Human menstrual blood-derived stromal/stem cells modulate functional features of natural killer cells

Potential mechanisms and therapeutic strategies for LPS-associated female fertility decline

As a major component of the outer membrane of Gram-negative bacteria, lipopolysaccharide (LPS) can be recognized by toll-like receptors (TLRs) and induce inflammation through MyD88 or the TIR domain-containing adapter-inducing interferon-β (TRIF) pathway. Previous studies have found that LPS-associated inflammatory/immune challenges were associated with ovarian dysfunction and reduced female fertility. However, the etiology and pathogenesis of female fertility decline associated with LPS are currently complex and multifaceted. In this review, PubMed was used to search for references on LPS and fertility decline so as to elucidate the potential mechanisms of LPS-associated female fertility decline and summarize therapeutic strategies that may improve LPS-associated fertility decline.

In-utero transfer of decidualized endometrial stromal cells increases the frequency of regulatory T cells and normalizes the abortion rate in the CBA/J × DBA/2 abortion model

Introduction

Failure to adequate decidualization leads to adverse pregnancy outcomes including pregnancy loss. Although there are plenty of reports underscoring immune dysfunction as the main cause of abortion in CBA/J females mated with DBA/2 males (CBA/J × DBA/2), little is known about the potential role of impaired endometrial decidualization.

Methods

Endometrial stromal cells (ESCs) from CBA/J mice were in-vitro decidualized, and the proteome profile of the secretome was investigated by membrane-based array. CBA/J mice were perfused In-utero with either decidualized ESCs (C×D/D), undecidualized ESCs (C×D/ND), or PBS (C×D/P) 12 days before mating with DBA/2 males. Control mice were not manipulated and were mated with male DBA/2 (C×D) or Balb/c (C×B) mice. On day 13.5 of pregnancy, reproductive parameters were measured. In-vivo tracking of EdU-labeled ESCs was performed using fluorescence microscopy. The frequency of regulatory T cells (Tregs) in paraaortic/renal and inguinal lymph nodes was measured by flow cytometry. The proliferation of pregnant CBA/J splenocytes in response to stimulation with DBA/2 splenocytes was assessed by 5,6-carboxyfluorescein diacetate succinimidyl ester (CFSE) flow cytometry.

Results

In C×D/D mice, the resorption rate was reduced to match that seen in the C×B group. Intrauterine perfused ESCs appeared in uterine stroma after 2 days, which remained there for at least 12 days. There was no difference in the number of implantation sites and embryo weight across all groups. The frequency of Tregs in the inguinal lymph nodes was similar across all groups, but it increased in the paraaortic/renal lymph nodes of C×D/D mice to the level found in C×B mice. No significant changes were observed in the proliferation of splenocytes from pregnant C×D/D compared to those of the C×D group in response to stimulation with DBA/2 splenocytes. Decidualization of ESCs was associated with a profound alteration in ESC secretome exemplified by alteration in proteins involved in extracellular matrix (ECM) remodeling, response to inflammation, senescence, and immune cell trafficking.

Discussion

Our results showed that the deficiency of Tregs is not the primary driver of abortion in the CBA/J × DBA/2 model and provided evidence that impaired endometrial decidualization probably triggers endometrial immune dysfunction and abortion in this model.

Potential for and challenges of menstrual blood as a non-invasive diagnostic specimen: current status and future directions

Menstrual blood, which is often discarded as a waste product, has emerged as a valuable source of health information. The components of menstrual blood, such as endometrial cells, immune cells, proteins, and microbial signatures, provide insights into health. Studies have shown encouraging results for using menstrual blood to diagnose a variety of conditions, including hormonal imbalances, cervical cancer, endometriosis, chlamydia, diabetes, and other endocrine disorders. This review examines the potential of menstrual blood as a non-invasive diagnostic specimen, exploring its composition, promising applications, and recent advances. This review also discusses challenges to utilizing menstrual blood testing, including ethical considerations, the lack of standardized collection protocols, extensive validation studies, and the societal stigma around menstruation. Overcoming these challenges will open new avenues for personalized medicine and revolutionize healthcare for individuals who menstruate.

The therapeutic potential of exosomes in immunotherapy

Exosomes are found in various tissues of the body and carry abundant contents including nucleic acids, proteins, and metabolites, which continuously flow between cells of various tissues and mediate important intercellular communication. In addition, exosomes from different cellular sources possess different physiopathological immunomodulatory effects, which are closely related to the immune regeneration of normal or abnormal organs and tissues. Here, we focus on the mechanistic interactions between exosomes and the human immune system, introduce the immuno-regenerative therapeutic potential of exosomes in common clinical immune-related diseases, such as infectious diseases, autoimmune diseases, and tumors, and reveal the safety and efficacy of exosomes as a novel cell-free immune regenerative therapy.

Immunomodulatory effects of extracellular vesicles from mesenchymal stromal cells: Implication for therapeutic approach in autoimmune diseases

Autoimmune disease is characterized by the proliferation of harmful immune cells, inducing tissue inflammation and ultimately causing organ damage. Current treatments often lack specificity, necessitating high doses, prolonged usage, and high recurrence rates. Therefore, the identification of innovative and safe therapeutic strategies is urgently required. Recent preclinical studies and clinical trials on inflammatory and autoimmune diseases have evidenced the immunosuppressive properties of mesenchymal stromal cells (MSCs). Studies have demonstrated that extracellular vesicles (EV) derived from MSCs can mitigate abnormal autoinflammation while maintaining safety within the diseased microenvironment. This study conducted a systematic review to elucidate the crucial role of MSC-EVs in alleviating autoimmune diseases, particularly focusing on their impact on the underlying mechanisms of autoimmune conditions such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and inflammatory bowel disease (IBD). By specifically examining the regulatory functions of microRNAs (miRNAs) derived from MSC-EVs, the comprehensive study aimed to enhance the understanding related to disease mechanisms and identify potential diagnostic markers and therapeutic targets for these diseases.

