Autologous menstrual blood-derived stromal cells transplantation for severe Asherman's syndrome

New advances in the treatment of thin endometrium

Thin endometrium (TE) is defined as a mid-luteal endometrial thickness ≤7mm. TE can affect endometrial tolerance, leading to lower embryo implantation rates and clinical pregnancy rates, and is also associated with impaired outcomes from assisted reproductive treatment. Herein, we systematically review TE causes, mechanisms, and treatments. TE pathogenesis has multiple causes, with the endometrium becoming thinner with age under hormonal influence. In addition, uterine cavity factors are important, as the inflammatory environment may affect expressions of certain genes thereby inhibiting endometrial stromal cell proliferation and promoting apoptosis. Long-term oral contraceptive use or the use of ovulation-promoting drugs are also definite factors contributing to endometrial thinning. Other patients have primary factors, for which the clinical etiology remains unknown. The main therapeutic strategies available for TE are pharmacological (including hormonal and vasoactive drugs), regenerative medicine, intrauterine infusion of growth factor-granulocyte colony-stimulating factor, autologous platelet-rich plasma, and complementary alternative therapies (including traditional Chinese herbal medicine and acupuncture). However, the associated mechanisms of action are currently unclear. Clinical scholars have proposed various approaches to improve treatment outcomes in patients with TE, and are exploring the principles of efficacy, offering potentials for novel treatments. It is hoped that this will improve TE tolerance, increase embryo implantation rates, and help more couples with infertility with effective treatments.

Menstrual blood-derived mesenchymal stem cells combined with collagen I gel as a regenerative therapeutic strategy for degenerated disc after discectomy in rats

BACKGROUND

Annulus fibrosis (AF) defects have been identified as the primary cause of disc herniation relapse and subsequent disc degeneration following discectomy. Stem cell-based tissue engineering offers a promising approach for structural repair. Menstrual blood-derived mesenchymal stem cells (MenSCs), a type of adult stem cell, have gained attention as an appealing source for clinical applications due to their potential for structure regeneration, with ease of acquisition and regardless of ethical issues.

METHODS

The differential potential of MenSCs cocultured with AF cells was examined by the expression of collagen I, SCX, and CD146 using immunofluorescence. Western blot and ELISA were used to examine the expression of TGF-β and IGF-I in coculture system. An AF defect animal model was established in tail disc of Sprague-Dawley rats (males, 8 weeks old). An injectable gel containing MenSCs (about 1*106/ml) was fabricated and transplanted into the AF defects immediately after the animal model establishment, to evaluate its repairment properties. Disc degeneration was assessed via magnetic resonance (MR) imaging and histological staining. Immunohistochemical analysis was performed to assess the expression of aggrecan, MMP13, TGF-β and IGF-I in discs with different treatments. Apoptosis in the discs was evaluated using TUNEL, caspase3, and caspase 8 immunofluorescence staining.

RESULTS

Coculturing MenSCs with AF cells demonstrated ability to express collagen I and biomarkers of AF cells. Moreover, the coculture system presented upregulation of the growth factors TGF-β and IGF-I. After 12 weeks, discs treated with MenSCs gel exhibited significantly lower Pffirrmann scores (2.29 ± 0.18), compared to discs treated with MenSCs (3.43 ± 0.37, p < 0.05) or gel (3.71 ± 0.29, p < 0.01) alone. There is significant higher MR index in disc treated with MenSCs gel than that treated with MenSCs (0.51 ± 0.05 vs. 0.24 ± 0.04, p < 0.01) or gel (0.51 ± 0.05 vs. 0.26 ± 0.06, p < 0.01) alone. Additionally, MenSCs gel demonstrated preservation of the structure of degenerated discs, as indicated by histological scoring (5.43 ± 0.43 vs. 9.71 ± 1.04 in MenSCs group and 10.86 ± 0.63 in gel group, both p < 0.01), increased aggrecan expression, and decreased MMP13 expression in vivo. Furthermore, the percentage of TUNEL and caspase 3-positive cells in the disc treated with MenSCs Gel was significantly lower than those treated with gel alone and MenSCs alone. The expression of TGF-β and IGF-I was higher in discs treated with MenSCs gel or MenSCs alone than in those treated with gel alone.

CONCLUSION

MenSCs embedded in collagen I gel has the potential to preserve the disc structure and prevent disc degeneration after discectomy, which was probably attributed to the paracrine of growth factors of MenSCs.

Endometrial mesenchymal stromal/stem cells improve regeneration of injured endometrium in mice

BACKGROUND

The monthly regeneration of human endometrial tissue is maintained by the presence of human endometrial mesenchymal stromal/stem cells (eMSC), a cell population co-expressing the perivascular markers CD140b and CD146. Endometrial regeneration is impaired in the presence of intrauterine adhesions, leading to infertility, recurrent pregnancy loss and placental abnormalities. Several types of somatic stem cells have been used to repair the damaged endometrium in animal models, reporting successful pregnancy. However, the ability of endometrial stem cells to repair the damaged endometrium remains unknown.

METHODS

Electrocoagulation was applied to the left uterine horn of NOD/SCID mice causing endometrial injury. Human eMSC or PBS was then injected into the left injured horn while the right normal horn served as controls. Mice were sacrificed at different timepoints (Day 3, 7 and 14) and the endometrial morphological changes as well as the degree of endometrial injury and repair were observed by histological staining. Gene expression of various inflammatory markers was assessed using qPCR. The functionality of the repaired endometrium was evaluated by fertility test.

RESULTS

Human eMSC successfully incorporated into the injured uterine horn, which displayed significant morphological restoration. Also, endometrium in the eMSC group showed better cell proliferation and glands formation than the PBS group. Although the number of blood vessels were similar between the two groups, gene expression of VEGF-α significantly increased in the eMSC group. Moreover, eMSC had a positive impact on the regeneration of both stromal and epithelial components of the mouse endometrium, indicated by significantly higher vimentin and CK19 protein expression. Reduced endometrial fibrosis and down-regulation of fibrosis markers were also observed in the eMSC group. The eMSC group had a significantly higher gene expression of anti-inflammatory factor Il-10 and lower mRNA level of pro-inflammatory factors Ifng and Il-2, indicating the role of eMSC in regulation of inflammatory reactions. The eMSC group showed higher implantation sites than the PBS group, suggesting better endometrial receptivity with the presence of newly emerged endometrial lining.

CONCLUSIONS

Our findings suggest eMSC improves regeneration of injured endometrium in mice.

Impaired receptivity of thin endometrium: therapeutic potential of mesenchymal stem cells

The endometrium is a resilient and highly dynamic tissue, undergoing cyclic renewal in preparation for embryo implantation. Cyclic endometrial regeneration depends on the intact function of several cell types, including parenchymal, endothelial, and immune cells, as well as adult stem cells that can arise from endometrial or extrauterine sources. The ability of the endometrium to undergo rapid, repeated regeneration without scarring is unique to this tissue. However, if this tissue renewal process is disrupted or dysfunctional, women may present clinically with infertility due to endometrial scarring or persistent atrophic/thin endometrium. Such disorders are rate-limiting in the treatment of female infertility and in the success of in vitro fertilization because of a dearth of treatment options specifically targeting the endometrium. A growing number of studies have explored the potential of adult stem cells, including mesenchymal stem cells (MSCs), to treat women with disorders of endometrial regeneration. MSCs are multipotent adult stem cells with capacity to differentiate into cells such as adipocytes, chondrocytes, and osteoblasts. In addition to their differentiation capacity, MSCs migrate toward injured sites where they secrete bioactive factors (e.g. cytokines, chemokines, growth factors, proteins and extracellular vesicles) to aid in tissue repair. These factors modulate biological processes critical for tissue regeneration, such as angiogenesis, cell migration and immunomodulation. The MSC secretome has therefore attracted significant attention for its therapeutic potential. In the uterus, studies utilizing rodent models and limited human trials have shown a potential benefit of MSCs and the MSC secretome in treatment of endometrial infertility. This review will explore the potential of MSCs to treat women with impaired endometrial receptivity due to a thin endometrium or endometrial scarring. We will provide context supporting leveraging MSCs for this purpose by including a review of mechanisms by which the MSC secretome promotes regeneration and repair of nonreproductive tissues.

