Inhibition of Transforming Growth Factor-β Receptor signaling promotes culture expansion of undifferentiated human Endometrial Mesenchymal Stem/stromal Cells. Sci Rep. 2015;5:15042. [PMID: 26461813 PMCID: PMC4602195 DOI: 10.1038/srep15042]

Steps towards the clinical application of endometrial and menstrual fluid mesenchymal stem cells for the treatment of gynecological disorders

INTRODUCTION

The human endometrium is a highly regenerative tissue that contains mesenchymal stem/stromal cells (MSCs). These MSCs are sourced via office-based biopsies and menstrual fluid, providing a less invasive and readily available option for cell-based therapies. This review provides an update on endometrial-derived MSCs as a treatment option for gynecological diseases.

AREAS COVERED

This narrative review covers the characterization and therapeutic mechanisms of endometrium biopsy-derived MSCs (eMSCs) and menstrual fluid-derived mesenchymal stromal cells (MenSCs), highlighting similarities and differences. It also covers studies of their application in preclinical animal models and in clinical trials as potential cell-based therapies for gynecological diseases.

EXPERT OPINION

eMSCs and MenSCs from a homologous tissue source have the potential to promote regenerative activity as a treatment for gynecological diseases. Both eMSCs and MenSCs demonstrate therapeutic benefits through their paracrine activity in tissue regeneration, immunomodulation, angiogenesis, and mitigating fibrosis. Further research is essential to establish standardized isolation and characterization protocols, particularly for heterogeneous MenSCs, and to fully understand their mechanisms of action. Implementing SUSD2 magnetic bead sorting for purifying eMSCs from endometrial tissues and menstrual fluid is crucial for their use in future cell-based therapies. Optimization of production, storage, and delivery methods will maximize their therapeutic effectiveness.

Integral Roles of the TGFβ Signaling Pathway in Uterine Function and Disease

The uterus is a complex organ that requires precise signaling networks to mediate functions necessary for homeostasis and reproductive processes. The transforming growth factor β (TGFβ) superfamily regulates integral signaling pathways throughout many physiological processes, including cell proliferation, differentiation, and development. In this review, we summarize the current understanding of how the TGFβ signaling family controls key uterine functions, with a specific focus on the endometrium. These uterine functions include endometrial receptivity, implantation, decidualization, placentation, remodeling, and regeneration. Improving our understanding of the signaling networks that regulate these processes is integral to identifying, diagnosing, and treating uterine and reproductive diseases such as endometriosis, adenomyosis, recurrent pregnancy loss, and recurrent implantation failure.

Amelioration of premature aging in Werner syndrome stem cells by targeting SHIP/AKT pathway

BACKGROUND

Pathogenic or null mutations in WRN helicase is a cause of premature aging disease Werner syndrome (WS). WRN is known to protect somatic cells including adult stem cells from premature senescence. Loss of WRN in mesenchymal stem cells (MSCs) not only drives the cells to premature senescence but also significantly impairs the function of the stem cells in tissue repair or regeneration.

RESULTS

In this study, we profiled the signaling pathways altered in WRN-deficient MSC and applied pharmacological method to activate the AKT signaling in these cells and examined their cellular phenotype related to aging. We found that the AKT signaling in WRN-deficient MSCs was significantly suppressed while the AKT upstream phosphatases (SHIP1/2) were upregulated. Knockdown or inhibition of SHIP1/2 could ameliorate premature senescence in WRN-deficient MSCs. Moreover, SHIP inhibition stimulated MSC proliferation and suppressed expression of pro-inflammatory cytokines IL-6 and IL-8. The stemness of WRN-deficient MSC was also improved upon pharmacological treatments with the inhibitors.

CONCLUSIONS

These results suggested that targeting the SHIP/AKT signaling pathway is beneficial to WRN-deficient stem cells and fibroblasts, which might be applied for improving the trophic function of MSC in, for instance, promoting angiogenesis.

Primary culture of endometrial mesenchymal stem cells derived from ectopic lesions of patients with adenomyosis

PURPOSE

This study aimed to establish a protocol for efficiently isolating and expanding adenomyotic lesion-derived endometrial mesenchymal stem cells (A-eMSCs) in vitro.

METHODS

Three different methods-namely, the enzymatic method, the explant method, and the enzymatic explant method-were employed to isolate A-eMSCs. The isolation and expansion efficiencies of these three methods were subsequently compared. The enzymatic explant method was then used, and the transforming growth factor beta type I receptor (TGF-βR1) inhibitor A83-01 was added to the culture medium to evaluate its impact on the isolation and expansion efficiencies of A-eMSCs.

RESULTS

The enzymatic explant method resulted in improved morphology, shorter cell confluence time, and greater SUSD2 enrichment in the isolation of primary endometrial cells compared to the other two methods. The proliferation and differentiation potential of A-eMSCs obtained by sorting primary endometrial cells via the enzymatic explant method were significantly higher than those obtained via the other two methods in vitro. Using the enzymatic explant method, culture medium containing A83-01 further reduced the confluence time of the cells and increased A-eMSCs enrichment during the primary endometrial cell isolation stage. Furthermore, A83-01 enhanced the proliferation and maintained the differentiation potential of A-eMSCs during the cell expansion stage.

CONCLUSION

Our study identified a robust, cost-effective, and efficient protocol for isolating and expanding A-eMSCs and providing an important foundation for further research on the pathogenesis and clinical treatment of AM.

M2 Macrophages are Major Mediators of Germline Risk of Endometriosis and Explain Pleiotropy with Comorbid Traits

Endometriosis is a common gynecologic condition that causes chronic life-altering symptoms including pain, infertility, and elevated cancer risk. There is an urgent need for new non-hormonal targeted therapeutics to treat endometriosis, but until very recently, the cellular and molecular signatures of endometriotic lesions were undefined, severely hindering the development of clinical advances. Integrating inherited risk data from analyses of >450,000 individuals with ∼350,000 single cell transcriptomes from 21 patients, we uncover M2-macrophages as candidate drivers of disease susceptibility, and nominate IL1 signaling as a central hub impacted by germline genetic variation associated with endometriosis. Extensive functional follow-up confirmed these associations and revealed a pleiotropic role for this pathway in endometriosis. Population-scale expression quantitative trail locus analysis demonstrated that genetic variation controlling IL1A expression is also associated with endometriosis risk variants. Manipulation of IL1 signaling in state-of-the-art in vitro decidualized assembloids impacted epithelial differentiation, and in an in vivo endometriosis model, treatment with anakinra (an interleukin-1 receptor antagonist) resulted in a significant, dose-dependent reduction in both spontaneous pain and evoked pain. Together these studies highlight non-diagnostic cell types as central to endometriosis susceptibility and support IL1 signaling as an important actionable pathway for this disease.

Fibrotic extracellular matrix impacts cardiomyocyte phenotype and function in an iPSC-derived isogenic model of cardiac fibrosis

Cardiac fibrosis occurs following insults to the myocardium and is characterized by the abnormal accumulation of non-compliant extracellular matrix (ECM), which compromises cardiomyocyte contractile activity and eventually leads to heart failure. This phenomenon is driven by the activation of cardiac fibroblasts (cFbs) to myofibroblasts and results in changes in ECM biochemical, structural and mechanical properties. The lack of predictive in vitro models of heart fibrosis has so far hampered the search for innovative treatments, as most of the cellular-based in vitro reductionist models do not take into account the leading role of ECM cues in driving the progression of the pathology. Here, we devised a single-step decellularization protocol to obtain and thoroughly characterize the biochemical and micro-mechanical properties of the ECM secreted by activated cFbs differentiated from human induced pluripotent stem cells (iPSCs). We activated iPSC-derived cFbs to the myofibroblast phenotype by tuning basic fibroblast growth factor (bFGF) and transforming growth factor beta 1 (TGF-β1) signalling and confirmed that activated cells acquired key features of myofibroblast phenotype, like SMAD2/3 nuclear shuttling, the formation of aligned alpha-smooth muscle actin (α-SMA)-rich stress fibres and increased focal adhesions (FAs) assembly. Next, we used Mass Spectrometry, nanoindentation, scanning electron and confocal microscopy to unveil the characteristic composition and the visco-elastic properties of the abundant, collagen-rich ECM deposited by cardiac myofibroblasts in vitro. Finally, we demonstrated that the fibrotic ECM activates mechanosensitive pathways in iPSC-derived cardiomyocytes, impacting on their shape, sarcomere assembly, phenotype, and calcium handling properties. We thus propose human bio-inspired decellularized matrices as animal-free, isogenic cardiomyocyte culture substrates recapitulating key pathophysiological changes occurring at the cellular level during cardiac fibrosis.

