Therapeutic Role of Mesenchymal Stem Cell-Derived Extracellular Vesicles in Female Reproductive Diseases

Ovarian fibrosis: molecular mechanisms and potential therapeutic targets

Ovarian fibrosis, characterized by the excessive proliferation of ovarian fibroblasts and the accumulation of extracellular matrix (ECM), serves as one of the primary causes of ovarian dysfunction. Despite the critical role of ovarian fibrosis in maintaining the normal physiological function of the mammalian ovaries, research on this condition has been greatly underestimated, which leads to a lack of clinical treatment options for ovarian dysfunction caused by fibrosis. This review synthesizes recent research on the molecular mechanisms of ovarian fibrosis, encompassing TGF-β, extracellular matrix, inflammation, and other profibrotic factors contributing to abnormal ovarian fibrosis. Additionally, we summarize current treatment approaches for ovarian dysfunction targeting ovarian fibrosis, including antifibrotic drugs, stem cell transplantation, and exosomal therapies. The purpose of this review is to summarize the research progress on ovarian fibrosis and to propose potential therapeutic strategies targeting ovarian fibrosis for the treatment of ovarian dysfunction.

Different origin-derived exosomes and their clinical advantages in cancer therapy

Exosomes, as a class of small extracellular vesicles closely related to the biological behavior of various types of tumors, are currently attracting research attention in cancer diagnosis and treatment. Regarding cancer diagnosis, the stability of their membrane structure and their wide distribution in body fluids render exosomes promising biomarkers. It is expected that exosome-based liquid biopsy will become an important tool for tumor diagnosis in the future. For cancer treatment, exosomes, as the "golden communicators" between cells, can be designed to deliver different drugs, aiming to achieve low-toxicity and low-immunogenicity targeted delivery. Signaling pathways related to exosome contents can also be used for safer and more effective immunotherapy against tumors. Exosomes are derived from a wide range of sources, and exhibit different biological characteristics as well as clinical application advantages in different cancer therapies. In this review, we analyzed the main sources of exosomes that have great potential and broad prospects in cancer diagnosis and therapy. Moreover, we compared their therapeutic advantages, providing new ideas for the clinical application of exosomes.

Effect of static magnetic field on gene expression of human umbilical cord mesenchymal stem cells by transcriptome analysis

PURPOSE

Static magnetic fields (SMFs) induce various biological reactions and have been applied in the biological therapy of diseases, especially in combination with mesenchymal stem cells (MSCs) and tissue engineering. However, the underlying influence of SMFs on MSCs gene expression remains largely unclear. In this study, we aim to investigate the effects of SMFs on gene expression of human MSCs.

MATERIALS AND METHODS

We exposed human MSCs to two different intensities (0.35 ​T and 1.0 ​T) of SMFs and observed the effects of SMFs on cell morphology. Subsequently, RNA-sequencing was performed to explore the gene expression changes.

RESULTS

Compared with control group cells, no significant differences in cell morphology were observed under a phase contrast inverted microscope, but the transcriptome of SMF-exposed MSCs were significantly changed in both 0.35 ​T and 1.0 ​T groups and the differential expressed genes are involved in multiple pathways, such as ubiquitin mediated proteolysis, TNF signaling pathway, NF-kappa B signaling pathway, TGF-beta signaling pathway, metabolic pathways, and apoptosis, which regulate the biological functions of MSCs.

CONCLUSIONS

SMFs stimulation could affect the gene expression of human MSCs and the biological effects vary by the different intensities of SMFs. These data offer the molecular foundation for future application of SMFs in stem cell technology as well as tissue engineering medicine.

Rethinking the application of nanoparticles in women's reproductive health and assisted reproduction

Nanoparticles and nanotechnology may present opportunities to revolutionize the prevention, treatment and diagnosis of a range of reproductive health conditions in women. These technologies are also used to improve outcomes of assisted reproductive technology. We highlight a range of these potential clinical uses of nanoparticles for polycystic ovary syndrome, endometriosis, uterine fibroids and sexually transmitted infections, considering in vitro and in vivo studies along with clinical trials. In addition, we discuss applications of nanoparticles in assisted reproductive technology, including sperm loading, gamete and embryo preservation and preventing preterm birth. Finally, we present some of the concerns associated with the medical use of nanoparticles, identifying routes for further exploration before nanoparticles can be applied to women's reproductive health in the clinic.

Incorporation of Decidual Stromal Cells Derived Exosomes in Sodium Alginate Hydrogel as an Innovative Therapeutic Strategy for Advancing Endometrial Regeneration and Reinstating Fertility

Intrauterine adhesion (IUA) stands as a prevalent medical condition characterized by endometrial fibrosis and scar tissue formation within the uterine cavity, resulting in infertility and, in severe cases, recurrent miscarriages. Cell therapy, especially with stem cells, offers an alternative to surgery, but concerns about uncontrolled differentiation and tumorigenicity limit its use. Exosomes, more stable and immunogenicity-reduced than parent cells, have emerged as a promising avenue for IUA treatment. In this study, a novel approach has been proposed wherein exosomes originating from decidual stromal cells (DSCs) are encapsulated within sodium alginate hydrogel (SAH) scaffolds to repair endometrial damage and restore fertility in a mouse IUA model. Current results demonstrate that in situ injection of DSC-derived exosomes (DSC-exos)/SAH into the uterine cavity has the capability to induce uterine angiogenesis, initiate mesenchymal-to-epithelial transformation (MET), facilitate collagen fiber remodeling and dissolution, promote endometrial regeneration, enhance endometrial receptivity, and contribute to the recovery of fertility. RNA sequencing and advanced bioinformatics analysis reveal miRNA enrichment in exosomes, potentially supporting endometrial repair. This finding elucidates how DSC-exos/SAH mechanistically fosters collagen ablation, endometrium regeneration, and fertility recovery, holding the potential to introduce a novel IUA treatment and offering invaluable insights into the realm of regenerative medicine.

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.

Human Umbilical Cord Mesenchymal Stem Cells Derived Exosomes Improved The Aged Mouse IVM Oocytes Quality

During assisted reproductive technology (ART) treatment, the aged women, especially those over 35 years old, have fewer mature oocytes and poorer quality of the oocytes comparing with the young women. In vitro maturation (IVM) technology facilitates the usage of immature oocytes, which is clinically important for the aged women. However, the maturation rate is low for the oocytes from the aged women. Human umbilical cord mesenchymal stem cells derived exosomes (HUCMSCs-exosomes), as important mediators of intercellular communication, have been widely used to restore ovarian function and improve female fertility. In this study, we isolated HUCMSCs-exosomes and collected the immature germinal vesicle oocytes from the naturally aged mouse model. And we added these HUCMSCs-exosomes to the conventional IVM culture system. The effects of HUCMSCs-exosomes on IVM oocytes were observed and analyzed from multiple aspects including maturation rate, spindle morphology, mitochondria function, and development potential. We found the quality of oocytes was improved by HUCMSCs-exosomes. Based on the results, we propose that HUCMSCs-exosomes may provide a novel and cell free strategy in the improvement of the IVM in elderly infertile women in the future.