S100A8/A9 promotes endometrial fibrosis via regulating RAGE/JAK2/STAT3 signaling pathway

Intrauterine adhesion (IUA) is characterized by endometrial fibrosis. S100A8/A9 plays an important role in inflammation and fibroblast activation. However, the role of S100A8/A9 in IUA remains unclear. In this study, we collect normal and IUA endometrium to verify the expression of S100A8/A9. Human endometrial stromal cells (hEnSCs) are isolated to evaluate fibrosis progression after S100A8/A9 treatment. A porcine IUA model is established by electrocautery injury to confirm the therapeutic effect of menstrual blood-derived stromal cells (MenSCs) on IUA. Our study reveals increased S100A8/A9 expression in IUA endometrium. S100A8/A9 significantly enhances hEnSCs proliferation and upregulates fibrosis-related and inflammation-associated markers. Furthermore, S100A8/A9 induces hEnSCs fibrosis through the RAGE-JAK2-STAT3 pathway. Transplantation of MenSCs in a porcine IUA model notably enhances angiogenesis, mitigates endometrial fibrosis and downregulates S100A8/A9 expression. In summary, S100A8/A9 induces hEnSCs fibrosis via the RAGE-JAK2-STAT3 pathway, and MenSCs exhibit marked effects on endometrial restoration in the porcine IUA model.

VitroGel-loaded human MenSCs promote endometrial regeneration and fertility restoration

Introduction: Intrauterine adhesions (IUA), also known as Asherman's syndrome, is caused by trauma to the pregnant or non-pregnant uterus, which leads to damaged endometrial basal lining and partial or total occlusion of the uterine chambers, resulting in abnormal menstruation, infertility, or recurrent miscarriage. The essence of this syndrome is endometrial fibrosis. And there is no effective treatment for IUA to stimulate endometrial regeneration currently. Recently, menstrual blood-derived stem cells (MenSCs) have been proved to hold therapeutic promise in various diseases, such as myocardial infarction, stroke, diabetes, and liver cirrhosis. Methods: In this study, we examined the effects of MenSCs on the repair of uterine adhesions in a rat model, and more importantly, promoted such therapeutic effects via a xeno-free VitroGel MMP carrier. Results: This combined treatment reduced the expression of inflammatory factors, increased the expression of anti-inflammatory factors, restricted the area of endometrial fibrosis, diminished uterine adhesions, and partially restored fertility, showing stronger effectiveness than each component alone and almost resembling the sham group. Discussion: Our findings suggest a highly promising strategy for IUA treatment.

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

Background

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

Methods

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

Results

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

Conclusions

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

Quantification of Endometrial Fibrosis Using Noninvasive MRI T2 Mapping: Initial Findings

BACKGROUND

Endometrial fibrosis may cause infertility. Accurate evaluation of endometrial fibrosis helps clinicians to schedule timely therapy.

PURPOSE

To explore T2 mapping for assessing endometrial fibrosis.

STUDY TYPE

Prospective.

POPULATION

Ninety-seven women with severe endometrial fibrosis (SEF) and 21 patients with mild to moderate endometrial fibrosis (MMEF), diagnosed by hysteroscopy, and 37 healthy women.

FIELD STRENGTH/SEQUENCE

3T, T2-weighted turbo spin echo (T2-weighted imaging) and multi-echo turbo spin echo (T2 mapping) sequences.

ASSESSMENT

Endometrial MRI parameters (T2, thickness [ET], area [EA], and volume [EV]) were measured by N.Z. and Q.H. (9- and 4-years' experience in pelvic MRI) and compared between the three subgroups. A multivariable model including MRI parameters and clinical variables (including age and body mass index [BMI]) was developed to predict endometrial fibrosis assessed by hysteroscopy.

STATISTICAL TESTS

Kruskal-Wallis; ANOVA; Spearman's correlation coefficient (rho); area under the receiver operating characteristic curve (AUC); binary logistic regression; intraclass correlation coefficient (ICC). P value <0.05 for statistical significance.

RESULTS

Endometrial T2, ET, EA, and EV of MMEF patients (185 msec, 8.2 mm, 168 mm2 , and 2181 mm3 ) and SEF patients (164 msec, 6.7 mm, 120 mm2 , and 1762 mm3 ) were significantly lower than those of healthy women (222 msec, 11.7 mm, 316 mm2 , and 3960 mm3 ). Endometrial T2 and ET of SEF patients were significantly lower than those of MMEF patients. Endometrial T2, ET, EA, and EV were significantly correlated to the degree of endometrial fibrosis (rho = -0.623, -0.695, -0.694, -0.595). There were significant strong correlations between ET, EA, and EV in healthy women and MMEF patients (rho = 0.850-0.908). Endometrial MRI parameters and the multivariable model accurately distinguished MMEF or SEF from normal endometrium (AUCs >0.800). Age, BMI, and MRI parameters in univariable analysis and age and T2 in multivariable analysis significantly predicted endometrial fibrosis. The reproducibility of MRI parameters was excellent (ICC, 0.859-0.980).

DATA CONCLUSION

T2 mapping has potential to noninvasively and quantitatively evaluate the degree of endometrial fibrosis.

EVIDENCE LEVEL

2 Technical Efficacy: Stage 2.

The effects of intraovarian injection of autologous menstrual blood-derived mesenchymal stromal cells on pregnancy outcomes in women with poor ovarian response

BACKGROUND

Assisted reproduction faces a significant obstacle in the form of poor ovarian response (POR) to controlled ovarian stimulation. To address this challenge, mesenchymal stem cell therapy has been proposed as a potential treatment for female infertility and/or restoration of ovarian function in POR women. Our previous research has demonstrated that menstrual blood-derived-mesenchymal stromal cells (MenSCs) injected into the ovaries of women with POR can increase pregnancy rates. The objective of this study was to examine whether MenSC therapy could enhance ovarian reserve parameters and pregnancy outcomes in a larger population of individuals with POR.

METHOD

This study consisted of 180 infertile individuals with POR who declined oocyte donation. Participants were divided into two groups: those who received bilateral MenSCs intraovarian injection and those who received no intervention. Our primary aim was to compare the rates of spontaneous pregnancy between the two groups, followed by an investigation of any alterations in the ovarian reserve parameters, such as serum FSH, AMH, and AFC levels, as well as the ICSI/IVF outcomes, in both groups of participants.

RESULTS

The MenSC therapy exhibited a favourable tolerability profile and did not raise any safety concerns. Following the 2-month follow-up period, women who received MenSC treatment demonstrated a significantly higher rate of spontaneous pregnancy (P < 0.005) and an improvement in anti-Müllerian hormone (AMH) levels (P = 0.0007) and antral follicle count (AFC) (P < 0.001), whereas the control group demonstrated a considerable decline in these parameters (Both P < 0.001). The MenSC therapy led to a greater number of mature oocytes and embryos among women who underwent ICSI/IVF. Our age subgroup analysis demonstrated a significant difference in the number of spontaneous pregnancies and ICSI/IVF outcomes between the treatment and control groups only among individuals below 40 years of age.

CONCLUSION

The results of our study indicate that MenSCs treatment may be a viable option for treating women experiencing POR. However, in order to be widely implemented in clinical practice, the clinical effectiveness of MenSCs therapy will need to be established through rigorous prospective randomized clinical trials.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05703308. Registered 01/26/2023, retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT05703308 . IRCT, IRCT20180619040147N4. Registered 08/01/2020.

