Clinical consequences of defective decidualization

MCM6 Inhibits Decidualization via Cross-Talking with ERK Pathway in Human Endometrial Stromal Cells

Decidualization plays an important role in the implantation of the embryo, but the molecular action implicated in this process is not completely known. Herein, we found that, compared with the proliferative endometrial tissues, the expression of minichromosome maintenance complex component 6 (MCM6) was markedly decreased in the secretory endometrial tissues. To verify the function of MCM6 in decidualization, in vitro decidualization model was constructed by treating human endometrial stromal cells (HESCs) with estrogen (E2) and progesterone (P4). Consistently, MCM6 level was downregulated in E2P4-treated HESCs. Administration of E2P4 accumulated HESCs in G1 cell cycle phase, leading to cell growth suppression. Ectopic expression of MCM6 promoted the transition of G1/S and restored the proliferation of HESCs that were inhibited by E2P4. MCM6 overexpression led to aberrant activation of extracellular signal-regulated kinase (ERK) and treatment with ERK agonist Ro 67-7476 restored MCM6 expression and cell proliferation inhibited by E2P4. Our data suggested that MCM6/ERK feedback loop plays a negative role in E2P4-induced decidualization and implies that MCM6 may be a promising target for meliorating uterine receptivity.

The Impacts of Inflammatory and Autoimmune Conditions on the Endometrium and Reproductive Outcomes

Background: A healthy pregnancy begins with an adequate endometrial state, even before the arrival of a blastocyst. Proper endometrial priming and the development of a tolerogenic decidua are key steps in creating the perfect environment for implantation and pregnancy. In these processes, the involvement of the maternal immune system seems to be of great relevance, modulating the different decidual immune populations to prepare the endometrium for a potential pregnancy. However, certain local pathologies of an inflammatory and autoimmune nature appear to have a direct impact on these phenomena, thus altering patients' reproductive outcomes. Methods: This literature review analyzes original articles, reviews, systematic reviews, and meta-analyses published between 1990 and 2024, concerning the impact of different inflammatory and autoimmune conditions on endometrial status and fertility. The included papers were obtained from Medline (Pubmed) and the Cochrane library. Results: There is evidence that endometriosis, adenomyosis, and chronic endometritis, through the promotion of a chronic inflammatory environment, are capable of altering endometrial immune populations, and, thus, processes essential for early pregnancy. Among other effects, these conditions have been linked to impaired decidualization, alterations in progesterone responsiveness, and hindered placentation. Similarly, antiphospholipid syndrome (APS), thyroid dysfunction, diabetes, and other pathologies related to glucose and gluten metabolism, due to their autoimmune nature, also appear to have a local impact on the uterine environment, affecting reproductive success through different mechanisms, including altered hormonal response and, again, impaired decidualization. Conclusions: The management of inflammatory and autoimmune diseases in assisted reproduction patients is gaining importance due to their direct impact on the endometrium. It is necessary to follow current expert recommendations and established therapeutic approaches in order to improve patients' prospects, ranging from antibiotic treatment in chronic endometritis to heparin and aspirin in APS, as well as hormonal treatments for endometriosis/adenomyosis or a gluten-free diet in celiac disease. All of them and the rest of the therapeutic perspectives, both current and under investigation, are presented throughout this work, assessing the possible improvements for reproductive outcomes.

Demystifying the landscape of endometrial immune microenvironment in luteal-phase from cuprotosis: Implications for the mechanism and treatment of RPL

BACKGROUND

Adaptive changes in the endometrial immune microenvironment during the luteal phase are essential for pregnancy, and their abnormalities are associated with recurrent pregnancy loss (RPL). Nevertheless, the specific mechanism is still unknown. Cuprotosis, an innovatively discovered type of programmed cell death, provides us with a pioneering perspective to decipher the landscape of luteal-phase endometrial immune microenvironment in RPL. This study aimed to analyze the immune landscape of luteal-phase endometrial microenvironment in RPL and explore the association of cuprotosis with it through integrative bioinformatics analysis.