Mesenchymal Stromal Cell-Based Products: Challenges and Clinical Therapeutic Options

Mesenchymal stromal cell (MSC)-based advanced therapy medicinal products (ATMPs) are being tried in a vast range of clinical applications. These cells can be isolated from different donor tissues by using several methods, or they can even be derived from induced pluripotent stem cells or embryonic stem cells. However, ATMP heterogeneity may impact product identity and potency, and, consequently, clinical trial outcomes. In this review, we discuss these topics and the need to establish minimal criteria regarding the manufacturing of MSCs so that these innovative therapeutics may be better positioned to contribute to the advancement of regenerative medicine.

Placenta: an old organ with new functions

The transition from oviparity to viviparity and the establishment of feto-maternal communications introduced the placenta as the major anatomical site to provide nutrients, gases, and hormones to the developing fetus. The placenta has endocrine functions, orchestrates maternal adaptations to pregnancy at different periods of pregnancy, and acts as a selective barrier to minimize exposure of developing fetus to xenobiotics, pathogens, and parasites. Despite the fact that this ancient organ is central for establishment of a normal pregnancy in eutherians, the placenta remains one of the least studied organs. The first step of pregnancy, embryo implantation, is finely regulated by the trophoectoderm, the precursor of all trophoblast cells. There is a bidirectional communication between placenta and endometrium leading to decidualization, a critical step for maintenance of pregnancy. There are three-direction interactions between the placenta, maternal immune cells, and the endometrium for adaptation of endometrial immune system to the allogeneic fetus. While 65% of all systemically expressed human proteins have been found in the placenta tissues, it expresses numerous placenta-specific proteins, whose expression are dramatically changed in gestational diseases and could serve as biomarkers for early detection of gestational diseases. Surprisingly, placentation and carcinogenesis exhibit numerous shared features in metabolism and cell behavior, proteins and molecular signatures, signaling pathways, and tissue microenvironment, which proposes the concept of "cancer as ectopic trophoblastic cells". By extensive researches in this novel field, a handful of cancer biomarkers has been discovered. This review paper, which has been inspired in part by our extensive experiences during the past couple of years, highlights new aspects of placental functions with emphasis on its immunomodulatory role in establishment of a successful pregnancy and on a potential link between placentation and carcinogenesis.

Interleukin-37 contributes to endometrial regenerative cell-mediated immunotherapeutic effect on chronic allograft vasculopathy

BACKGROUND AIMS

Chronic allograft vasculopathy (CAV) remains a predominant contributor to late allograft failure after organ transplantation. Several factors have already been shown to facilitate the progression of CAV, and there is still an urgent need for effective and specific therapeutic approaches to inhibit CAV. Human mesenchymal-like endometrial regenerative cells (ERCs) are free from the deficiencies of traditional invasive acquisition methods and possess many advantages. Nevertheless, the exact immunomodulation mechanism of ERCs remains to be elucidated.

METHODS

C57BL/6 (B6) mouse recipients receiving BALB/c mouse donor abdominal aorta transplantation were treated with ERCs, negative control (NC)-ERCs and interleukin (IL)-37-/-ERCs (ERCs with IL-37 ablation), respectively. Pathologic lesions and inflammatory cell infiltration in the grafts, splenic immune cell populations, circulating donor-specific antibody levels and cytokine profiles were analyzed on postoperative day (POD) 40. The proliferative capacities of Th1, Th17 and Treg subpopulations were assessed in vitro.

RESULTS

Allografts from untreated recipients developed typical pathology features of CAV, namely endothelial thickening, on POD 40. Compared with untreated and IL-37-/-ERC-treated groups, IL-37-secreting ERCs (ERCs and NC-ERCs) significantly reduced vascular stenosis, the intimal hyperplasia and collagen deposition. IL-37-secreting ERCs significantly inhibited the proliferation of CD4+T cells, reduced the proportions of Th1 and Th17 cells, but increased the proportion of Tregs in vitro. Furthermore, in vitro results also showed that IL-37-secreting ERCs significantly inhibited Th1 and Th17 cell responses, abolished B-cell activation, diminished donor-specific antibody production and increased Treg proportions. Notably, IL-37-secreting ERCs remarkably downregulated the levels of pro-inflammatory cytokines (interferon-γ, tumor necrosis factor-α, IL-1β, IL-6 and IL-17A) and increased IL-10 levels in transplant recipients.

CONCLUSIONS

The knockdown of IL-37 dramatically abrogates the therapeutic ability of ERCs for CAV. Thus, this study highlights that IL-37 is indispensable for ERC-mediated immunomodulation for CAV and improves the long-term allograft acceptance.

The effects of propolis-loaded chitosan nanoparticles and menstrual blood stem cells on LPS-induced ovarian inflammation in the murine ovary in vivo: An in vitro and in vivo study

Mammary glands infection via Gram-negative bacteria may cause infertility or reduced ovarian function. In the current study, a potential treatment for LPS-induced ovarian inflammation was developed. Propolis was loaded into chitosan nanoparticles and co-administered with menstrual blood stem cells (MenSCs) in mice infused with LPS. Various properties of propolis-loaded chitosan nanoparticles were evaluated using scanning electron microscopy, drug release assay, antibacterial assay, and radical scavenging assay. In vitro studies showed biocompatibility, anti-oxidative, and antibacterial properties of the developed propolis nanoformulation. In vivo study showed that mice treated with co-administration of propolis-loaded chitosan nanoparticles and MenSCs significantly increased the total ovarian follicle reserve in mice infused with LPS. Percentage of mature follicles in co-administration method was around 13.89 ± 1.72 %. Gene expression studies showed that the expression levels of inflammation related cytokines including IL6, IL8, IL-1β, and TNF-α were downregulated in this group compared with other groups. However, the expression levels of PTEN, AKT, FOXO3 did not show a significant difference between groups. The developed treatment may potentially considered as an approach for treating ovarian infection with gram-negative bacteria.

