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Cytokines and Chemokines during Human Embryo Implantation: Roles in Implantation and Early Placentation
Abstract
The complex processes of embryo implantation and early placentation require a plethora of locally acting molecules, which are themselves tightly regulated. Among these are cytokines (including chemotactic chemokines), which are synthesized by several cell types at the maternal-fetal interface. Those produced by endometrial epithelium may be secreted apically into the uterine lumen, where they affect blastocyst development, migration, and attachment, or basally with effects on the transformation of the underlying stroma. Decidualized stromal cells, which subsequently form a major component of the decidua of pregnancy, also produce cytokines that act to drive the decidualization process and chemokines that are chemoattractants both for leukocytes such as uterine natural killer cells and macrophages, and for trophoblast migration. Activated leukocytes within the developing decidua also contribute regulatory cytokines to the local microenvironment. Disturbances in the production of individual cytokines have been demonstrated in the endometrium of some infertile women and in those with recurrent miscarriage. It is important to establish whether a signature of endometrial cytokines may provide a clinically useful indication of women who will experience difficulty in establishing a viable pregnancy.
... on Open access IL-11 and monoclonal non-specific suppressor factor-b. 68 Precise modulation of cytokine secretion within the endometrial tissue is imperative for the recruitment of maternal uterine NK cells and macrophages. This recruitment is mediated through chemotactic signals and L-selectin expression, facilitating an orchestrated inflammatory response. ...
... Activated leucocytes recruited to the decidua generate a spectrum of regulatory cytokines, further enriching the pre-existing inflammatory microenvironment therein. 68 Consequently, the procedures of implantation and placentation inherently embody proinflammatory processes, orchestrated by an array of growth factors and proinflammatory cytokines. ...
Background
Synchronised physiological adaptations occur during pregnancy to achieve systemic, immune and neuroendocrine equilibrium in the mother’s body, allowing semiallogenic fetal growth.
Main text
Depending on the cytokine profile alterations occurring through pregnancy, the latter can be divided into three distinct phases. In the first immunological phase of pregnancy, proinflammatory cytokines promote inflammatory reactions needed for implantation. In the second phase, a possible change from proinflammatory to anti-inflammatory cytokines creates a symbiosis between maternal and fetal components, ensuring fetal development. In the third phase, inflammatory and cytolytic cytokines operate again to reinforce an inflammatory environment for parturition. The article offers a detailed account of immune adaptations during pregnancy and highlights the distinctive cytokine profiles that mark each phase.
Conclusion
By providing a simplified depiction of pregnancy phases based on cytokine profiles, the article aims to inspire more research in reproductive immunology and improve the management of pregnancy-related inflammation and infection.
... This activity can be correlated with uterine gland function. Secretions from the uterine gland contain growth factors, hormones, cytokines, and enzymes [26][27][28][29][30][31][32] important in regulating uterine receptivity, blastocyst implantation, and stromal cell decidualization [6,28,33,34] . The endometrial glands also provide histotrophic nutrition to the human conceptus during the initial 10-12 weeks of pregnancy before full establishment of the placenta [6,26,33,35] . ...
... This activity can be correlated with uterine gland function. Secretions from the uterine gland contain growth factors, hormones, cytokines, and enzymes [26][27][28][29][30][31][32] important in regulating uterine receptivity, blastocyst implantation, and stromal cell decidualization [6,28,33,34] . The endometrial glands also provide histotrophic nutrition to the human conceptus during the initial 10-12 weeks of pregnancy before full establishment of the placenta [6,26,33,35] . ...
The endometrium is composed of glandular and luminal epithelia supported by stromal connective tissue and multiple other cell types. It is a dynamic organ that undergoes physiological and functional alteration during the menstrual cycle. Organoids resemble the primary tissue of origin to recapitulate their corresponding biological and pathological characteristics. They are known for their ability to undergo extensive expansion while maintaining their genomic stability, facilitating their long-term storage and high-throughput screening. The development of the three-dimensional endometrial organoid system, which recapitulates the structural and functional characteristics of the endometrial glands, provides a powerful tool to study the normal endometrium and its related diseases. The Web of Science was searched for relevant literature using the keywords "endometrium", "endometrial gland", "organoid", and "culture model"; a total of 134 articles were selected. In this review, the characteristics, applications, and limitations of endometrial epithelial organoids are discussed.
... These assays suggest that MUC1 contributes to intrinsic adhesive properties when present on the human endometrial cell surface. Cytokines are involved in menstruation and implantation processes within the endometrium [37], where cytokine expression reaches a maximum in the midsecretory phase of the menstruation cycle, concurrent with the window of implantation [38]. Interestingly, proinflammatory cytokines TNFα and IFNγ are present within the human endometrium throughout the menstrual cycle. ...
... Interestingly, when IFNγ was used alone or in combination with TNFα, there was an increase in mucin glycosylation in both cell lines, however, when TNFα was used alone there was a decrease in mucin glycosylation. The variation in mucin expression and glycosylation within our models could be linked to the dysregulated cytokine release in infertile patients, suggesting that cytokine interaction with their receptors may indirectly effect blastocyst apposition and adhesion to the endometrium surface [38]. ...
Background
Sialyl-Lewis X/L-selectin high affinity binding interactions between transmembrane O-glycosylated mucins proteins and the embryo have been implicated in implantation processes within the human reproductive system. However, the adhesive properties of these mucins at the endometrial cell surface are difficult to resolve due to known discrepancies between in vivo models and the human reproductive system and a lack of sensitivity in current in vitro models. To overcome these limitations, an in vitro model of the human endometrial epithelial was interrogated with single molecule force spectroscopy (SMFS) to delineate the molecular configurations of mucin proteins that mediate the high affinity L-selectin binding required for human embryo implantation.
Results
This study reveals that MUC1 contributes to both the intrinsic and extrinsic adhesive properties of the HEC-1 cellular surface. High expression of MUC1 on the cell surface led to a significantly increased intrinsic adhesion force (148 pN vs. 271 pN, p < 0.001), whereas this adhesion force was significantly reduced (271 pN vs. 118 pN, p < 0.001) following siRNA mediated MUC1 ablation. Whilst high expression of MUC1 displaying elevated glycosylation led to strong extrinsic (> 400 pN) L-selectin binding at the cell surface, low expression of MUC1 with reduced glycosylation resulted in significantly less (≤200 pN) binding events.
Conclusions
An optimal level of MUC1 together with highly glycosylated decoration of the protein is critical for high affinity L-selectin binding. This study demonstrates that MUC1 contributes to cellular adhesive properties which may function to facilitate trophoblast binding to the endometrial cell surface through the L-selectin/sialyl-Lewis x adhesion system subsequent to implantation.
... It is widely accepted that cytokine networks function in the establishment of endometrial receptivity, suggesting that the immune system plays an important role in embryo-maternal crosstalk [97][98][99][100]. In mice, seminal fluid was demonstrated to affect immune cells to induce endometrial differentiation and promote embryo implantation by activating inflammation and inducing immunological changes in the female reproductive tract, which facilitate endometrial receptivity [101,102]. ...
... It is widely accepted that cytokine networks function in the establishment of endometrial receptivity, suggesting that the immune system plays an important role in embryo-maternal cross-talk [97][98][99][100]. In mice, seminal fluid was demonstrated to affect immune cells to induce endometrial differentiation and promote embryo implantation by activating inflammation and inducing immunological changes in the female reproductive tract, which facilitate endometrial receptivity [101,102]. ...
Embryo implantation in the uterus is an essential process for successful pregnancy in mammals. In general, the endocrine system induces sufficient embryo receptivity in the endometrium, where adhesion-promoting molecules increase and adhesion-inhibitory molecules decrease. Although the precise mechanisms remain unknown, it is widely accepted that maternal–embryo communications, including embryonic signals, improve the receptive ability of the sex steroid hormone-primed endometrium. The embryo may utilize repulsive forces produced by an Eph–ephrin system for its timely attachment to and subsequent invasion through the endometrial epithelial layer. Importantly, the embryonic signals are considered to act on maternal immune cells to induce immune tolerance. They also elicit local inflammation that promotes endometrial differentiation and maternal tissue remodeling during embryo implantation and placentation. Additional clarification of the immune control mechanisms by embryonic signals, such as human chorionic gonadotropin, pre-implantation factor, zona pellucida degradation products, and laeverin, will aid in the further development of immunotherapy to minimize implantation failure in the future.
... As in other species, the LE and GE of the human endometrium have distinct molecular signatures depending on the phase of the menstrual cycle (214). Components of histotroph in the uterine lumen of humans is similar to animals and includes ions, carbohydrates (glucose), amino acids, many different kinds of proteins, lipids, and extracellular vesicles (215)(216)(217)(218)(219)(220)(221)(222)(223)(224)(225)(226). The GE transcriptome, secretome, and metabolome represent a significant gap in our knowledge of uterine gland biology. ...
... The substances in uterine histotroph are presumed to be primarily from the uterine glands and important mediators of uterine receptivity, blastocyst implantation, stromal cell decidualization, and placental growth (155,174,224,228). Deficient glandular activity, usually described as a "secretory phase defect," is hypothesized to be a significant underlying cause of early pregnancy failure in humans (155,270). ...
All mammalian uteri contain glands in the endometrium that develop only or primarily after birth. Gland development or adenogenesis in the postnatal uterus is intrinsically regulated by proliferation, cell-cell interactions, growth factors and their inhibitors as well as transcription factors including forkhead box A2 (FOXA2) and estrogen receptor alpha (ESR1). Extrinsic factors regulating adenogenesis originate from other organs including the ovary, pituitary, and mammary gland. The infertility and recurrent pregnancy loss observed in uterine gland knockout sheep and mouse models support a primary role for secretions and products of the glands in pregnancy success. Recent studies in mice revealed that uterine glandular epithelia govern post-implantation pregnancy establishment through effects on stromal cell decidualization and placental development. In humans, uterine glands and, by inference, their secretions and products are hypothesized to be critical for blastocyst survival and implantation as well as embryo and placental development during the first trimester before the onset of fetal-maternal circulation. A variety of hormones and other factors from the ovary, placenta, and stromal cells impact secretory function of the uterine glands during pregnancy. This review will summarize new information related to the developmental biology of uterine glands and discuss novel perspectives on their functional roles in pregnancy establishment and success.
... Pregnancy is in part orchestrated by the intricate communication and coordination of maternal and fetal immune cells by cytokines and chemokines to establish and maintain the maternal-fetal interface 20 . Cytokines and chemokines play an important role in embryogenesis through the mediation of cell survival, proliferation, differentiation, and promotion of cell adhesion to specific sites to coordinate invasion of fetal trophoblasts into the maternal decidua [21][22][23][24] . Dysregulation in the establishment of a healthy placenta can result in maternal and fetal pathologies such as pre-eclampsia, spontaneous pre-term birth, intra-uterine growth restrictions, and resorption [25][26][27][28][29] . ...