Interleukin-33 promotes intrauterine adhesion formation in mice through the mitogen-activated protein kinase signaling pathway

IL-33 belongs to the inflammatory factor family and is closely associated with the inflammatory response. However, its role in the development of intrauterine adhesions (IUAs) remains unclear. In this study, the role of IL-33 in the formation of IUAs after endometrial injury was identified via RNA sequencing after mouse endometrial organoids were transplanted into an IUA mouse model. Major pathological changes in the mouse uterus, consistent with the expression of fibrotic markers, such as TGF-β, were observed in response to treatment with IL-33. This finding may be attributed to activation of the phosphorylation of downstream MAPK signaling pathway components, which are activated by the release of IL-33 in macrophages. Our study provides a novel mechanism for elucidating IUA formation, suggesting a new therapeutic strategy for the prevention and clinical treatment of IUAs.

Immunobiology of foreign body response to composite PLACL/gelatin electrospun nanofiber meshes with mesenchymal stem/stromal cells in a mouse model: Implications in pelvic floor tissue engineering and regeneration

Pelvic Organ Prolapse (POP) is a common gynaecological disorder where pelvic organs protrude into the vagina. While transvaginal mesh surgery using non-degradable polymers was a commonly accepted treatment for POP, it has been associated with high rates of adverse events such as mesh erosion, exposure and inflammation due to serious foreign body response and therefore banned from clinical use after regulatory mandates. This study proposes a tissue engineering strategy using uterine endometrium-derived mesenchymal stem/stromal cells (eMSC) delivered with degradable poly L-lactic acid-co-poly ε-caprolactone (PLACL) and gelatin (G) in form of a composite electrospun nanofibrous mesh (P + G nanomesh) and evaluates the immunomodulatory mechanism at the material interfaces. The study highlights the critical acute and chronic inflammatory markers along with remodelling factors that determine the mesh surgery outcome. We hypothesise that such a bioengineered construct enhances mesh integration and mitigates the Foreign Body Response (FBR) at the host interface associated with mesh complications. Our results show that eMSC-based nanomesh significantly increased 7 genes associated with ECM synthesis and cell adhesion including, Itgb1, Itgb2, Vcam1, Cd44, Cdh2, Tgfb1, Tgfbr1, 6 genes related to angiogenesis including Ang1, Ang2, Vegfa, Pdgfa, Serpin1, Cxcl12, and 5 genes associated with collagen remodelling Col1a1, Col3a1, Col6a1, Col6a2, Col4a5 at six weeks post-implantation. Our findings suggest that cell-based tissue-engineered constructs potentially mitigate the FBR response elicited by biomaterial implants. From a clinical perspective, this construct provides an alternative to current inadequacies in surgical outcomes by modulating the immune response, inducing angiogenesis and ECM synthesis during the acute and chronic phases of the FBR.

Regulation of self-renewal and senescence in primitive mesenchymal stem cells by Wnt and TGFβ signaling

BACKGROUND

The therapeutic application of multipotent mesenchymal stem cells (MSCs) encounters significant challenges, primarily stemming from their inadequate growth and limited self-renewal capabilities. Additionally, as MSCs are propagated, their ability to self-renew declines, and the exact cellular and molecular changes responsible for this are poorly understood. This study aims to uncover the complex molecular mechanisms that govern the self-renewal of primitive (p) MSCs.

METHODS

We grew pMSCs using two types of medium, fetal bovine serum (FM) and xeno-free (XM), at both low passage (LP, P3) and high passage (HP, P20). To evaluate LP and HP pMSCs, we examined their physical characteristics, cell surface markers, growth rate, colony-forming ability, BrdU assays for proliferation, telomerase activity, and potential to differentiate into three lineages. Moreover, we conducted RNA-seq to analyze their transcriptome and MNase-seq analysis to investigate nucleosome occupancies.

RESULTS

When grown in FM, pMSCs underwent changes in their cellular morphology, becoming larger and elongated. This was accompanied by a decrease in the expression of CD90 and CD49f, as well as a reduction in CFE, proliferation rate, and telomerase activity. In addition, these cells showed an increased tendency to differentiate into the adipogenic lineage. However, when grown in XM, pMSCs maintained their self-renewal capacity and ability to differentiate into multiple lineages while preserving their fibroblastoid morphology. Transcriptomic analysis showed an upregulation of genes associated with self-renewal, cell cycle regulation, and DNA replication in XM-cultured pMSCs, while senescence-related genes were upregulated in FM-cultured cells. Further analysis demonstrated differential nucleosomal occupancies in self-renewal and senescence-related genes for pMSCs grown in XM and FM, respectively. These findings were confirmed by qRT-PCR analysis, which revealed alterations in the expression of genes related to self-renewal, cell cycle regulation, DNA replication, differentiation, and senescence. To understand the underlying mechanisms, we investigated the involvement of Wnt and TGFβ signaling pathways by modulating them with agonists and antagonists. This experimental manipulation led to the upregulation and downregulation of self-renewal genes in pMSCs, providing further insights into the signaling pathways governing the self-renewal and senescence of pMSCs.

CONCLUSION

Our study shows that the self-renewal potential of pMSCs is associated with the Wnt pathway, while senescence is linked to TGFβ.

Mesenchymal Stromal Cells as a Driver of Inflammaging

Life expectancy and age-related diseases burden increased significantly over the past few decades. Age-related conditions are commonly discussed in a very limited paradigm of depleted cellular proliferation and maturation with exponential accumulation of senescent cells. However, most recent evidence showed that the majority of age-associated ailments, i.e., diabetes mellitus, cardiovascular diseases and neurodegeneration. These diseases are closely associated with tissue nonspecific inflammation triggered and controlled by mesenchymal stromal cell secretion. Mesenchymal stromal cells (MSCs) are known as the most common type of cells for therapeutic approaches in clinical practice. Side effects and complications of MSC-based treatments increased interest in the MSCs secretome as an alternative concept for validation tests in regenerative medicine. The most recent data also proposed it as an ideal tool for cell-free regenerative therapy and tissue engineering. However, senescent MSCs secretome was shown to hold the role of ‘key-driver’ in inflammaging. We aimed to review the immunomodulatory effects of the MSCs-secretome during cell senescence and provide eventual insight into the interpretation of its beneficial biological actions in inflammaging-associated diseases.

SMAD2/3 signaling in the uterine epithelium controls endometrial cell homeostasis and regeneration

The regenerative potential of the endometrium is attributed to endometrial stem cells; however, the signaling pathways controlling its regenerative potential remain obscure. In this study, genetic mouse models and endometrial organoids are used to demonstrate that SMAD2/3 signaling controls endometrial regeneration and differentiation. Mice with conditional deletion of SMAD2/3 in the uterine epithelium using Lactoferrin-iCre develop endometrial hyperplasia at 12-weeks and metastatic uterine tumors by 9-months of age. Mechanistic studies in endometrial organoids determine that genetic or pharmacological inhibition of SMAD2/3 signaling disrupts organoid morphology, increases the glandular and secretory cell markers, FOXA2 and MUC1, and alters the genome-wide distribution of SMAD4. Transcriptomic profiling of the organoids reveals elevated pathways involved in stem cell regeneration and differentiation such as the bone morphogenetic protein (BMP) and retinoic acid signaling (RA) pathways. Therefore, TGFβ family signaling via SMAD2/3 controls signaling networks which are integral for endometrial cell regeneration and differentiation.

Establishing 3D Endometrial Organoids from the Mouse Uterus

Endometrial tissue lines the inner cavity of the uterus and is under the cyclical control of estrogen and progesterone. It is a tissue that is composed of luminal and glandular epithelium, a stromal compartment, a vascular network, and a complex immune cell population. Mouse models have been a powerful tool to study the endometrium, revealing critical mechanisms that control implantation, placentation, and cancer. The recent development of 3D endometrial organoid cultures presents a state-of-the-art model to dissect the signaling pathways that underlie endometrial biology. Establishing endometrial organoids from genetically engineered mouse models, analyzing their transcriptomes, and visualizing their morphology at a single-cell resolution are crucial tools for the study of endometrial diseases. This paper outlines methods to establish 3D cultures of endometrial epithelium from mice and describes techniques to quantify gene expression and analyze the histology of the organoids. The goal is to provide a resource that can be used to establish, culture, and study the gene expression and morphological characteristics of endometrial epithelial organoids.