METHODS

The microarrays involving the luteal phase endometrial tissue of RPL were obtained from the GEO database. Differentially expressed genes (DEGs) of RPL were screened and key modules were detected by WGCNA. GO, KEGG, and GSEA immune enrichment analyses were performed on the DEGs in the most relevant modules to RPL. Then, the endometrial immune microenvironment landscape of RPL was analyzed, including immune infiltration analysis and correlation analysis between immune cells or immune functions. The interaction of cuprotosis-related genes (CRGs), the expression level between groups, the immune localization and their correlation with immune cells and immune function were analyzed. LASSO regression and Nomogram evaluated the diagnostic value of immune-related CRGS in RPL. Functional enrichment analysis was performed on the RPL signature CRGs. And RPL samples were grouped according to the expression of 7 RPL signature CRGs through unsupervised clustering analysis. After that, we analyzed the expression level of CRGs and immune infiltration, as well as performed immune function enrichment analysis in subtypes. In addition, we also screened potential drugs that might act on CRGs to improve the pathological mechanism of RPL.

RESULTS

In this study, we uncovered that DEGs and genes in key modules derived from weighted gene co-expression network analysis (WGCNA) were involved in immune regulation. And the immune infiltration landscape of RPL was significantly different from healthy controls. Furthermore, six hub genes were screened from CRGs based on Cytohubba, and their expression profilings were verified in RPL and normal mouse samples. Besides, seven CRGs closely associated with the immune regulation of RPL were identified by Spearman correlation analysis, including SLC31A1, LIAS, DLD, DLAT, DBT, ATP7B, and ATP7A, named as immune-related CRGs. Furthermore, three subgroups clustered according to these seven genes showed significant differences in immune landscape, suggesting a remarkable effect of CRGs on immune regulation. Last but not least, we analyzed the regulation network of transcription factors, miRNAs, and CRGs, and screened potential compounds for the treatment of RPL by targeting CRGs.

CONCLUSIONS

The abnormal endometrial immune microenvironment in the luteal phase was associated with the pathomechanism of RPL, and cuprotosis was closely involved in the immune microenvironment in the luteal phase endometrium of RPL. Collectively, this study revealed the potential contribution of CRGs to the pathogenesis of RPL, providing a novel breakthroughs in insights into the pathogenesis, diagnosis, and treatment of RPL.

Differential gene expression in decidualized human endometrial stromal cells induced by different stimuli

Decidualization can be induced by culturing human endometrial stromal cells (ESCs) with several decidualization stimuli, such as cAMP, medroxyprogesterone acetate (MPA) or Estradiol (E2). However, it has been unclear how decidualized cells induced by different stimuli are different. We compared transcriptomes and cellular functions of decidualized ESCs induced by different stimuli (MPA, E2 + MPA, cAMP, and cAMP + MPA). We also investigated which decidualization stimulus induces a closer in vivo decidualization. Differentially expressed genes (DEGs) and altered cellular functions by each decidualization stimuli were identified by RNA-sequence and gene-ontology analysis. DEGs was about two times higher for stimuli that use cAMP (cAMP and cAMP + MPA) than for stimuli that did not use cAMP (MPA and E2 + MPA). cAMP-using stimuli altered the cellular functions including angiogenesis, inflammation, immune system, and embryo implantation whereas MPA-using stimuli (MPA, E2 + MPA, and cAMP + MPA) altered the cellular functions associated with insulin signaling. A public single-cell RNA-sequence data of the human endometrium was utilized to analyze in vivo decidualization. The altered cellular functions by in vivo decidualization were close to those observed by cAMP + MPA-induced decidualization. In conclusion, decidualized cells induced by different stimuli have different transcriptome and cellular functions. cAMP + MPA may induce a decidualization most closely to in vivo decidualization.