Cannabis sativa has gained popularity as a “natural substance”, leading many to falsely assume that it is not harmful. This assumption has been documented amongst pregnant mothers, many of whom consider Cannabis use during pregnancy as benign. The purpose of this study was to validate a Cannabis smoke exposure model in pregnant rats by determining the plasma levels of cannabinoids and associated metabolites in the dams after exposure to either Cannabis smoke or injected cannabinoids. Maternal and fetal cytokine and chemokine profiles were also assessed after exposure. Pregnant Sprague–Dawley rats were treated daily from gestational day 6–20 with either room air, i.p. vehicle, inhaled high-Δ⁹-tetrahydrocannabinol (THC) (18% THC, 0.1% cannabidiol [CBD]) smoke, inhaled high-CBD (0.7% THC, 13% CBD) smoke, 3 mg/kg i.p. THC, or 10 mg/kg i.p. CBD. Our data reveal that THC and CBD, but not their metabolites, accumulate in maternal plasma after repeated exposures. Injection of THC or CBD was associated with fewer offspring and increased uterine reabsorption events. For cytokines and chemokines, injection of THC or CBD up-regulated several pro-inflammatory cytokines compared to control or high-THC smoke or high-CBD smoke in placental and fetal brain tissue, whereas smoke exposure was generally associated with reduced cytokine and chemokine concentrations in placental and fetal brain tissue compared to controls. These results support existing, but limited, knowledge on how different routes of administration contribute to inconsistent manifestations of cannabinoid-mediated effects on pregnancy. Smoked Cannabis is still the most common means of human consumption, and more preclinical investigation is needed to determine the effects of smoke inhalation on developmental and behavioural trajectories.
... The Wnt/β-catenin signaling pathway is highly conserved and plays a role in a variety of physiological processes, including proliferation, differentiation, apoptosis, invasion, migration, and homeostasis. Dysregulation of Wnt signaling leads to carcinogenesis (41,48,49). The detailed GO analysis revealed that EV proteins that were downregulated in patients with CC are associated with the Wnt signaling pathway. ...
Background
Cervical cancer (CC) is the fourth most common cancer in females worldwide. Existing biomarkers for CC, such as squamous cell carcinoma antigens, show low specificity. Hence, a novel biomarker for the diagnosis of CC is required. Through proteomic analysis, this study aimed to distinguish between the small extracellular vesicle (sEV) protein profiles of healthy controls (HC) and CC sera and to identify potential sEV proteins that can serve as biomarkers for CC diagnosis.
Methods
The number and size distribution of sEVs in HC and CC sera were measured using nanoparticle tracking analysis. Differential ultracentrifugation combined with size-exclusion chromatography was used to isolate and purify sEVs. Liquid chromatography-tandem mass spectrometry was used to identify and compare the protein profiles between patients with CC and HC. Differentially expressed extracellular vesicle (EV) proteins were validated using The Cancer Genome Atlas database.
Results
The EV particle concentration in patients with CC was marginally higher than that in HC. Proteomic and functional protein analyses revealed a difference in the EV protein profiles between HC and CC and identified proteins that can serve as biomarkers for CC.
Conclusions
This study provides insights into the potential of sEVs as less invasive biomarkers for CC diagnosis. Validation with a well-designed cohort should be performed to determine the clinical diagnostic value of specific protein markers for CC.
... This phase is characterized by the initial interaction between the blastocyst and the receptive endometrium, which is mediated by the binding of specific adhesion molecules on the surface of the blastocyst and the endometrial epithelium. This interaction triggers a cascade of events, including the release of cytokines and chemokines, which ultimately lead to the attachment of the blastocyst to the endometrium [21]. The inflammatory-like response during this phase helps to prepare the invasion phase of human implantation. ...
Assisted reproduction techniques have improved considerably in recent decades, but despite these advances, success rates remain relatively low. Endometrial immune profiling involves the analysis of cytokine biomarkers in the endometrium during the mid-luteal phase. This profiling aims to provide insights into the immune environment of the uterus. The aim is to identify immune disturbances and thus guide the development of personalized therapeutic approaches. The first part of the review looks back at the emergence of innovative concepts, highlighting the specificity of the human uterine environment at the time of implantation. Based on this new knowledge, biomarkers have been selected for endometrial immune profiling. The second part details the results of clinical studies conducted over the last ten years. These clinical results suggest that this approach can increase the rate of live births in patients suffering from repeated implantation failures or repeated pregnancy loss. Uterine immune profiling represents a clinical innovation that can significantly improve the performance of medically assisted reproduction treatments through personalized strategies tailored to the local immune profile. Innovation in personalized medicine for assisted reproduction is crucial to improving the success rates of fertility treatments, while reducing the risks and costs associated with ineffective or unnecessary interventions.
... Chemokines and their receptors also play important roles in trophoblast migration and immune cells recruitment at the maternal-fetal interface (86). The dNK cells secrete IL8, CXCL10, TNF, interferon (INF) g, TGF-b, and angiogenic factors such as VEGF-A, VEGF-C and PlGF (15,87). ...
Uterine spiral artery remodeling is necessary for fetal growth and development as well as pregnancy outcomes. During remodeling, trophoblasts invade the arteries, replace the endothelium and disrupt the vascular smooth muscle, and are strictly regulated by the local microenvironment. Elevated glucose levels at the fetal-maternal interface are associated with disorganized placental villi and poor placental blood flow. Hyperglycemia disturbs trophoblast proliferation and invasion via inhibiting the epithelial-mesenchymal transition, altering the protein expression of related proteases (MMP9, MMP2, and uPA) and angiogenic factors (VEGF, PIGF). Besides, hyperglycemia influences the cellular crosstalk between immune cells, trophoblast, and vascular cells, leading to the failure of spiral artery remodeling. This review provides insight into molecular mechanisms and signaling pathways of hyperglycemia that influence trophoblast functions and uterine spiral artery remodeling.
... The human endometrium is a dynamic tissue that undergoes repeated growth and regression with each menstrual cycle [1,2]. Structurally, the endometrium consists of a rich supply of microvasculature derived from myometrial arcuate arteries dividing into feeding radial arteries that give rise to spiral arterioles supplying the functional layer of the endometrium [3]. ...
In recent years, transcriptomics has enabled us to gain a deeper understanding of fundamental reproductive physiology, including the menstrual cycle, through a more precise molecular analysis. The endometrial mRNA transcript levels fluctuate during the normal menstrual cycle, indicating changes in the relative recruitment and abundance of inflammatory cells, as well as changes in the receptivity and remodeling of the endometrium. In addition to providing a more comprehensive understanding of the molecular underpinnings of pathological gynecological conditions such as endometriosis, leiomyomas, and adenomyosis through RNA sequencing, this has allowed researchers to create transcriptome profiles during both normal menstrual cycles and pathological gynecological conditions. Such insights could potentially lead to more targeted and personalized therapies for benign gynecological conditions. Here, we provide an overview of recent advances in transcriptome analysis of normal and pathological endometrium.
... IL-6 menstrual siklus boyunca insan endometriyumunda ve erken gebelik sırasında desidua da bulunur (28). Ayrıca ekstra villöz trofoblast hücrelerinin IL-6'yı eksprese ettiği ve bu sitokinin MMP'leri up-regüle ederek trofoblast invazyonuna etkileyebileceği rapor edilmiştir (29). ...
... Chemokines also regulate many biological processes such as angiogenesis and stem cell migration during embryo development. The chemokine signaling pathway is regulated in diverse cellular processes, such as angiogenesis, epithelial cell proliferation, and survival [42,43]. Intriguingly, chemokines are critical for cancer development and are highly functional in the tumor microenvironment [44]. ...
Background
Small extracellular vesicles (sEVs) are membrane vesicles released by healthy and malignant cells. sEVs are potential biomarkers for cancer diagnosis. Cervical cancer (CC) is the fourth most common cancer in females worldwide. Existing biomarkers, such as squamous cell carcinoma antigens, show low specificity. Hence, a novel biomarker for the diagnosis of CC is required. This study aimed to identify potential candidates in sEVs through proteomic analysis for the diagnosis of CC and to determine the EV protein profile to distinguish between healthy and CC serum samples.
Methods
The number and size distribution of sEVs in healthy controls (HC) and CC were measured using nanoparticle tracking analysis. Differential ultracentrifugation combined with size-exclusion chromatography was used to isolate and purify sEVs derived from the serum of HC and CC. The isolated sEVs were characterized using western blotting and transmission electron microscopy. Liquid chromatography-tandem mass spectrometry was used to identify and compare the protein profiles between CC and HC. EV proteins were validated using the TCGA database.
Results
The particle concentration in CC was marginally higher than that in HC. The mode size of the particles in CC was significantly smaller than that in the HC-derived particles. Proteomic and functional protein analyses revealed a difference in the EV protein profiles between HC and CC. We found three and 18 uniquely expressed proteins in HC and CC, respectively. Unique EV proteins in CC are involved in angiogenesis and the Ras, VEGF, and FAS signaling pathways, while EV proteins in HC are involved in cellular homeostasis. EV proteins such as C1QB, MYO3B, and NADSYN1 were significantly upregulated in CC and primary tumor tissues, whereas MAFK, OR13C9, PIK3C2, PLCB4, RAB12, and VIP were downregulated in CC sEVs and primary tumor tissues.
Conclusion
Our study provides useful insights into the potential of sEVs as noninvasive biomarkers for CC diagnosis. Validation with a well-designed cohort should be performed to assure the clinical diagnostic value of specific protein markers for CC sEVs.
... Последние годы особую роль в патогенезе репродуктивных потерь отводят хемокинам. В эксперименте как in vitro, так и in vivo показано, что хемокины участвуют в гравидарной трансформации эндометрия и успешной инвазии трофобласта в комплексе с другими медиаторами [12][13]. Показано, что процесс инвазии трофобласта, обусловленный полноценным взаимодействием бластоцисты и эндометрия, является приоритетным моментом последующего развития беременности и особая роль отводится молекулам фактора CXCL12 (SDF-1 -Stromal cell-derived factor-1), синтезируемому клетками трофобласта и эндометрия, как фактору, потенцирующему восприимчивость эндометрия к наступлению и развитию беременности [14][15][16][17]. ...
The immunological factor in the genesis of reproductive losses, including the use of in vitro fertilization technologies, remains not completely clear due to the multiple pathogenetic mechanisms of immunological interactions in the mother-placenta-fetus system. The purpose of this study is to study the expression of the factor SDF-1 (stromal cell-derived factor) in the endometrium during missed miscarriage using in vitro fertilization technologies. Abortive material 5-8 weeks’ old was studied using in vitro fertilization technologies with different variants of gravidar transformation of the endometrium. A total of 92 samples were studied, of which 77 were abortive material from a missed miscarriage after the use of in vitro fertilization technologies and 15 were samples of abortive material from a pregnancy terminated surgically. A histological study was performed by staining with hematoxylin and eosin with a description of the variants of gravidar transformation of the stroma and endometrial glands and an immunohistochemical study of the SDF-1 factor in the endometrium of the examined groups. Based on the histological picture, depending on the morphological variant of the transformation of the endometrium, 5 groups of cases were formed: complete transformation of the stroma and glands of the endometrium and stroma with glands of the secretory type; incomplete transformation of the stroma with glands of the secretory type, proliferative type, with both types and the control group of observations. The expression area of the marker in the endometrium (glands and stroma) was determined by morphometry. The results of the study showed a significant decrease in the expression of SDF-1 in the glands of the compact layer of the endometrium, regardless of the options for its transformation after the use of in vitro fertilization technologies, which is probably associated with a violation of the synthesis of the SDF-1 chemokine by glandulocytes at the stage of cyclic transformation of the endometrium. A significant increase in the expression of SDF-1 in the stroma of the endometrium is due to the initial violation of the its morphological and functional state in patients with infertility. Verification of stromal cell factor in the endometrium at the stage of pregravidar preparation will allow to correct this stage of the application of in vitro fertilization technologies for patients with endometrial dysfunction.