Body fluid-derived stem cells - an untapped stem cell source in genitourinary regeneration

Somatic stem cells have been obtained from solid organs and tissues, including the bone marrow, placenta, corneal stroma, periosteum, adipose tissue, dental pulp and skeletal muscle. These solid tissue-derived stem cells are often used for tissue repair, disease modelling and new drug development. In the past two decades, stem cells have also been identified in various body fluids, including urine, peripheral blood, umbilical cord blood, amniotic fluid, synovial fluid, breastmilk and menstrual blood. These body fluid-derived stem cells (BFSCs) have stemness properties comparable to those of other adult stem cells and, similarly to tissue-derived stem cells, show cell surface markers, multi-differentiation potential and immunomodulatory effects. However, BFSCs are more easily accessible through non-invasive or minimally invasive approaches than solid tissue-derived stem cells and can be isolated without enzymatic tissue digestion. Additionally, BFSCs have shown good versatility in repairing genitourinary abnormalities in preclinical models through direct differentiation or paracrine mechanisms such as pro-angiogenic, anti-apoptotic, antifibrotic, anti-oxidant and anti-inflammatory effects. However, optimization of protocols is needed to improve the efficacy and safety of BFSC therapy before therapeutic translation.

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

BACKGROUND

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

METHOD

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

RESULTS

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

CONCLUSION

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

TRIAL REGISTRATION

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

The developing role of extracellular vesicles in autoimmune diseases: special attention to mesenchymal stem cell-derived extracellular vesicles

Autoimmune diseases are complex, chronic inflammatory conditions initiated by the loss of immunological tolerance to self-antigens. Nowadays, there is no effective and useful therapy for autoimmune diseases, and the existing medications have some limitations due to their nonspecific targets and side effects. During the last few decades, it has been established that mesenchymal stem cells (MSCs) have immunomodulatory functions. It is proposed that MSCs can exert an important therapeutic effect on autoimmune disorders. In parallel with these findings, several investigations have shown that MSCs alleviate autoimmune diseases. Intriguingly, the results of studies have demonstrated that the effective roles of MSCs in autoimmune diseases do not depend on direct intercellular communication but on their ability to release a wide spectrum of paracrine mediators such as growth factors, cytokines and extracellular vehicles (EVs). EVs that range from 50 to 5,000 nm were produced by almost any cell type, and these nanoparticles participate in homeostasis and intercellular communication via the transfer of a broad range of biomolecules such as modulatory proteins, nucleic acids (DNA and RNA), lipids, cytokines, and metabolites. EVs derived from MSCs display the exact properties of MSCs and can be safer and more beneficial than their parent cells. In this review, we will discuss the features of MSCs and their EVs, EVs biogenesis, and their cargos, and then we will highlight the existing discoveries on the impacts of EVs from MSCs on autoimmune diseases such as multiple sclerosis, arthritis rheumatic, inflammatory bowel disease, Type 1 diabetes mellitus, systemic lupus erythematosus, autoimmune liver diseases, Sjögren syndrome, and osteoarthritis, suggesting a potential alternative for autoimmune conditions therapy.

Higher Improvement of Cardiac Function Following Myocardial Infarction using Menstrual Blood Stromal/Stem Cells (MenSCs) Suspended in Conditioned Medium versus Conditioned Medium Alone in Rat Model

Background

To evaluate the efficiency of Menstrual blood Stromal/Stem Cells (MenSCs) administration in Myocardial Infarction (MI), the effects of MenSCs and their derived conditioned Medium (CM) on cardiac function in MI rat model was assessed.

Methods

Animals were divided into four groups including sham group, MI group, MenSCs derived CM group (CM group), and MenSCs suspended in CM (MenSCs+CM) group. The injection of different groups was carried out 30 min after ligation of left anterior descending coronary artery into the infarct border zone.

Results

The results showed a significant reduction in scar size after injection of MenSCs+CM compared to MI group. Ejection fraction and fractional shortening of MenSCs+CM group were higher than CM and MI group at day 28. Administration of MenSCs+CM led to much more survival of cardiomyocytes, and prevention of meta-plastic development. Moreover, human mitochondrial transfer from MenSCs to cardiomyocytes was seen in group treated by MenSCs+CM. Indeed, MenSCs+CM treatment evoked nuclear factor-κB (NF-κB) down-regulation more than other treatments.

Conclusion

MenSCs+CM treatment could significantly ameliorate cardiac function by different mechanisms including inhibition of cartilaginous metaplasia, inhibition of NF-κB and mitochondrial transfer.

Application of Menstrual Blood Derived Stromal (stem) Cells Exert Greater Regenerative Potency Than Fibroblasts/Keratinocytes in Chronic Wounds of Diabetic Mice

Background

In this study we differentially showed the effects of cell-seeded bilayer scaffold wound dressing in accelerating healing process in diabetic ulcers that still remains as a major clinical challenge. The aim of the study was to compare immunomodulatory and angiogenic activity, and regenerative effect differences between Menstrual blood-derived Stem Cells (MenSCs) and foreskin-derived keratinocytes/fibroblasts.

Methods

The streptozotocin-induced diabetic mice model was developed in male C57/BL6 mice. A bilayer scaffold was fabricated by electrospining silk fibroin nano-fibers on human Amniotic Membrane (AM). Dermal fibroblasts and keratinocyte isolated from neonatal foreskin and MenSCs were isolated from the menstrual blood of healthy women. The diabetic mice were randomly divided into three groups including no treatment group, fibroblast/keratinocyte-seeded bilayer scaffold group (bSC+FK), and MenSCs-seeded bilayer scaffold group. The healing of full-thickness excisional wounds evaluations in the diabetic mice model in each group were evaluated at 3, 7, and 14 days after treatment.

Results

The gross and histological data sets significantly showed wound healing promotion via re-epithelialization and wound contraction along with enhanced regeneration in MenSCs-seeded bilayer scaffold group with the most similarity to adjacent intact tissue. Immunofluorescence staining of mouse skin depicted a descending trend of type III collagen along with the higher expression of involucrin as keratinocyte marker in the MenSCs-seeded bilayer nanofibrous scaffold group in comparison with other treatment groups from day 7 to day 14. Moreover, higher levels of CD31 and von Willebrand factor (VWF), and also a higher ratio of M2/M1 macrophages in association with higher levels of the neural marker were observed in the bSC+MenSCs group in comparison with bSC+FK and no treatment groups.

