Exosomes Derived from Human Umbilical Cord Mesenchymal Stem Cells Promote Proliferation of Allogeneic Endometrial Stromal Cells

UCMSCs-derived exosomal SLIT2 alleviates ischemic stroke through the β-catenin/TCF4/USP20 signaling pathway

BACKGROUND

Ischemic stroke (IS) is a disease that causes necrosis of brain tissues by inadequate blood supply to the brain. Umbilical cord mesenchymal stem cells (UCMSCs)-derived exosomes (UCMSCs-Exo) have been reported to alleviate IS, and slit guidance ligand 2 (SLIT2) could promote neurological repair after IS. The aim of this research was to explore the potential mechanism of UCMSCs-derived exosomal SLIT2 on IS progression.

METHODS

The middle cerebral artery occlusion (MCAO) rat and oxygen glucose deprivation/reperfusion (OGD/R)-induced cellular models were established, and then treated with UCMSCs-Exo. Cell viability and apoptosis were explored by cell counting kit-8 (CCK-8) assay and flow cytometry, respectively. The expressions of ubiquitin specific peptidase 20 (USP20) and related apoptotic proteins were determined using Western blot. Immunofluorescence and immunohistochemistry were performed to evaluate the effect of SLIT2 on β-catenin nuclear translocation. The association between transcription factor 4 (TCF4) and USP20 promoter was investigated by chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assys.

RESULTS

In the OGD/R-induced cell model, UCMSCs-derived exosomal SLIT2 increased cell viability, decreased apoptosis and promoted β-catenin nuclear translocation. Besides, β-catenin agonist (SKL2001) facilitated USP20 transcription by promoting TCF4 binding to USP20 promoter. Finally, TCF4 upregulated USP20 and inhibited OGD/R-induced cell damage. In the MCAO rat model, UCMSCs-derived exosomal SLIT2 mitigated IS by promoting β-catenin nuclear translocation, which activated the TCF4/USP20 pathway to inhibit apoptosis.

CONCLUSION

UCMSCs-derived exosomal SLIT2 activated TCF4 by promoting β-catenin nuclear translocation, which transcriptionally upregulated USP20 expression, thereby attenuating OGD/R-induced neuroncell damage and ultimately leading to inhibition of IS progression.

Advances in human umbilical cord mesenchymal stem cells-derived extracellular vesicles and biomaterial assemblies for endometrial injury treatment

Endometrial injury caused by repeated uterine procedures, infections, inflammation, or uterine artery dysfunction can deplete endometrial stem/progenitor cells and impair regeneration, thereby diminishing endometrial receptivity and evidently lowering the live birth, clinical pregnancy, and embryo implantation rates. Currently, safe and effective clinical treatment methods or gene-targeted therapies are unavailable, especially for severe endometrial injury. Umbilical cord mesenchymal stem cells and their extracellular vesicles are characterized by their simple collection, rapid proliferation, low immunogenicity, and tumorigenicity, along with their involvement in regulating angiogenesis, immune response, cell apoptosis and proliferation, inflammatory response, and fibrosis, Therefore, these cells and vesicles hold broad potential for application in endometrial repair. This article reviewed recent research on human umbilical cord mesenchymal stem cells as well as their extracellular vesicles in repairing endometrial injury.

Self-Assembled Peptide Hydrogels Loaded with Umbilical Cord-Derived Mesenchymal Stem Cells Repairing Injured Endometrium and Restoring Fertility

Endometrial injury is a major cause of infertility and recurrent miscarriage. However, no clinically available methods currently exist to effectively repair the damaged endometrium. Mesenchymal stem cells (MSCs) have emerged as a promising therapeutic approach for promoting tissue regeneration, yet a biocompatible scaffold capable of delivering MSCs and supporting their growth is needed. Herein, the study reports a peptide hydrogel scaffold, self-assembled from a peptide IVK8-RGD consisting of an ionic complementary peptide sequence IEVEIRVK and a bioactive sequence RGD, to load umbilical cord-derived mesenchymal stem cells (UC-MSCs). This peptide forms a hydrogel under the physiological condition through self-assembly, and the peptide hydrogel exhibits injectability and adhesiveness to uterus, making it suitable for endometrial repair. Importantly, this hydrogel supports the adhesion and proliferation of UC-MSCs in a 3D environment. In vivo experiments using rats with endometrial injury have shown that treatment with IVK8-RGD hydrogel loaded with UC-MSCs effectively restores endometrial thickness, inhibits fibrosis, and facilitates angiogenesis through activating Raf/MEK/ERK pathway, leading to significantly improved fertility and live birth rate. These findings demonstrate the potential of the UC-MSCs-loaded hydrogel in repairing damaged endometrium and may address the unmet clinical needs of treating recurrent miscarriage and infertility induced by endometrial damage.