Establishment of Murine Pregnancy Requires the Promyelocytic Leukemia Zinc Finger Transcription Factor

Using an established human primary cell culture model, we previously demonstrated that the promyelocytic leukemia zinc finger (PLZF) transcription factor is a direct target of the progesterone receptor (PGR) and is essential for progestin-dependent decidualization of human endometrial stromal cells (HESCs). These in vitro findings were supported by immunohistochemical analysis of human endometrial tissue biopsies, which showed that the strongest immunoreactivity for endometrial PLZF is detected during the progesterone (P4)-dominant secretory phase of the menstrual cycle. While these human studies provided critical clinical support for the important role of PLZF in P4-dependent HESC decidualization, functional validation in vivo was not possible due to the absence of suitable animal models. To address this deficiency, we recently generated a conditional knockout mouse model in which PLZF is ablated in PGR-positive cells of the mouse (Plzf d/d). The Plzf d/d female was phenotypically analyzed using immunoblotting, real-time PCR, and immunohistochemistry. Reproductive function was tested using the timed natural pregnancy model as well as the artificial decidual response assay. Even though ovarian activity is not affected, female Plzf d/d mice exhibit an infertility phenotype due to an inability of the embryo to implant into the Plzf d/d endometrium. Initial cellular and molecular phenotyping investigations reveal that the Plzf d/d endometrium is unable to develop a transient receptive state, which is reflected at the molecular level by a blunted response to P4 exposure with a concomitant unopposed response to 17-β estradiol. In addition to a defect in P4-dependent receptivity, the Plzf d/d endometrium fails to undergo decidualization in response to an artificial decidual stimulus, providing the in vivo validation for our earlier HESC culture findings. Collectively, our new Plzf d/d mouse model underscores the physiological importance of the PLZF transcription factor not only in endometrial stromal cell decidualization but also uterine receptivity, two uterine cellular processes that are indispensable for the establishment of pregnancy.

A Potential Role of CD82/KAI1 during Uterine Decidualization in Mice

The tumor metastasis suppressor gene CD82/KAI1 has been demonstrated to impact human trophoblast invasion and migration. Communication between trophoblasts and decidual stromal cells plays a crucial role in controlling the normal invasiveness of trophoblasts. However, whether CD82/KAI1 is involved in decidualization and what role it plays remain unclear. CD82/KAI1 demonstrates specific spatiotemporal expression patterns in stromal cells undergoing decidualization during pregnancy. This is observed in both naturally pregnant females post-implantation and pseudopregnant mice undergoing induced decidualization, as detected through in situ hybridization and immunofluorescence. CD82/KAI1 expression showed a significant time-dependent increase in cultured stromal cells after 24 and 48 h of progesterone (P4) and estrogen (E2) treatment. This was accompanied by a notable upregulation of decidualization markers, including cyclin D3 and PR. After transducing stromal cells with the adenovirus-overexpressing CD82/KAI1 for 48 h, the expression of cyclin D3 protein increased. Meanwhile, there was an attenuated expression of CD82/KAI1 due to an adenovirus siRNA knockdown, whereas cyclin D3 and PR expressions were not affected. Our findings suggest a potential role of CD82/KAI1 in regulating the process of decidualization, providing insights into stromal cell differentiation.

Antibiotic cured chronic endometritis remains a risk factor for early pregnancy loss in the subsequent frozen euploid embryo transfer

RESEARCH QUESTION

Do patients with antibiotic-cured chronic endometritis (CCE) have a comparable pregnancy outcome to those with non-chronic endometritis (NCE) in the subsequent frozen embryo transfer (FET) cycle?

DESIGN

A retrospective cohort analysis included 833 patients in their first FET cycles with single euploid embryo transfer. Chronic endometritis (≥5 CD138+ plasma cells per high-power field [CD138+/HPF]) was treated with standard antibiotic therapy. Patients were classified into two groups: the NCE group (n = 611, <5 CD138+/HPF) and the CCE group (n = 222, ≥5 CD138+/HPF and cured after antibiotic treatment). Pregnancy outcomes were compared. NCE group was divided into subgroup 1 (CD138+/HPF = 0) and subgroup 2 (CD138+/HPF = 1-4) for further analysis.