Conclusion

Healing symptoms in wounds dressed with keratinocyte/fibroblast-seeded bilayer scaffold was significantly lower than MenSCs-seeded bilayer scaffold done on impaired diabetic wound chronicity.

Biogenesis, Composition and Potential Therapeutic Applications of Mesenchymal Stem Cells Derived Exosomes in Various Diseases

Exosomes are nanovesicles with a wide range of chemical compositions used in many different applications. Mesenchymal stem cell-derived exosomes (MSCs-EXOs) are spherical vesicles that have been shown to mediate tissue regeneration in a variety of diseases, including neurological, autoimmune and inflammatory, cancer, ischemic heart disease, lung injury, and liver fibrosis. They can modulate the immune response by interacting with immune effector cells due to the presence of anti-inflammatory compounds and are involved in intercellular communication through various types of cargo. MSCs-EXOs exhibit cytokine storm-mitigating properties in response to COVID-19. This review discussed the potential function of MSCs-EXOs in a variety of diseases including neurological, notably epileptic encephalopathy and Parkinson's disease, cancer, angiogenesis, autoimmune and inflammatory diseases. We provided an overview of exosome biogenesis and factors that regulate exosome biogenesis. Additionally, we highlight the functions and potential use of MSCs-EXOs in the treatment of the inflammatory disease COVID-19. Finally, we covered a strategies and challenges of MSCs-EXOs. Finally, we discuss conclusion and future perspectives of MSCs-EXOs.

Aberrant epigenetic regulation of estrogen and progesterone signaling at the level of endometrial/endometriotic tissue in the pathomechanism of endometriosis

Endometriosis is a term referring to a condition whereby the endometrial tissue is found outside the uterine cavity. This progressive and debilitating condition affects up to 15% of women of reproductive age. Due to the fact that endometriosis cells may express estrogen receptors (ERα, Erβ, GPER) and progesterone (P4) receptors (PR-A, PR-B), their growth, cyclic proliferation, and breakdown are similar to the processes occurring in the endometrium. The underlying etiology and pathogenesis of endometriosis are still not fully explained. The retrograde transport of viable menstrual endometrial cells with the retained ability to attach within the pelvic cavity, proliferate, differentiate and invade into the surrounding tissue explains the most widely accepted implantation theory. Endometrial stromal cells (EnSCs) with clonogenic potential constitute the most abundant population of cells within endometrium that resemble the properties of mesenchymal stem cells (MSCs). Accordingly, formation of the endometriotic foci in endometriosis may be due to a kind of EnSCs dysfunction. Increasing evidence indicates the underestimated role of epigenetic mechanisms in the pathogenesis of endometriosis. Hormone-mediated epigenetic modifications of the genome in EnSCs or even MSCs were attributed an important role in the etiopathogenesis of endometriosis. The roles of excess estrogen exposure and P4 resistance were also found to be crucial in the development of epigenetic homeostasis failure. Therefore, the aim of this review was to consolidate the current knowledge regarding the epigenetic background of EnSCs and MSCs and the changed properties due to estrogen/P4 imbalances in the context of the etiopathogenesis of endometriosis.

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

BACKGROUND

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

AIM OF THE STUDY

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

METHODS

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

RESULTS

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

CONCLUSION

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

Greater angiogenic and immunoregulatory potency of bFGF and 5-aza-2'-deoxycytidine pre-treated menstrual blood stem cells in compare to bone marrow stem cells in rat model of myocardial infarction

BACKGROUND

This study is designed to compare the menstrual blood stem cells (MenSCs) and bone marrow stem cells (BMSCs)-secreted factors with or without pre-treatment regimen using basic fibroblast growth factor (bFGF) and 5-aza-2'-deoxycytidine (5-aza) and also regenerative capacity of pre-treated MenSCs and/or BMSCs in a rat model of myocardial infarction (MI).

METHODS

BMSCs and MenSCs were pre-treated with bFGF and 5-aza for 48 h and we compared the paracrine activity by western blotting. Furthermore, MI model was created and the animals were divided into sham, MI, pre-treated BMSCs, and pre-treated MenSCs groups. The stem cells were administrated via tail vain. 35 days post-MI, serum and tissue were harvested for further investigations.

RESULTS

Following pre-treatment, vascular endothelium growth factor, hypoxia-inducible factor-1, stromal cell-derived factor-1, and hepatocyte growth factor were significantly increased in secretome of MenSCs in compared to BMSCs. Moreover, systemic administration of pre-treated MenSCs, leaded to improvement of cardiac function, preservation of myocardium from further subsequent injuries, promotion the angiogenesis, and reduction the level of NF-κB expression in compared to the pre-treated BMSCs. Also, pre-treated MenSCs administration significantly decreased the serum level of Interleukin 1 beta (IL-1β) in compared to the pre-treated BMSCs and MI groups.

CONCLUSIONS

bFGF and 5-aza pre-treated MenSCs offer superior cardioprotection compare to bFGF and 5-aza pre-treated BMSCs following MI.

Immunization with placenta-specific 1 (plac1) induces potent anti-tumor responses and prolongs survival in a mouse model of melanoma

PURPOSE

Melanoma is a malignant and metastatic form of skin cancer, which is not diagnosed in early stages of the disease. Nowadays, immunotherapy is changing the treatment landscape for metastatic melanoma. Placenta-specific1 (PLAC1) is a cancer-testis-placenta (CTP) antigen with differential expression in melanoma tissues. Here, we evaluated the potential of plac1 to induce anti-cancer immune responses as well as to prevent cancer development in a mouse model of melanoma.

METHODS

Two proteins containing full extracellular domain (ED) of mouse plac1+KDEL3 and full ED of mouse plac1+ tetanus toxin P2 and P30+ pan DR epitope (PADRE) ​+ ​KDEL3 were produced and injected in mice to evaluate their capacity to induce anti-cancer immune responses as well as their potential to prevent melanoma development. Induction of plac1-specific humoral and cellular responses as well as tumor-associated parameters were tested in a series of 36 mice.