Mesenchymal Stem Cell-Derived Extracellular Vesicles Alleviate Brain Damage Following Subarachnoid Hemorrhage via the Interaction of miR-140-5p and HDAC7

Subarachnoid hemorrhage (SAH) triggers severe neuroinflammation and cognitive impairment, where microglial M1 polarization exacerbates the injury and M2 polarization mitigates damage. Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs), carrying microRNA (miR)-140-5p, offer therapeutic promise by targeting the cAMP/PKA/CREB pathway and modulating microglial responses, demonstrating a novel approach for addressing SAH-induced brain injury. This research explored the role of miR-140-5p delivered by MSC-EVs in mitigating brain damage following SAH. Serum from SAH patients and healthy individuals was analyzed for miR-140-5p and cAMP levels. The association between miR-140-5p levels, brain injury severity, and patient survival was examined, along with the target relationship between miR-140-5p and histone deacetylases 7 (HDAC7). MSC-EVs were characterized for their ability to cross the blood-brain barrier and modulate the HDAC7/AKAP12/cAMP/PKA/CREB axis, reducing M1 polarization and inflammation. The therapeutic effect of MSC-EV-miR-140-5p was demonstrated in an SAH mouse model, showing reduced neuronal apoptosis and improved neurological function. This study highlights the potential of MSC-EV-miR-140-5p in mitigating SAH-induced neuroinflammation and brain injury, providing a foundation for developing MSC-EV-based treatments for SAH.

The mechanisms of MicroRNA 21 in premature ovarian insufficiency mice with mesenchymal stem cells transplantation : The involved molecular and immunological mechanisms

Umbilical cord-derived mesenchymal stem cell (UCMSC) transplantation has been deeply explored for premature ovarian insufficiency (POI) disease. However, the associated mechanism remains to be researched. To explore whether and how the microRNA 21 (miR-21) functions in POI mice with UCMSCs transplantation, the autoimmune-induced POI mice model was built up, transplanted with or without UCMSCs transfect with the LV-hsa-miR-21-5p/LV-hsa-miR-21-5p-inhibition, with the transfection efficiency analyzed by QRT-PCR. Mice hormone secretion and the anti-Zona pellucida antibody (AZPAb) levels were analyzed, the ovarian morphological changes and folliculogenesis were observed, and the ovarian apoptosis cells were detected to evaluate ovarian function. The expression and localization of the PTEN/Akt/FOXO3a signal pathway-related cytokines were analyzed in mice ovaries.Additionally, the spleen levels of CD8 + CD28-T cells were tested and qualified with its significant secretory factor, interleukin 10 (IL-10). We found that with the LV-hsa-miR-21-5p-inhibition-UCMSCs transplantation, the mice ovarian function can be hardly recovered than mice with LV-NC-UCMSCs transplantation, and the PTEN/Akt/FOXO3a signal pathway was activated. The expression levels of the CD8 + CD28-T cells were decreased, with the decreased levels of the IL-10 expression. In contrast, in mice with the LV-hsa-miR-21-5p-UCMSCs transplantation, the injured ovarian function can be reversed, and the PTEN/AKT/FOXO3a signal pathway was detected activated, with the increased levels of the CD8 + CD28-T cells, and the increased serum levels of IL-10. In conclusion, miR-21 improves the ovarian function recovery of POI mice with UCMSCs transplantation, and the mechanisms may be through suppressing the PTEN/AKT/FOXO3a signal pathway and up-regulating the circulating of the CD8 + CD28-T cells.

Research progress on mechanism of follicle injury after frozen ovarian tissue transplantation and protective strategies

The iatrogenic ovarian dysfunction caused by cancer treatment have been increasing, along with the age at onset of malignant tumors getting younger, the survival of cancer patients being longer, as well as the delayed childbearing age for females; therefore it becomes a major clinical challenge to preserve the fertility of these patients. Ovarian tissue cryopreservation is the only solution for female cancer patients in prepubertal ages and those who cannot delay gonadotoxic therapy. However, the successful rate of cryopreservation and transplantation of ovarian tissue is still low at present due to the risk of ischemia and hypoxia of grafted tissues. Abnormal activation of primordial follicle and ischemia-reperfusion injury after blood supply recovery also cause massive loss of follicles in grafted ovarian tissues. It has been tried in various studies to reduce the damage of follicles during freezing and transplantation by adding certain drugs, and extend the duration of endocrine and reproductive function in patients with ovarian transplantation. For example, melatonin, N-acetylcysteine, erythropoietin or other antioxidants are used to reduce oxidative stress; mesenchymal stem cells derived from different tissues, basic fibroblast growth factor, vascular endothelial growth factor, angiopoietin 2 and gonadotropin are used to promote revascularization; anti-Müllerian hormone and rapamycin are used to reduce abnormal activation of primordial follicles. This article reviews the research progress on the main mechanisms of follicle loss after ovarian tissue transplantation, including hypoxia, ischemia-reperfusion injury and associated cell death, and abnormal activation of follicles; and explores the methods of reducing graft follicle loss to provide reference for improving the efficiency of ovarian tissue cryopreservation and transplantation.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Characterization and establishment of an immortalized rabbit ovary granulosa cell line for reproductive biology experiments

Granulosa cells (GCs) are the key components of ovarian follicles and regulate the maturation, communication, growth, and development of oocytes. GCs have great potential as human therapeutic models and in livestock breeding. In this study, we established an immortalized cell line (Im-RGCs) by transforming primary rabbit granulosa cells (Pri-RGCs) with lentivirus-mediated simian virus 40 Large T (SV40LT). Morphologically, Im-RGCs were indistinguishable from Pri-RGCs and maintained intact cell structure as observed by H&E staining. Also, Im-RGCs exhibited no significant change in cell proliferation, viability, and growth. Furthermore, GC-specific markers, such as FSHR, StAR, CYP11A1, and CYP19A1, were examined by PCR, immunofluorescence, and Western blotting. ELISA and karyotype analysis showed that Im-RGCs can synthesize steroid hormones and maintain the normal number of chromosomes during the infinite passage. Furthermore, soft-agar cloning and nude mice tumorigenic experiments indicated the absence of any malignancy transformation in Im-RGCs. In conclusion, we successfully established the immortalized granulosa cell line of rabbit follicles that can be used for biological, animal husbandry, and female reproductive research.