... The complex processes of embryo implantation and early placentation require a plethora of locally acting, highly regulated molecules, including cytokines (some are chemotactic) synthesized by several cell types at the maternal-fetal interface. Also, cytokines produced by the endometrium may affect blastocyst development, migration, and attachment (Salamonsen et al., 2007). The SPP1 gene is enriched in the PI3K-Akt signaling pathway (upregulated in HF versus LF ewes). ...
Fertility in ewes is closely linked to ovulation rate and can be predicted by transcriptome profiling to identify candidate genes, biomarkers, and underlying molecular mechanisms. Our objective was to explore the genetic basis of ewe fertility by combining RNA-Seq data analyses of ovarian tissues from high and low fertility ewes with published transcriptome studies (i.e., literature mining). Integration of these 2 sources identified 113 differentially expressed genes (DEGs) associated with ewe fertility. Among these, 21 genes (CTNNB1, BMPR1B, BMP2, GDF9, BMP15, FSHR, TGFBR2, C-MET, KIT, MMP9, FST, LHCGR, SPP1, CYP19, CTSS, C1QB, FGF1, FGF18, BMP7, INHBA, and PAX8) were identified as hub (highly connected) genes for ewe fertility and were subjected to protein-protein interaction (PPI) network, mRNA-miRNA regulatory bipartite network, and subnets construction. Gene ontology (GO) terms enrichment analysis of the DEG represented 28, 23, and 21 GO terms associated with ewe fertility in categories of biological process, molecular functions, and cellular components, respectively. Based on annotation results, DEGs have major roles in signaling pathways related to cytokine-cytokine receptor interactions, ovarian steroidogenesis, and the TGF-beta, MAPK, Hippo, PI3K-Akt, Rap1, and Ras signaling pathways. Identification of these genes, metabolic and signaling pathways, and their related functions, could provide new insights into biological mechanisms of transcriptome profiling in the ovary and inform future studies of biomarkers for ewe fertility.
... While the former primarily degrades the endometrium, the latter remodels the vasculature. Both of the cell population contributes towards successful implantation provided these are orchestrated with precise accuracy [63][64][65][66][67]. Several cytokines-hormone networks are known to mediate this regulation [68][69][70]. Previous studies from our lab reported the role of IL-1β and TGFβ as two such mediators [71]. ...
The peroxisome proliferator-activated receptor-alpha (PPARα) is a member of the ligand-dependent nuclear receptor superfamily known for their crucial role in lipid metabolism. The expression and role of PPARα in trophoblast cells are not very well known. Trophoblast invasion is one of the most critical processes required for successful implantation of the developing embryo into the maternal endometrium. Defects in this process are associated with adverse pregnancy outcomes such as FGR(Fetal Growth Restriction), preeclampsia, and choriocarcinoma. In this present study, we investigated the role of the ligand-activated transcription factor, Peroxisome proliferator-activated receptor (PPARα) in regulating trophoblast cell invasion using cell lines and explants-based models. Immunohistological localization of PPARα in human placental tissues showed a gestational variation with relatively low expression at term as compared to early trimester. PCR and Western Blot also confirmed this. Further to delineate the effect of PPAR alpha on trophoblast invasion, EVT derived HTR8/SVneo cell lines were stimulated with PPARα agonist, i.e., fenofibrate (FF). Fenofibrate stimulation led to an increased activation and nuclear translocation of PPARα, followed by reduced migration and invasion of these cells in a matrigel invasion assay (Boyden chamber). PPAR alpha stimulation also led to a reduced MMP-2/9 expression following our previous observation. Thus, we may conclude that PPARα to be playing a very important regulatory role in orchestrating the invasive trophoblast programme and hence it seems plausible for it to be associated with PE, which is often characterized by a shallow trophoblast invasion.
... Previous studies have highlighted the positive role of estrogen receptor α (ESR1) in the epithelial cells of the upper FRT, supporting fertilization or embryo development (Winuthayanon et al., 2015;. Both ESR1 and its ligand estrogen help build a barrier against pathogenic invasion by maintaining the epithelial thickness (Miyagawa and Iguchi, 2015) and promoting the secretion of antimicrobial peptides, cytokines, and chemokines (Salamonsen et al., 2007;Ochiel et al., 2008). Vaginal administration of estradiol has been used for the treatment of menopausal symptoms in humans. ...
Heat stress can have an impact on parental gamete maturation and reproduction functions. According to current research, the microbial composition of the vaginal cavity is species specific. Pregnancy, menstruation, and genital diseases have been linked to the dynamics of vaginal ecology. In this study, we characterized the vaginal microbiota and metabolites after heat stress. At the phylum level, the rabbit’s vaginal microbial composition of rabbit showed high similarity with that of humans. In the Heat group, the relative abundance of the dominant microbiota Actinobacteria, Bacteroidetes, and Proteobacteria increased, while the relative abundance of Firmicutes decreased. Furthermore, heat stress significantly increased the relative abundance of W5053, Helcococcus, Thiopseudomonas, ldiomaarina, atopostipes, and facklamia, whereas the relative abundance of 12 genera significantly decreased, including Streptococcus, UCG-005, Alistipes, [Eubacterium]_xylanophilum_group, Comamonas, RB41, Fastidiosipila, Intestinimonas, Arthrobacter, Lactobacillus, Leucobacter, and Family_xlll_AD3011_group. Besides, the relative concentrations of 158 metabolites differed significantly between the Heat and Control groups. Among them, the endocrine hormone estradiol (E2) increased in the Heat group and was positively associated with a number of metabolites such as linolelaidic acid (C18:2N6T), N-acetylsphingosine, N-oleoyl glycine, trans-petroselinic acid, syringic acid, 2-(1-adamantyl)-1-morpholinoethan-1-one, 5-OxoETE, and 16-heptadecyne-1,2,4-triol. Further, the majority of the differential metabolites were enriched in steroid biosynthesis and endocrine and other factor-regulated calcium reabsorption pathways, reflecting that heat stress may affect calcium metabolism, hormone-induced signaling, and endocrine balance of vaginal ecology. These findings provide a comprehensive depiction of rabbit vaginal ecology and reveal the effects of heat stress on the vagina via the analysis of vaginal microbiome and metabolome, which may provide a new thought for low female fertility under heat stress.
... Activated leukocytes in the developing decidua contribute to regulatory cytokines in the local microenvironment. (9) The mechanism of an increased immune response during the presence of an infectious agent is associated with a higher level of expression of mRNA encoding TLR4 and TLR2, recognizing bacterial LPS and lipopeptides, respectively, as mechanisms of bacterial persistence, (10)(11)(12)(13)(14) but under conditions of the endometrium chronic inflammation, we observe the activity of all studied cytokines, regardless of the presence of bacterial flora. ...
The purpose of this research was to study changes in endometrial cytokine concentrations in women suffering from reproductive disorders with and without chronic endometritis (CE) to justify pathogenetic treatment.
Methods and Results: The study included 100 women of reproductive age with reproductive disorders. Group 1 included 50 patients with reproductive disorders and CE; Group 2 included 50 patients with reproductive disorders and without CE. Later on, all patients were divided into the following subgroups: Sub1A (n=31), and Sub2A (n=16) with an isolated bacterial flora, Sub1B (n=19) and Sub2B (n=34) with the absence of bacterial flora. The control group consisted of 31 fertile women.
Endometrial aspiration pipe biopsy was performed on days 4-9 of the menstrual cycle (middle proliferative phase) using a disposable intrauterine probe (Taizhou Kechuang Medical Apparatus Co., Ltd, China) followed by histological examination of endometrial tissue. Laboratory diagnostics for sexually transmitted infections (STIs) was performed using the bacterial culture method. For the diagnosis of viral infection (HPV, HSV, CMV), cervical samples were studied using PCR. If STIs were detected, the patients were excluded from further research. Ultrasound examination of the pelvic organs was performed using the Aloka-5500 device with a 7MHz vaginal probe in two-dimensional visualization mode. The concentration of cytokines (IL-1β, INF-γ, TNF-α, ILs-4,6,8,10) in the endometrium was determined using the Protein Contour test systems (Saint Petersburg) and Multiskan EX ELISA Analyzer (Germany).
In both groups, reproductive disorders were accompanied by hypoprogesteronemia and relative hyperestrogenemia, significantly apparent in CE. We found a 3-fold increase in the level of tissue pro- and anti-inflammatory cytokines (IL-1β, IL-4,6,10, INF-γ), and a 4-fold increase in the level of TNF-α and IL-8 in Group 1, compared to the CG. In Group 2, we found a 1.4-fold increase in the levels of IL-1β and INF-γ, compared to the CG.
In Sub 1a, the levels of IL-6 and IL-8 were significantly higher than in the control group. In Sub1A, the isolated bacterial flora caused a cytokine inflammatory response characterized by a significant increase in the concentration of INF-γ and TNF-α, compared to Sub2A and Sub2B (P
... ESCs of women with RM show an abnormal response to decidualization in vitro, which is manifested by attenuated PRL production [33]. Decidualization is characterized by the secretory transformation of the uterine glands, the influx of specialized uterine natural killer cells and macrophages, and vascular remodeling [34]. The major secretory products of decidualization include PRL and IGFBP1. ...
Background
Recurrent miscarriage (RM) is a very frustrating problem for both couples and clinicians. To date, the etiology of RM remains poorly understood. Decidualization plays a critical role in implantation and the maintenance of pregnancy, and its deficiency is closely correlated with RM. The F-box protein S-phase kinase associated protein 2 (SKP2) is a key component of the SCF-type E3 ubiquitin ligase complex, which is critically involved in ErbB family-induced Akt ubiquitination, aerobic glycolysis and tumorigenesis. SKP2 is pivotal for reproduction, and SKP2-deficient mice show impaired ovarian development and reduced fertility.
Methods
Here, we investigated the expression and function of SKP2 in human decidualization and its relation with RM. A total of 40 decidual samples were collected. Quantitative PCR analysis, western blot analysis and immunohistochemistry analysis were performed to analyze the differential expression of SKP2 between RM and control cells. For in vitro induction of decidualization, both HESCs (human endometrial stromal cells) cell line and primary ESCs (endometrial stromal cells) were used to analyze the effects of SKP2 on decidualization via siRNA transfection.
Results
Compared to normal pregnant women, the expression of SKP2 was reduced in the decidual tissues from individuals with RM. After in vitro induction of decidualization, knockdown of SKP2 apparently attenuated the decidualization of HESCs and resulted in the downregulation of HOXA10 and FOXM1, which are essential for normal human decidualization. Moreover, our experiments demonstrated that SKP2 silencing reduced the expression of its downstream target GLUT1.