RESULTS

Sera of mice immunized with ED ​+ ​P2P30+PADRE ​+ ​KDEL3 contained antibodies able to react with surface plac1 in B16F10 ​cells. Both proteins induced proliferative cellular immune responses against B16F10 ​cells and plac1-specific cytotoxic T cells (CTL) and CD107a ​+ ​CTL responses, which was higher in mice immunized with ED ​+ ​P2P30+PADRE ​+ ​KDEL3. Splenocytes of mice vaccinated with ED ​+ ​P2P30+PADRE ​+ ​KDEL3 exerted a significant cytotoxicity against B16F10 ​cells. Vaccination with ED ​+ ​P2P30+PADRE ​+ ​KDEL3 significantly delayed B16F10-induced tumor onset, reduced tumor growth, and increased survival. Tumors induced by B16F10 expressed plac1 in vivo.

CONCLUSION

Our results pave the way for development of effective melanoma preventive vaccine in humans, although further studies are needed.

Stromal cells of the endometrium and decidua: in search of a name and an identity

Human endometrial and decidual stromal cells are the same cells in different environments (non-pregnancy and pregnancy, respectively). Although some authors consider decidual stromal cells to arise solely from the differentiation of endometrial stromal cells, this is a debatable issue given that decidualization processes do not end with the formation of the decidua, as shown by the presence of stromal cells from both the endometrium and decidua in both undifferentiated (non-decidualized) and decidualized states. Furthermore, recent functional and transcriptomic results have shown that there are differences in the decidualization process of endometrial and decidual stromal cells, with the latter having a greater decidualization capacity than the former. These differences suggest that in the terminology and study of their characteristics, endometrial and decidual stromal cells should be clearly distinguished, as should their undifferentiated or decidualized status. There is, however, considerable confusion in the designation and identification of uterine stromal cells. This confusion may impede a judicious understanding of the functional processes in normal and pathological situations. In the present article we analyse the different terms used in the literature for different types of uterine stromal cells, and propose that a combination of differentiation status (undifferentiated, decidualized) and localization (endometrium, decidua) criteria should be used to arrive at a set of accurate, unambiguous terms. The cell identity of uterine stromal cells is also a debatable issue: phenotypic, functional and transcriptomic studies in recent decades have related these cells to different established cells. We discuss the relevance of these associations in normal and pathological situations.

Therapeutic role of mesenchymal stem cell-derived exosomes in respiratory disease

Exosomes are extracellular vesicles found in various tissues, blood circulation, and tissue fluids, secreted into the extracellular environment by fusing a multivesicular body with a plasma membrane. Various cell types release these vesicles to contribute to many cellular functions, including intercellular communication, cell proliferation, differentiation, angiogenesis, response to stress, and immune system signaling. These natural nanoparticles have therapeutic effects in various diseases and exhibit a behavior similar to the cell from which they originated. In the meantime, exosomes derived from mesenchymal stem cells have attracted the attention of many researchers and physicians due to their unique ability to modulate the immune system, repair tissue and reduce inflammation. Numerous clinical and preclinical studies have examined the effect of MSC-derived exosomes in various diseases, and their results have been published in prestigious journals. This review article discusses the biogenesis and sources of exosomes, MSC-derived exosomes, the use of these exosomes in regenerative medicine, and treatments based on exosomes derived from stem cells in respiratory diseases.

Safety and efficacy study of allogeneic human menstrual blood stromal cells secretome to treat severe COVID-19 patients: clinical trial phase I & II

BACKGROUND

Cell-free Mesenchymal stromal cells (MSCs) have been considered due to their capacity to modulate the immune system and suppress cytokine storms caused by SARS-CoV-2. This prospective randomized double-blind placebo-controlled clinical trial aimed to assess the safety and efficacy of secretome derived from allogeneic menstrual blood stromal cells (MenSCs) as a treatment in patients with severe COVID-19.

METHODS

Patients with severe COVID-19 were randomized (1:1) to either MenSC-derived secretome treatment or the control group. Subjects received five intravenous infusions of 5 mL secretome or the same volume of placebo for five days and were monitored for safety and efficacy for 28 days after treatment. Adverse events, laboratory parameters, duration of hospitalization, clinical symptom improvement, dynamic of O₂ saturation, lymphocyte number, and serial chest imaging were analyzed.

RESULTS

All safety endpoints were observed without adverse events after 72 h of secretome injection. Within 28 days after enrollment, 7 patients (50%) were intubated in the treated group versus 12 patients (80%) in the control group. Overall, 64% of patients had improved oxygen levels within 5 days of starting treatment (P < 0.0001) and there was a survival rate of 57% in the treatment group compared to 28% in the control group was (P < 0.0001). Laboratory values revealed that significant acute phase reactants declined, with mean C-reactive protein, ferritin, and D-dimer reduction of 77% (P < 0.001), 43% (P < 0.001), and 42% (P < 0.05), respectively. Significant improvement in lymphopenia was associated with an increase in mean CD4⁺ and CD8⁺ lymphocyte counts of 20% (P = 0.06) and 15% (P < 0.05), respectively. Following treatment, percentage of pulmonary involvement showed a significant improvement in the secretome group (P < 0.0001). This improvement differed significantly between survivors and those who were dying (P < 0.005).

CONCLUSIONS

For the first time, this study demonstrated that in hospitalized patients with severe COVID-19, therapy with MenSCs-derived secretome leads to reversal of hypoxia, immune reconstitution, and downregulation of cytokine storm, with no adverse effects attributable to the treatment. Given these outcomes, it may be possible to use this type of treatment for serious inflammatory lung disease with a mechanism similar to COVID-19 in the future. However, it is necessary to evaluate the safety and efficacy of MenSCs-derived secretome therapy in clinical trials on a larger population of patients.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05019287. Registered 24AGUEST 2021, retrospectively registered, https://clinicaltrials.gov/ct2/show/record/NCT05019287 . IRCT, IRCT20180619040147N6. Registered 04/01/2021.

