Therapeutic Effect of Human Amniotic Epithelial Cells in Rat Models of Intrauterine Adhesions

Injectable, stable, and biodegradable hydrogel with platelet-rich plasma induced by l-serine and sodium alginate for effective treatment of intrauterine adhesions

The combination of pharmacological and physical barrier therapy is a highly promising strategy for treating intrauterine adhesions (IUAs), but there lacks a suitable scaffold that integrates good injectability, proper mechanical stability and degradability, excellent biocompatibility, and non-toxic, non-rejection therapeutic agents. To address this, a novel injectable, degradable hydrogel composed of poly(ethylene glycol) diacrylate (PEGDA), sodium alginate (SA), and l-serine, and loaded with platelet-rich plasma (PRP) (referred to as PSL-PRP) is developed for treating IUAs. l-Serine induces rapid gelation within 1 min and enhances the mechanical properties of the hydrogel, while degradable SA provides the hydrogel with strength, toughness, and appropriate degradation capabilities. As a result, the hydrogel exhibits an excellent scaffold for sustained release of growth factors in PRP and serves as an effective physical barrier. In vivo testing using a rat model of IUAs demonstrates that in situ injection of the PSL-PRP hydrogel significantly reduces fibrosis and promotes endometrial regeneration, ultimately leading to fertility restoration. The combined advantages make the PSL-PRP hydrogel very promising in IUAs therapy and in preventing adhesions in other internal tissue wounds.

Human amniotic epithelial stem cell is a cell therapy candidate for preventing acute graft-versus-host disease

Graft-versus-host disease (GVHD), an immunological disorder that arises from donor T cell activation through recognition of host alloantigens, is the major limitation in the application of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Traditional immunosuppressive agents can relieve GVHD, but they induce serious side effects. It is highly required to explore alternative therapeutic strategy. Human amniotic epithelial stem cells (hAESCs) were recently considered as an ideal source for cell therapy with special immune regulatory property. In this study, we evaluated the therapeutic role of hAESCs in the treatment of GVHD, based on our previous developed cGMP-grade hAESCs product. Humanized mouse model of acute GVHD (aGVHD) was established by injection of huPBMCs via the tail vein. For prevention or treatment of aGVHD, hAESCs were injected to the mice on day -1 or on day 7 post-PBMC infusion, respectively. We showed that hAESCs infusion significantly alleviated the disease phenotype, increased the survival rate of aGVHD mice, and ameliorated pathological injuries in aGVHD target organs. We demonstrated that hAESCs directly induced CD4+ T cell polarization, in which Th1 and Th17 subsets were downregulated, and Treg subset was elevated. Correspondingly, the levels of a series of pro-inflammatory cytokines were reduced while the levels of the anti-inflammatory cytokines were upregulated in the presence of hAESCs. We found that hAESCs regulated CD4+ subset polarization in a paracrine mode, in which TGFβ and PGE2 were selectively secreted to mediate Treg elevation and Th1/Th17 inhibition, respectively. In addition, transplanted hAESCs preserved the graft-versus-leukemia (GVL) effect by inhibiting leukemia cell growth. More intriguingly, hAESCs infusion in HSCT patients displayed potential anti-GVHD effect with no safety concerns and confirmed the immunoregulatory mechanisms in the preclinical study. We conclude that hAESCs infusion is a promising therapeutic strategy for post-HSCT GVHD without compromising the GVL effect. The clinical trial was registered at www.clinicaltrials.gov as #NCT03764228.

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/.

Knockdown of miR-27a reduces TGFβ-induced EMT and H2O2-induced oxidative stress through regulating mitochondrial autophagy

OBJECTIVES

The present research aimed at clarifying the role played by miR-27a in the context of intrauterine adhesion (IUA) by focusing on its impact on TGFβ1-induced epithelial-mesenchymal transition (EMT), migration, oxidative stress, and mitochondrial autophagy in endometrial stromal cells (ESCs).

METHODS

We employed the Cell Counting Kit CCK-8/WST-8 assay to assess ESC proliferation, flow cytometric analysis and an Annexin-V-FITCV-FITC Apoptosis Detection kit to determine cell apoptosis, and wound healing and transwell assays to evaluate cell migration. Besides, intracellular reactive oxygen species (ROS) levels measured by the Reactive Oxygen Species Assay Kit were analyzed by flow cytometry, and protein expression levels were quantified by Western blotting analysis.

RESULTS

Knockdown of miR-27a inhibited TGFβ1-induced EMT and H2O2-induced oxidative stress in ESCs. H2O2-induced miR-27a suppressed PINK1 expression, leading to inhibition of mitophagy. MiR-27a promoted TGFβ1 or H2O2-induced EMT through PINK1.