Rejuvenation of Senescent Mesenchymal Stem Cells to Prevent Age-Related Changes in Synovial Joints

Mesenchymal/medicinal stem/signaling cells (MSCs), well known for regenerative potential, have been involved in hundreds of clinical trials. Even if equipped with reparative properties, aging significantly decreases their biological activity, representing a major challenge for MSC-based therapies. Age-related joint diseases, such as osteoarthritis, are associated with the accumulation of senescent cells, including synovial MSCs. An impaired ability of MSCs to self-renew and differentiate is one of the main contributors to the human aging process. Moreover, senescent MSCs (sMSCs) are characterized by the senescence-messaging secretome (SMS), which is typically manifested by the release of molecules with an adverse effect. Many factors, from genetic and metabolic pathways to environmental stressors, participate in the regulation of the senescent phenotype of MSCs. To better understand cellular senescence in MSCs, this review discusses the characteristics of sMSCs, their role in cartilage and synovial joint aging, and current rejuvenation approaches to delay/reverse age-related pathological changes, providing evidence from in vivo experiments as well.

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

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

Expression of Fucosyltransferase 4 (FUT4) mRNA Is Increased in Endometrium from Women with Endometriosis

Endometriosis is a common gynecological disorder defined as the presence of endometrial-like tissue (glands and stroma) outside the uterus. The etiopathogenesis of endometriosis is still poorly recognized. It is speculated that stage-specific embryonic antigen 1 (SSEA-1)-positive stem-like glandular epithelial cells may contribute to the development of the disease. The synthesis of SSEA-1 is mediated by fucosyltransferase 4 encoded by the FUT4 gene. Therefore, this study aimed to evaluate the specific expression of FUT4 mRNA in biopsies of the endometrium from women with and without endometriosis. FUT4 mRNA levels were examined in 49 women with laparoscopically confirmed endometriosis and 28 controls by means of quantitative reverse-transcription polymerase chain reaction (qRT-PCR). The expression of FUT4 mRNA was significantly increased in the endometrium of patients with endometriosis when compared to the controls (p < 0.0001). Expression of FUT4 mRNA in the endometrium was correlated with the severity of endometriosis (rs = 0.5579, p < 0.0001); however, there were no differences in endometrial FUT4 mRNA expression when comparing endometriotic lesions from various locations. The discriminatory ability of FUT4 mRNA expression was evaluated by receiver-operating characteristics (ROC), which showed high statistical significance (AUC = 0.90, p < 0.0001), thus indicating that an increased level of endometrial FUT4 mRNA may serve as a specific marker for endometriosis.

Tissue-engineered repair material for pelvic floor dysfunction

Pelvic floor dysfunction (PFD) is a highly prevalent urogynecology disorder affecting many women worldwide, with symptoms including pelvic organ prolapse (POP), stress urinary incontinence (SUI), fecal incontinence, and overactive bladder syndrome (OAB). At present, the clinical treatments of PFD are still conservative and symptom-based, including non-surgical treatment and surgery. Surgical repair is an effective and durable treatment for PFD, and synthetic and biological materials can be used to enforce or reinforce the diseased tissue. However, synthetic materials such as polypropylene patches caused a series of complications such as mesh erosion, exposure, pain, and inflammation. The poor mechanical properties and high degradation speed of the biomaterial meshes resulted in poor anatomical reduction effect and limitation to clinical application. Therefore, the current treatment options are suboptimal. Recently, tissue-engineered repair material (TERM) has been applied to repair PFD and could markedly improve the prognosis of POP and SUI repair surgery in animal models. We review the directions and progression of TERM in POP and SUI repair. Adipose-derived stem cells (ADSCs) and endometrial mesenchymal stem cells (eMSCs) appear to be suitable cell types for scaffold seeding and clinical implantation. The multidisciplinary therapy approach to tissue engineering is a promising direction for tissue repair. More and longer follow-up studies are needed before determining cell types and materials for PFD repair.

TGFβ1-Pretreated Exosomes of Wharton Jelly Mesenchymal Stem Cell as a Therapeutic Strategy for Improving Liver Fibrosis

Background: Mesenchymal stem cells (MSCs) are the most promising tools for cell treatment and human tissue regeneration, e.g., in liver fibrosis. Mesenchymal stem cells repair tissue damage through paracrine mediators such as exosomes. Types and concentrations of inflammatory mediators, including transforming growth factor-beta (TGFβ1), in MSCs microenvironment can affect MSCs’ function and therapeutic potency. Objectives: This experimental study aimed to explore the effects of Wharton jelly MSCs (WJ-MSCs) exosomes on fibrotic gene expression and Smad2/3 phosphorylation (phospho-Smad2/3 (p-Smad2/3)). Moreover, we further investigated whether WJ-MSCs pretreatment with different concentrations of TGFβ1 changes the anti-fibrotic properties of their exosomes. Methods: After isolation from the umbilical cord, WJ-MSCs were characterized by observing differentiation and measuring surface biomarkers using flowcytometry. The WJ-MSC-derived exosomes were extracted and identified using transmission electron microscopy (TEM), dynamic light scattering (DLS), and western blotting. Real-time PCR and western blot for extracellular matrix (ECM) and p-Smad2/3 expression detection were used to investigate the effect of exosomes from untreated and TGFβ1-pretreated WJ-MSCs on activated hepatic stellate cells (HSCs). Results: Phospho-Smad2/3, α-smooth muscle actin (α-SMA), and collagen1α1 levels were enhanced following treatment with TGFβ1, whereas E-cadherin was decreased. However, the outcomes were reversed after treatment with WJ-MSC-derived exosomes. Exosomes from TGFβ1-pretreated WJ-MSCs induced a significant decrease in p-Smad2/3 levels in activated HSCs, accompanied by the upregulation of E-cadherin gene expression and downregulation of α-SMA and collagen1α1 when compared to untreated WJ-MSC-derived exosomes. The p-Smad2/3 proteins were significantly decreased (fold change: 0.23, P-value < 0.0001) after exposure to low-dose TGFβ1-pretreated WJ-MSC-derived exosomes (0.1 ng/mL), showing the best effect on activated HSCs. Conclusions: Exosomes derived from untreated WJ-MSCs could regress TGFβ-Smad2/3 signaling and the expression of fibrotic markers in activated LX-2 cells. However, these effects were significantly profound with applying exosomes derived from 0.1 ng/mL TGFβ-pretreated WJ-MSCs. We also observed the dose-response effects of TGFβ on WJ-MSCs-derived exosomes. Therefore, exosomes derived from TGFβ-pretreated WJ-MSCs may be critical in improving fibrosis and benefit liver fibrosis patients.

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

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

The fate of human SUSD2+ endometrial mesenchymal stem cells during decidualization

Regeneration of the endometrial stromal compartment in premenopausal women is likely maintained by the perivascular endometrial mesenchymal stem/stromal cells (eMSC) expressing sushi domain containing 2 (SUSD2). The fate of SUSD2+ eMSC during pregnancy and their role in decidualization is not fully known. The aim of our study was to determine the effect of progesterone on the stemness of the SUSD2+ eMSC isolated from non-pregnant uterine samples. Secondary objectives were to characterize the functional capacity including differentiation and clonogenicity assays of SUSD2+ eMSC isolated from decidua at full term and compare it to the capacity of those isolated from non-pregnant uterine samples. Progesterone treatment induced changes in the decidual gene expression profile in non-pregnant SUSD2+ eMSC. Data analysis of a publicly available single cell RNA-seq data set revealed differential expression of several mesenchymal and epithelial signature genes between the SUSD2+ eMSC and the decidual stromal cells, suggesting mesenchymal-to-epithelial transition occurs during decidualization. Histological analysis revealed a significantly lower abundance of SUSD2+ eMSC in 1st trimester and full term samples compared to non-pregnant samples, p = 0.0296 and 0.005, respectively. The differentiation and the colony forming capacity did not differ significantly between the cells isolated from non-pregnant and pregnant uterine samples. Our results suggest that SUSD2+ eMSC undergo decidualization in vitro, while maintaining MSC plasma membrane phenotype. Human eMSC seem to play an important role in the course of endometrial decidualization and embryo implantation. Pregnancy reduced the abundance of SUSD2+ eMSC, however eMSC function remains intact.

Understanding menstrual blood-derived stromal/stem cells: Definition and properties. Are we rushing into their therapeutic applications?

Cells with mesenchymal stem cell properties have been identified in menstrual blood and termed menstrual blood-derived stem/stromal cells (MenSCs). MenSCs have been proposed as ideal candidates for cell-based therapy in regenerative medicine and immune-related diseases. However, MenSCs identity has been loosely defined so far and there is controversy regarding their cell markers and differentiation potential. In this review, we outline the origin of MenSCs in the context of regenerating human endometrium, with attention to endometrial eMSCs as reference cells to understand MenSCs. We summarize the cell identity markers analyzed and the immunomodulatory and reparative properties reported. We also address the recent use of MenSCs in cell reprogramming. The main goal of this review is to contribute to the understanding of the identity and properties of MenSCs as well as to identify potential caveats and new venues that deserve to be explored to strengthen their potential applications.