Conclusions
Our study indicates a functional role of SKP2 in RM: downregulation of SKP2 in RM leads to impaired decidualization and downregulation of GLUT1 and consequently predisposes individuals to RM.
... This communication is regulated by several inflammatory cytokines and adhesion molecules. Collectively, the process of implantation poses an immune challenge between the embryo (as a semi-allogenic) body and the uterus [1][2][3]. The maternal immune system promotes immune tolerance toward the embryo to maintain a normal pregnancy while defending against infection. ...
Objective:
Lipopolysaccharide (LPS) from Gram-negative bacteria causes poor uterine receptivity by inducing excessive inflammation at the maternal-fetal interface. This study aimed to investigate the detrimental effects of LPS on the attachment and outgrowth of various types of trophoblastic spheroids on endometrial epithelial cells (ECC-1 cells) in an in vitro model of implantation.
Methods:
Three types of spheroids with JAr, JEG-3, and JAr mixed JEG-3 (JmJ) cells were used to evaluate the effect of LPS on early implantation events. ECC-1 cells were treated with LPS to mimic endometrial infection, and the expression of inflammatory cytokines and adhesion molecules was analyzed by quantitative real-time polymerase chain reaction and western blotting. The attachment rates and outgrowth areas were evaluated in the various trophoblastic spheroids and ECC-1 cells treated with LPS.
Results:
LPS treatment significantly increased the mRNA expression of inflammatory cytokines (CXCL1, IL-8, and IL-33) and decreased the protein expression of adhesion molecules (ITGβ3 and ITGβ5) in ECC-1 cells. The attachment rates of JAr and JmJ spheroids on ECC-1 cells significantly decreased after treating the ECC-1 cells with 1 and 10 μg/mL LPS. In the outgrowth assay, JAr spheroids did not show any outgrowth areas. However, the outgrowth areas of JEG-3 spheroids were similar regardless of LPS treatment. LPS treatment of JmJ spheroids significantly decreased the outgrowth area after 72 hours of coincubation.
Conclusion:
An in vitro implantation model using novel JmJ spheroids was established, and the inhibitory effects of LPS on ECC-1 endometrial epithelial cells were confirmed in the early implantation process.
... ESCs of women with RM show an abnormal response to decidualization in vitro, which is manifested by attenuated PRL production [33]. Decidualization is characterized by the secretory transformation of the uterine glands, the in ux of specialized uterine natural killer cells and macrophages, and vascular remodeling [34]. The major secretory products of decidualization include PRL and IGFBP1. ...
Background: Recurrent miscarriage (RM) is a very frustrating problem for both couples and clinicians. To date, the etiology of RM remains poorly understood. Decidualization plays a critical role in implantation and the maintenance of pregnancy, and its deficiency is closely correlated with RM. The F-box protein S-phase kinase associated protein 2 (SKP2) is a key component of the SCF-type E3 ubiquitin ligase complex, which is critically involved in ErbB family-induced Akt ubiquitination, aerobic glycolysis and tumorigenesis. SKP2 is pivotal for reproduction, and SKP2-deficient mice show impaired ovarian development and reduced fertility.
Methods: Here, we investigated the expression and function of SKP2 in human decidualization and its relation with RM. A total of 40 decidual samples were collected. Quantitative PCR analysis, western blot analysis and immunohistochemistry analysis were performed to analyze the differential expression of SKP2 between RM and control cells. For in vitro induction of decidualization, both HESCs (human endometrial stromal cells) cell line and primary ESCs (endometrial stromal cells) were used to analyze the effects of SKP2 on decidualization via siRNA transfection.
Results: Compared to normal pregnant women, the expression of SKP2 was reduced in the decidual tissues from individuals with RM. After in vitro induction of decidualization, knockdown of SKP2 apparently attenuated the decidualization of HESCs and resulted in the downregulation of HOXA10 and FOXM1, which are essential for normal human decidualization. Moreover, our experiments demonstrated that SKP2 silencing reduced the expression of its downstream target GLUT1.
Conclusions: Our study indicates a functional role of SKP2 in RM: downregulation of SKP2 in RM leads to impaired decidualization and downregulation of GLUT1 and consequently predisposes individuals to RM.
... Previous studies have also reported that disturbed maternal sleep may cause adverse obstetric outcomes, with augmentation of maternal inflammatory response [15,41]. Increased inflammation may interfere with the remodeling of spiral arteries in the placenta, thereby leading to PTB, FGR, and preeclampsia [42][43][44]. Thus, preventing reduced MSD may reduce maternal inflammation and prevent these adverse obstetric outcomes. ...
Abstract Background The adequate maternal sleep duration required for favorable obstetric outcomes is unknown. We evaluated the association between maternal sleep duration and low birth weight infants, small for gestational age infants, and macrosomia. Methods Participants enrolled in the Japan Environment and Children’s Study, a nationwide birth cohort study, with singleton pregnancies after 22 weeks, who gave birth between 2011 and 2014 were enrolled and categorized into five groups according to maternal sleep duration during pregnancy:
... Successful pregnancy depends on the induction of local maternal tolerance toward foreign fetus tissue actually there are multiple mechanisms like : angiogenesis, cytokine and hormonal balance, genetic and epigenetic as well as environmental factors influence pregnancy outcomes (Hunt et al., 2005, Piccinni., 2005, Salamonsen et al., 2007, Van and Oudejans 2013, Sharma 2014. ...
Forty cases of women sever from recurrent pregnancy loss (RPL) compared with 40 normal women for determining the cytokine gene polymorphism in the promoter region of : tumor necrosis factor-alpha TNF-α (-308 G/A), interleukin IL-6 (-634 G/C) and IL-10 (-592 C/A) in aborted women of Basra /Iraq. The results indicated that there was an association between RPL and the polymorphisms in inflammatory cytokines (IL-6, TNF-α), while IL-10 gene did not showed any effect on both cases of RPL and normal cases.
... Successful pregnancy depends on the induction of local maternal tolerance toward foreign fetus tissue actually there are multiple mechanisms like : angiogenesis, cytokine and hormonal balance, genetic and epigenetic as well as environmental factors influence pregnancy outcomes (Hunt et al., 2005, Piccinni., 2005, Salamonsen et al., 2007, Van and Oudejans 2013, Sharma 2014. ...
... Abnormalities in theirproduction are associated with infertility and miscarriages. [3,4] Microbial cells, neoplastic cells etc. exhibit similar actions necessary for their colonization. The presence of complextype oligosaccharides on the cell surface, metalloproteases, interstitial collagenase, serine proteases (plasminogen activator) mediate trophoblast and others invasion. ...
The implantation procedure involves a “biofilmic” mechanism of organism protection against threat. Immune-inflammatory procedures expressed by nutritional, molecular and biochemical factors related to homeostasis ensure successful incorporation of blastocyst in the uterine ecology. The feeding chain of the host mother, the embryo and their microbiota modifies the human intrinsic environment, hormone levels, fetal characteristics and growth.
This study was conducted to provide information about the effects of diet on implantation quality in an attempt to therapeutically synchronize the development of blastocyst within the nourishing mothers. The issue is generalized to all “windows of alien implantations”.
The formation of life (: fertilization) and its development is a consequence of biochemical reactions (: mitochondrial cycle, replication, regeneration, oxidation, apoptosis, etc.). Homeostasis is called the body’s ability to keep its internal ecosystem stable despite exo orendogenous changes. The whole process involves energy consumption, operative coordination of various organs, especially between the nervous and endocrine systems. Instability of homeostasispredisposesto“miscarriages”.
Key elements that enhance acid-base equilibrium, oxygen demands and indirectly implantation success are proteins, trace minerals, vitamins, omega-3 fatty acids, enzymes, fruit and vegetable phytonutrients, probiotics. Restriction of processed or foods polluted with endocrine disrupting chemicals and microbes, sugar, saturated and trans fatty acids prevents genetic deterioration, ageing and troublesome implantations. Balanced diet, digestion and hormone-dependent metabolism identifies the efficiency of our reproductive system and homeostatic implantation procedure.
Key words: Implantation; Nutrition; Diet; Microbiota; Oxidative Stress; Inflammation; Immunity
... T H cell, T helper cell; T reg cell; regulatory T cell. Republished with permission of Thieme, from reF. 267 ...
Recurrent pregnancy loss is a distressing pregnancy disorder experienced by ~2.5% of women trying to conceive. Recurrent pregnancy loss is defined as the failure of two or more clinically recognized pregnancies before 20–24 weeks of gestation and includes embryonic and fetal losses. The diagnosis of an early pregnancy loss is relatively straightforward, although progress in predicting and preventing recurrent pregnancy loss has been hampered by a lack of standardized definitions, the uncertainties surrounding the pathogenesis and the highly variable clinical presentation. The prognosis for couples with recurrent pregnancy loss is generally good, although the likelihood of a successful pregnancy depends on maternal age and the number of previous losses. Recurrent pregnancy loss can be caused by chromosomal errors, anatomical uterine defects, autoimmune disorders and endometrial dysfunction. Available treatments target the putative risk factors of pregnancy loss, although the effectiveness of many medical interventions is controversial. Regardless of the underlying aetiology, couples require accurate information on their chances of having a baby and appropriate support should be offered to reduce the psychological burden associated with multiple miscarriages. Future research must investigate the pathogenesis of recurrent pregnancy loss and evaluate novel diagnostic tests and treatments in adequately powered clinical trials.
... В ранее проведенных in vitro и in vivo исследованиях хемокины выделены как потенциальные факторы, регулирующие изменения в эндометрии на ранних сроках беременности [40]. Был сделан вывод о том, что хемокины, вероятно, принимают участие во взаимодействиях эндометрия и трофобласта Reviews и ответственны за успешную имплантацию и отторжение эмбриона, наряду с множеством других участников этого процесса [41]. ...
O.V. Prokhorova1, A.A. Olina2, G.Kh. Tolibova2, T.G. Tral’2
1Ural State Medical University, Yekaterinburg, Russian Federation
2D.O. Ott Research Institute of Obstetrics, Gynecology & Reproduction, St. Petersburg, Russian Federation
Chemotactic cytokines are a family of signaling proteins secreted by various human tissues. Their functioning is based on the ability to induce directed chemotaxis in nearby susceptible cells. This paper reviews recent published data on one of the most important homeostatic cytokines, stromal cell-derived factor-1 (SDF-1). The leading role of this factor in the pathogenesis of various conditions, i.e., toxic, ischemic, and necrotic tissue damage, carcinogenesis (including the mechanisms of invasion and metastasis) is demonstrated. SDF-1 acts as a powerful inductor of angiogenesis and stimulates the proliferation of endothelial cells in reproductive organs. This chemokine is one of the candidate factors involved in the regulation of proliferation and differentiation of human endometrium, i.e., the implementation of epithelial-stromal interaction of tissue elements in uterine mucosa. Clear understanding of the regulatory mechanisms of SDF-1-mediated signaling during trophoblast functioning and placental angiogenesis may help develop novel therapeutic approaches to pregnancy-related disorders.
Keywords: stromal cell-derived factor, chemokines, cytokines, pathogenesis, pregnancy, homeostasis.