CONCLUSIONS

miR-27a plays a crucial role in endometrial fibrosis. It regulates TGFβ1-induced EMT, migration, oxidative stress, and apoptosis in ESCs. Additionally, miR-27a impacts mitophagy through PINK1 suppression upon H2O2 induction. Our findings highlight miR-27a as a potential therapeutic target for IUA treatment, shedding light on its multifaceted involvement in the mechanism of intrauterine adhesion fibrosis.

Exosomal miR-543 derived from umbilical cord mesenchymal stem cells ameliorates endometrial fibrosis in intrauterine adhesion via downregulating N-cadherin

INTRODUCTION

Human umbilical cord mesenchymal stem cells (UCMSCs) play an important role in repairing the damaged endometrium of intrauterine adhesion (IUA). Meanwhile, exosomes released by UCMSCs can mediate intercellular communication by delivering miRNAs. It has been shown that miR-543 level was reduced in IUA tissues. However, the role of miR-543 in the progression of IUA remains largely unknown. Therefore, we investigated the role of UCMSCs-derived exosomal miR-543 in IUA.

METHODS

In this study, human endometrial epithelial cells (hEECs) were treated with TGF-β1 for mimicking endometrial fibrosis in vitro. In addition, the IUA-like mouse model in vivo was established by a dual damage method of curettage and LPS infection.

RESULTS

The level of miR-543 was markedly reduced in hEECs exposed to TGF-β1 and in endometrium tissues of IUA mice. Additionally, miR-543 could be transferred from UCMSCs to hEECs via exosomes. Meanwhile, exosomal miR-543-derived from UCMSCs significantly reduced the expressions of N-cadherin, α-SMA, fibronectin 1 and elevated the expression of E-cadherin in TGF-β1-treated hEECs. Furthermore, UCMSCs-derived exosomal miR-543 attenuated IUA-induced endometrial fibrosis in vivo, as shown by the decreased N-cadherin, α-SMA and fibronectin 1 protein expressions.

DISCUSSION

Collectively, UCMSCs-derived exosomal miR-543 was able to prevent endometrial fibrosis both in vitro and in vivo via downregulating N-cadherin. These results may provide an insight into the clinical treatment for IUA.

The Role of Endometrial Stem/Progenitor Cells in Recurrent Reproductive Failure

Recurrent implantation failure (RIF) and recurrent pregnancy loss (RPL), collectively referred to as recurrent reproductive failure (RRF), are both challenging conditions with many unanswered questions relating to causes and management options. Both conditions are proposed to be related to an aberrant endometrial microenvironment, with different proposed aetiologies related to a restrictive or permissive endometrium for an invading embryo. The impressive regenerative capacity of the human endometrium has been well-established and has led to the isolation and characterisation of several subtypes of endometrial stem/progenitor cells (eSPCs). eSPCs are known to be involved in the pathogenesis of endometrium-related disorders (such as endometriosis) and have been proposed to be implicated in the pathogenesis of RRF. This review appraises the current knowledge of eSPCs, and their involvement in RRF, highlighting the considerable unknown aspects in this field, and providing avenues for future research to facilitate much-needed advances in the diagnosis and management of millions of women suffering with RRF.

Regulating Early Biological Events in Human Amniotic Epithelial Stem Cells Using Natural Bioactive Compounds: Extendable Multidirectional Research Avenues

Stem cells isolated from perinatal tissue sources possess tremendous potential for biomedical and clinical applications. On the other hand, emerging data have demonstrated that bioactive natural compounds regulate numerous cellular and biochemical functions in stem cells and promote cell migration, proliferation, and attachment, resulting in maintaining stem cell proliferation or inducing controlled differentiation. In our previous studies, we have reported for the first time that various natural compounds could induce targeted differentiation of hAESCs in a lineage-specific manner by modulating early biological and molecular events and enhance the therapeutic potential of hAESCs through modulating molecular signaling. In this perspective, we will discuss the advantages of using naturally occurring active compounds in hAESCs and their potential implications for biological research and clinical applications.

Pregnancy Patterns Impact Live Birth Rate for Patients With Intrauterine Adhesions After Hysteroscopic Adhesiolysis: A Retrospective Cohort Study

Objective

The pregnancy patterns and other factors of live birth for patients with intrauterine adhesions (IUAs) were identified by analyzing the clinical features of pre-, intra-, and post-hysteroscopic adhesiolysis (HA).

Design

A total of 742 patients with IUAs who wanted to become pregnant underwent HA from January 2017 to May 2018 at the Third Xiangya Hospital of Central South University. The patient follow-up period was 2 years post-HA. A logistic regression was performed to analyze the clinical characteristics associated with a live birth for patients with IUAs. Pre-operative clinical indicators included age, gravidity, parity, abortion, IUA recurrence, menstrual patterns, disease course. Intraoperative clinical features assessed in the last operation were uterine cavity length, IUA appearance, IUA area, number of visible uterine cornua, number of visible tubal ostia, AFS scores. Pregnancy patterns were post-hysteroscopic adhesiolysis features.