Endometrial SUSD2+ Mesenchymal Stem/Stromal Cells in Tissue Engineering: Advances in Novel Cellular Constructs for Pelvic Organ Prolapse

Cellular therapy is an emerging field in clinical and personalised medicine. Many adult mesenchymal stem/progenitor cells (MSC) or pluripotent derivatives are being assessed simultaneously in preclinical trials for their potential treatment applications in chronic and degenerative human diseases. Endometrial mesenchymal stem/progenitor cells (eMSC) have been identified as clonogenic cells that exist in unique perivascular niches within the uterine endometrium. Compared with MSC isolated from other tissue sources, such as bone marrow and adipose tissue, eMSC can be extracted through less invasive methods of tissue sampling, and they exhibit improvements in potency, proliferative capacity, and control of culture-induced differentiation. In this review, we summarize the potential cell therapy and tissue engineering applications of eMSC in pelvic organ prolapse (POP), emphasising their ability to exert angiogenic and strong immunomodulatory responses that improve tissue integration of novel surgical constructs for POP and promote vaginal tissue healing.

Endometrial stem/progenitor cells and their roles in immunity, clinical application, and endometriosis

Endometrial stem/progenitor cells have been proved to exist in periodically regenerated female endometrium and can be divided into three categories: endometrial epithelial stem/progenitor cells, CD140b+CD146+ or SUSD2+ endometrial mesenchymal stem cells (eMSCs), and side population cells (SPs). Endometrial stem/progenitor cells in the menstruation blood are defined as menstrual stem cells (MenSCs). Due to their abundant sources, excellent proliferation, and autotransplantation capabilities, MenSCs are ideal candidates for cell-based therapy in regenerative medicine, inflammation, and immune-related diseases. Endometrial stem/progenitor cells also participate in the occurrence and development of endometriosis by entering the pelvic cavity from retrograde menstruation and becoming overreactive under certain conditions to form new glands and stroma through clonal expansion. Additionally, the limited bone marrow mesenchymal stem cells (BMDSCs) in blood circulation can be recruited and infiltrated into the lesion sites, leading to the establishment of deep invasive endometriosis. On the other hand, cell derived from endometriosis may also enter the blood circulation to form circulating endometrial cells (CECs) with stem cell-like properties, and to migrate and implant into distant tissues. In this manuscript, by reviewing the available literature, we outlined the characteristics of endometrial stem/progenitor cells and summarized their roles in immunoregulation, regenerative medicine, and endometriosis, through which to provide some novel therapeutic strategies for reproductive and cancerous diseases.

Tissue engineering to treat pelvic organ prolapse

Pelvic organ prolapse (POP) is a frequent chronic illness, which seriously affects women's living quality. In recent years, tissue engineering has made superior progress in POP treatment, and biological scaffolds have received considerable attention. Nevertheless, pelvic floor reconstruction still faces severe challenges, including the construction of ideal scaffolds, the selection of optimal seed cells, and growth factors. This paper summarizes the recent progress of pelvic floor reconstruction in tissue engineering, and discusses the problems that need to be further considered and solved to provide references for the further development of this field.

Self-renewal and differentiation of rat Epididymal basal cells using a novel in vitro organoid model

The epididymis is composed of a pseudostratified epithelium comprised of various cell types. Studies have shown that rat basal cells share common properties with adult stem cells and begin to differentiate in vitro in response to fibroblast growth factor and 5α-dihydrotestosterone. The characterization of rat basal cells is therefore necessary to fully understand the role of these cells. The objectives of this study were to assess the ability of single basal cells to develop organoids and to assess their ability to self-renew and differentiate in vitro. We isolated basal cells from the rat epididymis and established 3-dimensional cell cultures from the basal and non-basal cell fractions. Organoids were formed by single adult epididymal basal cells. Organoids were dissociated into single basal cells which were able to reform new organoids, and were maintained over 10 generations. Long-term culture of organoids revealed that these cells could differentiated into cells expressing the principal cell markers aquaporin 9 and cystic fibrosis transmembrane conductance regulator. Electron microscopy demonstrated that organoids were comprised of several polarized cell types displaying microvilli and the ability to form tight junctions. Additionally, organoids could be formed by basal cells from either the proximal or distal region of the epididymis, and are able to secrete clusterin, a protein implicated in the maturation of spermatozoa. These data indicate that rat basal cells can be used to derive epididymal organoids, and further supports that notion that these may represent a stem cell population in the epididymis.

Identification and characterisation of maternal perivascular SUSD2+ placental mesenchymal stem/stromal cells

Mesenchymal stem cells (MSCs) that meet the International Society for Cellular Therapy (ISCT) criteria are obtained from placental tissue by plastic adherence. Historically, no known single marker was available for isolating placental MSCs (pMSCs) from the decidua basalis. As the decidua basalis is derived from the regenerative endometrium, we hypothesised that SUSD2, an endometrial perivascular MSC marker, would purify maternal perivascular pMSC. Perivascular pMSCs were isolated from the maternal placenta using SUSD2 magnetic bead sorting and assessed for the colony-forming unit-fibroblasts (CFU-F), surface markers, and in vitro differentiation into mesodermal lineages. Multi-colour immunofluorescence was used to colocalise SUSD2 and α-SMA, a perivascular marker in the decidua basalis. Placental stromal cell suspensions comprised 5.1%SUSD2⁺ cells. SUSD2 magnetic bead sorting of the placental stromal cells increased their purity approximately two-fold. SUSD2⁺ pMSCs displayed greater CFU-F activity than SUSD2^- stromal fibroblasts (pSFs). However, both SUSD2⁺ pMSC and SUSD2^- pSF underwent mesodermal differentiation in vitro, and both expressed the ISCT surface markers. Higher percentages of cultured SUSD2⁺ pMSCs expressed the perivascular markers CD146, CD140b, and SUSD2 than SUSD2^- pSFs. These findings suggest that SUSD2 is a single marker that enriches maternal pMSCs, suggesting they may originate from eMSC. Placental decidua basalis can be used as an alternative source of MSC for clinical translation in situations where there is no access to endometrial tissue.

Generation of Hepatic Progenitor Cells from the Primary Hepatocytes of Nonhuman Primates Using Small Molecules

BACKGROUND

Since primates have more biological similarities to humans than do other animals, they are a valuable resource in various field of research, including biomedicine, regenerative medicine, and drug discovery. However, there remain limitations to maintenance and expansion of primary hepatocytes derived from nonhuman primates. To overcome these limitations, we developed a novel culture system for primate cells.

METHODS

Primary hepatocytes from Macaca fascicularis (mf-PHs) were isolated from hepatectomized liver. To generate chemically derived hepatic progenitor cells (mf-CdHs), mf-PHs were cultured with reprogramming medium containing A83-01, CHIR99021, and hepatocyte growth factor (HGF). The bi-potent differentiation capacity of mf-CdHs into hepatocytes and biliary epithelial cells was confirmed by treatment with hepatic differentiation medium (HDM) and cholangiocytic differentiation medium (CDM), respectively.

RESULTS

mf-PHs cultured with reprogramming medium showed rapid proliferation capacity in vitro and expressed progenitor-specific markers. Moreover, when cultured in HDM, these progenitor cells stably differentiated into hepatocyte-like cells expressing the mature hepatic markers. On the other hand, when cultured in CDM, the differentiated biliary epithelial cells expressed mature cholangiocyte characteristics.

CONCLUSION

The results of the present study demonstrate that we successfully induced the formation of hepatic progenitor cells from mf-PHs by culturing them with a combination of small molecules, including growth factors. These results offer a means of expanding nonhuman primate hepatocytes without genetic manipulation for cellular resource, preclinical applications and regenerative medicine for the liver.

Comparing the Effect of TGF-β Receptor Inhibition on Human Perivascular Mesenchymal Stromal Cells Derived from Endometrium, Bone Marrow and Adipose Tissues

Rare perivascular mesenchymal stromal cells (MSCs) with therapeutic properties have been identified in many tissues. Their rarity necessitates extensive in vitro expansion, resulting in spontaneous differentiation, cellular senescence and apoptosis, producing therapeutic products with variable quality and decreased potency. We previously demonstrated that A83-01, a transforming growth factor beta (TGF-β) receptor inhibitor, maintained clonogenicity and promoted the potency of culture-expanded premenopausal endometrial MSCs using functional assays and whole-transcriptome sequencing. Here, we compared the effects of A83-01 on MSCs derived from postmenopausal endometrium, menstrual blood, placenta decidua-basalis, bone marrow and adipose tissue. Sushi-domain-containing-2 (SUSD2⁺) and CD34⁺CD31⁻CD45⁻ MSCs were isolated. Expanded MSCs were cultured with or without A83-01 for 7 days and assessed for MSC properties. SUSD2 identified perivascular cells in the placental decidua-basalis, and their maternal origin was validated. A83-01 promoted MSC proliferation from all sources except bone marrow and only increased SUSD2 expression and prevented apoptosis in MSCs from endometrial-derived tissues. A83-01 only improved the cloning efficiency of postmenopausal endometrial MSCs (eMSCs), and expanded adipose tissue MSCs (adMSCs) underwent significant senescence, which was mitigated by A83-01. MSCs derived from bone marrow (bmMSCs) were highly apoptotic, but A83-01 was without effect. A83-01 maintained the function and phenotype in MSCs cultured from endometrial, but not other, tissues. Our results also demonstrated that cellular SUSD2 expression directly correlates with the functional phenotype.