MenSCs Transplantation Improve the Viability of Injured Endometrial Cells Through Activating PI3K/Akt Pathway

Endometrial injury is one of the leading causes of female infertility and is caused by intrauterine surgery, endometrial infection, repeated abortion, or genital tuberculosis. Currently, there is little effective treatment to restore the fertility of patients with severe intrauterine adhesions and thin endometrium. Recent studies have confirmed the promising therapeutic effects of mesenchymal stem cell transplantation on various diseases with definite tissue injury. The aim of this study is to investigate the improvements of menstrual blood-derived endometrial stem cells (MenSCs) transplantation on functional restoration in the endometrium of mouse model. Therefore, ethanol-induced endometrial injury mouse models were randomly divided into two groups: the PBS-treated group, and the MenSCs-treated group. As expected, the endometrial thickness and gland number in the endometrium of MenSCs-treated mice were significantly improved compared to those of PBS-treated mice (P < 0.05), and fibrosis levels were significantly reduced (P < 0.05). Subsequent results revealed that MenSCs treatment significantly promoted angiogenesis in the injured endometrium. Simultaneously, MenSCs enhance the proliferation and antiapoptotic capacity of endometrial cells, which is likely contributed by activating the PI3K/Akt signaling pathway. Further tests also confirmed the chemotaxis of GFP-labeled MenSCs towards the injured uterus. Consequently, MenSCs treatment significantly improved the pregnant mice and the number of embryos in pregnant mice. This study confirmed the superior improvements of MenSCs transplantation on the injured endometrium and uncovered the potential therapeutic mechanism, which provides a promising alternative for patients with serious endometrial injury.

Novel therapeutic strategies for injured endometrium: intrauterine transplantation of menstrual blood‑derived cells from infertile patients

BACKGROUND

Menstrual blood-derived cells show regenerative potential as a mesenchymal stem cell and may therefore be a novel stem cell source of treatment for refractory infertility with injured endometrium. However, there have been few pre-clinical studies using cells from infertile patients, which need to be addressed before establishing an autologous transplantation. Herein, we aimed to investigate the therapeutic capacity of menstrual blood-derived cells from infertile patients on endometrial infertility.

METHODS

We collected menstrual blood-derived cells from volunteers and infertile patients and confirmed their mesenchymal stem cell phenotype by flow cytometry and induction of tri-lineage differentiation. We compared the proliferative and paracrine capacities of these cells. Furthermore, we also investigated the regenerative potential and safety concerns of the intrauterine transplantation of infertile patient-derived cells using a mouse model with mechanically injured endometrium.

RESULTS

Menstrual blood-derived cells from both infertile patients and volunteers showed phenotypic characteristics of mesenchymal stem cells. In vitro proliferative and paracrine capacities for wound healing and angiogenesis were equal for both samples. Furthermore, the transplantation of infertile patient-derived cells into uterine horns of the mouse model ameliorated endometrial thickness, prevented fibrosis, and improved fertility outcomes without any apparent complications.

CONCLUSIONS

In our pre-clinical study, intrauterine transplantation of menstrual blood-derived cells may be a novel and attractive stem cell source for the curative and prophylactic therapy for injured endometrium. Further studies will be warranted for future clinical application.

Exploring the future potential of mesenchymal stem/stromal cells and their derivatives to support assisted reproductive technology for female infertility applications

Women's infertility impacts the quality of life of both patients and couples and has multifaceted dimensions that increase the number of challenges associated with female infertility and how to face them. Female reproductive disorders, such as premature ovarian failure (POF), endometriosis, Asherman syndrome (AS), polycystic ovary syndrome (PCOS), and preeclampsia, can stimulate infertility. In the last decade, translational medicine has advanced, and scientists are focusing on infertility therapy with innovative attitudes. Recent investigations have suggested that stem cell treatments could be safe and effective. Stem cell therapy has established a novel method for treating women's infertility as part of a regeneration approach. The chief properties and potential of mesenchymal stem/stromal cells (MSCs) in the future of women's infertility should be considered by researchers. Due to their high abundance, great ability to self-renew, and high differentiation capacity, as well as less ethical concerns, MSC-based therapy has been found to be an effective alternative strategy to the previous methods for treating female infertility, such as intrauterine insemination, in vitro fertilization, medicines, and surgical procedures. These types of stem cells exert their beneficial role by releasing active mediators, promoting cell homing, and contributing to immune modulation. Here we first provide an overview of MSCs and their crucial roles in both biological and immunological processes. The next large chapter covers current preclinical and clinical studies on the application of MSCs to treat various female reproductive disorders. Finally, we deliberate on the extant challenges that hinder the application of MSCs in female infertility and suggest plausible measures to alleviate these impediments.

Etiology, Risk Factors, and Management of Asherman Syndrome

Asherman syndrome is characterized by a triad of symptoms including pain, menstrual abnormalities, and infertility and is a result of intrauterine scar tissue after instrumentation of a gravid uterus. Saline sonohysterogram is typically the most sensitive diagnostic tool; however, hysteroscopy is the criterion standard for diagnosis. Treatment includes hysteroscopic-guided lysis of adhesion, with restoration of the anatomy of the uterine cavity. Several modalities are used in an attempt to reduce the reformation of scar tissue after surgery; however, there is no consensus on the ideal method. Stem cells and platelet-rich plasma are being explored as means of regenerative therapy for the endometrium, but data remain limited. At present, most individuals can have restoration of menstrual function; however, lower pregnancy rates and obstetric complications are not uncommon. These complications are worse for patients with a higher grade of disease. Efforts are needed in standardizing classification, reducing uterine instrumentation of the gravid uterus, and referring patients to health care professionals with clinical expertise in this area.

P65 mediated UBR4 in exosomes derived from menstrual blood stromal cells to reduce endometrial fibrosis by regulating YAP Ubiquitination

BACKGROUND

Intrauterine adhesion (IUA) is a recurrent and refractory reproductive dysfunction disorder for which menstrual blood-derived stromal cells (MenSCs) might be a promising intervention. We reported that administration of MenSCs-derived exosomes (MenSCs-EXO) could achieve similar therapeutic effects to MenSCs transplantation, including alleviating endometrial fibrosis and improving fertility in IUA rats. The mass spectrometry sequencing result suggested that UBR4, a member of the proteasome family, was abundantly enriched in MenSCs-EXO. This study aimed to investigate the key role of UBR4 in MenSCs-EXO for the treatment of IUA and the specific molecular mechanism.

RESULTS

UBR4 was lowly expressed in the endometrial stromal cells (EndoSCs) of IUA patients. MenSCs-EXO treatment could restore the morphology of IUA endometrium, reduce the extent of fibrosis, and promote endometrial and vascular proliferation. Knockdown of UBR4 in MenSCs did not affect the characteristics of exosomes but attenuated the therapeutic effect of exosomes. UBR4 in MenSCs-EXO could alleviate endometrial fibrosis by boosting YAP ubiquitination degradation and promoting YAP nuclear-cytoplasmic translocation. Moreover, P65 could bind to the UBR4 promoter region to transcriptionally promote the expression level of UBR4 in MenSCs.

CONCLUSION

Our study clarified that MenSCs-EXO ameliorated endometrial fibrosis in IUA primarily by affecting YAP activity mediated through UBR4, while inflammatory signaling P65 may affect UBR4 expression in MenSCs to enhance MenSCs-EXO therapeutic effects. This revealed a novel mechanism for the treatment of IUA with MenSCs-EXO, proposing a potential option for the clinical treatment of endometrial injury.

Unlocking the Potential of Mesenchymal Stem Cells in Gynecology: Where Are We Now?

Stem cells, with their remarkable capacity for differentiation into diverse cell types, are vital for the development as well as maintenance of health and homeostasis. Two unique abilities set them apart from other cells: self-renewal and the capacity for differentiation. They play important roles in embryogenesis, development, regeneration, and various other processes. Over the last decade, there has been increased interest in their potential use in the treatment of numerous diseases and disorders across multiple fields of medicine in acute, chronic, innate, and acquired diseases. Stem cells are key to maintaining the body's homeostasis and regulating growth and tissue functions. There are several types of stem cells-embryonic, adult, and human-induced pluripotent cells. Currently, mesenchymal stem cells are of great interest due to their regenerative, immunomodulatory, analgesic, and antimicrobial (anti-inflammatory) effects. Recent studies have shown the potent regenerative effect of stem cell therapy in gynecologic diseases such as infertility, Asherman syndrome, lichen sclerosus, polycystic ovary syndrome, premature ovarian insufficiency, genitourinary syndrome of menopause, and rectovaginal fistulas. Moreover, the successful isolation of oogonial stem cells could lead to a revolution in the field of gynecology and the potential treatment of the conditions discussed. This review aims to provide a better understanding of the latest therapeutic options involving stem cells and raise awareness of this promising yet not widely known topic in gynecology and medicine in general.