Evolution of biotechnological advances and regenerative therapies for endometrial disorders: a systematic review

BACKGROUND

The establishment and maintenance of pregnancy depend on endometrial competence. Asherman syndrome (AS) and intrauterine adhesions (IUA), or endometrial atrophy (EA) and thin endometrium (TE), can either originate autonomously or arise as a result from conditions (i.e. endometritis or congenital hypoplasia), or medical interventions (e.g. surgeries, hormonal therapies, uterine curettage or radiotherapy). Affected patients may present an altered or inadequate endometrial lining that hinders embryo implantation and increases the risk of poor pregnancy outcomes and miscarriage. In humans, AS/IUA and EA/TE are mainly treated with surgeries or pharmacotherapy, however the reported efficacy of these therapeutic approaches remains unclear. Thus, novel regenerative techniques utilizing stem cells, growth factors, or tissue engineering have emerged to improve reproductive outcomes.

OBJECTIVE AND RATIONALE

This review comprehensively summarizes the methodologies and outcomes of emerging biotechnologies (cellular, acellular, and bioengineering approaches) to treat human endometrial pathologies. Regenerative therapies derived from human tissues or blood which were studied in preclinical models (in vitro and in vivo) and clinical trials are discussed.

SEARCH METHODS

A systematic search of full-text articles available in PubMed and Embase was conducted to identify original peer-reviewed studies published in English between January 2000 and September 2023. The search terms included: human, uterus, endometrium, Asherman syndrome, intrauterine adhesions, endometrial atrophy, thin endometrium, endometritis, congenital hypoplasia, curettage, radiotherapy, regenerative therapy, bioengineering, stem cells, vesicles, platelet-rich plasma, biomaterials, microfluidic, bioprinting, organoids, hydrogel, scaffold, sheet, miRNA, sildenafil, nitroglycerine, aspirin, growth hormone, progesterone, and estrogen. Preclinical and clinical studies on cellular, acellular, and bioengineering strategies to repair or regenerate the human endometrium were included. Additional studies were identified through manual searches.

OUTCOMES

From a total of 4366 records identified, 164 studies (3.8%) were included for systematic review. Due to heterogeneity in the study design and measured outcome parameters in both preclinical and clinical studies, the findings were evaluated qualitatively and quantitatively without meta-analysis. Groups using stem cell-based treatments for endometrial pathologies commonly employed mesenchymal stem cells (MSCs) derived from the human bone marrow or umbilical cord. Alternatively, acellular therapies based on platelet-rich plasma (PRP) or extracellular vesicles are gaining popularity. These are accompanied by the emergence of bioengineering strategies based on extracellular matrix (ECM)-derived hydrogels or synthetic biosimilars that sustain local delivery of cells and growth factors, reporting promising results. Combined therapies that target multiple aspects of tissue repair and regeneration remain in preclinical testing but have shown translational value. This review highlights the myriad of therapeutic material sources, administration methods, and carriers that have been tested.

WIDER IMPLICATIONS

Therapies that promote endometrial proliferation, vascular development, and tissue repair may help restore endometrial function and, ultimately, fertility. Based on the existing evidence, cost, accessibility, and availability of the therapies, we propose the development of triple-hit regenerative strategies, potentially combining high-yield MSCs (e.g. from bone marrow or umbilical cord) with acellular treatments (PRP), possibly integrated in ECM hydrogels. Advances in biotechnologies together with insights from preclinical models will pave the way for developing personalized treatment regimens for patients with infertility-causing endometrial disorders such as AS/IUA, EA/TE, and endometritis.

REGISTRATION NUMBER

https://osf.io/th8yf/.