Influence of culture media on the derivation and phenotype of fetal-derived placental mesenchymal stem/stromal cells across gestation

INTRODUCTION

Derivation of pure fetal placental mesenchymal stem/stromal cells (pMSCs) is key to understand their role in placental development. However, isolated pMSCs are often contaminated by maternal-derived decidual MSCs (dMSCs). EGM-2 medium promotes the derivation of term fetal pMSCs, but the extent of first-trimester maternal pMSC contamination remains unclear. Culture media can also affect MSC phenotype. Here, we examined the effects of culture media on maternal pMSC contamination and fetal pMSC phenotype across gestation.

METHODS

pMSCs were derived from first-trimester or term placentae in advanced-DMEM/F12 medium or EGM-2 medium. Proportions of maternal (XX) and fetal (XY) cells in male pMSC cultures were determined by fluorescence in-situ hybridization. pMSC phenotype was analysed by flow cytometry, immunohistochemistry and Alamar blue proliferation assays.

RESULTS

When derived in advanced-DMEM/F12, all first trimester pMSC isolates exhibited maternal contamination (>72% XX cells, n = 5), whilst 7/9 term pMSC isolates were >98% fetal. When derived in EGM-2, all first trimester (n = 4) and term (n = 9) pMSC isolates contained 95-100% fetal cells. Fetal pMSCs in EGM-2 proliferated 2-fold (first-trimester) or 4-fold (term) faster than those in advanced-DMEM/F12 (p < 0.05, n = 3). Fetal pMSCs in both media expressed the generic MSC marker profile (CD90⁺, CD105+, CD73⁺, CD31-, CD34-, CD144-). However, pMSCs transferred from EGM-2 to advanced-DMEM/F12 increased expression of smooth muscle cell markers calponin and α-smooth muscle actin, and decreased expression of the vascular cell marker VEGFR2 (n = 3).

CONCLUSIONS

Deriving first-trimester pMSC in EGM-2 dramatically reduces maternal dMSC contamination. Media affects fetal pMSC phenotype, and careful consideration should be given to application specific culture conditions.

Impact of Sustained Transforming Growth Factor-β Receptor Inhibition on Chromatin Accessibility and Gene Expression in Cultured Human Endometrial MSC

Endometrial mesenchymal stem cells (eMSC) drive the extraordinary regenerative capacity of the human endometrium. Clinical application of eMSC for therapeutic purposes is hampered by spontaneous differentiation and cellular senescence upon large-scale expansion in vitro. A83-01, a selective transforming growth factor-β receptor (TGFβ-R) inhibitor, promotes expansion of eMSC in culture by blocking differentiation and senescence, but the underlying mechanisms are incompletely understood. In this study, we combined RNA-seq and ATAC-seq to study the impact of sustained TGFβ-R inhibition on gene expression and chromatin architecture of eMSC. Treatment of primary eMSC with A83-01 for 5 weeks resulted in differential expression of 1,463 genes. Gene ontology analysis showed enrichment of genes implicated in cell growth whereas extracellular matrix genes and genes involved in cell fate commitment were downregulated. ATAC-seq analysis demonstrated that sustained TGFβ-R inhibition results in opening and closure of 3,555 and 2,412 chromatin loci, respectively. Motif analysis revealed marked enrichment of retinoic acid receptor (RAR) binding sites, which was paralleled by the induction of RARB, encoding retinoic acid receptor beta (RARβ). Selective RARβ inhibition attenuated proliferation and clonogenicity of A83-01 treated eMSC. Taken together, our study provides new insights into the gene networks and genome-wide chromatin changes that underpin maintenance of an undifferentiated phenotype of eMSC in prolonged culture.

Endometrial and Menstrual Blood Mesenchymal Stem/Stromal Cells: Biological Properties and Clinical Application

A highly proliferative mesenchymal stem/stromal cell (MSC) population was recently discovered in the dynamic, cyclically regenerating human endometrium as clonogenic stromal cells that fulfilled the International Society for Cellular Therapy (ISCT) criteria. Specific surface markers enriching for clonogenic endometrial MSC (eMSC), CD140b and CD146 co-expression, and the single marker SUSD2, showed their perivascular identity in the endometrium, including the layer which sheds during menstruation. Indeed, cells with MSC properties have been identified in menstrual fluid and commonly termed menstrual blood stem/stromal cells (MenSC). MenSC are generally retrieved from menstrual fluid as plastic adherent cells, similar to bone marrow MSC (bmMSC). While eMSC and MenSC share several biological features with bmMSC, they also show some differences in immunophenotype, proliferation and differentiation capacities. Here we review the phenotype and functions of eMSC and MenSC, with a focus on recent studies. Similar to other MSC, eMSC and MenSC exert immunomodulatory and anti-inflammatory impacts on key cells of the innate and adaptive immune system. These include macrophages, T cells and NK cells, both in vitro and in small and large animal models. These properties suggest eMSC and MenSC as additional sources of MSC for cell therapies in regenerative medicine as well as immune-mediated disorders and inflammatory diseases. Their easy acquisition via an office-based biopsy or collected from menstrual effluent makes eMSC and MenSC attractive sources of MSC for clinical applications. In preparation for clinical translation, a serum-free culture protocol was established for eMSC which includes a small molecule TGFβ receptor inhibitor that prevents spontaneous differentiation, apoptosis, senescence, maintains the clonogenic SUSD2+ population and enhances their potency, suggesting potential for cell-therapies and regenerative medicine. However, standardization of MenSC isolation protocols and culture conditions are major issues requiring further research to maximize their potential for clinical application. Future research will also address crucial safety aspects of eMSC and MenSC to ensure these protocols produce cell products free from tumorigenicity and toxicity. Although a wealth of data on the biological properties of eMSC and MenSC has recently been published, it will be important to address their mechanism of action in preclinical models of human disease.

Emerging Nano/Micro-Structured Degradable Polymeric Meshes for Pelvic Floor Reconstruction

Pelvic organ prolapse (POP) is a hidden women's health disorder that impacts 1 in 4 women across all age groups. Surgical intervention has been the only treatment option, often involving non-degradable meshes, with variable results. However, recent reports have highlighted the adverse effects of meshes in the long term, which involve unacceptable rates of erosion, chronic infection and severe pain related to mesh shrinkage. Therefore, there is an urgent unmet need to fabricate of new class of biocompatible meshes for the treatment of POP. This review focuses on the causes for the downfall of commercial meshes, and discusses the use of emerging technologies such as electrospinning and 3D printing to design new meshes. Furthermore, we discuss the impact and advantage of nano-/microstructured alternative meshes over commercial meshes with respect to their tissue integration performance. Considering the key challenges of current meshes, we discuss the potential of cell-based tissue engineering strategies to augment the new class of meshes to improve biocompatibility and immunomodulation. Finally, this review highlights the future direction in designing the new class of mesh to overcome the hurdles of foreign body rejection faced by the traditional meshes, in order to have safe and effective treatment for women in the long term.

Transforming growth factor-β1 in intrauterine adhesion

Intrauterine adhesion (IUA), led by trauma to the basal layer, can prevent the endometrium from growing, resulting in complications in females, such as infertility and amenorrhea. Transforming growth factor-β1 (TGF-β1) plays a crucial role in inducing and promoting the differentiation and proliferation of mesenchymal cells, in the secretion of extracellular matrix-associated components, and is a major cytokine in initiating and terminating tissue repair downstream of the TGF-β/Smad signaling pathway. Some evidence supports that TGF-β1 is closely associated with the occurrence and development of IUA, and is regarded as an early risk factor of disease recurrence. Furthermore, the role of TGF-β1 has been demonstrated to be potentially regulated by a variety of cytokines, hormones, enzymes, and microRNAs. This review provides an overview of the expression, function, and regulation of TGF-β1 in IUA, with a brief discussion and perspectives on its future clinical implications on the diagnosis and treatment of IUA.