For citation: Prokhorova O.V., Olina A.A., Tolibova G.Kh., Tral’ T.G. Stromal cell-derived factor: pathological and clinical potentialities. Russian Journal of Woman and Child Health. 2020;3(3):198–204. DOI: 10.32364/2618-8430-2020-3-3-196-204.
... Th1 cells typically secrete pro-inflammatory cytokines, such as interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), and interleukin-2 (IL-2) (27) whereas Th2 cells secrete anti-inflammatory cytokines, such as IL-4, IL-6, and IL-10, and appear to have immunosuppressive effects that are important for the healthy continuation of pregnancy (28). The balance of pro-and anti-inflammatory cytokines depends entirely on the ratio of Th1 and Th2 cells (29). It is possible to measure cytokine levels from serum, plasma, placenta, or endometrial lavage samples (30). ...
Despite recent advances in assisted reproductive methods and treatments in sustaining fetal viability, recurrent implantation failure (RIF) and recurring pregnancy loss (RPL) still pose significant problems in the context of in vitro fertilization (IVF). Recent studies focused on the role of immunological factors in the etiology of RIF and RPL. They demonstrated that infertile patients might suffer from dysregulated immune system cell activities, including CD4+ T helper (Th1, Th2, Th17, and Tregs), peripheral natural killer (pNK), uterine natural killer (uNK) cells. Researchers have investigated the use and efficacy of immunosuppressant drugs such as glucocorticoids, intravenous immunoglobulin, and TNF-α blockers in achieving successful implantation in infertile women but the efficacy of these treatments remains to be fully established. We conclude that, although the relationship between immunology and infertility is clear, there is still a long way to go to reach a thorough understanding.
... 15,41 Increased inflammation may interfere with the remodeling of spiral arteries in the placenta, thereby leading to PTB, FGR, and preeclampsia. [42][43][44] Thus, preventing reduced MSD may reduce maternal inflammation and prevent these adverse obstetric outcomes. Further, maternal inflammatory stress is also affected by lifestyle, including dietary habits and exercises 45,46 ; and comprehensive modification of these lifestyles may help in reducing inflammatory stress. ...
... IL-1α protein was previously detected in mouse (Simón et al., 1994;Terranova and Rice, 1997) and human (De Los Santos et al., 1998) oocytes, theca and cumulus cells (Kol et al., 1999), showing that ovarian cells synthesize IL-1α. Moreover, IL-1β was found to be produced by ovarian granulosa cells of preovulatory follicles (Salamonsen et al., 2007;Trundley and Moffett, 2004). The presence of IL-1RA was demonstrated in granulosa and cumulus cells of mares (Martoriati et al., 2002) and human (De Los Santos et al., 1998). ...
Tumour necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) are cytokines that are involved in the development, proliferation and apoptosis of ovarian follicular cells in domestic mammals. The expression of these cytokines in various follicular compartments, depending on the stage of follicle development, demonstrates their involvement in the control of primordial follicle growth up to the preovulatory stage. The mechanism of action of these factors depends on the presence of their receptors that transduce their biological actions. This review shows the expression sites of TNF-α, IL-1β and their receptors in ovarian follicles, and discusses the mechanism of action of these cytokines during follicle development, oocyte maturation and ovulation in domestic animals.
... Endometrial glands produce and secrete a cocktail of molecules, the histotroph, including amino acids, glucose and growth factors, which appear to be involved in embryo survival, trophectoderm activation, endometrial invasion and nourishment of the implanted embryo [48][49][50][51][52][53][54][55][56]. Leukemia inhibitory Int. ...
Implantation of the embryo into the uterine endometrium is one of the most finely-regulated processes that leads to the establishment of a successful pregnancy. A plethora of factors are released in a time-specific fashion to synchronize the differentiation program of both the embryo and the endometrium. Indeed, blastocyst implantation in the uterus occurs in a limited time frame called the “window of implantation” (WOI), during which the maternal endometrium undergoes dramatic changes, collectively called “decidualization”. Decidualization is guided not just by maternal factors (e.g., estrogen, progesterone, thyroid hormone), but also by molecules secreted by the embryo, such as chorionic gonadotropin (CG) and interleukin-1β (IL-1 β), just to cite few. Once reached the uterine cavity, the embryo orients correctly toward the uterine epithelium, interacts with specialized structures, called pinopodes, and begins the process of adhesion and invasion. All these events are guided by factors secreted by both the endometrium and the embryo, such as leukemia inhibitory factor (LIF), integrins and their ligands, adhesion molecules, Notch family members, and metalloproteinases and their inhibitors. The aim of this review is to give an overview of the factors and mechanisms regulating implantation, with a focus on those involved in the complex crosstalk between the blastocyst and the endometrium.
... ATCCâCRL-4003ä, the human endometrial stromal cell line (hESC), was purchased from American Type Culture Collection (ATCC), and cultured as previously described (Salamonsen, Hannan, & Dimitriadis, 2007). 1% antibiotics and puromycin were mixed with 10% charcoal stripped fetal calf serum and transferred to DMEM/F12, which was used to culture the human stromal cells, followed by an 8-day in vitro decidualization using 10 nM estradiol-17 b, 1 mM medroxy-progesterone acetate as well as 0.5 mM 8-Br-Camp (Sigma). ...
Decidualization of endometrial stromal cells (ESCs) accompanied with embryo implantation is a key process in mammalian reproduction. Evidence suggests that maintenance of decidual cells function is essential. As a critical part in post-transcriptional gene regulation, microRNAs (miRNAs/miR) have been confirmed to be involved in decidualization. However, whether microRNAs regulate decidual cells function has not been reported. Aiming to clarify the role and potential mechanism of miRNAs in decidual cells, artificial induced decidualization model in mice was established. There are 94 differentially expressed miRNAs (≥two-fold change) between decidualized and non-decidualized tissues, including 60 upregulated and 34 downregulated miRNAs. Of the differentially expressed miRNAs, mmu-miR-21a is up-regulated. RT-qPCR also confirmed the up-regulation of mmu-miR-21a following decidualization in vivo and in vitro, and bioinformatic analysis and luciferase activity assay revealed Pdcd4 to be the target gene of mmu-miR-21a. Inhibition of mmu-miR-21a restrained secretory function of decidual cells induced by mESCs, accompanied with increase of Pdcd4 expression and resulted in the increase of cell apoptosis. In addition, we also determined the expression of hsa-miR-21 and Pdcd4 in human proliferative endometrial tissues and decidua tissues. hsa-miR-21 showed higher expression in human decidua tissues compared with proliferative endometrial tissues, while expression of Pdcd4 was contrary to that of hsa-miR-21. Similarly, cell apoptosis increased significantly in human endometrial stromal cell line in response to inhibition of hsa-miR-21. Collectively, we conclude that mmu-miR-21a/hsa-miR-21 may play a key role in regulating the function of decidual cells by inhibiting cell apoptosis through targeting Pdcd4.
... In contrast to the upregulated production of proinflammatory cytokines associated with PD, other cytokines (e.g., the anti-inflammatory cytokine IL-4) can exert the counteracting protective effect on pregnancy. Thus, elevated amounts of IL-4 during pregnancy provide maternal immunosuppressive effect against developing fetoplacental complex [4,[10][11][12]. IL-4 restricts production of pro-inflammatory cytokines IL-1β, IL-6, IL-8, IL-12, and TNF-α by macrophages, inhibits generation of reactive oxygen and nitrogen species, activates macrophages, and induces proliferation of NK cells [13]. ...
Preterm birth is not only medical, but also a social problem. The global goal of medicine is prevention of preterm labor and identification of risk factors leading to preterm birth. The objective of our study was to find the association between polymorphic markers in the cytokine IL-β, TNF-α, IL-1Ra, and IL-4 genes and development of preterm labor. The prospective study was conducted in 108 pregnant women with the risk of preterm birth. The main group consisted of 66 women whose pregnancy ended with preterm delivery despite the ongoing therapy. The comparison group included 42 women with the full-term delivery. The dominant T allele of the cytokine IL-1β gene polymorphism rs1143634 (3953C→T) was 7.6 times more common in women with preterm delivery vs. the comparison group (36.4 and 4.8%, respectively; RR, 1.802; 95% CI, 1.420–2.288; p < 0.05); its homozygous form was detected only in women with preterm delivery at the very early gestation age (less than 26 weeks). The dominant proinflammatory allele 2R of the IL-1 receptor antagonist gene (IL-1Ra) was 1.5 times more common in women with preterm delivery than in the comparison group (63.6 and 42.8%, respectively; RR, 1.400; 95% CI, 1.009–1.943; p < 0.05), which makes the 2R allele the risk factor for preterm birth. The 2R/2R and 2R/4R genotypes led to a very early and early preterm delivery, respectively. The combination of three or four proinflammatory genotypes was detected only in women with a very early preterm delivery, which confirms that the combination of several proinflammatory genotypes is an extremely unfavorable factor for the full-term pregnancy. Identification of genetic polymorphisms in the interleukin genes at the periconceptional stage will help to prevent the risk of preterm delivery, which will reduce the incidence of preterm births, as well as perinatal morbidity and mortality.
... 1 Chemokines are small, chemotactic cytokines, named such due to their ability to recruit leukocytes, many of which have been linked to implantation and placental development. 2 Namely, trophoblast-derived C-X-C motif chemokine ligand 12 (CXCL12) is a crucial factor that stimulates trophoblast cell survival, migration, and invasion. 3,4 We recently demonstrated that the signaling axis initiated by CXCL12 binding to its receptor, C-X-C motif chemokine receptor 4 (CXCR4), drives placental vascularization. ...
Problem:
Chemokines help coordinate inflammation within the fetal-maternal microenvironment during gestation. The chemokine CXCL12 signaling through its receptor CXCR4 regulates inflammatory activity, but this phenomenon is not well understood during pregnancy, and there are no reports exploring the role of this pair in peripheral immune tolerance during gestation. Herein, we hypothesize that intrauterine CXCL12-CXCR4 signaling governs local and systemic immunomodulatory dynamics during early gestation in ewes.
Method of study:
Osmotic pumps were surgically installed for intrauterine infusion of a CXCR4 inhibitor, AMD3100, beginning on day 12 post-breeding in sheep. Endometrial tissues were collected on day 35 of gestation and evaluated for inflammatory potential, Akt pathway activation, and autophagy induction. Demonstrative of peripheral immune activity, levels of select cytokines were assessed in daily blood samples collected throughout the study, as well as in corpus luteum and spleen on day 35.
Results:
Anti-inflammatory IL10 was primarily localized to endometrial glandular epithelium with lower abundance when CXCR4 was antagonized. Inhibition of CXCR4 at the fetal-maternal interface resulted in less activation of Akt in endometrium, while evidence of autophagy induction was greater. Corpora lutea from ewes receiving intrauterine AMD3100 exhibited lower interferon gamma (IFNG) expression. Blood inflammatory potential was differentially altered in a temporal fashion throughout infusion. IL10 abundance in spleen was greater following CXCR4 inhibition at the fetal-maternal interface, while IFNG was less.