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

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

Role of Natural Killer Cells during Pregnancy and Related Complications

A high number of leucocytes reside in the human endometrium and are distributed differentially during the menstrual cycle and pregnancy. During early pregnancy, decidual natural killer (dNK) cells are the most common type of natural killer (NK) cells in the uterus. The increase in the number of uterine NK (uNK) cells during the mid-secretory phase of the menstrual cycle, followed by further increase of dNK cells in early pregnancy, has heightened interest in their involvement during pregnancy. Extensive research has revealed various roles of dNK cells during pregnancy including the formation of new blood vessels, migration of trophoblasts, and immunological tolerance. The present review article is focused on the significance of NK cells during pregnancy and their role in pregnancy-related diseases. The article will provide an in-depth review of cellular and molecular interactions during pregnancy and related disorders, with NK cells playing a pivotal role. Moreover, this study will help researchers to understand the physiology of normal pregnancy and related complications with respect to NK cells, so that future research work can be designed to alleviate the complications.

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.

The remarkable effect of menstrual blood stem cells seeded on bilayer scaffold composed of amniotic membrane and silk fibroin aiming to promote wound healing in diabetic mice

INTRODUCTION

Impaired chronic wound healing frequently occurs in diabetic patients. We hypothesized that menstrual blood-derived mesenchymal stem cells (MenSCs) in combination with bilayer scaffold consisted of human amniotic membrane (AM) and electrospun silk fibroin nanofibers could potentially promote wound healing in diabetic mice.

METHODS & METHODS

Two bilateral full-thickness wounds were created on dorsal skin of type-1 diabetic mice model and animals were equally divided in four groups including: no-treatment group (NT), amniotic membrane treated group (AM), bilayer scaffold treated group (bSC), and MenSCs-seeded bilayer scaffold treated group (bSC + MenSCs). Wound healing evaluations were performed at 3, 7, and 14 days after their treatment. The wound healing was analyzed by macroscopic and microscopic evaluations, and immunofluorescence staining of involucrin (IVL), type III collagen, CD31/ von Willebrand factor (vWF), and PGP9.5 were performed. Furthermore, number of neutrophils and macrophages and subpopulation of macrophages were assessed. In addition, the expression of Egr2, Mmp9, CXCL12, IDO1, Ptgs2 and VEGFA transcripts involved in wound repair were also analyzed.

RESULTS

After 14 days, the best epidermal and dermal regeneration belonged to the cases received bSC + MenSCs as wound dressing. Moreover, the wound healing was typically faster in this group compared to other groups. Immunofluorescence evaluation represented higher levels of CD31 and VWF, higher ratio of M2/M1 macrophages, greater expression of IVL, and higher levels of the PGP9.5 in the bSC + MenSCs group in comparison with other groups. Expression analysis of assessed genes also supported assumption of more regeneration and healing in the bSC + MenSCs group versus other groups.

CONCLUSION

These results indicate that enhanced immunomodulatory and reparative properties of MenSCs in conjunction with bilayer scaffold specified this cellular skin substitute for modulating wound chronicity and contribution to resolution of wound healing process in diabetic ulcer.

2, 3, 7, 8-Tetrachlorodibenzo-p-dioxin potential impacts on peripheral blood mononuclear cells of endometriosis women

Endometriosis happens following the implantation of endometrial-derived tissues outside the uterine cavity. It has been suggested that 2, 3, 7, 8-Tetrachlorodibenzo-p-dioxin (TCDD) is involved in endometriosis development. Furthermore, aryl hydrocarbon receptor (AHR), as a TCDD receptor, has been demonstrated to regulate immune responses. Nonetheless, data regarding the mechanisms, through which TCDD influences the immune system in endometriosis, are still inconclusive. Therefore, frequency of regulatory T cells (Tregs) and the expression of FOXP3, AHR and indoleamine 2, 3-dioxygenase 1 (IDO1) from endometriosis and non-endometriosis individuals were investigated in the absence and presence of TCDD; also, the concentration of IL-6 and kynurenine in the supernatant of cultures was assessed. The impact of TCDD-treated PBMCs on the migration capacity of menstrual blood-derived stromal stem cells (MenSCs) and monocyte chemoattractant protein-1 (MCP-1) and IL-6 production was determined. Here, we found that AHR and IDO1 expression levels were lower in endometriosis PBMCs; however, TCDD treatment increased AHR, FOXP3, IDO1, IL-6, and Treg levels in the endometriosis group (P ≤ 0.05-0.0001). TCDD-treated PBMCs increased the migration capacity of MenSCs and up-regulated MCP-1 and IL-6 levels in the PBMCs/MenSCs co-culture (P ≤ 0.01-0.0001). In conclusion, these results shed light on the probable mechanisms, through which AHR activation by chemical toxicants can impact inflammatory immune mediators involved in the development of endometriosis; also, these data support the idea that TCDD could promote endometriosis progression.

Effects of Mesenchymal Stem Cell-Derived Exosomes on Autoimmune Diseases

Recent years, the immunosuppressive properties of mesenchymal stem cells (MSCs) have been demonstrated in preclinical studies and trials of inflammatory and autoimmune diseases. Emerging evidence indicates that the immunomodulatory effect of MSCs is primarily attributed to the paracrine pathway. As one of the key paracrine effectors, mesenchymal stem cell-derived exosomes (MSC-EXOs) are small vesicles 30-200 nm in diameter that play an important role in cell-to-cell communication by carrying bioactive substances from parental cells. Recent studies support the finding that MSC-EXOs have an obvious inhibitory effect toward different effector cells involved in the innate and adaptive immune response. Moreover, substantial progress has been made in the treatment of autoimmune diseases, including multiple sclerosis (MS), systemic lupus erythematosus (SLE), type-1 diabetes (T1DM), uveitis, rheumatoid arthritis (RA), and inflammatory bowel disease (IBD). MSC-EXOs are capable of reproducing MSC function and overcoming the limitations of traditional cell therapy. Therefore, using MSC-EXOs instead of MSCs to treat autoimmune diseases appears to be a promising cell-free treatment strategy. In this review, we review the current understanding of MSC-EXOs and discuss the regulatory role of MSC-EXOs on immune cells and its potential application in autoimmune diseases.