Biomaterial Fg/P(LLA-CL) regulates macrophage polarization and recruitment of mesenchymal stem cells after endometrial injury

The process of endometrial repair after injury involves the synergistic action of various cells including immune cells and stem cells. In this study, after combing Fibrinogen(Fg) with poly(L-lacticacid)-co-poly(ε-caprolactone)(P(LLA-CL)) by electrospinning, we placed Fg/P(LLA-CL) into the uterine cavity of endometrium-injured rats, and bioinformatic analysis revealed that Fg/P(LLA-CL) may affect inflammatory response and stem cell biological behavior. Therefore, we verified that Fg/P(LLA-CL) could inhibit the lipopolysaccharide (LPS)-stimulated macrophages from switching to the pro-inflammatory M1 phenotype in vitro. Moreover, in the rat model of endometrial injury, Fg/P(LLA-CL) effectively promoted the polarization of macrophages towards the anti-inflammatory M2 phenotype and enhanced the presence of mesenchymal stem cells at the injury site. Overall, Fg/P(LLA-CL) exhibits significant influence on macrophage polarization and stem cell behavior in endometrial injury, justifying further exploration for potential therapeutic applications in endometrial and other tissue injuries.

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.

Umbilical cord mesenchymal stem cell-derived exosomes inhibits fibrosis in human endometrial stromal cells via miR-140-3p/FOXP1/Smad axis

Endometrial fibrosis is the histologic appearance of intrauterine adhesion (IUA). Emerging evidences demonstrated umbilical cord mesenchymal stem cell-derived exosomes (UCMSC-exo) could alleviate endometrial fibrosis. But the specific mechanism is not clear. In this study, we explored the effect of UCMSC-exo on endometrial fibrosis, and investigated the possible role of miR-140-3p/FOXP1/Smad axis in anti-fibrotic properties of UCMSC-exo. UCMSC-exo were isolated and identified. Transforming growth factor-β (TGF-β) was used to induce human endometrial stromal cell (HESC) fibrosis. Dual luciferase assay was performed to verify the relationship between miR-140-3p and FOXP1. The expressions of fibrotic markers, SIP1, and p-Smad2/p-Smad3 in HESCs stimulated with UCMSC-exo were detected by western blot. In addition, the effects of miR-140-3p mimic, miR-140-3p inhibitor and FOXP1 over-expression on endometrial fibrosis were assessed. The isolated UCMSC-exo had a typical cup-shaped morphology and could be internalized into HESCs. The expressions of fibrotic markers were significantly increased by TGF-β, which was reversed by UCMSC-exo. MiR-140-3p in UCMSC-exo ameliorated TGf-β-induced HESCs fibrosis. FOXP1 was identified as the direct target of miR-140-3p, which could inversely regulate miR-140-3p's function on HESCs fibrosis. Furthermore, we demonstrated that miR-140-3p in UCMSC-exo regulated Smad signal pathway to exert the anti-fibrotic effect in HESCs. The anti-fibrotic effect of UCMSC-derived exosomes against HESC fibrosis was at least partially achieved by miR-140-3p/FOXP1/Smad axis.

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.

Exosomes: potential diagnostic markers and drug carriers for adenomyosis

Adenomyosis is a common benign gynecological disorder and an important factor leading to infertility in fertile women. Adenomyosis can cause deep lesions and is persistent and refractory in nature due to its tumor-like biological characteristics, such as the ability to implant, adhere, and invade. The pathogenesis of adenomyosis is currently unclear. Therefore, new therapeutic approaches are urgently required. Exosomes are nanoscale vesicles secreted by cells that carry proteins, genetic materials and other biologically active components. Exosomes play an important role in maintaining tissue homeostasis and regulating immune responses and metabolism. A growing body of work has shown that exosomes and their contents are key to the development and progression of adenomyosis. This review discusses the current research progress, future prospects and challenges in this emerging therapeutic tool by providing an overview of the changes in the adenomyosis uterine microenvironment and the biogenesis and functions of exosomes, with particular emphasis on the role of exosomes and their contents in the regulation of cell migration, proliferation, fibrosis formation, neovascularization, and inflammatory responses in adenomyosis.