RESULTS

The rate of early pregnancy loss (EPL), incorporating all losses before 10 weeks' gestation, was significantly higher in the CCE group than the NCE group (21.2% versus 14.2%, P = 0.016), and the difference was statistically significant (adjusted odds ratio [AOR] 1.68, 95% confidence interval [CI] 1.11-2.55). No significant differences were observed between the two groups with regard to other pregnancy outcomes. In the subgroup analysis, the EPL rate and biochemical pregnancy rate were significantly higher in subgroup 2 than subgroup 1 (17.2% versus 9.4%, AOR 2.21, 95% CI 1.30-3.74; 12.2% versus 6.9%, AOR 2.01, 95% CI 1.09-3.68).

CONCLUSIONS

Chronic endometritis cured by standard antibiotic therapy remains a risk factor for EPL in FET cycles, although no differences were found in live birth rates between patients with CCE or with NCE.

USP7 promotes decidualization of ESCs by STAT3/PR axis during early pregnancy

Decidualization is an essential process for embryo implantation during early pregnancy. Defective decidualization is a critical leading cause of early pregnancy loss (EPL). Ubiquitin-specific protease 7 (USP7) is a deubiquitinating enzyme that is involved in uterine function. This study aimed to explore the underlying mechanism by which USP7 regulates decidualization in EPL. We found that USP7 was downregulated in the decidual tissue of EPL patients. Upregulation of USP7 enhanced decidualization in endometrial stromal cells (ESCs), with increased decidualized biomarkers IGFBP1 and PRL and progesterone receptor A/B (PR-A/B) expression. Moreover, we found that signal transducer and activator of transcription 3 (STAT3) is a direct target of USP7 in ESCs. USP7 bound to STAT3 by deubiquitination and increased STAT3 levels in ESCs. Suppression of STAT3 impeded the USP7-promoted cell viability, decidualization, and PR-A/B expression of ESCs. USP7 promoted the decidualization of ESCs through the STAT3/PR signaling pathway during early pregnancy, which provides new insight into the pathological mechanism of EPL and may contribute to the clinical treatment of EPL.

High incidence of decidualization failure in infertile women

Purpose

Decidualization is an important event for embryo implantation and successful pregnancy. Impaired decidualization leads to implantation failure and miscarriage. However, it is unclear how often decidualization failure occurs in infertile women. By analyzing the endometrium at late-secretory phase, we investigated the incidence and pathogenesis of decidualization failure among infertile women.

Methods

Endometrial dating was performed on the endometria obtained in the late-secretory phase from 33 infertile women. Endometrial dating of more than 2 days delay was taken as an indication of decidualization failure. The expression of essential transcription factors for decidualization (FOXO1, WT1, and C/EBPβ) was examined by immunohistochemistry.

Results

Among 32 cases, 20 cases (62.5%) showed decidualization failure. These patients tended to have a history of more frequent miscarriages than those without decidualization failure. The percentage of cells that immunostained positive for the expression of three transcription factors was significantly lower in the patients with decidualization failure than in those without decidualization failure. Serum progesterone levels measured in the mid- and late-secretory phase were not significantly different between the cases with and without decidualization failure.

Conclusions

The incidence of decidualization failure is high in infertile women.

The Pathological Role of miRNAs in Endometriosis

Association studies investigating miRNA in relation to diseases have consistently shown significant alterations in miRNA expression, particularly within inflammatory pathways, where they regulate inflammatory cytokines, transcription factors (such as NF-κB, STAT3, HIF1α), and inflammatory proteins (including COX-2 and iNOS). Given that endometriosis (EMS) is characterized as an inflammatory disease, albeit one influenced by estrogen levels, it is natural to speculate about the connection between EMS and miRNA. Recent research has indeed confirmed alterations in the expression levels of numerous microRNAs (miRNAs) in both endometriotic lesions and the eutopic endometrium of women with EMS, when compared to healthy controls. The undeniable association of miRNAs with EMS hints at the emergence of a new era in the study of miRNA in the context of EMS. This article reviews the advancements made in understanding the pathological role of miRNA in EMS and its association with EMS-associated infertility. These findings contribute to the ongoing pursuit of developing miRNA-based therapeutics and diagnostic markers for EMS.