Exosomes as Theranostic Agents in Reproduction System

Exosomes (Exos), belonging to extracellular vesicles, are cell-derived nano-sized vesicles with the potential to carry different kinds of biological molecules. Many studies have proved the impacts of exosomal cargo on several biological processes in female and male reproductive systems. It is also hypothesized that changes in exosomal cargo are integral to the promotion of certain pathological conditions, thus Exos can be used as valid biomarkers for the diagnosis of infertility and other abnormal conditions. Here, efforts are made to collect some recent data related to the physiological significance of Exos in the reproductive system, and their potential therapeutic effects. It is anticipated that the current review article will lay the groundwork for elucidating the source and mechanisms by which Exos control the reproductive system additionally supplying fresh methods and concepts for the detection and treatment of disorders associated with fertility for future studies.

Bone Marrow Mesenchymal Stem Cell-Derived Exosomes Ameliorate Aging-Induced BTB Impairment in Porcine Testes by Activating Autophagy and Inhibiting ROS/NLRP3 Inflammasomes via the AMPK/mTOR Signaling Pathway

As a pivotal player in spermatogenesis, the blood-testis barrier (BTB) made from junction apparatus coexisting in Sertoli cells (SCs) is impaired with an increase in age and ultimately induces spermatogenic dysfunction or even infertility. It has been corroborated that bone marrow mesenchymal stem cell (BMSC) transplantation can efficiently repair and regenerate the testicular function. As vital mediators of cell-to-cell communication, MSC-derived exosomes (Exos) can directly serve as therapeutic agents for tissue repair and regeneration. However, the therapeutic value of BMSC-Exos in aging-induced BTB damage remains to be confirmed. In this study, we explored that the old porcine testes had defective autophagy, which aggravated BTB disruption in SCs. BMSC-Exos could decrease ROS production and NLRP3 inflammasome activation but enhanced autophagy and tight junction (TJ) function in D-gal-triggered aging porcine SCs and mouse model testes, according to in vitro and in vivo experiments. Furthermore, rapamycin, NAC, MCC950, and IL-1Ra restored the TJ function in D-gal-stimulated aging porcine SCs, while BMSC-Exos' stimulatory effect on TJ function was inhibited by chloroquine. Moreover, the treatment with BMSC-Exos enhanced autophagy in D-gal-induced aging porcine SCs by means of the AMPK/mTOR signal transduction pathway. These findings uncovered through the present study that BMSC-Exos can enhance the BTB function in aging testes by improving autophagy via the AMPK/mTOR signaling pathway, thereby suppressing ROS production and NLRP3 inflammasome activation.

Application of mesenchymal stem cell therapy for premature ovarian insufficiency: Recent advances from mechanisms to therapeutics

The incidence of premature ovarian insufficiency (POI) is increasing worldwide, particularly among younger women, posing a significant challenge to fertility. In addition to menopausal symptoms, POI leads to several complications that profoundly affect female reproductive function and overall health. Unfortunately, current clinical treatment strategies for this condition are limited and often yield unsatisfactory outcomes. These approaches typically involve hormone replacement therapy combined with psychological support. Recently, mesenchymal stem cell (MSC) therapies for POI have garnered considerable attention in global research. MSCs can restore ovarian reproductive and endocrine functions through diverse mechanisms, including controlling differentiation, promoting angiogenesis, regulating ovarian fibrosis, inhibiting apoptosis, enhancing autocrine and paracrine effects, suppressing inflammation, modulating the immune system, and genetic regulation. This editorial offers a succinct summary of the application of MSC therapy in the context of POI, providing evidence for groundbreaking medical approaches that have potential to enhance reproductive health and overall well-being for women.

Mesenchymal Stem Cell-Derived Exosomes in Various Chronic Liver Diseases: Hype or Hope?

Chronic liver conditions are associated with high mortality rates and have a large adverse effect on human well-being as well as a significant financial burden. Currently, the only effective treatment available for the effects of liver failure and cirrhosis resulting from the progression of several chronic liver diseases is liver transplantation carried out at the original location. This implies that developing novel and effective treatments is imperative. Regenerative medicine has long been associated with stem cell therapy. Mesenchymal stem cells (MSCs), a type of cell with great differentiation potential, have become the preferred source for stem cell therapy. According to recent studies, MSCs' paracrine products-rather than their capacity for differentiation-play a significant therapeutic effect. MSC exosomes, a type of extracellular vesicle (MSC-EV), came into view as the paracrine substances of MSCs. According to research, MSC exosomes can maintain tissue homeostasis, which is necessary for healthy tissue function. All tissues contain them, and they take part in a variety of biological activities that support cellular activity and tissue regeneration in order to preserve tissue homeostasis. The outcomes support the use of MSCs and the exosomes they produce as a therapeutic option for a range of diseases. This review provides a brief overview of the source of MSC-EVs and outlines their physiological roles and biochemical capabilities. The elucidation of the role of MSC-EVs in the recovery and repair of hepatic tissues, as well as their contribution to maintaining tissue homeostasis, is discussed in relation to different chronic liver diseases. This review aims to provide new insights into the unique roles that MSC-EVs play in the treatment of chronic liver diseases.

Regeneration and anti-inflammatory effects of stem cells and their extracellular vesicles in gynecological diseases

There are many gynecological diseases, among which breast cancer (BC), cervical cancer (CC), endometriosis (EMs), and polycystic ovary syndrome (PCOS) are common and difficult to cure. Stem cells (SCs) are a focus of regenerative medicine. They are commonly used to treat organ damage and difficult diseases because of their potential for self-renewal and multidirectional differentiation. SCs are also commonly used for difficult-to-treat gynecological diseases because of their strong directional differentiation ability with unlimited possibilities, their tendency to adhere to the diseased tissue site, and their use as carriers for drug delivery. SCs can produce exosomes in a paracrine manner. Exosomes can be produced in large quantities and have the advantage of easy storage. Their safety and efficacy are superior to those of SCs, which have considerable potential in gynecological treatment, such as inhibiting endometrial senescence, promoting vascular reconstruction, and improving anti-inflammatory and immune functions. In this paper, we review the mechanisms of the regenerative and anti-inflammatory capacity of SCs and exosomes in incurable gynecological diseases and the current progress in their application in genetic engineering to provide a foundation for further research.