GARP is a key molecule for mesenchymal stromal cell responses to TGF-β and fundamental to control mitochondrial ROS levels

Multipotent mesenchymal stromal cells (MSCs) have emerged as a promising cell therapy in regenerative medicine and for autoimmune/inflammatory diseases. However, a main hurdle for MSCs-based therapies is the loss of their proliferative potential in vitro. Here we report that glycoprotein A repetitions predominant (GARP) is required for the proliferation and survival of adipose-derived MSCs (ASCs) via its regulation of transforming growth factor-β (TGF-β) activation. Silencing of GARP in human ASCs increased their activation of TGF-β which augmented the levels of mitochondrial reactive oxygen species (mtROS), resulting in DNA damage, a block in proliferation and apoptosis. Inhibition of TGF-β signaling reduced the levels of mtROS and DNA damage and restored the ability of GARP-/low ASCs to proliferate. In contrast, overexpression of GARP in ASCs increased their proliferative capacity and rendered them more resistant to etoposide-induced DNA damage and apoptosis, in a TGF-β-dependent manner. In summary, our data show that the presence or absence of GARP on ASCs gives rise to distinct TGF-β responses with diametrically opposing effects on ASC proliferation and survival.

Electrospun Nanofiber Meshes With Endometrial MSCs Modulate Foreign Body Response by Increased Angiogenesis, Matrix Synthesis, and Anti-Inflammatory Gene Expression in Mice: Implication in Pelvic Floor

Purpose

Transvaginal meshes for the treatment of Pelvic Organ Prolapse (POP) have been associated with severe adverse events and have been banned for clinical use in many countries. We recently reported the design of degradable poly L-lactic acid-co-poly ε-caprolactone nanofibrous mesh (P nanomesh) bioengineered with endometrial mesenchymal stem/stromal cells (eMSC) for POP repair. We showed that such bioengineered meshes had high tissue integration as well as immunomodulatory effects in vivo. This study aimed to determine the key molecular players enabling eMSC-based foreign body response modulation.

Methods

SUSD2⁺ eMSC were purified from single cell suspensions obtained from endometrial biopsies from cycling women by magnetic bead sorting. Electrospun P nanomeshes with and without eMSC were implanted in a NSG mouse skin wound repair model for 1 and 6 weeks. Quantitative PCR was used to assess the expression of extracellular matrix (ECM), cell adhesion, angiogenesis and inflammation genes as log₂ fold changes compared to sham controls. Histology and immunostaining were used to visualize the ECM, blood vessels, and multinucleated foreign body giant cells around implants.

Results

Bioengineered P nanomesh/eMSC constructs explanted after 6 weeks showed significant increase in 35 genes associated with ECM, ECM regulation, cell adhesion angiogenesis, and immune response in comparison to P nanomesh alone. In the absence of eMSC, acute inflammatory genes were significantly elevated at 1 week. However, in the presence of eMSC, there was an increased expression of anti-inflammatory genes including Mrc1 and Arg1 by 6 weeks. There was formation of multinucleated foreign body giant cells around both implants at 6 weeks that expressed CD206, a M2 macrophage marker.

Conclusion

This study reveals that eMSC modulate the foreign body response to degradable P nanomeshes in vivo by altering the expression profile of mouse genes. eMSC reduce acute inflammatory and increase ECM synthesis, angiogenesis and anti-inflammatory gene expression at 6 weeks while forming newly synthesized collagen within the nanomeshes and neo-vasculature in close proximity. From a tissue engineering perspective, this is a hallmark of a highly successful implant, suggesting significant potential as alternative surgical constructs for the treatment of POP.

Tissue engineering approaches for treating pelvic organ prolapse using a novel source of stem/stromal cells and new materials

PURPOSE OF REVIEW

Nondegradable transvaginal polypropylene meshes for treating pelvic organ prolapse (POP) are now generally unavailable or banned. In this review, we summarize recent developments using tissue engineering approaches combining alternate degradable scaffolds with a novel source of mesenchymal stem/stromal cells from human endometrium (eMSC).

RECENT FINDINGS

Tissue engineering constructs comprising immunomodulatory, reparative eMSC and biomimetic materials with nanoarchitecture are a promising approach for vaginal repair and improving outcomes of POP surgery. Culture expansion of eMSC that maintains them (and other MSC) in the undifferentiated state has been achieved using a small molecule transforming growth factor-β receptor inhibitor, A83-01. The mechanism of action of A83-01 has been determined and its suitability for translation into the clinic explored. Novel blends of electrospun synthetic and natural polymers combined with eMSC shows this approach promotes host cell infiltration and slows biomaterial degradation that has potential to strengthen the vaginal wall during healing. Improving the preclinical ovine transvaginal surgical model by adapting the human clinical POP-Quantification system for selection of multiparous ewes with vaginal wall weakness enables assessment of this autologous eMSC/nanobiomaterial construct.

SUMMARY

A tissue engineering approach using autologous eMSC with degradable nanobiomaterials offers a new approach for treating women with POP.

Inhibition of DNA Methyltransferase by RG108 Promotes Pluripotency-Related Character of Porcine Bone Marrow Mesenchymal Stem Cells

Mesenchymal stem/stromal cells (MSCs) have been identified in almost all adult human tissues and been used in numerous clinical trials for a variety of diseases. Studies have shown that MSCs would undergo cellular senescence when cultured over a long term, which is brought on by increased epigenetic modifications, including DNA methylation. However, the mechanism of MSCs senescence is not well studied. In this study, the effects of RG108, a DNA methyltransferase inhibitor (DNMTi), on senescence, apoptosis, and pluripotency gene expressions in porcine bone marrow (pBM)-MSCs were investigated. First, we determined the optimized dose and time of RG108 treatment in pBM-MSCs to be 10 μM for 48 hours, respectively. Under these conditions, the pluripotency genes (NANOG, POU5F1), the anti-senescence genes (TERT, bFGF), and the anti-apoptosis gene (BCL2) were increased, whereas the apoptotic gene (BAX) was decreased. RG108 protected against apoptosis when pBM-MSC induces apoptosis with H₂O₂ for 1.5 hours. We also found that RG108 significantly induced the expression of NANOG and POU5F1 by decreasing DNA methylation in gene promoter regions. These results indicate that an optimized dose of RG108 may promote the pluripotency-related character of pBM-MSCs through improving cellular anti-senescence, anti-apoptosis, and pluripotency, which provide a better cell origin for stem cell therapy.

Suppression of transforming growth factor-beta signaling enhances spermatogonial proliferation and spermatogenesis recovery following chemotherapy

STUDY QUESTION

Could small molecules (SM) which target (or modify) signaling pathways lead to increased proliferation of undifferentiated spermatogonia following chemotherapy?

SUMMARY ANSWER

Inhibition of transforming growth factor-beta (TGFb) signaling by SM can enhance the proliferation of undifferentiated spermatogonia and spermatogenesis recovery following chemotherapy.

WHAT IS KNOWN ALREADY

Spermatogonial stem cells (SSCs) hold great promise for fertility preservation in prepubertal boys diagnosed with cancer. However, the low number of SSCs limits their clinical applications. SM are chemically synthesized molecules that diffuse across the cell membrane to specifically target proteins involved in signaling pathways, and studies have reported their ability to increase the proliferation or differentiation of germ cells.

STUDY DESIGN, SIZE, DURATION

In our experimental study, spermatogonia were collected from four brain-dead individuals and used for SM screening in vitro. For in vivo assessments, busulfan-treated mice were treated with the selected SM (or vehicle, the control) and assayed after 2 (three mice per group) and 5 weeks (two mice per group).

PARTICIPANTS/MATERIALS, SETTING, METHODS

We investigated the effect of six SM on the proliferation of human undifferentiated spermatogonia in vitro using a top–bottom approach for screening. We used histological, hormonal and gene-expression analyses to assess the effect of selected SM on mouse spermatogenesis. All experiments were performed at least in triplicate and were statistically evaluated by Student’s t-test and/or one-way ANOVA followed by Scheffe’s or Tukey’s post-hoc.

MAIN RESULTS AND THE ROLE OF CHANCE

We found that administration of SB431542, as a specific inhibitor of the TGFb1 receptor (TGFbR1), leads to a two-fold increase in mouse and human undifferentiated spermatogonia proliferation. Furthermore, injection of SB to busulfan-treated mice accelerated spermatogenesis recovery as revealed by increased testicular size, weight and serum level of inhibin B. Moreover, SB administration accelerated both the onset and completion of spermatogenesis. We demonstrated that SB promotes proliferation in testicular tissue by regulating the cyclin-dependent kinase (CDK) inhibitors 4Ebp1 and P57 (proliferation inhibitor genes) and up-regulating Cdc25a and Cdk4 (cell cycle promoting genes).

LIMITATIONS, REASONS FOR CAUTION

The availability of human testis was the main limitation in this study.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first study to report acceleration of spermatogenesis recovery following chemotherapy by administration of a single SM. Our findings suggest that SB is a promising SM and should be assessed in future clinical trials for preservation of fertility in men diagnosed with cancer or in certain infertility cases (e.g. oligospermia).