Update on antiadhesion barriers and therapeutics in gynecological surgery

PURPOSE OF REVIEW

Postoperative adhesions remain a clinical challenge to both patients and providers, as they are associated with significant complications and a high economic burden. This article provides a clinical review of currently available antiadhesive agents and promising new therapies that have advanced past animal studies.

RECENT FINDINGS

Several agents have been investigated on their ability to reduce adhesion formation; however, there is no widely acceptable option. The few available interventions are barrier agents and while low-quality evidence suggests that they may be more effective than no treatment, there is no general agreement on their overall efficacy. There is an abundance of research on new solutions; however, their clinical efficacy is yet to be determined.

SUMMARY

Although a wide range of therapeutics have been investigated, majority are halted in animal models with only a select few being studied in humans and ultimately available in the market. Many agents have shown effectiveness in reducing adhesion formation, however, that has not been translated to improvement in clinically relevant outcomes; hence the need for high-quality large randomized trials.

Targeting endometrial inflammation in intrauterine adhesion ameliorates endometrial fibrosis by priming MSCs to secrete C1INH

Intrauterine adhesion (IUA) is a common cause of uterine infertility and its histopathologic characteristic is endometrial fibrosis. A shortage of stem cells in the endometrial basalis has been recognized as a common cause of IUA development because approximately 90% of patients suffer from IUA after endometrial injury. In this study, we provide evidence that persistent inflammation is the main contributor to endometrial fibrosis in IUA patients. We further found that treating an IUA-like mouse model with ITI-hUC-MSCs (hUC-MSCs reprogrammed by IL-1β, TNF-α and IFN-γ) significantly decreased endometrial inflammation and fibrosis. Mechanistically, high levels of complement 1 inhibitor (C1INH) secreted by ITI-hUC-MSCs prevented inflammation from inducing profibrotic CD301+ macrophage polarization by downregulating the JAK-STAT signaling pathway. In conclusion, persistent inflammation in the endometria of IUA patients provides macrophage polarization with a profibrotic niche to promote endometrial fibrosis, and the powerful immunomodulatory effects of ITI-hUC-MSCs improve the immune microenvironment of endometrial regeneration.

Treatment options for endometrial hypoproliferation

PURPOSE OF REVIEW

Endometrial hypoproliferation refers to the failure of the endometrium to reach optimal thickness during fresh or frozen embryo transfer cycles in women undergoing infertility treatment with in-vitro fertilization (IVF). This review discusses the treatment options for endometrial hypoproliferation.

RECENT FINDINGS

Apart from factors related to the embryo quality, ultrasonographic findings associated with the endometrium, such as endometrial thickness, endometrial pattern and subendometrial blood flow, are considered key factors associated with the outcome of assisted reproductive treatment. To date, a consensus has not been reached regarding the definition of thin endometrium, while thresholds of 6, 7 or 8 mm have been used in the literature. Strategies to increase endometrial thickness can be reviewed in three groups: endocrine approaches, vitamins & supplements, and new experimental therapeutic interventions. Some of the recently introduced experimental therapeutic interventions such as platelet-rich plasma injection, stem cell treatment and tissue bioengineering are exciting potential therapies that need to be further studied.

SUMMARY

Despite a large number of publications on the topic, diagnosing and treating endometrial hypoproliferation remains a challenge. Well designed studies are needed to establish a widely accepted endometrial thickness cut-off value below which endometrial hypoproliferation is diagnosed and to generate meaningful data that would allow an evidence-based discussion of available therapeutic options with patients.

The Therapeutic Potential of Multipotent Mesenchymal Stromal Cell-Derived Extracellular Vesicles in Endometrial Regeneration

Disruption of endometrial regeneration, fibrosis formation, and intrauterine adhesions underlie the development of "thin" endometrium and/or Asherman's syndrome (AS) and are a common cause of infertility and a high risk for adverse obstetric outcomes. The methods used (surgical adhesiolysis, anti-adhesive agents, and hormonal therapy) do not allow restoration of the regenerative properties of the endometrium. The experience gained today with cell therapy using multipotent mesenchymal stromal cells (MMSCs) proves their high regenerative and proliferative properties in tissue damage. Their contribution to regenerative processes is still poorly understood. One of these mechanisms is based on the paracrine effects of MMSCs associated with the stimulation of cells of the microenvironment by secreting extracellular vesicles (EVs) into the extracellular space. EVs, whose source is MMSCs, are able to stimulate progenitor cells and stem cells in damaged tissues and exert cytoprotective, antiapoptotic, and angiogenic effects. This review described the regulatory mechanisms of endometrial regeneration, pathological conditions associated with a decrease in endometrial regeneration, and it presented the available data from studies on the effect of MMSCs and their EVs on endometrial repair processes, and the involvement of EVs in human reproductive processes at the level of implantation and embryogenesis.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Endometrial Receptivity During the Preimplantation Period: A Narrative Review

Endometrial receptivity is a complex and critical process fundamental to achieving a successful pregnancy. While researchers have made significant strides in understanding the underlying mechanisms governing endometrial receptivity, effective diagnostic and therapeutic strategies remain scarce. This review article aims to elucidate the various factors that contribute to endometrial receptivity, including the hormonal regulation and molecular mechanisms that govern this process, as well as potential biomarkers for assessing endometrial receptivity. One of the major challenges in identifying reliable biomarkers for endometrial receptivity is the intricate nature of the process itself. Nonetheless, recent advances in transcriptomic and proteomic technologies have identified several candidate biomarkers that could potentially enhance our ability to predict endometrial receptivity. Furthermore, emerging technologies such as single-cell RNA sequencing and mass spectrometry-based proteomics hold great promise for providing novel insights into the molecular mechanisms underlying endometrial receptivity. Despite the lack of reliable biomarkers, various therapeutic strategies have been proposed to improve endometrial receptivity. One promising approach involves the transplantation of mesenchymal stem cells (MSCs), which have been shown to increase endometrial thickness and receptivity in both animal models and clinical trials. Growth factors, cytokines, and exosomes derived from MSCs and other cell types may also have therapeutic potential for addressing endometrial dysfunction.

Intraovarian Administration of Autologous Menstrual Blood Derived-Mesenchymal Stromal Cells in Women with Premature Ovarian Failure

BACKGROUND

Premature ovarian failure (POF) is a well-known cause of infertility, particularly in women under the age of 40. POF is also associated with elevated gonadotropin levels, amenorrhea and sex-hormone deficiency.

AIM OF THE STUDY

In this study, the therapeutic potential of autologous mesenchymal stromal cells obtained from menstrual blood (Men-MSCs) for patients with POF was evaluated.

METHODS

15 POF patients were included in the study. The cultured Men-MSCs were confirmed by flow cytometry, karyotype, endotoxin and mycoplasma and were then injected into the patients' right ovary by vaginal ultrasound guidance and under general anesthesia and aseptic conditions. Changes in patients' anti-Müllerian hormone (AMH), antral follicle count (AFC), follicle-stimulating hormone (FSH), luteal hormone (LH), and estradiol (E2) levels, as well as general flushing and vaginal dryness were followed up to one year after treatment.

RESULTS

All patients were satisfied with a decrease in general flushing and vaginal dryness. 4 patients (2.9%) showed a spontaneous return of menstruation without additional pharmacological treatment. There was a significant difference in AFC (0 vs. 1 ± 0.92 count, p value ≤0.001%), FSH (74 ± 22.9 vs. 54.8 ± 17.5 mIU/mL, p-value ≤0.05%), E2 (10.2 ± 6 vs. 21.8 ± 11.5 pg/mL p-value ≤0.01%), LH (74 ± 22.9 vs. 54.8 ± 17.5 IU/L,p-value ≤0.01%) during 3 months post-injection. However, there were no significant changes in AMH (p-value ≥0.05%). There were also no significant differences in assessed parameters between 3 and 6 months after cell injection.