The function of exosomes in ovarian granulosa cells

Granulosa cells (GCs), as the basic components of ovarian tissue, play an indispensable role in maintaining normal ovarian functions such as hormone synthesis and ovulation. The abnormality of GCs often leads to ovarian endocrine disorders, which exert a negative effect on life quality and life expectancy. However, the pathogenesis and treatment of diseases are still poorly understood. Exosomes contain regulatory molecules and can transmit biological information in cell interaction. The role of exosomes in GCs has been studied extensively. This review summarizes the regulatory function of exosomes in GCs, as well as their participation in etiopathogenesis and their promising application in treatment when it comes to ovarian endocrine diseases, which can help us better understand ovarian diseases from the perspective of GCs.

Current knowledge on the role of extracellular vesicles in endometrial receptivity

Endometrial receptivity has been widely understood as the capacity of the endometrium to receive implantable embryos. The establishment of endometrial receptivity involves multiple biological processes including decidualization, tissue remodeling, angiogenesis, immune regulation, and oxidative metabolism. Extracellular vesicles (EVs) are lipid-bilayer-membrane nanosized vesicles mediating cell-to-cell communication. Recently, EVs and their cargo have been proven as functional factors in the establishment of endometrial receptivity. In this review, we comprehensively summarized the alteration of endometrium/embryo-derived EVs during the receptive phase and retrospected the current findings which revealed the pivotal role and potential mechanism of EVs to promote successful implantation. Furthermore, we highlight the potentiality and limitations of EVs being translated into clinical applications such as biomarkers of endometrial receptivity or reproductive therapeutic mediators, and point out the direction for further research.

Stem cells and exosomes: as biological agents in the diagnosis and treatment of polycystic ovary syndrome (PCOS)

A typical condition of the female reproductive system is polycystic ovary syndrome (PCOS). Hyperinsulinemia, insulin resistance, obesity, and hyperandrogenism are just a few of the metabolic abnormalities linked to this disease. Type 2 diabetes, hypertension, and cardiovascular disease are further issues related to PCOS. One consequence of this syndrome for which numerous treatment procedures have been developed is infertility. Metformin and clomiphene, two common allopathic medications used to treat PCOS, both have drawbacks and are ineffective. It is vital to seek novel therapeutic modalities to address these constraints. Exosomes (EXOs) are a particular class of extracellular vesicles that cells release, and they are known to play a significant role in mediating intercellular communication. A wide range of cargo, including lipids, proteins, mRNA, miRNAs, and numerous other noncoding RNAs, are contained in the nanoscale lipid bilayer exosomes. The cytokine effects of stem cells and EXOs derived from them enable the defense against metabolic diseases like PCOS. Moreover, EXO microRNAs can potentially be employed as biomarkers in the detection and management of PCOS. In this study, the potential of stem cells and exosomes are specifically investigated in the diagnosis and treatment of PCOS as one of the diseases of the female reproductive system.

Efficacy of Mesenchymal Stem Cell-Derived Extracellular Vesicles in the Animal Model of Female Reproductive Diseases: A Meta-Analysis

BACKGROUND

Female reproductive disorders, such as premature ovarian insufficiency (POI), intrauterine adhesion (IUA) or thin endometrium, and polycystic ovary syndrome (PCOS), are the main factors affecting fertility. Mesenchymal stem cells derived-extracellular vesicles (MSC-EVs) have gained traction as a new potential treatment and were widely studied in these diseases. However, their impact is still not fully clear.

METHODS

A systematic search of PubMed, Web of Science, EMBASE, the Chinese National Knowledge of Infrastructure, and WanFang online databases was performed up to September 27th, 2022, and the studies of MSC-EVs-based therapy on the animal models of female reproductive diseases were included. The primary outcomes were anti-Müllerian hormone (AMH) in POI and endometrial thickness in IUA, respectively.

RESULTS

28 studies (POI, N = 15; IUA, N = 13) were included. For POI, MSC-EVs improved AMH at 2 weeks (SMD 3.40, 95% CI 2.02 to 4.77) and 4 weeks (SMD 5.39, 95% CI 3.43 to 7.36) compared with placebo, and no difference was found when compared with MSCs in AMH (SMD -2.03, 95% CI -4.25 to 0.18). For IUA, MSC-EVs treatment could increase the endometrial thickness at 2 weeks (WMD 132.36, 95% CI 118.99 to 145.74), but no improvement was found at 4 weeks (WMD 166.18, 95% CI -21.44 to 353.79). The combination of MSC-EVs with hyaluronic acid or collagen had a better effect on the endometrial thickness (WMD 105.31, 95% CI 85.49 to 125.13) and glands (WMD 8.74, 95% CI 1.34 to 16.15) than MSC-EVs alone. The medium dose of EVs may allow for great benefits in both POI and IUA.

CONCLUSIONS

MSC-EVs treatment could improve the functional and structural outcomes in female reproductive disorders. The combination of MSC-EVs with HA or collagen may enhance the effect. These findings can accelerate the translation of MSC-EVs treatment to human clinical trials.

Follicular Fluid-Derived Small Extracellular Vesicles Alleviate DHEA-Induced Granulosa Cell Apoptosis by Delivering LINC00092

Polycystic ovary syndrome (PCOS) is a perplexing condition in females of reproductive age. Dysplasia of ovarian granulosa cell (GC) is implicated in PCOS. Follicular fluid (FF)-extracellular vesicles (Evs) are important in cell-cell communication during follicular development. The current study elaborated on the function and mechanism of FF-Evs in the viability and apoptosis of GC cells in PCOS development. Human GC cells KGN were treated with dehydroepiandrosterone (DHEA) to mimic a PCOS-like condition in vitro, which were further co-cultured with the FF-derived Evs (FF-Evs). The FF-Evs treatment significantly reduced DHEA-induced apoptosis of KGN cells while promoting cell viability and migration. The lncRNA microarray analysis showed that FF-Evs mainly deliver LINC00092 into the KGN cells. Knockdown of LINC00092 negated the protective effect of FF-Evs against DHEA-induced damage on KGN cells. Moreover, by performing bioinformatics analyses and biotin-labeled RNA pull-down assay, we found that LINC00092 could bind to the RNA binding protein LIN28B and inhibit its binding to pre-microRNA-18-5p, which allowed biogenesis of pre-miR-18-5p and increased the expression of miR-18b-5p, a miRNA with known alleviating role in PCOS by suppressing the PTEN mRNA. Collectively, the present work demonstrates that FF-Evs can alleviate DHEA-induced GC damage by delivering LINC00092.

Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) alleviate excessive autophagy of ovarian granular cells through VEGFA/PI3K/AKT/mTOR pathway in premature ovarian failure rat model

BACKGROUND

Premature ovarian failure (POF) is one of the leading causes of female infertility and is accompanied by abnormal endocrine, seriously affecting female quality of life. Previous studies have demonstrated that mesenchymal stem cells (MSCs) transplantation is a promising therapeutic strategy for POF. However, the mechanism remains obscure. This study aims to investigate the therapeutic effect of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) on ovarian function in the POF rat model and explore the underlying mechanisms.

METHODS

The ovarian function was evaluated by ovarian morphology, histology, estrous cycle, hormone levels (AMH, E2, FSH, and LH), and fertility ability to investigate the effect of hUC-MSCs on the POF rats model. The cytokines levels were assayed in serum using protein array to explore the mechanisms of hUC-MSCs therapy for POF. The excessive autophagy levels were evaluated using a co-culture system of 3D MSCs spheroids with human ovarian granulosa cell line (KGN) or primary ovarian granulosa cells (GCs) to understand the paracrine effect of hUC-MSCs on GCs. The related proteins expression of autophagy and PI3K/AKT/mTOR pathway was detected using Western Blotting and/or in various inhibitors supplement to further demonstrate that vascular endothelial growth factor A (VEGFA) secreted by hUC-MSCs can alleviate excessive autophagy of ovarian GCs via PI3K/AKT/mTOR signaling pathway. The ovarian culture model in vitro was applied to confirm the mechanism.

RESULTS

The ovarian function of POF and the excessive autophagy of ovarian GCs were restored after hUC-MSCs transplantation. The protein array result demonstrated that VEGF and PI3K/AKT might improve ovarian function. in vitro experiments demonstrated that VEGFA secreted by hUC-MSCs could decrease oxidative stress and inhibit excessive autophagy of ovarian GCs via PI3K/AKT/mTOR pathway. The ovarian culture model results confirmed this mechanism in vitro.

CONCLUSION

The hUC-MSCs can alleviate excessive autophagy of ovarian GCs via paracrine VEGFA and regulate the PI3K/AKT/mTOR signaling pathway, thereby improving the ovarian function of POF.

Human umbilical cord mesenchymal stem cell-derived extracellular vesicles improve ovarian function in rats with primary ovarian insufficiency by carrying miR-145-5p

OBJECTIVE

Stem cell/exosome therapy is a novel strategy for primary ovarian insufficiency (POI). This paper is to examine the role of human umbilical cord mesenchymal stem cell-derived extracellular vesicles (hUCMSC-EVs) in POI.

METHODS

hUCMSC-EVs were extracted and identified. POI rats were induced by cyclophosphamide for 15 days and treated with EV or GW4869 every 5 days and euthanized 28 days later. Vaginal smears were observed for 21 days. Serum hormone levels (FSH/E2/AMH) were measured by ELISA. Ovarian morphology, follicle numbers, and granulosa cell (GC) apoptosis were observed by HE and TUNEL staining. GCs extracted from Swiss albino rats were cyclophosphamide-induced to establish the POI cell model, followed by oxidative injury and apoptosis evaluation with the help of DCF-DA fluorescence, ELISA, and flow cytometry. The relation between miR-145-5p and XBP1 was predicted on StarBase and validated by dual-luciferase assay. miR-145-5p and XBP1 levels were measured by RT-qPCR and Western blot.

RESULTS

EV treatment reduced irregular estrus cycle incidence since day 7, increased E2 and AMH levels and all-stage follicle numbers, reduced FSH level, GC apoptosis, and atretic follicle numbers in POI rats. EV treatment diminished GC oxidative injury and apoptosis in vitro. miR-145-5p knockdown in hUCMSC-EVs partly abolished hUCMSC-EV-mediated effects on GCs and ovarian function in vivo and on GC oxidative injury and apoptosis in vitro. Silencing XBP1 partially negated miR-145-5p knockdown-exerted effects on GCs in vitro.

CONCLUSION

miR-145-5p carried by hUCMSC-EVs attenuates GC oxidative injury and apoptosis and thus extenuates ovarian injury and improves ovarian function in POI rats.

Therapeutic effects of human umbilical cord mesenchymal stem cell-derived extracellular vesicles on ovarian functions through the PI3K/Akt cascade in mice with premature ovarian failure

Premature ovarian failure (POF) mainly refers to ovarian dysfunction in females younger than forty. Mesenchymal stem cells (MSCs) are considered an increasingly promising therapy for POF. This study intended to uncover the therapeutic effects of human umbilical cord MSC-derived extracellular vesicles (hucMSCEVs) on POF. hucMSCs were identified by observing morphology and examining differentiation capabilities. EVs were extracted from hucMSCs and later identified utilizing nanoparticle tracking analysis, transmission electron microscopy, and Western blotting. POF mouse models were established by injecting D-galactose (Dgal). The estrous cycles were assessed through vaginal cytology, and serum levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), anti-mullerian hormone (AMH), estradiol (E2), and progesterone (P) were measured by ELISA. The human ovarian granulosa cell line KGN was used for in vitro experiments. The uptake of hucMSC-EVs by KGN cells was detected. After D-gal treatment, cell proliferation and apoptosis were assessed via CCK-8 assay and flow cytometry. The PI3K/Akt pathway-related proteins were determined by Western blotting. Our results revealed that POF mice had prolonged estrous cycles, increased FSH and LH levels, and decreased AMH, E2, and P levels. Treatment with hucMSC-EVs partially counteracted the above changes. D-gal treatment reduced proliferation and raised apoptosis in KGN cells, while hucMSC-EV treatment annulled the changes. D-gal-treated cells exhibited downregulated p-PI3K/PI3K and p-Akt/Akt levels, while hucMSC-EVs activated the PI3K/Akt pathway. LY294002 suppressed the roles of hucMSC-EVs in promoting KGN cell proliferation and lowering apoptosis. Collectively, hucMSC-EVs facilitate proliferation and suppress apoptosis of ovarian granulosa cells by activating the PI3K/Akt pathway, thereby alleviating POF.

Recent Insights into Noncoding RNAs in Primary Ovarian Insufficiency: Focus on Mechanisms and Treatments

CONTEXT

Primary ovarian insufficiency (POI) is a heterogeneous disease with an unknown underlying trigger or root cause. Recently many studies evaluated noncoding RNAs (ncRNAs), especially microRNAs (miRNAs), long noncoding RNA (lncRNAs), circular RNAs (circRNAs), and small interfering RNAs (siRNAs) for their associations with POI.