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by Royan Institute and National Institute for Medical Research Development (NIMAD, grant no 963337) granted to H.B. The authors have no conflict of interest to report.

TGF-β Signaling in Cellular Senescence and Aging-Related Pathology

Aging is broadly defined as the functional decline that occurs in all body systems. The accumulation of senescent cells is considered a hallmark of aging and thought to contribute to the aging pathologies. Transforming growth factor-β (TGF-β) is a pleiotropic cytokine that regulates a myriad of cellular processes and has important roles in embryonic development, physiological tissue homeostasis, and various pathological conditions. TGF-β exerts potent growth inhibitory activities in various cell types, and multiple growth regulatory mechanisms have reportedly been linked to the phenotypes of cellular senescence and stem cell aging in previous studies. In addition, accumulated evidence has indicated a multifaceted association between TGF-β signaling and aging-associated disorders, including Alzheimer’s disease, muscle atrophy, and obesity. The findings regarding these diseases suggest that the impairment of TGF-β signaling in certain cell types and the upregulation of TGF-β ligands contribute to cell degeneration, tissue fibrosis, inflammation, decreased regeneration capacity, and metabolic malfunction. While the biological roles of TGF-β depend highly on cell types and cellular contexts, aging-associated changes are an important additional context which warrants further investigation to better understand the involvement in various diseases and develop therapeutic options. The present review summarizes the relationships between TGF-β signaling and cellular senescence, stem cell aging, and aging-related diseases.

3D bioprinted endometrial stem cells on melt electrospun poly ε-caprolactone mesh for pelvic floor application promote anti-inflammatory responses in mice

Endometrial mesenchymal stem/stromal cells (eMSCs) exhibit excellent regenerative capacity in the endometrial lining of the uterus following menstruation and high proliferative capacity in vitro. Bioprinting eMSCs onto a mesh could be a potential therapy for Pelvic Organ Prolapse (POP). This study reports an alternative treatment strategy targeting vaginal wall repair using bioprinting of eMSCs encapsulated in a hydrogel and 3D melt electrospun mesh to generate a tissue engineering construct. Following a CAD, 3D printed poly ε-caprolactone (PCL) meshes were fabricated using melt electrospinning (MES) at different temperatures using a GMP clinical grade GESIM Bioscaffolder. Electron and atomic force microscopies revealed that MES meshes fabricated at 100 °C and with a speed 20 mm/s had the largest open pore diameter (47.2 ± 11.4 μm) and the lowest strand thickness (121.4 ± 46 μm) that promoted optimal eMSC attachment. An Aloe Vera-Sodium Alginate (AV-ALG) composite based hydrogel was optimised to a 1:1 mixture (1%AV-1%ALG) and eMSCs, purified from human endometrial biopsies, were then bioprinted in this hydrogel onto the MES printed meshes. Acute in vivo foreign body response assessment in NSG mice revealed that eMSC printed on MES constructs promoted tissue integration, eMSC retention and an anti-inflammatory M2 macrophage phenotype characterised by F4/80⁺CD206⁺ colocalization. Our results address an unmet medical need highlighting the potential of 3D bioprinted eMSC-MES meshes as an alternative approach to overcome the current challenges with non-degradable knitted meshes in POP treatment. STATEMENT OF SIGNIFICANCE: This study presents the first report of bioprinting mesenchymal stem cells derived from woman endometrium (eMSCs) to boost Pelvic Organ Prolapse (POP) treatment. It impacts over 50% of elderly women with no optimal treatment at present. The overall study is conducted in three stages as fabricating a melt electrospun (MES) mesh, bioprinting eMSCs into a Ca²⁺ free Aloe Vera-Alginate (AV-Alg) based hydrogel and in vivo study. Our data showed that AV-ALG hydrogel potentially suppresses the foreign body response and further addition of eMSCs triggered a high influx of anti-inflammatory CD206⁺ M2 macrophages. Our final construct demonstrates a favourable foreign body response to predict expected tissue integration, therefore, provides a potential for developing an alternative treatment for POP.

Composite mesh design for delivery of autologous mesenchymal stem cells influences mesh integration, exposure and biocompatibility in an ovine model of pelvic organ prolapse

The widespread use of synthetic transvaginal polypropylene mesh for treating Pelvic Organ Prolapse (POP) has been curtailed due to serious adverse effects highlighted in 2008 and 2011 FDA warnings and subsequent legal action. We are developing new synthetic mesh to deliver endometrial mesenchymal stem cells (eMSC) to improve mesh biocompatibility and restore strength to prolapsed vaginal tissue. Here we evaluated knitted polyamide (PA) mesh in an ovine multiparous model using transvaginal implantation and matched for the degree of POP. Polyamide mesh dip-coated in gelatin and stabilised with 0.5% glutaraldehyde (PA/G) were used either alone or seeded with autologous ovine eMSC (eMSC/PA/G), which resulted in substantial mesh folding, poor tissue integration and 42% mesh exposure in the ovine model. In contrast, a two-step insertion protocol, whereby the uncoated PA mesh was inserted transvaginally followed by application of autologous eMSC in a gelatin hydrogel onto the mesh and crosslinked with blue light (PA + eMSC/G), integrated well with little folding and no mesh exposure. The autologous ovine eMSC survived 30 days in vivo but had no effect on mesh integration. The stiff PA/G constructs provoked greater myofibroblast and inflammatory responses in the vaginal wall, disrupted the muscularis layer and reduced elastin fibres compared to PA + eMSC/G constructs. This study identified the superiority of a two-step protocol for implanting synthetic mesh in cellular compatible composite constructs and simpler surgical application, providing additional translational value.

Mesenchymal stem cell-based bioengineered constructs: foreign body response, cross-talk with macrophages and impact of biomaterial design strategies for pelvic floor disorders

An excessive foreign body response (FBR) has contributed to the adverse events associated with polypropylene mesh usage for augmenting pelvic organ prolapse surgery. Consequently, current biomaterial research considers the critical role of the FBR and now focuses on developing better biocompatible biomaterials rather than using inert implants to improve the clinical outcomes of their use. Tissue engineering approaches using mesenchymal stem cells (MSCs) have improved outcomes over traditional implants in other biological systems through their interaction with macrophages, the main cellular player in the FBR. The unique angiogenic, immunomodulatory and regenerative properties of MSCs have a direct impact on the FBR following biomaterial implantation. In this review, we focus on key aspects of the FBR to tissue-engineered MSC-based implants for supporting pelvic organs and beyond. We also discuss the immunomodulatory effects of the recently discovered endometrial MSCs on the macrophage response to new biomaterials designed for use in pelvic floor reconstructive surgery. We conclude with a focus on considerations in biomaterial design that take into account the FBR and will likely influence the development of the next generation of biomaterials for gynaecological applications.

Endometriotic Peritoneal Fluid Promotes Myofibroblast Differentiation of Endometrial Mesenchymal Stem Cells

During the development of endometriosis, the presence of fibrotic tissues in and surrounding endometriotic lesions may lead to subsequent adhesion, anatomic distortion, and chronic pain. Therefore, studies aimed at clarifying the underlying mechanisms of fibrogenesis in endometriosis could potentially provide a novel strategy for effective treatment. Mesenchymal stem cells (MSCs) play a key role in fibrotic diseases by differentiating into myofibroblasts in appropriate microenvironment. In this study, we collected endometrial and endometriotic tissues from patients with endometriosis (n = 32) and control patients without endometriosis (n = 20) to compare the expression of fibrotic proteins and investigate the effect of endometriotic peritoneal fluid (PF) on myofibroblast differentiation of endometrial MSCs. We found that the expression of fibrotic proteins, including alpha-smooth muscle actin (α-SMA), type I collagen (collagen I), connective tissue growth factor (CTGF), and fibronectin, and the extent of fibrosis extremely enhanced in ectopic endometria compared with eutopic endometria from the same patients with endometriosis and normal endometria from patients without endometriosis. We next isolated and identified endometrial MSCs and found that treatment with endometriotic PF strongly induced endometrial MSCs to differentiate into myofibroblasts concomitant with the activation of Smad2/3. Moreover, ectopic endometrial MSCs expressed elevated collagen I, α-SMA, fibronectin, and CTGF. Sushi domain containing-2 (SUSD2), a marker of endometrial MSCs, and α-SMA, a well-recognized marker for myofibroblasts, colocalized extensively in ectopic endometria while seldom in normal and eutopic endometria. These findings suggest that ectopic endometrial MSCs are probably more susceptible to myofibroblast differentiation because of the long-term influence of endometriotic PF. All together, we report for the first time that endometriotic PF promotes myofibroblast differentiation of endometrial MSCs. This understanding will greatly improve our understanding of the pathophysiology of endometriosis and help design better therapeutics.