Conclusion:
Intrauterine CXCL12-CXCR4 signaling governs endometrial and systemic inflammation; disruption of this axis may have detrimental impacts on offspring and maternal health. This article is protected by copyright. All rights reserved.
... Consequently, the embryoendometrial dialogue requires several endogenous molecules produced in the endometrium and/or the embryo (Glencross et al. 1973, Tabibzadeh & Babaknia 1995, Spencer et al. 1996, Tabibzadeh 1998, Paria et al. 2000, Paria et al. 2001, Paria et al. 2002, Riesewijk et al. 2003, Dey et al. 2004, Giudice 2004, Bauersachs et al. 2006, Wang & Dey 2006, Spencer et al. 2007, Bauersachs et al. 2009, Boomsma et al. 2009). Among these molecules are adhesion molecules, namely integrins, cadherins, and selectins (Lessey 1997, Tabibzadeh 1998, cytokines (Salamonsen et al. 2000, Achache & Revel 2006, Ledee et al. 2007, growth factors/ growth factor receptors (Cross et al. 1994, Carson et al. 2000, Norwitz et al. 2001, Paria et al. 2001, Lim et al. 2002 as well as chemokines (Salamonsen et al. 2007). Integrins, for example, are involved in cell-cell and cell-substrate interactions (Albelda & Buck 1990) and appropriate endometrial expression is necessary for receptivity in humans (Lessey 1997). ...
... Successful pregnancy depends on the induction of local maternal tolerance toward foreign fetus tissue actually there are multiple mechanisms like : angiogenesis, cytokine and hormonal balance, genetic and epigenetic as well as environmental factors influence pregnancy outcomes (Hunt et al., 2005, Piccinni., 2005, Salamonsen et al., 2007, Van and Oudejans 2013, Sharma 2014. ...
ABSTRACT: Forty cases of women sever from recurrent pregnancy loss (RPL) compared
with 40 normal women for determining the cytokine gene polymorphism in the promoter
region of : tumor necrosis factor-alpha TNF-α (-308 G/A), interleukin IL-6 (-634 G/C) and IL10
(-592 C/A) in aborted women of Basra /Iraq. The results indicated that there was an
association between RPL and the polymorphisms in inflammatory cytokines (IL-6, TNF-α),
while IL-10 gene did not showed any effect on both cases of RPL and normal cases
... Trophoblasts are placental cells that originate in early pregnancy C. de Weerth 4 and play an important role in embryonic implantation and nutrition (Beijers et al., 2014). In vitro experiments have shown that while some inflammatory markers promote trophoblast invasion, others interfere with trophoblast implantation (Salamonsen, Hannan, & Dimitriadis, 2007;Sharma, Godbole, & Modi, 2016). ...
Maternal psychological stress, depression, and anxiety during pregnancy (prenatal stress; PNS) are thought to impact fetal development with long-term effects on offspring outcome. These effects would include physical and mental health, including psychopathology. Maternal sleep, diet, and exercise during pregnancy are lifestyle behaviors that are understudied and often solely included in PNS studies as confounders. However, there are indications that these lifestyle behaviors may actually constitute essential mediators between PNS and fetal programming processes. The goal of this theoretical review was to investigate this idea by looking at the evidence for associations between PNS and sleep, diet, and exercise, and by piecing together the information on potential underlying mechanisms and causal pathways through which these factors may affect the offspring. The analysis of the literature led to the conclusion that sleep, diet, and exercise during pregnancy, may have fundamental roles as mediators between PNS and maternal pregnancy physiology. By integrating these lifestyle behaviors into models of prenatal programming of development, a qualitatively higher and more comprehensive understanding of the prenatal origins of psychopathology can be obtained. The review finalizes by discussing some of the present challenges facing the field of PNS and offspring programming, and offering solutions for future research.
... Importantly, these different stages are accompanied by changes in vaginal secretory proteins such as cytokines, chemoattractants, and antimicrobial molecules 12 . E 2 signaling in the vagina induces the formation of a physical barrier by maintaining the thickness of the vaginal epithelium and increasing the secretion of antimicrobial peptides, cytokines and chemokines (which recruit and activate immune cells) [13][14][15] . The epithelial lining of the vagina is also covered by a layer of glycoprotein-containing mucus, namely mucins, that protects the vagina from infectious agents 16,17 . ...
In the female reproductive tract, the innate immune system is modulated by two sex steroid hormones, estrogen and progesterone. A cyclical wave of neutrophils in the vaginal lumen is triggered by chemokines and correlates with circulating estrogen levels. Classical estrogen signaling in the female reproductive tract is activated through estrogen receptor α (encoded by the Esr1 gene). To study the role of estrogen action in the vagina, we used a mouse model in which Esr1 was conditionally ablated from the epithelial cells (Wnt7acre/+; Esr1f/f). Histological evidence showed that in response to a physical stress, the lack of ESR1 caused the vaginal epithelium to deteriorate due to the absence of a protective cornified layer and a reduction in keratin production. In the absence of ESR1 in the vaginal epithelial tissue, we also observed an excess of neutrophil infiltration, regardless of the estrous cycle stage. The histological presence of neutrophils was found to correlate with persistent enzymatic activity in the cervical-vaginal fluid. Together, these findings suggest that ESR1 activity in the vaginal epithelial cells is required to maintain proper structural integrity of the vagina and immune response, both of which are necessary for protecting the vagina against physical damage and resetting the vaginal environment.
İmplantasyon; gebelikte embriyo ile endometriyum epiteli arasında sürekli olarak temasın sağlanmasıdır. Endometriyumun implantasyona açık olduğu dönem; implantasyon penceresi olarak tanımlanmaktadır. İmplantasyon penceresi döneminde birçok molekül etkili olmaktadır. Hormonlar, sitokinler, kemokinler, adezyon molekülleri, büyüme faktörleri ve çeşitli genlerin etkisi ile bu süreç koordineli bir şekilde yönetilmektedir. İmplantasyon bu faktörlerin etkisi ile sırasıyla apozisyon, adezyon ve invazyon aşamalarından oluşmaktadır. Bu aşamalar sadece implantasyon penceresinde gerçekleşebilmektedir. Başarılı bir implantasyon olmadan, embriyonun gebeliğin diğer dönemlerine geçişi mümkün değildir ve gebelik erken embriyonik ölümle sonuçlanmaktadır. Bu açıdan multifaktöriyel birçok molekülün koordinasyonuyla meydana gelen implantasyonda, implantasyon penceresi zaman aralığı gebelik sürecindeki kritik noktalardan biridir. Bu derlemede sağlıklı bir gebeliğin oluşabilmesi için gerekli olan başarılı bir implantasyon ve implantasyon penceresi hakkında bilgi verilmeye çalışılmıştır. Fakat bilinmelidir ki, implantasyon mekanizmaları tüm bilinenlere rağmen hala tam olarak aydınlatılamamıştır.
Updated in light of recent research findings on fertilization, implantation and early pregnancy, this new edition combines the expertise of a wide range of internationally renowned authors to produce an authoritative, multidisciplinary approach to the management of first-trimester complications. Several international guidelines and consensus statements have been released since publication of the first edition and this has stimulated new focussed research questions that are addressed. The book's key recommendations provide clinicians with the tools to improve the patient's experience of the management of first-trimester complications. By combining essential elements of scientific research and clinical care, Early Pregnancy continues to set a benchmark for evidence-based management and will be essential reading for obstetricians, gynaecologists, neonatologists, ultrasonographers, and nurses seeking an understanding of the reproductive science of early pregnancy.
Die pädiatrische Akute Lymphatische Leukämie ist heutzutage gut behandelbar. Trotzdem ist die Prognose im Falle eines Rezidives weiterhin schlecht. Die häufigsten extramedullären Orte für Rezidive sind das zentrale Nervensystem und der Hoden. Um ein Rezidiv im Hoden zu verhindern, ist es nötig die zellulären und molekularen Vorgänge zu verstehen. Dafür wurde Patientenmaterial auf seine Expression bestimmter Oberflächenmoleküle analysiert. Verglichen wurden Proben von Patienten mit verschiedenen Rezidiv-Arten. Um die funktionellen Aspekte der Hodenphysiologie auf die Leukämiezellmigration und -lokalisation zu untersuchen wurde ein PDX-ALL Mausmodel mit Hodenbeteiligung etabliert. Um potenziell involvierte Chemokin-Chemokinrezeptor-Achsen zu identifizieren, wurden 55 Knochenmarksproben von Patienten untersucht. Die Expressionsmuster der Rezeptoren wurde mittels Durchflusszytometrie analysiert. Es wurde festgestellt, dass CXCR4 meistens sehr hoch exprimiert wird. Deshalb wurde anschließend der Einfluss der CXCR4-CXCL12 Achse in in vitro Versuchen mit Hilfe primären Hodenstromas untersucht. Um verschiedene Subpopulationen zu untersuchen, wurde die Isolation von Hodenmakrophagen, Sertoli Zellen und Peritubulären Zellen aus der Maus etabliert und ihr Einfluss auf ALL Zellen untersucht. Es wurde festgestellt, dass Hodenmakrophagen bei Tumorkontakt ihren Phänotyp zugunsten einer tumorfördernden Subpopulation verändern. Zu guter Letzt wurde ein adaptives PDX-ALL Mausmodel mit Hodenbeteiligung entwickelt. Dabei wurden die Hoden von vorpubertären Mäusen bevorzugt infiltriert. Die Bedeutung der CXCR4-CXCL12 Achse für die Hodeninfiltration wurde in einem in vivo Versuch validiert. Während Knochenmark und Milz nach einer anti-CXCR4 Gabe kleine ALL Populationen aufwiesen, war der Hoden komplett Tumor-frei. Das Model kann für Versuche genutzt werden, um weitere Signalwege zu identifizieren, welche in die Hoden gerichtete Migration und das Überleben der Zellen involviert sind.
The endometrium is composed of glandular and luminal epithelia supported by stromal connective tissue and multiple other
cell types. It is a dynamic organ that undergoes physiological and functional alteration during the menstrual cycle. Organoids
resemble the primary tissue of origin to recapitulate their corresponding biological and pathological characteristics. They are
known for their ability to undergo extensive expansion while maintaining their genomic stability, facilitating their long-term storage
and high-throughput screening. The development of the three-dimensional endometrial organoid system, which recapitulates the
structural and functional characteristics of the endometrial glands, provides a powerful tool to study the normal endometrium and
its related diseases. The Web of Science was searched for relevant literature using the keywords “endometrium,” “endometrial
gland,” “organoid,” and “culture model”; a total of 134 articles were selected. In this review, the characteristics, applications, and
limitations of endometrial epithelial organoids are discussed.