Before Is Better: Innovative Multidisciplinary Preconception Care in Different Clinical Contexts

CONTEXT

Implementation of pre-conception care units is still very limited in Italy. Nowadays, the population's awareness of the reproductive risks that can be reduced or prevented is very low. Purpose and main findings: We presented a new personalized multidisciplinary model of preconception care aimed at identifying and possibly reducing adverse reproductive events. We analyzed three cohorts of population: couples from the general population, infertile or subfertile couples, and couples with a previous history of adverse reproductive events. The proposal involves a deep investigation regarding family history, the personal histories of both partners, and reproductive history.

PRINCIPAL CONCLUSIONS

Preconception care is still neglected in Italy and under-evaluated by clinicians involved in natural or in vitro reproduction. Adequate preconception counseling will improve maternal and fetal obstetrical outcomes.

Exploring the presence of markers of decidualization in the fallopian tubes: a systematic review

The fallopian tubes (FTs) are part of the female upper genital tract. The healthy FT provides the biological environment for successful fertilization and facilitates the subsequent movement of the conceptus to the endometrial cavity. However, when the FT is damaged, as with salpingitis, pyosalpinx, and hydrosalpinx, it may increase the risk of an ectopic pregnancy, a life-threatening condition. Decidualization refers to a multifactorial process by which the endometrium changes to permit blastocyst implantation. The decidualization reaction is vital for endometrial receptivity during the window of implantation. To date, no comprehensive review that collates evidence on decidualization in the human FT has been conducted. Therefore, the aim of this review is to compile the current evidence on cellular decidualization occurring in the healthy and pathological FT in women of reproductive age. A literature search was conducted using five databases and identified 746 articles, 24 of which were analyzed based on inclusion and exclusion criteria. The available evidence indicates that the FT are able to undergo decidual changes under specific circumstances; however, the exact mechanism by which this occurs is poorly understood. Further research is needed to elucidate the mechanism by which decidualization can occur in the FT.

Endometrial and placental stem cells in successful and pathological pregnancies

The endometrium is a dynamic tissue that undergoes extensive remodeling during the menstrual cycle and further gets modified during pregnancy. Different kinds of stem cells are reported in the endometrium. These include epithelial stem cells, endometrial mesenchymal stem cells, side population stem cells, and very small embryonic-like stem cells. Stem cells are also reported in the placenta which includes trophoblast stem cells, side population trophoblast stem cells, and placental mesenchymal stem cells. The endometrial and placental stem cells play a pivotal role in endometrial remodeling and placental vasculogenesis during pregnancy. The dysregulation of stem cell function is reported in various pregnancy complications like preeclampsia, fetal growth restriction, and preterm birth. However, the mechanisms by which it does so are yet elusive. Herein, we review the current knowledge of the different type of stem cells involved in pregnancy initiation and also highlight how their improper functionality leads to pathological pregnancy.

Silicon dioxide nanoparticles compromise decidualization via autophagy impairment to possibly cause embryo resorption

The wide application of silicon dioxide nanoparticles (SiO₂NPs) has raised concerns about their harmful effects on reproduction. The purpose of this research was to investigate the toxic effects and the possible mechanisms by which SiO₂NPs affect decidualization and pregnancy progression. We found that SiO₂NPs could inhibit decidualization, both in mice and in human endometrial stromal cells (HESCs). Embryo resorption was also evident in mice treated with SiO₂NPs. When HESCs were treated with SiO₂NPs, decidualization was inhibited and there was an increase in intracellular lysosomes and autophagosomes as well as the blockage of autophagic flux. Interestingly, a reduction of autophagosome accumulation via 3-methyladenine (3MA) significantly restored the decidualization of HESCs. In summary, our results indicate that SiO₂NPs can affect embryo survival by impairing decidualization through a dysfunctional autophagic process.