The biological behavior optimization of human periodontal ligament stem cells via preconditioning by the combined application of fibroblast growth factor-2 and A83-01 in in vitro culture expansion

BACKGROUND

As the optimal source of seed cells in periodontal tissue engineering, periodontal ligament stem cells (PDLSCs) have always been researched to improve cell expansion due to their limited resource and spontaneous differentiation in vitro cultivation. Fibroblast growth factor-2 (FGF-2) has been proven to stimulate bone marrow mesenchymal stem cells (BMMSCs) proliferation and maintain their pluripotency when being added to the culture medium. As a small molecule inhibitor of transforming growth factor-beta receptors (TGF-βRs), A83-01 can also promote cell proliferation. Therefore, the aim of this study was to verify whether the combined application of FGF-2 and A83-01 could augment cell quantity and quality during in vitro culture.

METHODS

PDLSCs were preconditioned with A83-01, FGF-2, or their combination. A cell counting kit-8 (CCK8) assay, cell apoptosis assay, ALP activity assay, Alizarin Red S staining assay, RT-PCR assay, Western blot assay and ELISA were used to determine the sustained effects of different preconditioning strategies on the proliferation, apoptosis, stemness, osteogenic differentiation and paracrine action of PDLSCs.

RESULTS

The combined application of FGF-2 and A83-01 significantly augmented cell expansion, reduced cell apoptosis, magnified stemness expression, promoted later osteogenic differentiation and mineralization and increased paracrine action of PDLSCs compared with the control. Moreover, the combination presented significant advantages in enhancing proliferation, stemness expression and paracrine action over FGF-2 alone.

CONCLUSIONS

The combined application of A83-01 and FGF-2 may be an improved strategy for PDLSCs biological behavior optimization in culture expansion and advantageous for reinforcing proliferation, stemness expression and cytokine secretion over FGF-2 alone.

Covalent Attachment of Fibronectin onto Emulsion-Templated Porous Polymer Scaffolds Enhances Human Endometrial Stromal Cell Adhesion, Infiltration, and Function

A novel strategy for the surface functionalization of emulsion-templated highly porous (polyHIPE) materials as well as its application to in vitro 3D cell culture is presented. A heterobifunctional linker that consists of an amine-reactive N-hydroxysuccinimide ester and a photoactivatable nitrophenyl azide, N-sulfosuccinimidyl-6-(4'-azido-2'-nitrophenylamino)hexanoate (sulfo-SANPAH), is utilized to functionalize polyHIPE surfaces. The ability to conjugate a range of compounds (6-aminofluorescein, heptafluorobutylamine, poly(ethylene glycol) bis-amine, and fibronectin) to the polyHIPE surface is demonstrated using fluorescence imaging, FTIR spectroscopy, and X-ray photoelectron spectroscopy. Compared to other existing surface functionalization methods for polyHIPE materials, this approach is facile, efficient, versatile, and benign. It can also be used to attach biomolecules to polyHIPE surfaces including cell adhesion-promoting extracellular matrix proteins. Cell culture experiments demonstrated that the fibronectin-conjugated polyHIPE scaffolds improve the adhesion and function of primary human endometrial stromal cells. It is believed that this approach can be employed to produce the next generation of polyHIPE scaffolds with tailored surface functionality, enhancing their application in 3D cell culture and tissue engineering whilst broadening the scope of applications to a wider range of cell types.

The Transcriptome of Human Endometrial Mesenchymal Stem Cells Under TGFβR Inhibition Reveals Improved Potential for Cell-Based Therapies

Mesenchymal stem/stromal cells (MSCs) are multipotent cells with favorable properties for cell therapies and regenerative medicine. Human endometrium harbors a small population of perivascular, clonogenic MSCs (eMSCs) identified by the SUSD2 marker. As for other MSCs, eMSCs require extensive in vitro expansion to generate clinically relevant numbers of cells, resulting in spontaneous differentiation, replicative senescence and cell death, decreasing therapeutic potency. We previously demonstrated that A83-01, a TGF-β receptor inhibitor, maintained eMSC clonogenicity, promoted proliferation, prevented apoptosis and maintained MSC function in vitro. Here we compare the transcriptome of passaged eMSCs from six women cultured with and without A83-01 for 7 days. We identified 1206 differentially expressed genes (DEG) using a false discovery rate cut-off at 0.01 and fold change >2. Significant enrichment of genes involved in anti-inflammatory responses, angiogenesis, cell migration and proliferation, and collagen fibril and extracellular matrix organization were revealed. TGF-β, Wnt and Akt signaling pathways were decreased. Anti-fibrotic and anti-apoptotic genes were induced, and fibroblast proliferation and myofibroblast related genes were downregulated. We found increased MSC potency genes (TWIST1, TWIST2, JAG1, LIFR, and SLIT2) validating the enhanced potency of A83-01-treated eMSCs, and importantly no pluripotency gene expression. We also identified eMSCs’ potential for secreting exosomes, possibly explaining their paracrine properties. Angiogenic and cytokine protein arrays confirmed the angiogenic, anti-fibrotic and immunomodulatory phenotype of A83-01-treated eMSCs, and increased angiogenic activity was functionally demonstrated in vitro. eMSCs culture expanded with A83-01 have enhanced clinically relevant properties, suggesting their potential for cell-therapies and regenerative medicine applications.

Crosstalk between SOX2 and cytokine signaling in endometrial carcinoma

Endometrial carcinoma is a cancer derived from oncogenesis of the regenerating uterine cavity, in which cytokine stimulation shapes cell differentiation and tissue remodeling. Expression of the stem cell factors SOX2, OCT4, NANOG, and MYC has been linked to tumor malignancy in several cancers. However, how these stem cell factors crosstalk with cytokine signaling to promote malignancy in endometrial carcinoma is still elusive. Here we report that the expression of SOX2 and MYC, but not that of OCT4 and NANOG, correlate with poor histological differentiation and prognosis, while SOX2 expression is negatively associated with MYC level. We found that SOX2-high endometrial carcinoma cells possessed a higher colony-forming ability than their SOX2-low counterparts, and knockdown of SOX2 attenuated the colony-forming ability. We observed that SOX2 regulated EGFR expression in a SOX2–EGFR positive feedback loop. EGF stimulation induced SOX2 expression and promoted migration of endometrial carcinoma cells, whereas TGF-β stimulation inhibited SOX2 expression and attenuated the colony-forming ability. Immunohistochemistry analysis revealed that SOX2 expression correlated with lymph node infiltration of endometrial carcinoma. Our findings support that cytokine-induced stem cell factor SOX2 possesses oncogenic properties, with the potential to serve as a prognostic biomarker in endometrial carcinoma.

Extracellular matrix deposited by Wharton's jelly mesenchymal stem cells enhances cell expansion and tissue specific lineage potential

This article aims to explore whether Wharton's jelly (WJ) derived mesenchymal stem cells (MSCs) (WJ-MSCs) decellularized extracellular matrix (dECM) can rejuvenate MSCs during in vitro expansion. Passage 10 synovium-derived mesenchymal stem cells (SDSCs) and WJ-MSCs were expanded on plastic flasks (PL) or dECMs derived from SDSCs and WJ-MSCs. Flow cytometry was applied to evaluate surface phenotypes and proliferation capacity. Early (7 days) and late (21 days) chondrogenic potentials were assessed using histology, immunohistochemistry, and real-time polymerase chain reaction (PCR). Western blot analysis was applied to evaluate the potential involvement of MAPK and Wnts signals during the proliferation and chondrogenic processes. Cells were further evaluated for their osteogenic potential using alkaline phosphatase staining and RT-PCR and adipogenic potential using oil red O staining and RT-PCR. Compared to PL expanded cells, dECMs yielded expanded cells with better proliferation capacity as well as decreased percentage of HLA-DR positive SDSCs. Meanwhile, a decrease in CD105 median fluorescence intensity of WJ-MSCs groups were observed compared to the corresponding SDSCs groups. Moreover, both SDSCs and WJ-MSCs acquired better chondrogenic potential after dECM treatment, as evidenced by increased pellet sizes and increased expression of chondrogenic marker genes. WJ-MSCs dECM was inferior to SDSCs dECM in enhancing early stage chondrogenic differentiation, which was compensated during late stage chondrogenesis, despite causing an increased type X collagen accumulation. p-JNK and p-38 were implicated in the expansion and late chondrogenic differentiation stages, respectively. However, dECM preconditioning did not enhance either osteogenic or adipogenic potential of SDSCs and WJ-MSCs. WJ-MSCs dECM is superior to SDSCs dECM on enhancing proliferation, lowering immunogenicity and promoting late stage chondrogenesis.