 region for microbiota. Microbiota data were compared between two groups using α-diversity, ß-diversity and Nonmetric Multidimensional Scaling based on Weighted Unifrac distance. RESULTS: At the phyla level, the dominant bacteria included Proteobacteria, Firmicutes, Bacteroidetes and Actinobacteria. Proteobacteria accounted for more than 64.48%. At the genus level, the proportions of Klebsiella, Shewanella, and Lactobacillus were higher in patients with IUA than in non- IUA participants (20.67% and 8.77%, P=0.006, 13.37% and 4.53%, P=0.175, 12.74% and 6.95%, P=0.882; respectively). The proportion of Acinetobacter was significantly lower in patients with IUA than in non- IUA participants (P=0.005). CONCLUSIONS: Endometrial microbiota differ between patients with IUA and infertility patients without intrauterine lesions, and the potential variation of endometrial microbiota might cause IUA.

Logistic regression analyses of factors affecting fertility of intrauterine adhesions patients.

BACKGROUND: Intrauterine adhesion (IUA) prevalence is difficult to measure, but appears to have increased over the last few decades. The reproductive outcomes following hysteroscopic adhesiolysis (HA) for moderate-severe IUAs were unsatisfactory, and few studies have analyzed the clinical characteristics pre-, intra- and post-HA to determine the main risk factors for infertility in patients with IUAs. METHODS: This retrospective observational study included 406 patients, desiring fertility, who had undergone HA between January 1st, 2016 to May 31st, 2017, and had moderate-to-severe IUA [5-12 on the American Fertility Society (AFS) classification scale]. Logistic regression was performed to analyze the data of the clinical characteristics associated with IUA. RESULTS: A total of 406 IUA patients were initially collected. Twenty-six [26] were lost during follow-up or excluded by other criteria; 380 were included in the study with a follow-up period ranging from 2 to 3 years. There were 215 patients (56.6%) that became pregnant, of whom 18 spontaneously miscarried, 5 birthed prematurely (31-36 gestational weeks), 182 delivered at term, and 10 were pregnant at the end of the study. A bivariate and binary logistic regression analysis showed that an age of >30 years, cohesive IUA, lack of increased menstrual volume, and more than 2 times undergoing HA procedure were the risk factors for infertility in IUA patients (P<0.05). CONCLUSIONS: Age, severity of IUA, increased menstrual volume, and HA procedures were the dominant factors affecting reproductive outcomes and may be regarded as potential predictors for evaluating IUA prognosis.

The role of preoperative 3D-ultrasound in intraoperative judgement for hysteroscopic adhesiolysis.

BACKGROUND: Hysteroscopic adhesiolysis (HA) remains the mainstay of treatment for intrauterine adhesions (IUA). In cases of moderate or severe IUA, the assistance of various adjunctive aids are usually sought to improve HA's success rate. Among these, intraoperative transabdominal ultrasound (TAS) is the most common; however, it has certain limitations. Preoperative three-dimensional transvaginal ultrasound (3D-TVUS) has been accepted as a non-invasive way to provide accurate information about the uterine cavity. This prospective, non-randomized controlled study will assess the effects of pre-operative 3D-TVUS prior to HA in improving the surgeon's intraoperative judgement. METHODS: A total of 362 patients, who met the inclusion criteria, aged between 18 and 45 years and diagnosed with moderate or severe IUA underwent HA at our hospital from March 2018 to December 2018. Participants were divided into 2 groups; the study group; n=182 performed 3D-TVUS evaluation prior to HA, and the control group; n=180 underwent HA without preoperative 3D-TVUS evaluation. The following basic information were collected prospectively for both groups: age, parity, history of abortion, degree of IUA, surgical complications and number of hysteroscopic interventions. The data obtained from 3D-TVUS in the study group was carefully studied at the preoperative stage by the operator and was integrated into intraoperative findings, further assisting with intraoperative decisions. The guiding value of preoperative 3D-TVUS for HA was evaluated by comparing and analyzing the postoperative exposure rate of clearly visible tubal ostia between the groups. RESULTS: Based on the basic information (P>0.05) collected preoperatively, there were no statistically significant differences between the groups. Postoperatively, the study group had a better surgical success rate with a more significant AFS score reduction (4.71±2.05; P<0.0001) and better morphological restoration of the uterine cavity, with more adhesion-free uterine horns and more clearly visible fallopian tube ostia (P<0.0001) following HA. CONCLUSIONS: This study showed that preoperative 3D-TVUS evaluation helped the hysteroscopists with their intraoperative decision-making while carrying out HA. In comparison to those who did not perform preoperative 3D ultrasound, those who underwent 3D-TVUS evaluation had a better surgical success rate in retrieving the fallopian tube ostia and the restoration of normal uterine cavity morphology.

[In vivo tracing of human amniotic mesenchymal stem cells labeled with PKH26 in rat intrauterine adhesions model].

To observe the migration of human amniotic mesenchymal stem cells (hAMSCs) labeled with PKH26 in the endometrium of rats intrauterine adhesion. hAMSCs were isolated, identified and labeled with PKH26 to detect the biological characteristics of the cells. Rat intrauterine adhesion models were established using mechanical and infective method and PKH26-labeled hAMSCs were transplanted through the tail vein. The distribution of PKH26 labeled hAMSCs in the endometrium of rats were observed with the fluorescence confocal microscope. The results showed that PKH26 stain had no significant effect on cell activity, cycle, apoptosis and so on. PKH26-labeled positive cells were mainly distributed in injured endometrium of rats. It shows that the PKH26 labeling technique is a safe and effective method for tracing the human amniotic mesenchymal stem cells in the treatment of intrauterine adhesions.