E2F2 is upregulated by the ERK pathway and regulates decidualization via MCM4

Cell cycle modulation is an important event during decidualization. E2F2 is a transcription regulator that plays a vital role in cell cycle regulation. However, the biological role of E2F2 in decidualization has not yet been identified. In this study, estrogen (E2) and progestin (P4)-induced in vitro and in vivo decidualization models were applied. Our data showed that the expression levels of E2F2 and its downstream target MCM4 were downregulated in the uterus tissues of E2P4-treated mice compared with control mice. In hESCs, exposure to E2P4 resulted in a significant decrease in E2F2 and MCM4 expression. E2P4 treatment reduced hESC proliferation and ectopic expression of E2F2 or MCM4 elevated the viability of E2P4-treated hESCs. In addition, ectopic expression of E2F2 or MCM4 restored the expression of G1 phase-associated proteins. The ERK pathway was inactivated in E2P4-treated hESCs. Treatment with ERK agonist Ro 67-7476 restored the expression of E2F2, MCM4, and G1 phase-associated proteins that were inhibited by E2P4. Moreover, Ro 67-7476 retracted the levels of IGFBP1 and PRL that were induced by E2P4. Collectively, our results indicate that E2F2 is regulated by ERK signaling and contributes to decidualization via regulation of MCM4. Therefore, E2F2/MCM4 cascade may serve as promising targets for alleviating decidualization dysfunction.

Endometrial Microbiota and Immune Tolerance in Pregnancy

Recent studies have demonstrated that the uterus has its own microbiota. However, there is no consensus on endometrial microbiota composition, thus its role in the healthy uterine environment is still a frontier topic. Endometrial receptivity is key to embryo implantation, and in this specific context immunological tolerance against fetal antigens and the tightly regulated expression of inflammatory mediators are fundamental. According to recent evidence, endometrial microbiota may interact in a very dynamic way with the immune system during the peri-conceptional stage and later during pregnancy. For this reason, a condition of dysbiosis might lead to adverse pregnancy outcomes. The aim of this review is to summarize the evidence on the molecular mechanisms by which the endometrial microbiota may interact with the immune system. For this purpose, the link between dysbiosis and reproductive disorders, such as infertility, recurrent pregnancy loss (RPL), and preterm birth, will be discussed. In conclusion, the most recent findings from molecular analyses will be reported to illustrate and possibly overcome the intrinsic limitations of uterine microbiota detection (low endometrial biomass, high risk of contamination during sampling, and lack of standardization).

Antinuclear antibodies positivity in women in reproductive age: From infertility to adverse obstetrical outcomes - A meta-analysis

This systematic review and meta-analysis were designed to identify possible correlations between isolated serum antinuclear antibody (ANA) and (i) infertility in the context of in-vitro fertilization (IVF), (ii) idiopathic recurrent pregnancy losses (RPL), and (iii) second/ third trimester pregnancy complications. We performed a systematic review and meta-analysis of the literature in PubMed Library database from inception to March 2022 following PRISMA guidelines. Our pooled results showed a lower pregnancy rate among ANA-positive women undergoing IVF/ICSI compared to ANA-negative women undergoing the same procedures (279/908 versus 1136/2347, random effect, odds ratio -OR- 0.50, 95% confidence interval -CI- 0.38-0.67, p 0.00001, I² = 58%). We also reported a higher miscarriage rate among ANA-positive compared to ANA-negative women (48/223 versus 109/999, random effect, OR: 3.25 95% CI: 1.57-6.76, p = 0.002, I² = 61%) and a lower implantation rate (320/1489 versus 1437/4205, random effect, OR: 0.51, 95% CI: 0.36-0.72, p = 0.0001, I² = 78%). Regarding RPL, pooled results demonstrated a higher prevalence of ANA-positivity in RPL women compared to controls (698/2947 versus 240/3145, random effect, OR: 3.22, 95% CI: 2.12-4.88, p 0.00001, I² 77%), either using > 2 or > 3 pregnancy losses threshold for defining RPL. Heterogeneity of reporting outcome did not allow a quantitative analysis and led to no clear demonstration of an effect of serum ANA on the incidence of stillbirth, preeclampsia and hypertensive disorders. In conclusion, the unfavorable effect of serum ANA was observed in women following IVF. Similarly, ANA were associated with the risk of RPL, while data were unconclusive in terms of late pregnancy complications.