Exosomes from Human Umbilical Cord Mesenchymal Stem Cells Facilitates Injured Endometrial Restoring in Early Repair Period through miR-202-3p Mediating Formation of ECM

Endometrial damage repair disorder is the main reason of intrauterine adhesions (IUA) and thin endometrium (TA), which is caused by curettage or infection. Exosomal miRNAs derived from human umbilical cord mesenchymal stem cells (hucMSCs) were reported to play an important role in damage repair disorder, including endometrial fibrosis. In this study, we aimed to investigate the role of hucMSCs-derived exosomal microRNA-202-3p (miR-202-3p) in endometrial damage repair. We established rat endometrial injury model according to curettage to mimic women curettage abortion operation. The miRNA array analysis indicated that miR-202-3p was increased and matrix metallopeptidase 11 (MMP11) was decreased in the exosomes-treated rat uterine tissues. Bioinformatics analysis suggested that MMP11 is the target gene of miR-202-3p. We observed that the mRNA and protein of MMP11 were significantly decreased in exosome treatment group on day 3, and the components of extracellular matrix (ECM) COL1A1, COL3A1, COLVI and fibronectin (FN) protein were increased. And we found that when the injured human stromal cells were treated with miR-202-3p overexpression exosomes, the COLVI and FN were also upregulated in protein and mRNA expression level. For the first time MMP11 was proved to be the target gene of miR-202-3p by dual luciferase reporter system. At last, we found the state of stromal cells was better in miR-202-3p overexpression exosomes group compared to exosomes group, and miR-202-3p overexpression exosomes markedly upregulated the FN and collagen on day 3 after endometrial injury. We thought that miR-202-3p overexpression exosomes promoted endometrial repair by regulating ECM remodeling in early repair of damaged endometrium. Taken together, these experimental findings may provide a theoretical basis for understanding endometrial repair and an insight into the clinical treatment for IUA. Human umbilical cord mesenchymal stem cells exosomal miR-202-3p could regulate the expression of MMP11 and promote the accumulation of extracellular matrix, such as COL1A1, COL3A1, COLVI, FN, in the early repair period of endometrial injury.

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

RESEARCH QUESTION

What is the specific mechanism of umbilical cord mesenchymal stem cell-derived exosomes (UCMSC-exos) in regulating endometrial repair and regeneration?

DESIGN

In this study, UCMSC-exos were harvested by differential ultracentrifugation from umbilical cord mesenchymal stem cell culture supernatant and identified with western blotting, transmission electron microscopy and nanoparticle tracking analysis. Transforming growth factor-β1 (TGFβ1) at different concentrations was used to construct the intrauterine adhesions cell model. The fibrotic markers were assessed by quantitative reverse transcription-polymerase chain reaction and western blotting. The effects of miR-145-5p over-expression on endometrial fibrosis were assessed. Dual luciferase assay was performed to verify the relationship between miR-145-5p and zinc finger E-box binding homeobox 2 (ZEB2).

RESULTS

The isolated UCMSC-exos had a typical cup-shaped morphology, expressed the specific exosomal markers Alix, CD63 and TSG101, and were approximately 50-150 nm in diameter. TGFβ1 at 10 ng/ml significantly promoted endometrial fibrosis, which was reversed by 20 µg/ml UCMSC-exos. Exosomal miR-145-5p ameliorated TGFβ1-induced endometrial fibrosis. ZEB2 was inversely regulated by exosomal miR-145-5p as a direct target.

CONCLUSIONS

UCMSC-exos might reverse endometrial stromal cell fibrosis by regulating the miR-145-5p/ZEB2 axis, representing a potential novel strategy to promote endometrial repair.

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.

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.

Anti-Viral Activities of Umbilical Cord Mesenchymal Stem Cell-Derived Small Extracellular Vesicles Against Human Respiratory Viruses