Results

Among the 742 IUA patients, 348 (46.9%) had a live birth and 394 (53.1%) did not. A bivariate and binary logistic regression analysis showed that IUA patients’ pregnancy patterns, age, number of visible tubal ostia noted by a second-look hysteroscopy, and American Fertility Society (AFS) scores were significantly related to the live birth rate (P < 0.05).

Conclusions

Pregnancy patterns, age, number of visible tubal ostia, and AFS scores were significantly related to the live birth rate and may be considered potential predictors of the live birth rate in IUA patients. The indications of assisted reproductive technology (ART) might be a better choice for patients with recurrent IUAs.

Extracorporeal Shock Wave Therapy Combined with Platelet-Rich Plasma during Preventive and Therapeutic Stages of Intrauterine Adhesion in a Rat Model

Intrauterine adhesion (IUA) is caused by artificial endometrial damage during intrauterine cavity surgery. The typical phenotype involves loss of spontaneous endometrium recovery and angiogenesis. Undesirable symptoms include abnormal menstruation and infertility; therefore, prevention and early treatment of IUA remain crucial issues. Extracorporeal shockwave therapy (ESWT) major proposed therapeutic mechanisms include neovascularization, tissue regeneration, and fibrosis. We examined the effects of ESWT and/or platelet-rich plasma (PRP) during preventive and therapeutic stages of IUA by inducing intrauterine mechanical injury in rats. PRP alone, or combined with ESWT, were detected an increased number of endometrial glands, elevated vascular endothelial growth factor protein expression (hematoxylin-eosin staining and immunohistochemistry), and reduced fibrosis rate (Masson trichrome staining). mRNA expression levels of nuclear factor-kappa B, tumor necrosis factor-α, transforming growth factor-β, interleukin (IL)-6, collagen type I alpha 1, and fibronectin were reduced during two stages. However, PRP alone, or ESWT combined with PRP transplantation, not only increased the mRNA levels of vascular endothelial growth factor (VEGF) and progesterone receptor (PR) during the preventive stage but also increased PR, insulin-like growth factor 1 (IGF-1), and IL-4 during the therapeutic stage. These findings revealed that these two treatments inhibited endometrial fibrosis and inflammatory markers, thereby inhibiting the occurrence and 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.

Making More Womb: Clinical Perspectives Supporting the Development and Utilization of Mesenchymal Stem Cell Therapy for Endometrial Regeneration and Infertility

The uterus is a homeostatic organ, unwavering in the setting of monthly endometrial turnover, placental invasion, and parturition. In response to ovarian steroid hormones, the endometrium autologously prepares for embryo implantation and in its absence will shed and regenerate. Dysfunctional endometrial repair and regeneration may present clinically with infertility and abnormal menses. Asherman's syndrome is characterized by intrauterine adhesions and atrophic endometrium, which often impacts fertility. Clinical management of infertility associated with abnormal endometrium represents a significant challenge. Endometrial mesenchymal stem cells (MSC) occupy a perivascular niche and contain regenerative and immunomodulatory properties. Given these characteristics, mesenchymal stem cells of endometrial and non-endometrial origin (bone marrow, adipose, placental) have been investigated for therapeutic purposes. Local administration of human MSC in animal models of endometrial injury reduces collagen deposition, improves angiogenesis, decreases inflammation, and improves fertility. Small clinical studies of autologous MSC administration in infertile women with Asherman's Syndrome suggested their potential to restore endometrial function as evidenced by increased endometrial thickness, decreased adhesions, and fertility. The objective of this review is to highlight translational and clinical studies investigating the use of MSC for endometrial dysfunction and infertility and to summarize the current state of the art in this promising area.

The potential role of multifunctional human amniotic epithelial cells in pancreatic islet transplantation