CONCLUSION

According to the findings of this study, administration of Men-MSCs improved ovarian function and menstrual restoration in some POF patients.

Autologous Human Mesenchymal Stem Cell-Based Therapy in Infertility: New Strategies and Future Perspectives

Infertility could be associated with a few factors including problems with physical and mental health, hormonal imbalances, lifestyles, and genetic factors. Given that there is a concern about the rise of infertility globally, increased focus has been given to its treatment for the last several decades. Traditional assisted reproductive technology (ART) has been the prime option for many years in solving various cases of infertility; however, it contains significant risks and does not solve the fundamental problem of infertility such as genetic disorders. Attention toward the utilization of MSCs has been widely regarded as a promising option in the development of stem-cell-based infertility treatments. This narrative review briefly presents the challenges in the current ART treatment of infertility and the various potential applications of autologous MSCs in the treatment of these reproductive diseases.

Endometrial Stem Cells and Their Applications in Intrauterine Adhesion

Intrauterine adhesion (IUA), resulting from pregnancy or nonpregnant uterine trauma, is one of the major causes of abnormal menstruation, infertility, or repeated pregnancy loss. Although a few methods, including hysteroscopy and hormone therapy, are routinely used for its diagnosis and treatment, they cannot restore tissue regeneration. Stem cells, which have self-renewal and tissue regeneration abilities, have been proposed as a promising therapy for patients with severe IUAs. In this review, we summarize the origin and features of endometrium-associated stem cells and their applications in the treatment of IUAs based on animal models and human clinical trials. We expect that this information will help to elucidate the underlying mechanism for tissue regeneration and to improve the design of stem cell-based therapies for IUAs.

Endometriosis Stem Cells as a Possible Main Target for Carcinogenesis of Endometriosis-Associated Ovarian Cancer (EAOC)

Endometriosis is a serious recurrent disease impairing the quality of life and fertility, and being a risk for some histologic types of ovarian cancer defined as endometriosis-associated ovarian cancers (EAOC). The presence of stem cells in the endometriotic foci could account for the proliferative, migrative and angiogenic activity of the lesions. Their phenotype and sources have been described. The similarly disturbed expression of several genes, miRNAs, galectins and chaperones has been observed both in endometriotic lesions and in ovarian or endometrial cancer. The importance of stem cells for nascence and sustain of malignant tumors is commonly appreciated. Although the proposed mechanisms promoting carcinogenesis leading from endometriosis into the EAOC are not completely known, they have been discussed in several articles. However, the role of endometriosis stem cells (ESCs) has not been discussed in this context. Here, we postulate that ESCs may be a main target for the carcinogenesis of EAOC and present the possible sequence of events resulting finally in the development of EAOC.

Human Umbilical Cord-Based Therapeutics: Stem Cells and Blood Derivatives for Female Reproductive Medicine

There are several conditions that lead to female infertility, where traditional or conventional treatments have limited efficacy. In these challenging scenarios, stem cell (SC) therapies have been investigated as alternative treatment strategies. Human umbilical cord (hUC) mesenchymal stem cells (hUC-MSC), along with their secreted paracrine factors, extracts, and biomolecules, have emerged as promising therapeutic alternatives in regenerative medicine, due to their remarkable potential to promote anti-inflammatory and regenerative processes more efficiently than other autologous treatments. Similarly, hUC blood derivatives, such as platelet-rich plasma (PRP), or isolated plasma elements, such as growth factors, have also demonstrated potential. This literature review aims to summarize the recent therapeutic advances based on hUC-MSCs, hUC blood, and/or other plasma derivatives (e.g., extracellular vesicles, hUC-PRP, and growth factors) in the context of female reproductive medicine. We present an in-depth analysis of the principal molecules mediating tissue regeneration, compiling the application of these therapies in preclinical and clinical studies, within the context of the human reproductive tract. Despite the recent advances in bioengineering strategies that sustain delivery and amplify the scope of the therapeutic benefits, further clinical trials are required prior to the wide implementation of these alternative therapies in reproductive medicine.

Research progress of stem cell therapy for endometrial injury

Endometrial damage is an important factor leading to infertility and traditional conventional treatments have limited efficacy. As an emerging technology in recent years, stem cell therapy has provided new hope for the treatment of this disease. By comparing the advantages of stem cells from different sources, it is believed that menstrual blood endometrial stem cells have a good application prospect as a new source of stem cells. However, the clinical utility of stem cells is still limited by issues such as colonization rates, long-term efficacy, tumor formation, and storage and transportation. This paper summarizes the mechanism by which stem cells repair endometrial damage and clarifies the material basis of their effects from four aspects: replacement of damaged sites, paracrine effects, interaction with growth factors, and other new targets. According to the pathological characteristics and treatment requirements of intrauterine adhesion (IUA), the research work to solve the above problems from the aspects of functional bioscaffold preparation and multi-functional platform construction is also summarized. From the perspective of scaffold materials and component functions, this review will provide a reference for comprehensively optimizing the clinical application of stem cells.

Cell therapy for the treatment of reproductive diseases and infertility: an overview from the mechanism to the clinic alongside diagnostic methods

Infertility is experienced by 8%-12% of adults in their reproductive period globally and has become a prevalent concern. Besides routine therapeutic methods, stem cells are rapidly being examined as viable alternative therapies in regenerative medicine and translational investigation. Remarkable progress has been made in understanding the biology and purpose of stem cells. The affected pluripotent stem cells (iPSCs) and mesenchymal stem cells (MSCs) are further studied for their possible use in reproductive medicine, particularly for infertility induced by premature ovarian insufficiency and azoospermia. Accordingly, this study discusses current developments in the use of some kinds of MSCs such as adipose-derived stem cells, bone marrow stromal cells, umbilical cord MSCs, and menstrual blood MSCs. These methods have been used to manage ovarian and uterine disorders, and each technique presents a novel method for the therapy of infertility.

Stem cell therapy in the treatment of organic and dysfunctional endometrial pathology

BACKGROUND

Intrauterine adhesions caused by postpartum curettage, spontaneous abortions, interrupted pregnancies, endometrial ablations, infections and inflammations, can lead to a loss of endometrial function, with consequent hypomenorrhea and infertility in women of reproductive age. In a non-negligible percentage of cases, the available surgical methods and hormone therapy, with sequential administration of estrogen and progesterone, are ineffective. In fact, severe damage to the basal layer of the endometrium causes the loss of endometrial cell precursors and leads to the failure of regeneration of the functional layer to which the endometrium is cyclically exposed. Today, many researchers are evaluating the use of stem cells of different origins as a potential therapy to restore endometrial function.

METHODS

Our interest has been focused on adipose-derived stromal/stem cells (ADSCs) obtained by collecting subcutaneous adipose tissue and subsequently treating it with the MilliGraft^® method. This procedure produces a cell suspension, the stromal vascular fraction (SVF), which includes ADSCs and soluble factors such as proteins and extracellular vesicles (exosomes). The SVF thus obtained was characterized in its cellular composition and its functional factors. Our clinical protocol for the future use of adipose tissue in endometrial regeneration in its different phases is presented.

RESULTS

The data obtained, even though they still require further support and implementation, show the regenerative properties of SVF obtained from adipose tissue using a mechanical method.

CONCLUSIONS

These findings can contribute to the development of cell therapies using stem cells of different derivations which are increasingly being utilized in the treatment of endometrial lesions from adherent or dysfunctional pathologies.

Gender bias and menstrual blood in stem cell research: A review of pubmed articles (2008–2020)

Despite proven scientific quality of menstrual blood mesenchymal cells, research and science output using those cells is still incipient, which suggests there is a resistance to the study of this type of cell by scientists, and a lack of attention to its potential for cell therapy, regenerative medicine and bioengineering. This study analyzes the literature about the menstrual blood mesenchymal stromal/stem cells (mbMSC) on the PubMed database between 2008–2020 and the social attention it received on Twitter. A comparative analysis showed that mbMSC accounts for a very small portion of mesenchymal cell research (0.25%). Most first authors are women (53.2%), whereas most last authors are men (63.74%), reinforcing an already known, and still significant, gender gap between last and corresponding authors. Menstrual blood tends to be less used in experiments and its scientific value tends to be underestimated, which brings gender bias to a technical and molecular level. Although women are more positive in the mbMSC debate on Twitter, communication efforts toward visibility and public interest in menstrual cells has room to grow.