When Less Is More – Pipelle Endometrial Sampling for Quantification of Uterine Natural Killer Cells in Patients With Recurrent Implantation Failure or Habitual Abortion

Despite recent advancements in reproductive medicine, recurrent implantation failure and habitual abortion remain ongoing issues. One of the most important aspects of successful implantation is the intricate immune response and regulation necessary for the acceptance of the hemiallogenic embryo. The most numerous immune cells in the decidua are uterine natural killer cells (uNK). Studies suggest that changes in the uNK count and physiology may be responsible for the aforementioned pathological conditions. Thus, testing for uNK may provide valuable insights into their pathogenesis. The study compared Pipelle endometrial sampling with conventional curettage to find out whether the less invasive Pipelle method is a viable alternative of tissue collection. Tissue samples from 14 patients obtained by both methods were examined. The average size of tissue samples obtained with Pipelle was 17 mm2, samples obtained with curettage had on average 34 mm2. Using immunohistochemical visualization of CD56 (NK cells) and granzyme B antigens (serine protease-expressing activation state of NK cells), it was found that the average total count of CD56 / mm2 was 115 for Pipelle and 120 for curettage, respectively. The study also proved a correlation between granzyme B positivity and identification of NK cells clusters. The results indicated that Pipelle endometrial sampling seems a suitable method of tissue harvesting for the purpose of uNK cells examination. Pipelle endometrial sampling is safe, cost-effective and can be performed on an outpatient basis without the need of anesthesia or analgesia. Several issues remain yet to be solved: how to standardize the subsequent uNK testing, how to interpret the results and finally yet importantly, how to use this knowledge in personalized treatment protocols.

Alleviation of Severe Skin Insults Following High-Dose Irradiation with Isolated Human Fetal Placental Stromal Cells

Skin exposure to high-dose irradiation, as commonly practiced in radiotherapy, affects the different skin layers, causing dry and wet desquamation, hyperkeratosis fibrosis, hard to heal wounds and alopecia and damaged hair follicles. Fetal tissue mesenchymal stromal cells (f-hPSC) were isolated from excised human fetal placental tissue, based on their direct migration from the tissue samples to the tissue dish. The current study follows earlier reports on for the mitigation of acute radiation syndrome following whole body high-dose exposure with remotely injected f-hPSC. Both the head only and a back skin flap of mice were irradiated with 16 &18 Gy, respectively, by 6MeV clinical linear accelerator electron beam. In both locations, the irradiated skin areas developed early and late radiation induced skin damages, including cutaneous fibrosis, lesions, scaring and severe hair follicle loss and reduced hair pigmentation. Injection of 2 × 106 f-hPSC, 3 and 8 weeks following 16 Gy head irradiation, and 1 and 4 weeks following the 18 Gy back skin only irradiation, resulted in significantly faster healing of radiation induced damages, with reduction of wet desquamation as measured by surface moisture level and minor recovery of the skin viscoelasticity. Detailed histological morphometry showed a clear alleviation of radiation induced hyperkeratosis in f-hPSC treated mice, with significant regain of hair follicles density. Following 16 Gy head irradiation, the hair follicles density in the scalp skin was reduced significantly by almost a half relative to the controls. A nearly full recovery of hair density was found in the f-hPSC treated mice. In the 18 Gy irradiated back skin, the hair follicles density dropped in a late stage by ~70% relative to naïve controls. In irradiated f-hPSC treated mice, it was reduced by only ~30% and was significantly higher than the non-treated group. Our results suggest that local injections of xenogeneic f-hPSC could serve as a simple, safe and highly effective non-autologous pro-regenerative treatment for high-dose radiation induced skin insults. We expect that such treatment could also be applied for other irradiated organs.