EVIDENCE ACQUISITION

In this review, we outline the biogenesis of various ncRNAs relevant to POI and summarize the evidence for their roles in the regulation of disease occurrence and progression. Articles from 2003 to 2022 were selected for relevance, validity, and quality from results obtained in PubMed and Google Scholar using the following search terms: noncoding RNAs; primary ovarian insufficiency; premature ovarian failure; noncoding RNAs and primary ovarian insufficiency/premature ovarian failure; miRNAs and primary ovarian insufficiency/premature ovarian failure; lncRNAs and primary ovarian insufficiency/premature ovarian failure; siRNAs and primary ovarian insufficiency/premature ovarian failure; circRNAs and primary ovarian insufficiency/premature ovarian failure; pathophysiology; and potential treatment. All articles were independently screened for eligibility by the authors.

EVIDENCE SYNTHESIS

This review summarizes the biological functions and synthesis of miRNAs, lncRNAs, siRNAs, and circRNAs in POI and discusses the findings of clinical and in vitro and in vivo studies. Although there is variability in the findings of individual studies, overall the available literature justifies the conclusion that dysregulated ncRNAs play significant roles in POI.

CONCLUSION

The potential of ncRNAs in the treatment of POI requires further investigation, as ncRNAs derived from mesenchymal stem cell-secreted exosomes play pivotal roles and have considerable therapeutic potential in a multitude of diseases.

Homogenous subpopulation of human mesenchymal stem cells and their extracellular vesicles restore function of endometrium in an experimental rat model of Asherman syndrome

BACKGROUND

Asherman syndrome (AS), or intrauterine adhesions, is a main cause of infertility in reproductive age women after endometrial injury. Mesenchymal stem cells (MSCs) and their extracellular vesicles (EVs) are promising candidates for therapies that repair damaged endometria. However, concerns about their efficacy are attributed to heterogeneity of the cell populations and EVs. A homogenous population of MSCs and effective EV subpopulation are needed to develop potentially promising therapeutic options in regenerative medicine.

METHODS

AS model was induced by mechanical injury in adult rat uteri. Then, the animals were treated immediately with homogeneous population of human bone marrow-derived clonal MSCs (cMSCs), heterogenous parental MSCs (hMSCs), or cMSCs-derived EV subpopulations (EV20K and EV110K). The animals were sacrificed two weeks post-treatment and uterine horns were collected. The sections were taken, and hematoxylin-eosin was used to examine the repair of endometrial structure. Fibrosis was measured by Masson's trichrome staining and α-SMA and cell proliferation by Ki67 immunostaining. The function of the uteri was explored by the result of mating trial test. Expression changes of TNFα, IL-10, VEGF, and LIF were assayed by ELISA.

RESULTS

Histological analysis indicated fewer glands, thinner endometria, increased fibrotic areas, and decreased proliferation of epithelial and stroma of the uteri in the treated compared with intact and sham-operated animals. However, these parameters improved after transplantation of both types of cMSCs and hMSCs and/or both cryopreserved EVs subpopulations. The cMSCs demonstrated more successful implantation of the embryos in comparison with hMSCs. The tracing of the transplanted cMSCs and EVs showed that they migrated and localized in the uteri. Protein expression analysis results demonstrated downregulation of proinflammatory factor TNFα and upregulation of anti-inflammatory cytokine IL-10, and endometrial receptivity cytokines VEGF and LIF in cMSC- and EV20K-treated animals.

CONCLUSION

Transplantation of MSCs and EVs contributed to endometrial repair and restoration of reproductive function, likely by inhibition of excessive fibrosis and inflammation, enhancement of endometrial cell proliferation, and regulation of molecular markers related to endometrial receptivity. Compared to classical hMSCs, cMSCs were more efficient than hMSCs in restoration of reproductive function. Moreover, EV20K is more cost-effective and feasible for prevention of AS in comparison with conventional EVs (EV110K).

Frontier Review of the Molecular Mechanisms and Current Approaches of Stem Cell-Derived Exosomes

Exosomes are effective therapeutic vehicles that may transport their substances across cells. They are shown to possess the capacity to affect cell proliferation, migration, anti-apoptosis, anti-scarring, and angiogenesis, via the action of transporting molecular components. Possessing immense potential in regenerative medicine, exosomes, especially stem cell-derived exosomes, have the advantages of low immunogenicity, minimal invasiveness, and broad clinical applicability. Exosome biodistribution and pharmacokinetics may be altered, in response to recent advancements in technology, for the purpose of treating particular illnesses. Yet, prior to clinical application, it is crucial to ascertain the ideal dose and any potential negative consequences of an exosome. This review focuses on the therapeutic potential of stem cell-derived exosomes and further illustrates the molecular mechanisms that underpin their potential in musculoskeletal regeneration, wound healing, female infertility, cardiac recovery, immunomodulation, neurological disease, and metabolic regulation. In addition, we provide a summary of the currently effective techniques for isolating exosomes, and describe the innovations in biomaterials that improve the efficacy of exosome-based treatments. Overall, this paper provides an updated overview of the biological factors found in stem cell-derived exosomes, as well as potential targets for future cell-free therapeutic applications.

Human Umbilical Cord Mesenchymal Stem Cell-Derived Exosome Repairs Endometrial Epithelial Cells Injury Induced by Hypoxia via Regulating miR-663a/CDKN2A Axis

Aim

Thin endometrium remains a severe clinical challenge with no effective therapy to date. We aimed at exploring the role and molecular mechanism of human umbilical cord mesenchymal stem cell- (hucMSC-) derived exosomes (hucMSC-Ex) in repairing hypoxic injury of endometrial epithelial cells (EECs).

Methods

Exosomes were harvested from the conditioned medium of hucMSC and characterized using western blot, transmission electron microscopy (TEM), flow cytometry, and nanoparticle tracking analysis (NTA). EECs were subjected to hypoxic conditions before cocultured with hucMSC-Ex. Cell viability, apoptosis, and migration were determined with CCK-8, flow cytometry, and wound healing assay, respectively. Apoptosis/EMT-related proteins were detected by western blot. The miRNA profiling was determined by RNA sequencing. The expression of miR-663a and CDKN2A was measured by qRT-PCR. MiR-663a in EECs was overexpressed by transfecting with miR-663a mimics.

Results

Mesenchymal stem cells (MSCs) markers CD73, CD90, and CD106 were positively expressed in hucMSCs. Exosome isolated from hucMSC expressed CD63 and TSG101, and were 100-150 nm in diameter. HucMSC-Ex promoted cell proliferation inhibited by hypoxia. And hucMSC-Ex also inhibited hypoxia-induced apoptosis, migration, and EMT of EECs by upregulating the expression of Bcl-2 and E-cadherin and downregulating Bax and N-cadherin levels. Further, bioinformatics research found that hucMSC-Ex coculture can significantly upregulate the expression of miR-663a and decrease the expression of CDKN2A in hypoxia-induced EECs. Furthermore, miR-663a overexpression inhibited CDKN2A expression and increased the expression of Bcl-2 and E-cadherin in hypoxia-induced EECs.