Amniotic membrane extract-enriched hydrogel augments the therapeutic effect of menstrual blood-derived stromal cells in a rat model of intrauterine adhesion

We previously demonstrated that transplantation of menstrual blood-derived stromal cells (MenSCs) is a safe and effective therapy for treating intrauterine adhesions (IUA). However, improving the colonization and therapeutic efficiency of MenSCs is still needed before full clinical application. Here, we established an amniotic membrane extract (AME)-enriched RGD hydrogel, and evaluated the therapeutic effect of this adjuvant combined with MenSCs transplantation in an IUA rat model. Our results indicated that AME promoted the proliferation and secretion of MenSCs in vitro, up-regulated the expression of apoptosis-suppressing gene BCL2 and down-regulated the expression of apoptosis-related genes Caspase-3 and Caspase-8. The AME-enriched hydrogel was biocompatible, and improved the survival of MenSCs in vitro and in vivo. It also promoted the retention of MenSCs in IUA uterus and augmented the effects of MenSCs on improving uterus morphology, endometrial proliferation, endometrial receptivity and fibrosis suppression. In addition, co-transplantation of MenSCs with AME-enriched hydrogel markedly down-regulated the expressions of inflammation-related genes IL10 and TGFβ while up-regulated the IL4/IFN-γ ratio in the IUA endometrium, and improved the expressions of cell proliferation-related antigen, gland-regeneration-related marker leucine-rich repeat-containing G-protein coupled receptor 5 (LGR5), angiogenesis-related marker platelet and endothelial cell adhesion molecule 1 (PECAM1), endometrial receptivity related genes ITGα5 and ITGβ3. Our study suggested that AME and MenSCs had a synergistic effect. Co-transplantation of MenSCs with AME-enriched hydrogel provided a promising approach for stem cell-based IUA treatment.

Platelet-derived exosomes induce cell proliferation and wound healing in human endometrial cells

Aim: To investigate the regenerative effects of a platelet-derived purified exosome product (PEP) on human endometrial cells. Materials & methods: Endometrial adenocarcinoma cells (HEC-1A), endometrial stromal cells (T HESC) and menstrual blood-derived stem cells (MenSC) were assessed for exosome absorption and subsequent changes in cell proliferation and wound healing properties over 48 h. Results: Cell proliferation increased in PEP treated T HESC (p < 0.0001) and MenSC (p < 0.001) after 6 h and in HEC-1A (p < 0.01) after 12 h. PEP improved wound healing after 6 h in HEC-1A (p < 0.01) and MenSC (p < 0.0001) and in T HESC between 24 and 36 h (p < 0.05). Conclusion: PEP was absorbed by three different endometrial cell types. PEP treatment increased cell proliferation and wound healing capacity.

Stem Cells and Organs-on-chips: New Promising Technologies for Human Infertility Treatment

Having biological children remains an unattainable dream for most couples with reproductive failure or gonadal dysgenesis. The combination of stem cells with gene editing technology and organ-on-a-chip models provides a unique opportunity for infertile patients with impaired gametogenesis caused by congenital disorders in sex development or cancer survivors. But how will these technologies overcome human infertility? This review discusses the regenerative mechanisms, applications, and advantages of different types of stem cells for restoring gametogenesis in infertile patients, as well as major challenges that must be overcome before clinical application. The importance and limitations of in vitro generation of gametes from patient-specific human-induced pluripotent stem cells (hiPSCs) will be discussed in the context of human reproduction. The potential role of organ-on-a-chip models that can direct differentiation of hiPSC-derived primordial germ cell-like cells to gametes and other reproductive organoids is also explored. These rapidly evolving technologies provide prospects for improving fertility to individuals and couples who experience reproductive failure.

Recent progress of Bioinspired Hydrogel-based delivery system for endometrial repair

Endometrial injury is the main fact leading to infertility. Current treatments of endometrial injury present many problems, such as unable to achieve desired effects due to low retention and the inherent potential risk of injury. Besides, it is important to the development of bioinspired material that can mimic the natural tissue and possess native tissue topography. Hydrogel is a kind of bioinspired superhydrophilic materials with unique characteristics, such as excellent biocompatibility, biodegradability, porosity, swelling, and cross-linkage. These unique physiochemical properties of bioinspired hydrogels enable their promising application as novel delivery platform and alternative therapies for endometrial injury. In this mini review, we summarize the recent advances in bioinispred hydrogel-based delivery system for endometrial repair, including as a post-operative physical barrier and therapeutic delivery system. In addition, present status, limitations, and future perspectives are also discussed.

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

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

Clinical Evaluation of Autologous and Allogeneic Stem Cell Therapy for Intrauterine Adhesions: A Systematic Review and Meta-Analysis

Objective

Intrauterine adhesions (IUAs) are a major cause of female infertility. Stem cells can be used to restore endometrial function owing to their regenerative abilities. We compared the safety and efficacy of autologous and allogeneic stem cell treatments in patients with recurrent IUA after conventional therapy based on a systematic review of the related literature.

Methods

The PubMed, Embase, and Cochrane databases were systematically searched. All analysis were performed using Review Manager 5.4. We compared improvements in endometrial thickness, pregnancy rates, menstruation, and side effects after autologous and allogeneic stem cell therapy. The study was registered with PROSPERO, CRD 42022322870.

Results

Our search returned 154 reports, 10 of which met the inclusion criteria, representing 116 patients. Of these, 44 patients in two studies were treated with allogeneic stem cells and 72 patients in eight studies were treated with autologous stem cells. Improvements in endometrial thickness and pregnancy rates after intrauterine device treatment were compared between the autologous and allogeneic stem cell groups. Endometrial thickness increased more after autologous stem cell IUA treatment (mean difference, 1.68; 95% confidence interval [CI]: 1.30–2.07; P < 0.00001), and the pregnancy rate was also improved (relative risk, 1.55; 95% CI: 1.19–2.02, P < 0. 001). No obvious and serious adverse reactions were observed during stem cell therapy in either group.

Conclusions

This meta-analysis and systematic review of the results of randomized trials of autologous and allogeneic stem cell treatments for IUA suggests that autologous stem cells have a better effect in improving the endometrium thickness and pregnancy rate.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022322870.

Recent Developments in Biomaterial-Based Hydrogel as the Delivery System for Repairing Endometrial Injury

Endometrial injury caused by intrauterine surgery often leads to pathophysiological changes in the intrauterine environment, resulting in infertility in women of childbearing age. However, clinical treatment strategies, especially for moderate to severe injuries, often fail to provide satisfactory therapeutic effects and pregnancy outcomes. With the development of reproductive medicine and materials engineering, researchers have developed bioactive hydrogel materials, which can be used as a physical anti-adhesion barrier alone or as functional delivery systems for intrauterine injury treatment by loading stem cells or various active substances. Studies have demonstrated that the biomaterial-based hydrogel delivery system can provide sufficient mechanical support and improve the intrauterine microenvironment, enhance the delivery efficiency of therapeutic agents, prolong intrauterine retention time, and perform efficiently targeted repair compared with ordinary drug therapy or stem cell therapy. It shows the promising application prospects of the hydrogel delivery system in reproductive medicine. Herein, we review the recent advances in endometrial repair methods, focusing on the current application status of biomaterial-based hydrogel delivery systems in intrauterine injury repair, including preparation principles, therapeutic efficacy, repair mechanisms, and current limitations and development perspectives.