Endometrial mesenchymal stem/stromal cells: The Enigma to code messages for generation of functionally active regulatory T cells

Background

Regulatory T cells (Tregs) play an important role in fine-tuning of immune responses and are pivotal for a successful pregnancy. Recently, the importance of mesenchymal stem cells in regulation of immune responses in general and Tregs in particular has been highlighted. Here, we hypothesized that menstrual stromal/stem cells (MenSCs) contribute to uterine immune system regulation through induction of functionally active Tregs.

Methods

MenSCs were collected from 18 apparently healthy women and characterized. Bone marrow mesenchymal stem cells (BMSCs) served as a control. The effect of MenSCs on proliferation of anti-CD3/CD28-stimulated T CD4 + cells and generation of Tregs with or without pre-treatment with mitomycin C, IFN-γ and IL-1β was evaluated by flow cytometry. The potential role of IDO, PGE2, IL-6, IL-10, and TGF-β on proliferation of T CD4 + cells and generation of Tregs was assessed using blocking antibodies or agents. IDO activity was evaluated in MenSCs and BMSCs culture supernatants by a colorimetric assay. IL-10 and IFN-γ production in MenSCs-primed T CD4 + was measured using intracellular staining. To investigate the functional properties of Tregs induced by MenSCs, Treg cells were isolated and their functional property to inhibit proliferation of anti-CD3/CD28-stimulated PBMCs was assessed by flow cytometry.

Results

According to the results, proliferation of T CD4 + lymphocytes was enhanced in the presence of MenSCs, while pre-treatment of MenSCs with pro-inflammatory cytokines reversed this effect. PGE2 and IDO were the major players in MenSCs-induced T cell proliferation. Non-treated MenSCs decreased the frequency of Tregs, whereas after pre-treatment with IFN-γ and IL-1β, they induced functional Tregs with ability to inhibit the proliferation of anti-CD3/CD28-stimulated PBMCs. This effect was mediated through IL-6, IL-10, TGF-β and IDO. IFN-γ/IL-1β-treated MenSCs induced IL-10 and IFN-γ production in CD4 + T cells.

Conclusion

Collectively, these findings indicate that immunomodulatory impact of menstrual blood stem cells (MenSCs) on generation of Tregs and inhibition of T cells proliferation is largely dependent on pre-treatment with IFN-γ and IL-1β. This is the first report on immunomodulatory impact of MenSCs on Tregs and highlights the pivotal role of endometrial stem cells in regulation of local endometrial immune responses.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02603-3.

Role of Transforming Growth Factor-β1 in Regulating Fetal-Maternal Immune Tolerance in Normal and Pathological Pregnancy

Transforming growth factor-β (TGF-β) is composed of three isoforms, TGF-β1, TGF-β2, and TGF-β3. TGF-β1 is a cytokine with multiple biological functions that has been studied extensively. It plays an important role in regulating the differentiation of immune cells and maintaining immune cell functions and immune homeostasis. Pregnancy is a carefully regulated process. Controlled invasion of trophoblasts, precise coordination of immune cells and cytokines, and crosstalk between trophoblasts and immune cells play vital roles in the establishment and maintenance of normal pregnancy. In this systematic review, we summarize the role of TGF-β1 in regulating fetal-maternal immune tolerance in healthy and pathological pregnancies. During healthy pregnancy, TGF-β1 induces the production of regulatory T cells (Tregs), maintains the immunosuppressive function of Tregs, mediates the balance of M1/M2 macrophages, and regulates the function of NK cells, thus participating in maintaining fetal-maternal immune tolerance. In addition, some studies have shown that TGF-β1 is dysregulated in patients with recurrent spontaneous abortion or preeclampsia. TGF-β1 may play a role in the occurrence and development of these diseases and may be a potential target for the treatment of these diseases.

Cyclical endometrial repair and regeneration

Uniquely among adult tissues, the human endometrium undergoes cyclical shedding, scar-free repair and regeneration during a woman's reproductive life. Therefore, it presents an outstanding model for study of such processes. This Review examines what is known of endometrial repair and regeneration following menstruation and parturition, including comparisons with wound repair and the influence of menstrual fluid components. We also discuss the contribution of endometrial stem/progenitor cells to endometrial regeneration, including the importance of the stem cell niche and stem cell-derived extracellular vesicles. Finally, we comment on the value of endometrial epithelial organoids to extend our understanding of endometrial development and regeneration, as well as therapeutic applications.

Estrogen- and Progesterone (P4)-Mediated Epigenetic Modifications of Endometrial Stromal Cells (EnSCs) and/or Mesenchymal Stem/Stromal Cells (MSCs) in the Etiopathogenesis of Endometriosis

Endometriosis is a common chronic inflammatory condition in which endometrial tissue appears outside the uterine cavity. Because ectopic endometriosis cells express both estrogen and progesterone (P4) receptors, they grow and undergo cyclic proliferation and breakdown similar to the endometrium. This debilitating gynecological disease affects up to 15% of reproductive aged women. Despite many years of research, the etiopathogenesis of endometrial lesions remains unclear. Retrograde transport of the viable menstrual endometrial cells with retained ability for attachment within the pelvic cavity, proliferation, differentiation and subsequent invasion into the surrounding tissue constitutes the rationale for widely accepted implantation theory. Accordingly, the most abundant cells in the endometrium are endometrial stromal cells (EnSCs). These cells constitute a particular population with clonogenic activity that resembles properties of mesenchymal stem/stromal cells (MSCs). Thus, a significant role of stem cell-based dysfunction in formation of the initial endometrial lesions is suspected. There is increasing evidence that the role of epigenetic mechanisms and processes in endometriosis have been underestimated. The importance of excess estrogen exposure and P4 resistance in epigenetic homeostasis failure in the endometrial/endometriotic tissue are crucial. Epigenetic alterations regarding transcription factors of estrogen and P4 signaling pathways in MSCs are robust in endometriotic tissue. Thus, perspectives for the future may include MSCs and EnSCs as the targets of epigenetic therapies in the prevention and treatment of endometriosis. Here, we reviewed the current known changes in the epigenetic background of EnSCs and MSCs due to estrogen/P4 imbalances in the context of etiopathogenesis of endometriosis. Graphical Abstract.