Miscarriage can cause significant physical and psychological harm to women. The stromal cell-derived factor 1 (SDF-1, also known as CXCL12)/C-X-C motif chemokine receptor 4 (CXCR4) and C-X-C motif chemokine receptor 7 (CXCR7) axis can promote the proliferation and invasion of trophoblast cells in early pregnancy, and maintain immune tolerance at the maternal-fetal interface to aid with pregnancy success. From our findings, the serum CXCL12 level of women who have miscarried (n = 25) was significantly lower than that of healthy early pregnancy women (n = 20) by ELISA (P < .001). Additionally, CXCL12 levels in normal non-pregnant women (n = 20) were significantly lower than those in early pregnancy women (P < .001) and women who have miscarried (P < .001). Quantitative real-time PCR detected no significant difference in the mRNA transcription levels of CXCR4 and CXCR7 in the decidua tissues of women with early pregnancy (n = 20) and miscarriage (n = 20) (P = .724, P = .281, respectively). However, Western blot and immunohistochemistry of CXCR4 and CXCR7 in decidual tissue of women who have miscarried (n = 20) were significantly lower than those in early pregnancy women (n = 20) (P < .05 for both). Therefore, we believe that the increased serum CXCL12 levels in pregnant offspring may benefit normal pregnancy maintenance. The low level of CXCL12 in peripheral blood and the low expression of CXCR4 and CXCR7 proteins in decidua may be associated with the occurrence of early spontaneous abortion, and the clinical application value of serum CXCL12 in predicting adverse pregnancy outcomes is worth further exploring.
Cytokine support of embryonic development includes promotion of implantation and protection of blastomeres from cell stress and apoptosis. Correlations between embryo quality and concentrations of specific cytokines in culture media of human embryos have been investigated for many years. The aim of this study was to assess the concentrations of cytokines in preimplantation embryo culture media and to investigate their relationships with embryo quality and in vitro fertilization (IVF) outcomes. Seventy-two samples were obtained from 39 infertile couples undergoing IVF or intracytoplasmic sperm injection treatment between October 2018 and May 2019. Each embryo was cultured separately, and the embryo culture medium was collected 72 h after fertilization. Before embryo transfer on day 3, a morphological evaluation of each embryo was performed. Cytokine concentrations of each culture medium were analyzed for 23 selected cytokines using the Multiplex Cytokine/Chemokine Panel II Assay (Merck Millipore®). The results were categorized into two groups (top-quality and non-top-quality embryos). The median age of the 39 patients was 34 years. Nine of 23 cytokines were quantified and compared between the top-quality embryo group and non-top-quality embryo group. Among the nine cytokines, CCL15, CCL27, and CXCL-12 were significantly elevated in the top-quality embryo group. These results suggested that specific cytokines measured in human embryo culture media can be used to predict embryo quality and IVF outcomes.
Pregnancy presents the maternal immune system with a unique immunological challenge since it has to defend against pathogens while tolerating paternal allo-antigens expressed by fetal tissues. T helper (Th) cells play a central role in modulating immune responses and recent advances have defined distinct contributions of various Th cell subsets throughout each phase of human pregnancy, while dysregulation in Th responses show association with multiple obstetrical complications. In addition to localized decidual mechanisms, modulation of Th cell immunity during gestation is mediated largely by oscillations in sex hormone concentrations. Aberrant Th cell responses also underlie several autoimmune disorders while pregnancy-induced changes in the balance of Th cell immunity has been shown to exert favorable outcomes in the progression Th1 and Th17 driven autoimmune conditions only to be followed by post-partal exacerbations in disease.
Research question
What is the difference in endometrial transcriptomics between women with normal and with low mid-luteal progesterone during the implantation window?
Design
An endometrial biopsy and serum progesterone concentration were taken from participants during the mid-luteal phase (LH+7 to LH+9). A total of 12 participants were recruited and categorized into two groups based on their progesterone concentrations: normal progesterone (>15 ng/ml, n = 6) and low progesterone (<15 ng/ml, n = 6). Global endometrial gene expression between the two groups was compared by microarray techniques. Principal component analysis was used to display the gene's expression pattern. Pathway and gene ontology enrichment analysis were performed to determine the biological mechanism of progesterone on the endometrium.
Results
Several key genes related to endometrial receptivity were found to be regulated by progesterone. With regard to gene ontology and pathway analysis, progesterone was shown to be mainly involved in structure morphogenesis predominantly during a process of decidualization, extracellular matrix–receptor interaction and cell adhesion. Distinct differences were observed in the transcriptomic profiles between the two groups, indicating potential impairment of endometrial receptivity in women with suboptimal progesterone concentrations. There was a relatively similar pattern of gene expression between endometrial samples with progesterone concentrations approximately 10 ng/ml and >15 ng/ml. Thus, a progesterone concentration of between 10 and 15 ng/ml appears to be sufficient to induce endometrial receptivity.
Conclusions
Abnormally low progesterone below the threshold of 10–15 ng/ml during the implantation window results in aberrant endometrial gene expression that may affect implantation potential.
Gestational complications, including preeclampsia and gestational diabetes, have long-term adverse consequences for offspring’s metabolic and cardiovascular health. A low-grade systemic inflammatory response is likely mediating this. Here, we examine the consequences of LPS-induced gestational inflammation on offspring’s health in adulthood. LPS was administered to pregnant C57Bl/6J mice on gestational day 10.5. Maternal plasma metabolomics showed oxidative stress, remaining for at least 5 days after LPS administration, likely mediating the consequences for the offspring. From weaning on, all offspring was fed a control diet; from 12 to 24 weeks of age, half of the offspring received a western-style diet (WSD). The combination of LPS-exposure and WSD resulted in hyperphagia and increased body weight and body fat mass in the female offspring. This was accompanied by changes in glucose tolerance, leptin and insulin levels and gene expression in liver and adipose tissue. In the hypothalamus, expression of genes involved in food intake regulation was slightly changed. We speculate that altered food intake behaviour is a result of dysregulation of hypothalamic signalling. Our results add to understanding of how maternal inflammation can mediate long-term health consequences for the offspring. This is relevant to many gestational complications with a pro-inflammatory reaction in place.
Spontaneous abortion (SA) is a common pregnancy failure, but the cause of numerous cases remains unexplained. Decidual immune cells (DICs)-mediated cytokine microenvironment is involved in pregnancy and regulated by many microRNAs, but whether microRNA-146a-5p (miR-146a) regulate the decidual cytokine microenvironment and the potential mechanisms in unexplained SA pathogenesis have rarely been reported. In this study, the levels of cytokines and miR-146a in healthy and unexplained SA deciduae were first investigated, and the correlation between them was analyzed. Then, the effect of miR-146a inhibitor on cytokines was assessed in healthy deciduae-derived DICs. Third, the downstream targets and related molecular mechanisms of miR-146a were analyzed by bioinformatics, and the levels of the predicted targets in deciduae were assessed, followed by the correlation analysis between the levels of miR-146a and the targets. Finally, the effect of miR-146a on the predicted targets and inflammatory cytokines was validated in unexplained SA deciduae-derived DICs. As a result, decreased miR-146a correlated with the cytokine disorder in unexplained SA deciduae, and inhibition of miR-146a promoted pro-inflammatory response in healthy deciduae-derived DICs. One hundred four target genes and related molecular mechanisms of miR-146a were predicted, among which the toll-like receptor (TLR) pathway might be associated with the decidual cytokine regulation. Upregulation of miR-146a inhibited the expression of the predicted molecules enriched in the TLR pathway and improved the cytokine disorder in unexplained SA deciduae-derived DICs. Collectively, miR-146a improves the decidual cytokine microenvironment by regulating the TLR pathway in unexplained SA, providing novel potential targets for further therapeutic research.
In dieser Dissertation wurden murine Aorta-Explantate im experimentellen Ansatz des "Aortic Ring Assay" über elf Tage kultiviert, erstmalig die Differenzierung zu F4/80(+)-Makrophagen gezeigt und eine nahezu vollständige Depletion dieser Zellen durch Clodronat-Liposomen bewirkt. Diese Adventitia-generierten Makrophagen wurden als die Hauptquelle des lokal gebildeten VEGF nachgewiesen. Die daraus resultierende Depletion des parakrin wirkenden VEGF resultierte in einer teilweisen Konservierung der CD34(+) „Vaskulogenen Zone“ der aortalen Adventitia. Zu der Bestätigung dieser Ergebnisse wurde experimentell über den VEGF-Rezeptor-Blocker E7080 in das VEGF-VEGFR-2 System eingegriffen. Die Versuchsansätze mit diesem Rezeptorblocker resultierten in einem ähnlichen Ergebnis wie die Versuche unter Makrophagen-Depletion.
Previous studies highlighted chemokines as potential factors regulating changes in the endometrium during early pregnancy. The current study aimed to screen the effects of a broad range of chemokines and indicate those that are involved in porcine luminal epithelial (LE) cell remodelling. Messenger RNA expression of chemokines (CCL2, CCL4, CCL5, CCL8, CXCL2, CXCL8, CXCL10 and CXCL12) and both the mRNA and protein expression of their receptors (CCR1, CCR2, CCR3, CCR5, CXCR2, CXCR3, CXCR4) were detected in LE cells. Exogenous CCL8 enhanced the proliferative and migration potential of LE cells and their motility in the environment with its stable concentration. The adhesive properties of LE cells were negatively affected by CCL8. However, CXCL12 positively affected the proliferation, motility and adhesion of LE cells as well as caused a decrease in MUC1 mRNA expression. To conclude, our studies determined that exogenous chemokines affected critical endometrial epithelial cell functions in the context of embryo implantation. We suggest that of all the examined factors, chemokine CCL8 participates in the establishment of a proper environment for embryo implantation, whereas CXCL12, apart from participation in endometrial receptivity, promotes embryo attachment.
The implantation of fertilized ova and the formation of the placenta are crucial steps in reproduction. This review summarizes current information about these steps, including some of the molecular mechanisms that mediate them and how they may go awry, with consequent loss of the pregnancy.
The fetus is considered to be an allograft that, paradoxically, survives pregnancy despite the laws of classical transplantation immunology. There is no direct contact of the mother with the embryo, only with the extraembryonic placenta as it implants in the uterus. No convincing evidence of uterine maternal T-cell recognition of placental trophoblast cells has been found, but instead, there might be maternal allorecognition mediated by uterine natural killer cells that recognize unusual fetal trophoblast MHC ligands.
Does the manipulation of gametes and embryos as practised in human IVF invoke perturbations in fetal and neonatal phenotype?
There is increasing evidence that the answer is ‘yes’, although the degree of perturbation may be less acute than observed
in other species. However, the long-term consequences are not known, and may prove to be considerable. There is now a substantial
body of evidence from animal models suggesting that assisted reproductive technologies (ART) are associated with altered outcomes
in fetal and neonatal development. Epigenetic modification of gene expression is an attractive hypothesis that accounts for
these differences and is one of a number of causal pathways that may be activated by cellular stress invoked during manipulation.
Here we widen the debate to propose that environment-induced cellular stress also acts to modify fetal and placental gene
expression, potentially also contributing to phenotype skewing after ART.
Trophoblast adhesion to the uterine wall is the requisite first step of implantation and, subsequently, placentation. At the
maternal-fetal interface, we investigated the expression of selectin adhesion systems that enable leukocyte capture from the
bloodstream. On the maternal side, human uterine epithelial cells up-regulated selectin oligosaccharide-based ligands during
the window of receptivity. On the fetal side, human trophoblasts expressed L-selectin. This ligand-receptor system was functional,
because beads coated with the selectin ligand 6-sulfo sLex bound to trophoblasts, and trophoblasts bound to ligand-expressing uterine luminal epithelium in tissue sections. These results
suggest that trophoblast L-selectin mediates interactions with the uterus and that this adhesion mechanism may be critical
to establishing human pregnancy.