In situ delivery of apoptotic bodies derived from mesenchymal stem cells via a hyaluronic acid hydrogel: A therapy for intrauterine adhesions

Stem cell-based and stem cell-derived exosome-based therapies have shown promising potential for endometrial regeneration and the clinical treatment of intrauterine adhesions (IUAs). Evidence shows that apoptosis occurs in a majority of grafted stem cells, and apoptotic bodies (ABs) play a critical role in compensatory tissue regeneration. However, the therapeutic potential of AB-based therapy and its mechanism have not been explored in detail. Here, a cell-free therapeutic strategy was developed by incorporating mesenchymal stem cell-derived ABs into a hyaluronic acid (HA) hydrogel to achieve endometrial regeneration and fertility restoration. Specifically, we found that the ABs could induce macrophage immunomodulation, cell proliferation, and angiogenesis in vitro. The HA hydrogel promoted the retention of ABs and facilitated their continuous release. In a murine model of acute endometrial damage and a rat model of IUAs, in situ injection of the AB-laden HA hydrogel could efficiently reduce fibrosis and promote endometrial regeneration, resulting in the fertility restoration. Consequently, ABs show good potential as therapeutic vesicles, and the AB-laden HA hydrogel appears to be a clinically feasible and cell-free alternative for endometrial regeneration and IUA treatment.

●

Human umbilical cord derived apoptotic bodies induce macrophage immunomodulation, cell proliferation and angiogenesis

●

A strategy of apoptotic bodies associated with hyaluronic acid hydrogel promotes apoptotic bodies retention and continuous release

●

The implantation of the apoptotic body-laden hyaluronic acid hydrogel into uterine cavity effectively promoted endometrial regeneration and fertility restoration in a rodent model of intrauterine adhesion

Human Platelet-Rich Plasma Facilitates Angiogenesis to Restore Impaired Uterine Environments with Asherman’s Syndrome for Embryo Implantation and Following Pregnancy in Mice

Asherman’s syndrome (AS) is caused by intrauterine adhesions and inactive endometrium from repeated curettage of the uterine endometrium. AS is a major cause of recurrent implantation failure and miscarriage and is very difficult to treat because of the poor recovery of endometrial basal cells. Platelet-rich plasma (PRP) has abundant growth factors that may induce angiogenesis and cell proliferation. Here, we demonstrate that human PRP (hPRP) significantly enhances angiogenesis to restore embryo implantation, leading to successful pregnancy in mice with AS. In mice with AS, hPRP treatment considerably reduced the expression of fibrosis markers and alleviated oligo/amenorrhea phenotypes. Mice with AS did not produce any pups, but the hPRP therapy restored their infertility. AS-induced abnormalities, such as aberrantly delayed embryo implantation and intrauterine growth retardation, were considerably eliminated by hPRP. Furthermore, hPRP significantly promoted not only the elevation of various angiogenic factors, but also the migration of endometrial stromal cells. It also increased the phosphorylation of STAT3, a critical mediator of wound healing, and the expression of tissue remodeling genes in a fibrotic uterus. PRP could be a promising therapeutic strategy to promote angiogenesis and reduce fibrosis in impaired uterine environments, leading to successful embryo implantation for better clinical outcomes in patients with AS.

Menstrual blood-derived stem cells and its mitochondrial treatment improve the ovarian condition of aged mice

Aging causes a decline in ovarian function and may contribute to ovarian failure and infertility. We investigated the effect of menstrual blood-derived mesenchymal stem cells (MenSCs) and their mitochondria on ovarian function in aged mice. We performed two treatment protocols: i) ovaries of recipient aged mice were treated in vivo with MenSCs 3D alginate gel; ii) ovaries were injected with mitochondria suspension and then incubated with mitochondrial 3D gel. Seven days after treatment, ovaries were harvested for histological assessment by HE staining and transcriptomic analysis by RNA-seq. Our data showed that after incubation with stem cell 3D gel, the MenSCs could be detected in the recipient mouse ovary. HE staining showed that the follicular state of aging ovary improved with both treatments. RNA-seq analysis showed that mitochondrial pathway-related genes were upregulated and significantly enriched in the ovaries treated by MenSCs or their mitochondria. Conclusions: Treatment with MenSCs or their mitochondria can enhance the expression of mitochondrial pathway-related genes and promote the recovery of ovarian function in aged mice.

Endometrium Derived Stem Cells as Potential Candidates in Nervous System Repair

Limited cell division and lack of endogenous repair mechanisms in the central nervous system, hampers tissue repair following neurodegenerative diseases or tissue injuries. Unlike central nervous system; peripheral nervous system has some capacity to repair after injury, but in case of critical sized defects the use of supporting cells in the neural guidance channels seems inevitable to obtain a satisfactory functional recovery. Stem cell therapies have provided new frontiers in the repair of nervous system largely through paracrine secretion mechanisms. The therapeutic potential of stem cells differs according to their tissue of origin, mode of isolation, administration route, and passage number. During the past decades, studies have been focused on stem cells harvested from disposable tissues such as menstrual blood or biopsies from endometrium. These cells are characterized by their high differentiation and proliferation potential, ease of harvest, and lack of ethical concerns. In the current review, we will discuss the prospects and challenges of endometrial stem cells' application in nervous system repair.

Therapeutic Potential of Menstrual Blood-Derived Stem Cell Transplantation for Intrauterine Adhesions

An increasing number of women experience intrauterine adhesion as a result of intrauterine operations, such as induced abortion, which can cause infertility, recurrent abortion and amenorrhea. Although some strategies have been applied clinically, such as hysteroscopy adhesiolysis of intrauterine adhesions, the results have not been promising. As regenerative medicine develops, research on menstrual blood-derived stem cell transplantation is increasing due to the properties of these cells, including self-renewal, differentiation, angiogenesis, anti-inflammation and immunomodulation. As a result, menstrual blood-derived stem cells may be an ideal cell source for the treatment of intrauterine adhesion. Excitingly, it has been reported that autologous menstrual blood stem cells could recovery injured endometrium and improve infertility in patients with refractory intrauterine adhesion. In this review, we discuss the possible potential of menstrual blood-derived stem cell transplantation for intrauterine adhesion, including the antifibrosis, angiogenesis, anti-inflammation and immunoregulation properties of the cells, which brings hopes for clinical therapy.

A Novel Xeno-Free Method to Isolate Human Endometrial Mesenchymal Stromal Cells (E-MSCs) in Good Manufacturing Practice (GMP) Conditions

The cyclic regeneration of human endometrium is guaranteed by the proliferative capacity of endometrial mesenchymal stromal cells (E-MSCs). Due to this, the autologous infusion of E-MSCs has been proposed to support endometrial growth in a wide range of gynecological diseases. We aimed to compare two different endometrial sampling methods, surgical curettage and vacuum aspiration biopsy random assay (VABRA), and to validate a novel xeno-free method to culture human E-MSCs. Six E-MSCs cell samples were isolated after mechanical tissue homogenization and cultured using human platelet lysate. E-MSCs were characterized for the colony formation capacity, proliferative potential, and multilineage differentiation. The expression of mesenchymal and stemness markers were tested by FACS analysis and real-time PCR, respectively. Chromosomal alterations were evaluated by karyotype analysis, whereas tumorigenic capacity and invasiveness were tested by soft agar assay. Both endometrial sampling techniques allowed efficient isolation and expansion of E-MSCs using a xeno-free method, preserving their mesenchymal and stemness phenotype, proliferative potential, and limited multi-lineage differentiation ability during the culture. No chromosomal alterations and invasive/tumorigenic capacity were observed. Herein, we report the first evidence of efficient E-MSCs isolation and culture in Good Manufacturing Practice compliance conditions, suggesting VABRA endometrial sampling as alternative to surgical curettage.

Cell-based therapy in thin endometrium and Asherman syndrome

Numerous treatment strategies have so far been proposed for treating refractory thin endometrium either without or with the Asherman syndrome. Inconsistency in the improvement of endometrial thickness is a common limitation of such therapies including tamoxifen citrate as an ovulation induction agent, acupuncture, long-term pentoxifylline and tocopherol or tocopherol only, low-dose human chorionic gonadotropin during endometrial preparation, aspirin, luteal gonadotropin-releasing hormone agonist supplementation, and extended estrogen therapy. Recently, cell therapy has been proposed as an ideal alternative for endometrium regeneration, including the employment of stem cells, platelet-rich plasma, and growth factors as therapeutic agents. The mechanisms of action of cell therapy include the cytokine induction, growth factor production, natural killer cell activity reduction, Th17 and Th1 decrease, and Treg cell and Th2 increase. Since cell therapy is personalized, dynamic, interactive, and specific and could be an effective strategy. Despite its promising nature, further research is required for improving the procedure and the safety of this strategy. These methods and their results are discussed in this article.