Conclusions

HucMSC-Ex promoted cell proliferation, inhibited cell apoptosis, migration, and EMT in hypoxia-induced EECs, thereby alleviating hypoxia-induced EECs injury, which may be related to its regulation of miR-663a/CDKN2A expression. Our study indicated that hucMSC-Ex might benefit for repairing thin endometrium.

Mesenchymal stem cells-derived exosomes as a promising new approach for the treatment of infertility caused by polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a multifactorial metabolic and most common endocrine disorder that its prevalence, depending on different methods of evaluating PCOS traits, varies from 4% to 21%. Chronic low-grade inflammation and irregular apoptosis of granulosa cells play a crucial role in the pathogenesis of PCOS infertility. Mesenchymal stem cells (MSCs)-derived exosomes and extracellular vesicles (EVs) are lipid bilayer complexes that act as a means of intercellular transferring of proteins, lipids, DNA and different types of RNAs. It seems that this nanoparticles have therapeutic effects on the PCOS ovary such as regulating immunity response, anti-inflammatory (local and systemic) and suppress of granulosa cells (GCs) apoptosis. Although there are few studies demonstrating the effects of exosomes on PCOS and their exact mechanisms is still unknown, in the present study we reviewed the available studies of the functions of MSC-derived exosome, EVs and secretome on apoptosis of granulosa cells and inflammation in the ovary. Therefore, the novel cell-free therapeutic approaches for PCOS were suggested in this study.

Animal models in intrauterine adhesion research

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

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.

Biological mechanisms and applied prospects of mesenchymal stem cells in premature ovarian failure

Premature ovarian failure (POF), also known as primary ovarian insufficiency (POI), refers to the loss of ovarian function in women after puberty and before the age of 40 characterized by high serum gonadotropins and low estrogen, irregular menstruation, amenorrhea, and decreased fertility. However, the specific pathogenesis of POF is unexplained, and there is no effective therapy for its damaged ovarian tissue structure and reduced reserve function. Mesenchymal stem cells (MSCs), with multidirectional differentiation potential and self-renewal ability, as well as the cytokines and exosomes they secrete, have been studied and tested to play an active therapeutic role in a variety of degenerative pathologies, and MSCs are the most widely used stem cells in regenerative medicine. MSCs can reverse POI and enhance ovarian reserve function through differentiation into granulosa cells (GCs), immune regulation, secretion of cytokines and other nutritional factors, reduction of GCs apoptosis, and promotion of GCs regeneration. Many studies have proved that MSCs may have a restorative effect on the structure and fertility of injured ovarian tissues and turn to be a useful clinical approach to the treatment of patients with POF in recent years. We intend to use MSCs-based therapy to completely reverse POI in the future.

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.

Trophic and immunomodulatory effects of adipose tissue derived stem cells in a preclinical murine model of endometriosis

Endometriosis, which exhibits enigmatic pathological features such as stromal fibrosis and proliferation of ectopic epithelial cells, is known as a refractory disease. Mesenchymal stem cells modulate the fibrosis in stromal tissues through their trophic and immunomodulatory properties. To investigate the potential of stem cells in treating endometriosis, we examined the secondary morphology and molecular alterations in endometriosis-like lesions after the administration of adipose tissue-derived stem cells (ASCs) to an experimental murine model of endometriosis. The infused ASCs were found integrated in the endometriosis-like lesions. Accompanied by the suppression of stromal fibrosis and proliferation of endometriotic epithelial cells, the infusion of ASCs with stemness potential (early passage of ASCs) suppressed the growth of endometriosis-like lesions and inhibited the expression of pro-inflammatory and pro-fibrotic cytokines, whereas no significant attenuation of endometriosis-like lesions occurred after the infusion of ASCs without stemness potential (late passage of ASCs). Accordingly, the trophic and immunomodulatory properties of ASCs may regulate fibrosis in endometriosis-like lesions, suggesting that regenerative medicine could be recognized as an innovative treatment for patients with endometriosis through the accumulation of evidence of preclinical efficacy.

Visual Analysis of Uterine Adhesion Research Based on CiteSpace: Bibliometric Analysis From 2006 to 2021

Background

Intrauterine adhesionis caused by a variety of reasons, such as damage of the endometrial basal layer, adhesion or occlusion of the uterine cavity or cervix in different degrees. Seriously endangering women's physical and mental health.

Objective

The purpose of this paper is to analyze the research development of intrauterine adhesions in recent 15 years, explore the future development direction, and promote the development of this field.

Methods

With intrauterine adhesions and Ashman's syndrome as the theme, the related literatures from January 2006 to July 2021 in the Web of Science were searched, and the visual atlas was analyzed by CiteSpace software.

Results

A total of 644 literatures were included. The key words related to intrauterine adhesion mainly include adhesion, pregnancy, expression, intrauterine adhesions, women, adhesion molecule, diagnosis, activation, hysteroscopy and fertility, etc. Six clusters were obtained by keywords analysis, involving hysteroscopy, placenta, office hysteroscopy, uterus and laparoscopy. Co-occurrence of keywords shows that the research focus in recent years is on endometrial repair and regeneration.

Conclusions

Through the bibliometric analysis of WOS research on intrauterine adhesions in recent 15 years, the comprehensive analysis of countries, institutions, authors and keywords is obtained, which has a clear guiding significance for guiding the future development of intrauterine adhesions.

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.

Potential of Mesenchymal Stem Cell-Derived Exosomes as a Novel Treatment for Female Infertility Caused by Bacterial Infections

Neisseria gonorrhoeae and Chlamydia trachomatis are the most common causes of bacterial sexually transmitted diseases (STDs) with complications in women, including pelvic inflammatory disease (PID), ectopic pregnancy, and infertility. The main concern with these infections is that 70% of infected women are asymptomatic and these infections ascend to the upper female reproductive tract (FRT). Primary infection in epithelial cells creates a cascade of events that leads to secretion of pro-inflammatory cytokines that stimulate innate immunity. Production of various cytokines is damaging to mucosal barriers, and tissue destruction leads to ciliated epithelial destruction that is associated with tubal scarring and ultimately provides the conditions for infertility. Mesenchymal stem cells (MSCs) are known as tissue specific stem cells with limited self-renewal capacity and the ability to repair damaged tissues in a variety of pathological conditions due to their multipotential differentiation capacity. Moreover, MSCs secrete exosomes that contain bioactive factors such as proteins, lipids, chemokines, enzymes, cytokines, and immunomodulatory factors which have therapeutic properties to enhance recovery activity and modulate immune responses. Experimental studies have shown that local and systemic treatment of MSC-derived exosomes (MSC-Exos) suppresses the destructive immune response due to the delivery of immunomodulatory proteins. Interestingly, some recent data have indicated that MSC-Exos display strong antimicrobial effects, by the secretion of antimicrobial peptides and proteins (AMPs), and increase bacterial clearance by enhancing the phagocytic activity of host immune cells. Considering MSC-Exos can secrete different bioactive factors that can modulate the immune system and prevent infection, exosome therapy is considered as a new therapeutic method in the treatment of inflammatory and microbial diseases. Here we intend to review the possible application of MSC-Exos in female reproductive system bacterial diseases.