The endemic and pandemic caused by respiratory virus infection are a major cause of mortality and morbidity globally. Thus, broadly effective antiviral drugs are needed to treat respiratory viral diseases. Small extracellular vesicles derived from human umbilical cord mesenchymal stem cells (U-exo) have recently gained attention as a cell-free therapeutic strategy due to their potential for safety and efficacy. Anti-viral activities of U-exo to countermeasure respiratory virus-associated diseases are currently unknown. Here, we tested the antiviral activities of U-exo following influenza A/B virus (IFV) and human seasonal coronavirus (HCoV) infections in vitro. Cells were subject to IFV or HCoV infection followed by U-exo treatment. U-exo treatment significantly reduced IFV or HCoV replication and combined treatment with recombinant human interferon-alpha protein (IFN-α) exerted synergistically enhanced antiviral effects against IFV or HCoV. Interestingly, microRNA (miR)-125b, which is one of the most abundantly expressed small RNAs in U-exo, was found to suppress IFV replication possibly via the induction of IFN-stimulated genes (ISGs). Furthermore, U-exo markedly enhanced RNA virus-triggered IFN signaling and ISGs production. Similarly, human nasal epithelial cells cultured at the air-liquid interface (ALI) studies broadly effective anti-viral and anti-inflammatory activities of U-exo against IFV and HCoV, suggesting the potential role of U-exo as a promising intervention for respiratory virus-associated diseases.

Exosomes Derived From CTF1-Modified Bone Marrow Stem Cells Promote Endometrial Regeneration and Restore Fertility

Background: Thin endometrial tissue is a leading cause of embryo transfer failure, potentially contributing to sustained infertility and associated adverse outcomes. The application of exosomes derived from autologous or allogeneic bone marrow-derived stem cells (BMSCs) has been used to promote uterine repair following injury, and there is also prior evidence that stem cell transplantation can bolster fertility. Genetic modifications represent a primary approach to enhancing exosomal therapy strategies. The present study thus explored the effects of Cardiotrophin-1 (CTF1)-modified BMSCs-exo on fertility-related outcomes.

Methods: An adenoviral vector was used to generate CTF1-overexpressing BMSCs (C-BMSCs), after which exosomes were isolated from control BMSCs (BMSC-exos) and C-BMSCs (C-BMSC-exos). The angiogenic effects of C-BMSC-exo treatment were assessed through analyses of endothelial cell proliferation and tube formation. Model rats exhibiting endometrial thinning were administered C-BMSCs-exo, after which the effects of such treatment were assessed through H&E staining, Masson’s trichrome staining, and immunofluorescence analyses. The mechanistic basis for the proangiogenic effects of CTF1 as a driver of endometrial regeneration was additionally explored.

Results: C-BMSC-exo treatment of HUVECs was associated with enhanced neovascularization, as evidenced by improved in vitro proliferation, migration, and tube formation. Importantly, such treatment was also linked to tissue regeneration, neovascularization, and the suppression of localized tissue fibrosis in vivo. Regenerated endometrial tissue exhibited higher embryo receptivity and was associated with higher birth rates in treated rats. The upregulation of the JAK/PI3K/mTOR/STAT3 signaling pathways in C-BMSC-exo-treated rats may underscore the mechanistic basis whereby CTF1 can positively impact endometrial angiogenesis and regeneration.

Conclusion: Our data suggest that exosomes produced by CTF1-modified BMSCs can more effectively promote the regeneration of endometrial and myometrial tissues, driving neovascularization in a manner that improves endometrial receptivity in a rat model system, highlighting the therapeutic promise of this approach for patients diagnosed with endometrial thinning.

MiR-455-5p upregulation in umbilical cord mesenchymal stem cells attenuates endometrial injury and promotes repair of damaged endometrium via Janus kinase/signal transducer and activator of transcription 3 signaling

Umbilical cord mesenchymal stem cells (UCMSCs) are regarded as an ideal source for clinical use. Increasing evidence has suggested that microRNAs (miRNAs) work as a crucial regulator in the development of plentiful diseases, including intrauterine adhesions (IUA). Herein, we investigated the specific impacts of UCMSCs overexpressing miR-455-5p in IUA. UCMSCs were cocultured with endometrial stromal cells (ESCs). Thirty-two female mice were divided into four different treated groups: sham, model, model + UCMSC-miR-NC and model + UCMSC-miR-455-5p. Mice in model groups were induced by uterine curettage. MiR-455-5p overexpressed UCMSCs facilitated the proliferation and cell cycle progression of ESCs according to 5-ethynyl-2′-deoxyuridine assay and flow cytometry analysis. Hematoxylin-eosin and Masson staining revealed that miR-455-5p upregulation in UCMSCs increased the number of endometrial glands and suppressed endometrial fibrosis in murine uterine tissues. Western blotting displayed that miR-455-5p overexpressed UCMSCs promoted the activation of Janus kinase/signal transducer and activator of transcription 3 (JAK/STAT3) signaling in ESCs and murine uterine tissues. Mechanistically, miR-455-5p targeted 3’ untranslated region of suppressor of cytokine signaling 3 (SOCS3), which was confirmed by luciferase reporter assay. Reverse transcription quantitative polymerase chain reaction demonstrated that miR-455-5p was lowly expressed and SOCS3 was highly expressed in murine uterine tissues of IUA model. Moreover, Pearson correlation analysis showed that their expression was inversely correlated. Rescue assays suggested that inhibiting JAK/STAT3 signaling reversed effects of miR-455-5p on the behaviors of ESCs. The results indicated that miR-455-5p overexpression in UCMSCs helps to attenuate endometrial injury and repair damaged endometrium by activating SOCS3-mediated JAK/STAT3 signaling.