Therapeutic effects of menstrual blood-derived endometrial stem cells on mouse models of streptozotocin-induced type 1 diabetes

BACKGROUND

Type 1 diabetes (T1D), a chronic metabolic and autoimmune disease, seriously endangers human health. In recent years, mesenchymal stem cell (MSC) transplantation has become an effective treatment for diabetes. Menstrual blood-derived endometrial stem cells (MenSC), a novel MSC type derived from the decidual endometrium during menstruation, are expected to become promising seeding cells for diabetes treatment because of their noninvasive collection procedure, high proliferation rate and high immunomodulation capacity.

AIM

To comprehensively compare the effects of MenSC and umbilical cord-derived MSC (UcMSC) transplantation on T1D treatment, to further explore the potential mechanism of MSC-based therapies in T1D, and to provide support for the clinical application of MSC in diabetes treatment.

METHODS

A conventional streptozotocin-induced T1D mouse model was established, and the effects of MenSC and UcMSC transplantation on their blood glucose and serum insulin levels were detected. The morphological and functional changes in the pancreas, liver, kidney, and spleen were analyzed by routine histological and immunohistochemical examinations. Changes in the serum cytokine levels in the model mice were assessed by protein arrays. The expression of target proteins related to pancreatic regeneration and apoptosis was examined by western blot.

RESULTS

MenSC and UcMSC transplantation significantly improved the blood glucose and serum insulin levels in T1D model mice. Immunofluorescence analysis revealed that the numbers of insulin⁺ and CD31⁺ cells in the pancreas were significantly increased in MSC-treated mice compared with control mice. Subsequent western blot analysis also showed that vascular endothelial growth factor (VEGF), Bcl2, Bcl-xL and Proliferating cell nuclear antigen in pancreatic tissue was significantly upregulated in MSC-treated mice compared with control mice. Additionally, protein arrays indicated that MenSC and UcMSC transplantation significantly downregulated the serum levels of interferon γ and tumor necrosis factor α and upregulated the serum levels of interleukin-6 and VEGF in the model mice. Additionally, histological and immunohistochemical analyses revealed that MSC transplantation systematically improved the morphologies and functions of the liver, kidney, and spleen in T1D model mice.

CONCLUSION

MenSC transplantation significantly improves the symptoms in T1D model mice and exerts protective effects on their main organs. Moreover, MSC-mediated angiogenesis, antiapoptotic effects and immunomodulation likely contribute to the above improvements. Thus, MenSC are expected to become promising seeding cells for clinical diabetes treatment due to their advantages mentioned above.

Endometrial Stem/Progenitor Cells–Their Role in Endometrial Repair and Regeneration

The human endometrium is a remarkable tissue, undergoing ~450 cycles of proliferation, differentiation, shedding (menstruation), repair, and regeneration over a woman's reproductive lifespan. Post-menstrual repair is an extremely rapid and scar-free process, with re-epithelialization of the luminal epithelium completed within 48 h of initiation of shedding. Following menstruation, the functionalis grows from the residual basalis layer during the proliferative phase under the influence of rising circulating estrogen levels. The regenerative capacity of the endometrium is attributed to stem/progenitor cells which reside in both the epithelial and stromal cell compartments of the basalis layer. Finding a definitive marker for endometrial epithelial progenitors (eEPCs) has proven difficult. A number of different markers have been suggested as putative progenitor markers including, N-cadherin, SSEA-1, AXIN2, SOX-9 and ALDH1A1, some of which show functional stem cell activity in in vitro assays. Each marker has a unique location(s) in the glandular epithelium, which has led to the suggestion that a differentiation hierarchy exists, from the base of epithelial glands in the basalis to the luminal epithelium lining the functionalis, where epithelial cells express different combinations of markers as they differentiate and move up the gland into the functionalis away from the basalis niche. Perivascular endometrial mesenchymal stem cells (eMSCs) can be identified by co-expression of PDGFRβ and CD146 or by a single marker, SUSD2. This review will detail the known endometrial stem/progenitor markers; their identity, location and known interactions and hierarchy across the menstrual cycle, in particular post-menstrual repair and estrogen-driven regeneration, as well as their possible contributions to menstruation-related disorders such as endometriosis and regeneration-related disorder Asherman's syndrome. We will also highlight new techniques that allow for a greater understanding of stem/progenitor cells' role in repair and regeneration, including 3D organoids, 3D slice cultures and gene sequencing at the single cell level. Since mouse models are commonly used to study menstruation, repair and regeneration we will also detail the mouse stem/progenitor markers that have been investigated in vivo.

In vitro and in silico analysis of a E559K mutation on cartilage oligomeric matrix protein

Pseudoachondroplasia (PSACH) is known as an autosomal dominant disorder associated with mutations in the gene of cartilage oligomeric matrix protein (COMP). The pathomolecular mechanisms of PSACH as a result of C-terminal globular region (CTD) mutations remain unclear. A heterozygous mutation (E559 K) in a Chinese family diagnosed with PSACH was reported in this study. To understand the pathogenesis of this mutation, we studied chondrogenic differentiation of patient menstrual blood-derived stem cells (MenSCs), and the impact of the mutation on structural changes of COMP was investigated using all-atom molecular dynamics simulation. The results suggested that the interactions with calcium and other molecules in the mutant structure were affected resulting in misfolding of the protein, which leads to ER stress and finally affects the survival of chondrocytes. The findings may promote the understanding of the pathomolecular mechanisms of PSACH, and possibly the development of drugs to treat the disease.

Nonfreezing Low Temperature Maintains the Viability of Menstrual Blood-Derived Endometrial Stem Cells Under Oxygen-Glucose Deprivation Through the Sustained Release of Autophagy-Produced Energy

Between the completion of the mesenchymal stem cell (MSCs) preparation and the transplantation into the patient, there is a time interval during which the quality control and transport of MSC products occur, which usually involves suspending the cells in normal saline in an oxygen-glucose deprivation (OGD) microenvironments. Thus, how to effectively maintain MSC viability during the abovementioned time interval is bound to play a significant role in the therapeutic effect of MSC-based therapies. Recently, menstrual blood-derived endometrial stem cells (MenSCs) have attracted extensive attention in regenerative medicine due to their superior biological characteristics, including noninvasive protocols for their collection, abundant source material, stable donation, and autotransplantation. Therefore, this study aimed to mainly determine the effect of storage temperature on the maintenance of MenSC viabilities in an OGD microenvironment, and to preliminarily explore its potential mechanism. Simultaneously, the effects of solvents commonly used in the clinic on MenSC viability were also examined to support the clinical application of MenSCs. Consequently, our results demonstrated that in the OGD microenvironment, a nonfreezing low temperature (4°C) was suitable and cost-effective for MenSC storage, and the maintenance of MenSC viability stored at 4°C was partly contributed by the sustained releases of autophagy-produced energy. Furthermore, the addition of human serum albumin effectively inhibited the cell sedimentations in the MenSC suspension. These results provide support and practical experience for the extensive application of MenSCs in the clinic.

Stem Cell Therapies for Human Infertility: Advantages and Challenges

Physical and mental health and hormonal imbalance are associated with the problems related to infertility and reproductive disorders. The rate of infertility has increased globally over the years, due to various reasons. Given the psychosocial implications of infertility and its effects on the life of the affected people, there has been an increased focus on its treatment over the last several years. Assisted reproductive technology can only solve about 50% of the cases. Moreover, it contains significant risks and does not solve the fundamental problem of infertility. As pluripotent stem cells have the potential to differentiate into almost any type of cell, they have been widely regarded as a promising option in the development of stem cell-based fertility treatments, which could even correct genetic diseases in offspring. These advancements in reproductive biotechnology present both challenges and possibilities for solving infertility problems caused by various unexplainable factors. This review briefly presents the different types of infertility disorders and the potential applications of stem cells in the treatment of these reproductive diseases.