Cell-Free Fat Extract Improves Ovarian Function and Fertility in Mice With Advanced Age

The reduction in the quantity and quality of oocytes is the major factor affecting fertility in women with advanced age, who tend to experience delayed childbearing and declined fertility rate. However, effective therapeutic strategies to combat this decrease in ovarian function are lacking in clinical practice. Thus, identifying a new method to rescue ovarian function and improve reproduction in natural age-related decline in fertility is necessary. Cell-free fat extract (CEFFE) has been verified to possess diverse active proteins exerting anti-aging and proliferation-promoting effects. Nonetheless, whether CEFFE can rescue the decline in aged-related ovarian function and improve the fertility of females with advanced age remains unclear. In this study, a natural aging mouse model, exhibiting similarities to the physiological changes of ovarian senescence, was used to observe the anti-aging effect of CEFFE on ovarian functions. We found that CEFFE, injected via the veins, could recover the levels of the sex hormone, increase angiogenesis and the number of growth follicles in the natural aging mice model. Moreover, CEFFE promoted the development of embryos and increased the litter size of aged mice. Transcriptome analysis of the aged mouse ovaries revealed that CEFFE treatment upregulated the expression of genes involved in the repair of DNA damage. And both in vivo and in vitro experiment proved that CEFFE improved the function of granulosa cells, including promoting proliferation, alleviating senescence, and rescuing DNA damage in aged granulosa cells. Collectively, our study implied that CEFFE improved the ovarian function and fertility of naturally aging mice by ameliorating the overall microenvironment of ovary, which provided a theoretical basis for new anti-aging therapeutic strategies for cell-free therapy in ovaries.

Research Progress on the Treatment of Premature Ovarian Failure Using Mesenchymal Stem Cells: A Literature Review

Premature ovarian failure (POF) has become one of the main causes of infertility in women of childbearing age and the incidence of POF is increasing year by year, seriously affecting the physical and mental health of patients and increasing the economic burden on families and society as a whole. The etiology and pathogenesis of POF are complex and not very clear at present. Currently, hormone replacement therapy is mainly used to improve the symptoms of low estrogen, but cannot fundamentally solve the fertility problem. In recent years, stem cell (SC) transplantation has become one of the research hotspots in the treatment of POF. The results from animal experiments bring hope for the recovery of ovarian function and fertility in patients with POF. In this article, we searched the published literature between 2000 and 2020 from the PubMed database (https://pubmed.ncbi.nlm.nih.gov), and summarized the preclinical research data and possible therapeutic mechanism of mesenchymal stem cells (MSCs) in the treatment of POF. Our aim is to provide useful information for understanding POF and reference for follow-up research and treatment of POF.

The Latest Developments in Immunomodulation of Mesenchymal Stem Cells in the Treatment of Intrauterine Adhesions, Both Allogeneic and Autologous

Intrauterine adhesion (IUA) is an endometrial fibrosis disease caused by repeated operations of the uterus and is a common cause of female infertility. In recent years, treatment using mesenchymal stem cells (MSCs) has been proposed by many researchers and is now widely used in clinics because of the low immunogenicity of MSCs. It is believed that allogeneic MSCs can be used to treat IUA because MSCs express only low levels of MHC class I molecules and no MHC class II or co-stimulatory molecules. However, many scholars still believe that the use of allogeneic MSCs to treat IUA may lead to immune rejection. Compared with allogeneic MSCs, autologous MSCs are safer, more ethical, and can better adapt to the body. Here, we review recently published articles on the immunomodulation of allogeneic and autologous MSCs in IUA therapy, with the aim of proving that the use of autologous MSCs can reduce the possibility of immune rejection in the treatment of IUAs.

Application of Bioactive Hydrogels for Functional Treatment of Intrauterine Adhesion

Intrauterine adhesion (IUA) is a common endometrial disease and one of the main causes of infertility in women of childbearing age. Current treatment strategies, such as hysteroscopic adhesion resection, hysteroscopic transcervical resection of adhesion (TCRA), the use of local hormone drugs, and anti-adhesion scaffold implantation, do not provide a satisfactory pregnancy outcome for moderate-severe IUA, which presents a great challenge in reproductive medicine. With the development of material engineering, various bioactive and functional hydrogels have been developed using natural and synthetic biomaterials. These hydrogels are not only used as barely physical barriers but are also designed as vectors of hormone drugs, growth factors, and stem cells. These characteristics give bioactive hydrogels potentially important roles in the prevention and treatment of IUA. However, there is still no systematic review or consensus on the current advances and future research direction in this field. Herein, we review recent advances in bioactive hydrogels as physical anti-adhesion barriers, in situ drug delivery systems, and 3D cell delivery and culture systems for seeded cells in IUA treatment. In addition, current limitations and future perspectives are presented for further research guidance, which may provide a comprehensive understanding of the application of bioactive hydrogels in intrauterine adhesion treatment.

The Role of Noncoding RNA in the Pathophysiology and Treatment of Premature Ovarian Insufficiency

Premature ovarian insufficiency (POI) is defined as a loss of ovarian function before the age of 40 years, with a prevalence rate estimated at approximately 1%. It causes infertility and is related to serious long-term health consequences, including reduced life expectancy, increased cardiovascular risk, decreased bone mineral density and neurological disorders. There is currently no effective therapy for POI that is widely available in clinical practice; therefore, the treatment of patients with POI is based on hormone replacement therapy. One of the recent advances in the understanding of the pathophysiology of POI has been the role of microRNAs (miRNAs) and other noncoding RNAs (ncRNAs) in the disease. Moreover, intensive research on human folliculogenesis and reproductive biology has led to the development of novel promising therapeutic strategies with the use of exosomal miRNAs derived from mesenchymal stem cells to restore ovarian function in POI patients. This narrative review focuses on the new studies concerning the role of ncRNAs in the pathogenesis of POI, together with their potential as biomarkers of the disease and targets for therapy.