Exosome-shuttled miR-7162-3p from human umbilical cord derived mesenchymal stem cells repair endometrial stromal cell injury by restricting APOL6

BACKGROUND

Recent studies have shown that exosomes (Exos) derived from stem cells can be used as paracrine factors to regenerate cells and tissues via shuttling miRNAs. Exos derived from human umbilical cord derived mesenchymal stem cells (UCMSCs) have been found to alleviate mifepristone-induced endometrial stromal cell (ESC) injury in vitro. Information on the functions and mechanisms of Exos from UCMSC-induced endometrial repair is limited and requires more study.

METHODS

UCMSC-Exos were isolated and identified by Transmission Electron Microscopy, Nanoparticle Tracking Analysis software, and western blot assays. The damaged-ESC model and the UCMSC co-culture system were established, while GW4869, a noncompetitive neutral sphingomyelinase (N-SMase) inhibitor, was used to investigate the effects of UCMSC-Exos on mifepristone-induced ESC injury. Cell apoptosis of damaged ESCs treated with UCMSCs was detected using the TUNEL assay and flow cytometry analysis. Then, miRNA microarrays were performed to detect differentially expressed miRNA profiles in both UCMSCs and ESCs after co-culturing. A subset of upregulated miRNAs was validated by qRT-PCR, and miRNA mimics/inhibitor were used to investigate the functions of miR-7162-3p. The miRNA-mRNA interactions were predicted by Targetscan software, while the miRNA binding sites were predicted by miRcode software. Moreover, dual-luciferase reporter, western blot assays and qPCR were conducted to identify the regulatory mechanisms between miR-7162-3p and APOL6.

RESULTS

UCMSCs attenuated mifepristone-induced endometrial stromal cell apoptosis by Exos, while three miRNAs (miR-6831-5p, miR-4669, and miR-7162-3p) were both upregulated in UCMSCs and ESCs after co-culture, and were candidate effectors of UCMSC-Exos-mediated endometrial repair. We showed that miR-7162-3p was shuttled by Exos from UCMSCs and regulated the expression of APOL6 by targeting its 3'-UTR in ESCs.

CONCLUSIONS

These results showed UCMSC-Exos protected ESCs from mifepristone-induced apoptosis and played an active role in repairing the damaged ESCs by in vitro shuttling of miR-7162-3p. The miR-7162-3p-overexpressed UCMSC-Exos may therefore be used in cell-free therapy of endometrial injury.

Adult stem cells in endometrial regeneration: Molecular insights and clinical applications