Pancreatic islet cell transplantation has proven efficacy as a treatment for type 1 diabetes mellitus, chiefly in individuals who are refractory to conventional insulin replacement therapy. At present its clinical use is restricted, firstly by the limited access to suitable donor organs but also due to factors associated with the current clinical transplant procedure which inadvertently impair the long-term functionality of the islet graft. Of note, the physical, biochemical, inflammatory, and immunological stresses to which islets are subjected, either during pretransplant processing or following implantation are detrimental to their sustained viability, necessitating repeated islet infusions to attain adequate glucose control. Progressive decline in functional beta (β)-cell mass leads to graft failure and the eventual re-instatement of exogenous insulin treatment. Strategies which protect and/or preserve optimal islet function in the peri-transplant period would improve clinical outcomes. Human amniotic epithelial cells (HAEC) exhibit both pluripotency and immune-privilege and are ideally suited for use in replacement and regenerative therapies. The HAEC secretome exhibits trophic, anti-inflammatory, and immunomodulatory properties of relevance to islet graft survival. Facilitated by β-cell supportive 3D cell culture systems, HAEC may be integrated with islets bringing them into close spatial arrangement where they may exert paracrine influences that support β-cell function, reduce hypoxia-induced islet injury, and alter islet alloreactivity. The present review details the potential of multifunctional HAEC in the context of islet transplantation, with a focus on the innate capabilities that may counter adverse events associated with the current clinical transplant protocol to achieve long-term islet graft function.

MiR-543 Inhibits the Migration and Epithelial-To-Mesenchymal Transition of TGF-β-Treated Endometrial Stromal Cells via the MAPK and Wnt/β-Catenin Signaling Pathways

Intrauterine adhesion (IUA) is one of the most prevalent reproductive system diseases in females. MicroRNAs (miRNAs) are reported to be master regulators in a variety of diseases, including IUA, but the role of microRNA-543 (miR-543) in IUA remains to be elucidated. In this study, we observed that miR-543 was downregulated in transforming growth factor-beta (TGF-β)-treated endometrial stromal cells (ESCs). Functionally, we observed that miR-543 suppressed the migration, epithelial-to-mesenchymal transition (EMT), and inhibited expression of extracellular matrix (ECM) proteins in TGF-β-treated ESCs. Mechanistically, MAPK1 is targeted by miR-543 after prediction and screening. A luciferase reporter assay demonstrated that miR-543 complementarily binds with the 3' untranslated region of mitogen-activated protein kinase 1 (MAPK1), and western blot analysis indicated that miR-543 negatively regulates MAPK1 protein levels. In addition, results from rescue assays showed that miR-543 inhibits the migration and EMT of TGF-β-treated ESCs by targeting MAPK1. In addition, we observed that miR-543 inactivates the Wnt/β-catenin signaling pathway through inhibiting the phosphorylation of MAPK1 and β-catenin. Finally, we confirmed that miR-543 represses migration, EMT and inhibits levels of ECM proteins in TGF-β-treated ESCs by targeting the Wnt/β-catenin signaling pathway. Our results demonstrated that miR-543 suppresses migration and EMT of TGF-β-treated ESCs by targeting the MAPK and Wnt/β-catenin pathways.

Mesenchymal stem cells for restoring endometrial function: An infertility perspective

BACKGROUND

Mesenchymal stem cells (MSCs) can be derived from several tissues such as bone marrow, placenta, adipose tissue, or endometrial tissue. MSCs gain a lot of attention for cell-based therapy due to their characteristics including differentiation ability and immunomodulatory effect. Preclinical and clinical studies demonstrated that MSCs can be applied to treat female infertility by improving of the functions of ovary and uterus. This mini- review focuses on the current study of treatment of endometrial infertility by using MSCs.

METHODS

The present study performed a literature review focusing on the effect of MSCs for treatment of women infertility caused by endometrial dysfunction.

RESULTS

Bone marrow-, umbilical cord-, adipose-, amniotic-, and menstruation-derived MSCs enhance endometrial cell proliferation, injury repairs as well as reducing scar formation. The beneficial mechanism probably via immunomodulatory, cell differentiation, stimulates endometrial cell proliferation and down-regulation of fibrosis genes. The major advantage of using MSCs is to improve endometrial functions resulting in increased implantation and pregnancy.

CONCLUSIONS

MSCs exhibit a potential for endometrial infertility treatment. Adipose- and menstruation-derived stem cells show advantages over other sources because the cells can be derived easily and do not causes graft rejection after autologous transplantation.

Human Amniotic Epithelial Stem Cells: A Promising Seed Cell for Clinical Applications

Perinatal stem cells have been regarded as an attractive and available cell source for medical research and clinical trials in recent years. Multiple stem cell types have been identified in the human placenta. Recent advances in knowledge on placental stem cells have revealed that human amniotic epithelial stem cells (hAESCs) have obvious advantages and can be used as a novel potential cell source for cellular therapy and clinical application. hAESCs are known to possess stem-cell-like plasticity, immune-privilege, and paracrine properties. In addition, non-tumorigenicity and a lack of ethical concerns are two major advantages compared with embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). All of the characteristics mentioned above and other additional advantages, including easy accessibility and a non-invasive application procedure, make hAESCs a potential ideal cell type for use in both research and regenerative medicine in the near future. This review article summarizes current knowledge on the characteristics, therapeutic potential, clinical advances and future challenges of hAESCs in detail.