Intrinsic Angiogenic Potential and Migration Capacity of Human Mesenchymal Stromal Cells Derived from Menstrual Blood and Bone Marrow

Several therapies are being developed to increase blood circulation in ischemic tissues. Despite bone marrow-derived mesenchymal stromal cells (bmMSC) are still the most studied, an interesting and less invasive MSC source is the menstrual blood, which has shown great angiogenic capabilities. Therefore, the aim of this study was to evaluate the angiogenic properties of menstrual blood-derived mesenchymal stromal cells (mbMSC) in vitro and in vivo and compared to bmMSC. MSC’s intrinsic angiogenic capacity was assessed by sprouting and migration assays. mbMSC presented higher invasion and longer sprouts in 3D culture. Additionally, both MSC-spheroids showed cells expressing CD31. mbMSC and bmMSC were able to migrate after scratch wound in vitro, nonetheless, only mbMSC demonstrated ability to engraft in the chick embryo, migrating to perivascular, perineural, and chondrogenic regions. In order to study the paracrine effects, mbMSC and bmMSC conditioned mediums were capable of stimulating HUVEC’s tube-like formation and migration. Both cells expressed VEGF-A and FGF2. Meanwhile, PDGF-B was expressed exclusively in mbMSC. Our results indicated that mbMSC and bmMSC presented a promising angiogenic potential. However, mbMSC seems to have additional advantages since it can be obtained by non-invasive procedure and expresses PDGF-B, an important molecule for vascular formation and remodeling.

MenSCs exert a supportive role in establishing a pregnancy-friendly microenvironment by inhibiting TH17 polarization

OBJECTIVES

Uncontrolled TH17 differentiation has been suggested to play a role in the pathogenesis of pregnancy loss. We recently showed that menstrual blood stromal/stem cells (MenSCs) alter functional features of natural killer cells. Here, we hypothesized that MenSCs could modulate differentiation of TH17 cells.

METHOD

MenSCs were collected from 18 apparently healthy women and characterized. Bone marrow mesenchymal stem cells (BMSCs) served as a control. TH17 polarization and proliferation of purified T CD4+ cells were assessed by flow cytometry in a well-defined co-culture system containing T CD4+ cells and MenSCs or BMSCs. Indoleamine 2,3-Dioxygenase (IDO) activity was evaluated in MenSC and BMSC culture supernatants by a colorimetric assay. The impact of MenSCs on expression of transcription factors, RORC, T-bet, Gata3, NRP-1 and Helios were studied by qPCR.

RESULTS

MenSCs significantly inhibited TH17 differentiation (p = 0.0383) and percentage of the cells co-expressing IL-17 and IFN-γ (p = 0.0023). PGE2 blockade significantly reduced percentage and proliferation of T CD4+IL-17+ (p = 0.003, p = 0.0018), T CD4+ IFN-γ+ (p = 0.002, p = 0.0022) and T CD4+IL-17+ IFN-γ+ (p = 0.004, p = 0.02) cells. MenSCs produced a considerable activity of IDO (p = 0.0002), induced a significant rise in the Treg frequency (p = 0.0091) and a sharp increase in TH17/Tregs ratio (p = 0.0022). MenSCs increased expression of NRP1 (p = 0.001), while downregulated expression of RORC in T cells (p = 0.001).

CONCLUSION

Our results suggest a supportive role for MenSCs in establishing a pregnancy-friendly microenvironment in the uterus and put forth the idea that inherent abnormalities of MenSCs may be a basis for dysregulated endometrial immune network leading to pregnancy loss.

Natural killer cells in recurrent miscarriage: An overview

Recurrent Miscarriage is an early pregnancy complication which affects about 1-3 % of child-bearing couples. The mechanisms involved in the occurrence of recurrent miscarriages are not clearly understood. In the last decade Natural Killer cells have been studied in peripheral blood and uterus in order to determine if there are specific characteristics of Natural Killer cells associated with miscarriage. Different authors have described an increased number of uterine and peripheral blood Natural Killer cells in women with recurrent miscarriages compared to control women. However, its relationship with miscarriage has not been confirmed. In patients with recurrent miscarriage a lack of inhibition of decidua Natural Killer cells can be observed, which leads to a more activated state characterized by higher levels of proinflammatory cytokines. In peripheral blood, it has been also reported a dysfunctional cytokine production by Natural Killer cells, with an increase of interferon-γ levels and a decrease of Interleukin-4. Significant progress has been made in the last decade in understanding the biology of Natural Killer cells, including the identification of new receptors that also contribute to the activation and regulation of Natural Killer cells. In this review, we summarize the current progress in the study of Natural Killer cells in recurrent miscarriage.

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.

Menstrual blood-derived stem cells: toward therapeutic mechanisms, novel strategies, and future perspectives in the treatment of diseases

Menstrual blood-derived stem cells (MenSCs) have great potential in the treatment of various diseases. As a novel type of mesenchymal stem cells (MSCs), MenSCs have attracted more interest due to their therapeutic effects in both animal models and clinical trials. Here, we described the differentiation, immunomodulation, paracrine, homing, and engraftment mechanisms of MenSCs. These include differentiation into targeting cells, immunomodulation with various immune cells, the paracrine effect on secreting cytokines, and homing and engraftment into injured sites. To better conduct MenSC-based therapy, some novel hotspots were proposed such as CRISPR (clustered regularly interspaced short palindromic repeats)/cas9-mediated gene modification, exosomes for cell-free therapy, single-cell RNA sequence for precision medicine, engineered MenSC-based therapy for the delivery platform, and stem cell niches for improving microenvironment. Subsequently, current challenges were elaborated on, with regard to age of donor, dose of MenSCs, transplantation route, and monitoring time. The management of clinical research with respect to MenSC-based therapy in diseases will become more normative and strict. Thus, a more comprehensive horizon should be considered that includes a combination of traditional solutions and novel strategies. In summary, MenSC-based treatment has a great potential in treating diseases through diverse strategies, and more therapeutic mechanisms and novel strategies need to be elucidated for future regenerative medicine and clinical applications.