Endometrial damage is an important cause of female reproductive problems, manifested as menstrual abnormalities, infertility, recurrent pregnancy loss, and other complications. These conditions are collectively termed "Asherman syndrome" (AS) and are typically associated with recurrent induced pregnancy terminations, repeated diagnostic curettage and intrauterine infections. Cancer treatment also has unexpected detrimental side effects on endometrial function in survivors independently of ovarian effects. Endometrial stem cells act in the regeneration of the endometrium and in repair through direct differentiation or paracrine effects. Nonendometrial adult stem cells, such as bone marrow-derived mesenchymal stem cells and umbilical cord-derived mesenchymal stem cells, with autologous and allogenic applications, can also repair injured endometrial tissue in animal models of AS and in human studies. However, there remains a lack of research on the repair of the damaged endometrium after the reversal of tumors, especially endometrial cancers. Here, we review the biological mechanisms of endometrial regeneration, and research progress and challenges for adult stem cell therapy for damaged endometrium, and discuss the potential applications of their use for endometrial repair after cancer remission, especially in endometrial cancers. Successful application of such cells will improve reproductive parameters in patients with AS or cancer. Significance: The endometrium is the fertile ground for embryos, but damage to the endometrium will greatly impair female fertility. Adult stem cells combined with tissue engineering scaffold materials or not have made great progress in repairing the injured endometrium due to benign lesions. However, due to the lack of research on the repair of the damaged endometrium caused by malignant tumors or tumor therapies, the safety and effectiveness of such stem cell-based therapies need to be further explored. This review focuses on the molecular insights and clinical application potential of adult stem cells in endometrial regeneration and discusses the possible challenges or difficulties that need to be overcome in stem cell-based therapies for tumor survivors. The development of adult stem cell-related new programs will help repair damaged endometrium safely and effectively and meet fertility needs in tumor survivors.

Upregulated Talin1 synergistically boosts β-estradiol-induced proliferation and pro-angiogenesis of eutopic and ectopic endometrial stromal cells in adenomyosis

Adenomyosis (ADS) is an estrogen-dependent gynecological disease with unspecified etiopathogenesis. Local hyperestrogenism may serve a key role in contributing to the origin of ADS. Talin1 is mostly identified to be overexpressed and involved in the progression of numerous human carcinomas through mediating cell proliferation, adhesion and motility. Whether Talin1 exerts an oncogenic role in the pathogenesis of ADS and puts an extra impact on the efficacy of estrogen, no relevant data are available yet. Here we demonstrated that the adenomyotic eutopic and ectopic endometrial stromal cells (ADS_Eu_ESC and ADS_Ec_ESC) treated with β-estradiol (β-E₂) presented stronger proliferative and pro-angiogenetic capacities, accompanied by increased expression of PCNA, Ki67, VEGFB and ANGPTL4 proteins. Meanwhile, these promoting effects were partially abrogated by Fulvestrant (ICI 182780, an estrogen-receptor antagonist). Aberrantly upregulation of Talin1 mRNA and protein level was observed in ADS endometrial specimens and stromal cells. Through performing functional experiments in vitro, we further determined that merely overexpression of Talin1 (OV-Talin1) also enhanced ADS stromal cell proliferation and pro-angiogenesis, while the most pronounced facilitating effects were found in the co-intervention group of OV-Talin1 plus β-E₂ treatment. Results from the xenograft nude mice model showed that the hypodermic endometrial lesions from co-intervention group had the highest mean weight and volume, compared with that of individual OV-Talin1 or β-E₂ treatment. The expression levels of PCNA, Ki67, VEGFB and ANGPTL4 in the lesions were correspondingly elevated the most in the co-intervention group. Our findings unveiled that overexpressed Talin1 might cooperate withβ-E₂ in stimulating ADS endometrial stromal cell proliferation and neovascularization, synergistically promoting the growth and survival of ectopic lesions. These results may be beneficial to provide a new insight for clarifying the pathogenesis of ADS.

Microenvironment-Protected Exosome-Hydrogel for Facilitating Endometrial Regeneration, Fertility Restoration, and Live Birth of Offspring

Thin endometrium is a primary cause of failed embryo transfer, resulting in long-term infertility and negative family outcomes. While hormonal treatments have greatly improved fertility results for some women, these responses remain unsatisfactory due to damage and infection of the complex endometrial microenvironment. In this study, a multifunctional microenvironment-protected exosome-hydrogel is designed for facilitating endometrial regeneration and fertility restoration via in situ microinjection and endometrial regeneration. This exosome hydrogel is formulated via Ag⁺ -S dynamic coordination and fusion with adipose stem cell-derived exosomes (ADSC-exo), yielding an injectable preparation that is sufficient to mitigate infection risk while also possessing the antigenic contents and paracrine signaling activity of the ADSC source cells, enabling regeneration of the endometrial microenvironment. In vitro, this exosome-hydrogel exerts an outstanding neovascularization-promoting effect, increased human umbilical vein endothelial cell proliferation and tube formation for 1.87 and 2.2 folds. In vivo, microenvironment-protected exosome-hydrogel also reveals to promote neovascularization and tissue regeneration while suppressing local tissue fibrosis. Importantly, regenerated endometrial tissue is more receptive to give embryos and birth to a healthy newborn. This microenvironment-protected exosome-hydrogel system offers a convenient, safe, and noninvasive approach for repairing thin endometrium and fertility restoration.