Implantation Failure in Endometriosis Patients: Etiopathogenesis

Embryo implantation requires adequate dialogue between a good quality embryo and a receptive endometrium. This implantation is still considered as the black box of reproductive medicine. Endometriosis is a highly prevalent chronic inflammatory disease, concerning about 10% of women of reproductive age and is one of the major causes of female infertility. The mechanisms involved in endometriosis-related infertility, an event not yet completely understood, are multifactorial and include anatomical changes, reduction in ovarian reserve, endocrine abnormalities, genetic profile, immunity markers, inflammatory mediators, or altered endometrial receptivity. In this article, we will focus on the impact of endometriosis on embryo quality and on endometrial receptivity. Results: Poor oocyte and embryo quality seem to promote a lower pregnancy rate, more than the endometrium itself in women with endometriosis. Other studies report the contrary. In addition, hormonal imbalance observed in the endometrium could also alter the embryo implantation. Conclusions: Controversial results in the literature add difficulties to the understanding of the mechanisms that lead to embryo implantation disorders. Furthermore, either oocyte/embryo impairment, altered endometrium, or both may cause impaired implantation. New prospective, randomized, and controlled studies are necessary to determine the origin of the defects that make conception more difficult in the case of endometriosis and adenomyosis.

Endometrial Epithelial ARID1A Is Required for Uterine Immune Homeostasis during Early Pregnancy

A growing body of work suggests epigenetic dysregulation contributes to endometriosis pathophysiology and female infertility. The chromatin remodeling complex subunit AT-rich interaction domain 1A (ARID1A) must be properly expressed to maintain normal uterine function. Endometrial epithelial ARID1A is indispensable for pregnancy establishment in mice through regulation of endometrial gland function; however, ARID1A expression is decreased in infertile women with endometriosis. We hypothesized that ARID1A performs critical operations in the endometrial epithelium necessary for fertility besides maintaining gland function. To identify alterations in uterine gene expression resulting from loss of epithelial ARID1A, we performed RNA-sequencing analysis on pre-implantation uteri from Ltf^iCre/+Arid1a^f/f and control mice. Differential expression analysis identified 4181 differentially expressed genes enriched for immune-related ingenuity canonical pathways including agranulocyte adhesion and diapedesis and natural killer cell signaling. RT-qPCR confirmed an increase in pro-inflammatory cytokine and macrophage-related gene expression but a decrease in natural killer cell signaling. Immunostaining confirmed a uterus-specific increase in macrophage infiltration. Flow cytometry delineated an increase in inflammatory macrophages and a decrease in uterine dendritic cells in Ltf^iCre/+Arid1a^f/f uteri. These findings demonstrate a role for endometrial epithelial ARID1A in suppressing inflammation and maintaining uterine immune homeostasis, which are required for successful pregnancy and gynecological health.

(Dis)similarities between the Decidual and Tumor Microenvironment

Placenta-specific trophoblast and tumor cells exhibit many common characteristics. Trophoblast cells invade maternal tissues while being tolerated by the maternal immune system. Similarly, tumor cells can invade surrounding tissues and escape the immune system. Importantly, both trophoblast and tumor cells are supported by an abetting microenvironment, which influences invasion, angiogenesis, and immune tolerance/evasion, among others. However, in contrast to tumor cells, the metabolic, proliferative, migrative, and invasive states of trophoblast cells are under tight regulatory control. In this review, we provide an overview of similarities and dissimilarities in regulatory processes that drive trophoblast and tumor cell fate, particularly focusing on the role of the abetting microenvironments.

Fetal inflammatory response at the fetomaternal interface: A requirement for labor at term and preterm

Human parturition at term and preterm is an inflammatory process synchronously executed by both fetomaternal tissues to transition them from a quiescent state t an active state of labor to ensure delivery. The initiators of the inflammatory signaling mechanism can be both maternal and fetal. The placental (fetal)-maternal immune and endocrine mediated homeostatic imbalances and inflammation are well reported. However, the fetal inflammatory response (FIR) theories initiated by the fetal membranes (amniochorion) at the choriodecidual interface are not well established. Although immune cell migration, activation, and production of proparturition cytokines to the fetal membranes are reported, cellular level events that can generate a unique set of inflammation are not well discussed. This review discusses derangements to fetal membrane cells (physiologically and pathologically at term and preterm, respectively) in response to both endogenous and exogenous factors to generate inflammatory signals. In addition, the mechanisms of inflammatory signal propagation (fetal signaling of parturition) and how these signals cause immune imbalances at the choriodecidual interface are discussed. In addition to maternal inflammation, this review projects FIR as an additional mediator of inflammatory overload required to promote parturition.