Functional assays to assess the therapeutic potential of extracellular vesicles

An important aspect in the development of extracellular vesicle (EV) therapeutics is identifying and quantifying the key features defining their identity, purity, sterility, potency and stability to ensure batch-to-batch reproducibility of their therapeutic efficacy. Apart from EV-inherent features, therapeutic efficacy depends on a variety of additional parameters, like dosing, frequency of application, and administration route, some of which can be addressed only in clinical trials. Before initiating clinical trials, EV-inherent features should be tested in well-standardized quantitative assays in vitro or in appropriate animal models in vivo. Ideally, such assays would predict if a particular EV preparation has the potential to achieve its intended therapeutic effects, and could be further developed into formal potency assays as published by the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use guidelines. Furthermore, such assays should facilitate the comparison of EV preparations produced in different batches, on different manufacturing platforms or deriving from different cell sources. For now, a wide spectrum of in vitro and in vivo assays has been used to interrogate the therapeutic functions of EVs. However, many cannot accurately predict therapeutic potential. Indeed, several unique challenges make it difficult to set up reliable assays to assess the therapeutic potential of EVs, and to develop such assays into formal potency tests. Here, we discuss challenges and opportunities around in vitro and in vivo testing of EV therapeutic potential, including the need for harmonization, establishment of formal potency assays and novel developments for functional testing.

Exosomes derived from human amniotic epithelial cells accelerate diabetic wound healing via PI3K-AKT-mTOR-mediated promotion in angiogenesis and fibroblast function

Background

Diabetic wounds are one of the most common and serious complications of diabetes mellitus, characterized by the dysfunction of wound-healing-related cells in quantity and quality. Our previous studies revealed that human amniotic epithelial cells (hAECs) could promote diabetic wound healing by paracrine action. Interestingly, numerous studies demonstrated that exosomes derived from stem cells are the critical paracrine vehicles for stem cell therapy. However, whether exosomes derived from hAECs (hAECs-Exos) mediate the effects of hAECs on diabetic wound healing remains unclear. This study aimed to investigate the biological effects of hAECs-Exos on diabetic wound healing and preliminarily elucidate the underlying mechanism.

Methods

hAECs-Exos were isolated by ultracentrifugation and identified by transmission electron microscopy, dynamic light scattering and flow cytometry. A series of in vitro functional analyses were performed to assess the regulatory effects of hAECs-Exos on human fibroblasts (HFBs) and human umbilical vein endothelial cells (HUVECs) in a high-glycemic microenvironment. High-throughput sequencing and bioinformatics analyses were conducted to speculate the related mechanisms of actions of hAECs-Exos on HFBs and HUVECs. Subsequently, the role of the candidate signaling pathway of hAECs-Exos in regulating the function of HUVECs and HFBs, as well as in diabetic wound healing, was assessed.

Results

hAECs-Exos presented a cup- or sphere-shaped morphology with a mean diameter of 105.89 ± 10.36 nm, were positive for CD63 and TSG101 and could be internalized by HFBs and HUVECs. After that, hAECs-Exos not only significantly promoted the proliferation and migration of HFBs, but also facilitated the angiogenic activity of HUVECs in vitro. High-throughput sequencing revealed enriched miRNAs of hAECs-Exos involved in wound healing. Kyoto Encyclopedia of Genes and Genomes and Gene Ontology analyses have shown that the target genes of the top 15 miRNAs were highly enriched in the PI3K-AKT pathway. Further functional studies demonstrated that the PI3K-AKT-mTOR pathway was necessary for the induced biological effects of hAECs-Exos on HFBs and HUVECs, as well as on wound healing, in diabetic mice.

Conclusions

Our findings demonstrated that hAECs-Exos represent a promising, novel strategy for diabetic wound healing by promoting angiogenesis and fibroblast function via activation of the PI3K-AKT-mTOR pathway.