Immunological rejection of the fetus due to recognition of paternal antigens by the maternal immune system, resulting in abnormal immune cells and cytokine production, is postulated to be one cause of unexplained pregnancy loss. Although there is evidence for this in rodents, there is less evidence in humans. This article focuses on studies in humans, and reviews the recent literature on the differences in immune cells and molecules in normal fertile women and women with recurrent miscarriage (RM). Although much of the evidence is contradictory, these studies do suggest differences in the expression of some immune cells and molecules in women with RM. Differences in the CD56+ population of cells are seen, and there is some evidence for an alteration in the ratio of Th1 and Th2 cytokines produced by peripheral blood monocytes (PBMCs) and clones of decidual CD4+ cells. There is also some evidence for differences in endometrial cytokine production, and in particular decreased production of pro-inflammatory cytokines such as interleukin-6. Possible reasons for the variations in data are discussed, and the importance of compartment (peripheral blood, endometrium or decidua) in which the cells and molecules are measured and the timing of the sampling, both with respect to the menstrual cycle and pregnancy (at the time or just after miscarriage) is emphasized.
At the human feto-maternal interface, trophoblasts differentiate towards extravillous trophoblasts (EVTs) and form the cell column. EVTs acquire invasive activity in the distal part of the cell column and begin to migrate into the maternal tissue. We previously reported that dipeptidyl peptidase IV(DPPIV) is expressed on EVTs in the proximal part of cell column and is involved in the inhibition of their migration. Because DPPIV has been shown to degrade several chemokines, we examined possible roles of chemokines in EVT migration.
Immunohistochemistry demonstrated that C-C chemokine receptor 1 (CCR1) was hardly detected on cytotrophoblasts and syncytiotrophoblast but was expressed on EVTs in the cell column. In vitro, CCR1 protein was also present on the surface of EVTs that grew out from chorionic villous explants cultured under 20% O2. Chemokines that can bind to CCR1 (CCR1 ligands), such as regulated on activation, normal T cell expressed and secreted (RANTES) and macrophage inflammatory protein-1α (MIP-1α), were confirmed in the decidual tissues by RT-PCR and immunohistochemistry. These CCR1 ligands promoted the migration of the EVTs that were isolated from the explant cultures in vitro. These results indicate that CCR1 is expressed on trophoblasts as they differentiate to EVTs and that CCR1 ligands produced from the decidual tissue induce EVT migration.
By contrast, CCR1 was scarcely expressed on EVTs that grew out from villous explants cultured in 1% O2, indicating that a relatively high oxygenic environment is needed to induce CCR1 expression. Moreover, CCR1 expression on the isolated EVTs was significantly reduced in the presence of decidua-conditioned medium. Such regulation of CCR1 by surrounding oxygenic and decidual environments supports a close correlation between EVT invasion and their expression of CCR1.
This study demonstrates that trophoblasts acquire CCR1 as they differentiate to an invasive phenotype at the villus-anchoring sites and indicates a novel role for the chemokine-CCR1 system in the initial step of trophoblastic invasion towards the maternal tissue.
Decidualization of endometrial stromal cells is a prerequisite for human implantation and occurs in vivo in response to progesterone and involves activation of the protein kinase A (PKA) pathway. The objective of this study was to determine the molecular signatures and patterns of gene expression during stimulation of this pathway with an analog of cAMP. Endometrial stromal cells from two subjects were treated with or without 8-Br-cAMP (1 mM) for 0, 2, 12, 24, 36, and 48 h and were processed for microarray analysis, screening for 12,686 genes and ESTs. Most abundantly upregulated genes included neuropeptides, immune genes, IGF family members, cell cycle regulators, extracellular matrix proteases, cholesterol trafficking, cell growth and differentiation, hormone signaling, and signal transduction. Most abundantly downregulated genes included activator of NF-kappaB, actin/tropomyosin/calmodulin binding protein, cyclin B, IGFBP-5, alpha1 type XVI collagen, lipocortin III, l-kynurenine hydrolase, frizzle-related protein, and cyclin E2. RT-PCR validated upregulation of IGFBP-1, preprosomatostatin, and IL-11, and Northern analysis validated their kinetic upregulation. RT-PCR confirmed downregulation of IGFBP-5, cyclin B, and TIL-4. K-means analysis revealed four major patterns of up- and downregulated genes, and genes within each ontological group were categorized into these four kinetic patterns. Within each ontological group different patterns of temporal gene expression were observed, indicating that even genes within one functional category are regulated differently during activation of the PKA pathway in human endometrial stromal cells. Overall, the data demonstrate kinetic reprogramming of genes within specific functional groups and changes in genes associated with nucleic acid binding, cell proliferation, decreased G protein signaling, increased STAT pathway signaling, structural proteins, cellular differentiation, and secretory processes. These changes are consistent with cAMP modulating early events (0-6 h) primarily involving cell cycle regulation, subsequent events (12-24 h) involving cellular differentiation (including changes in morphology and secretory phenotype), and late events (24-48 h) mediating more specialized function, including immune modulators, in the human endometrial stromal cell.
The objective of this study was to assess the LIF (leukemia inhibitory factor) concentration in uterine flushing and serum (ELISA) of women with proven fertility, infertile women and women with recurrent miscarriage. In addition, progesterone level was determined in serum. A decreased production of LIF in the uterine microenvironment was found in states of impaired fertility. With a cut-off point of 8.23 pg/ml for LIF level in uterine flushings we have achieved 86.7% sensitivity and 100% specificity in detection of women with idiopathic infertility compared to fertile controls. No correlation between LIF in serum and uterine flushing was demonstrated, rendering LIF measurements in serum useless for diagnosis of impaired infertility. We conclude that LIF measurement in uterine flushing could be a useful diagnostic tool to predict unsuccessful implantation.
Human endometrium possesses a unique immunological environment enabling implantation of the semiallogeneic embryo. Large populations of macrophages and uterine-specific natural killer cells infiltrate the implantation site, believed to be important modulators of trophoblast invasion and decidualization. In the absence of pregnancy, there is a dramatic influx of neutrophils, eosinophils, and macrophages, likely to be critical for focal inflammatory endometrial destruction. However, little is known regarding selective recruitment of leukocyte subtypes. We employed a gene array approach to analyze the expression of 21 chemokines in endometrium. Real-time RT-PCR and immunohistochemistry was conducted to verify expression patterns and determine cellular source. Nine chemokines were highly abundant in human endometrium: monocyte chemotactic protein-3, eotaxin, fractalkine, macrophage inflammatory protein-1beta, 6Ckine, IL-8, hemofiltrate CC chemokine-1 and -4, and macrophage-derived chemokine. Chemokine mRNA was generally up-regulated during endometrial receptivity and early pregnancy, particularly of macrophage and natural killer chemoattractants. Chemokine protein was predominantly localized to epithelial glands, whereas differentiated stromal cells were a major source of chemokines after decidualization. This is the first study to use an unbiased approach to screen for endometrial chemokines, and we report the selective regulation of chemokines, corresponding to the recruitment of distinct leukocyte subpopulations required for pregnancy and menstruation.
A clear parallelism between the different steps in human embryo-endometrial apposition/adhesion/invasion and leukocyte-endothelium rolling/adhesion/extravasation can be established. During human implantation and leukocyte trafficking, a first wave of soluble mediators regulates the expression and functional activity of adhesion molecules such as L-selectin and integrins, which mediate both processes. Apical surfaces of human endometrial epithelium and endothelium are key elements for the initiation of molecular interactions to capture the blastocyst or leukocyte, respectively. Subsequently, the blastocyst and the leukocyte migrate through the epithelium and endothelium toward their final destination, the endometrial stroma, to initiate placentation or the inflammatory foci as part of the immune response. Similarities between the intermediate molecular mechanisms of these two physiologically unrelated processes are discussed.
In humans, fetal cytotrophoblasts leave the placenta and enter the uterine wall, where they preferentially remodel arterioles. The fundamental mechanisms that govern these processes are largely unknown. Previously, we have shown that invasive cytotrophoblasts express several chemokines, as well as the receptors with which they interact. Here, we report that these ligand-receptor interactions stimulate cytotrophoblast migration to approximately the same level as a growth factor cocktail that includes serum. Additionally, cytotrophoblast commitment to uterine invasion was accompanied by rapid downregulation of EPHB4, a transmembrane receptor associated with venous identity, and upregulation of ephrin B1. Within the uterine wall, the cells also upregulated expression of ephrin B2, an EPH transmembrane ligand that is associated with arterial identity. In vitro cytotrophoblasts avoided EPHB4-coated substrates; upon co-culture with 3T3 cells expressing this molecule, their migration was significantly inhibited. As to the mechanisms involved, cytotrophoblast interactions with EPHB4 downregulated chemokine-induced but not growth factor-stimulated migration. We propose that EPHB4/ephrin B1 interactions generate repulsive signals that direct cytotrophoblast invasion toward the uterus, where chemokines stimulate cytotrophoblast migration through the decidua. When cytotrophoblasts encounter EPHB4 expressed by venous endothelium, ephrin B-generated repulsive signals and a reduction in chemokine-mediated responses limit their interaction with veins. When they encounter ephrin B2 ligands expressed in uterine arterioles, migration is permitted. The net effect is preferential cytotrophoblast remodeling of arterioles, a hallmark of human placentation.
Implantation involves an intricate discourse between the embryo and uterus and is a gateway to further embryonic development. Synchronizing embryonic development until the blastocyst stage with the uterine differentiation that takes place to produce the receptive state is crucial to successful implantation, and therefore to pregnancy outcome. Although implantation involves the interplay of numerous signalling molecules, the hierarchical instructions that coordinate the embryo-uterine dialogue are not well understood. This review highlights our knowledge about the molecular development of preimplantation and implantation and the future challenges of the field. A better understanding of periimplantation biology could alleviate female infertility and help to develop novel contraceptives.
Transforming growth factor beta (TGFbeta) superfamily members are closely associated with tissue remodelling events and reproductive processes. This review summarises the current state of knowledge regarding the expression and actions of TGFbeta superfamily members in the uterus, during the menstrual cycle and establishment of pregnancy. TGFbetas and activin beta subunits are abundantly expressed in the endometrium, where roles in preparation events for implantation have been delineated, particularly in promoting decidualisation of endometrial stroma. These growth factors are also expressed by epithelial glands and secreted into uterine fluid, where interactions with preimplantation embryos are anticipated. Knockout models and embryo culture experiments implicate activins, TGFbetas, nodal and bone morphogenetic proteins (BMPs) in promoting pre- and post-implantation embryo development. TGFbeta superfamily members may therefore be important in the maternal support of embryo development. Following implantation, invasion of the decidua by fetal trophoblasts is tightly modulated. Activin promotes, whilst TGFbeta and macrophage inhibitory cytokine-1 (MIC-1) inhibit, trophoblast migration in vitro, suggesting the relative balance of TGFbeta superfamily members participate in modulating the extent of decidual invasion. Activins and TGFbetas have similar opposing actions in regulating placental hormone production. Inhibins and activins are produced by the placenta throughout pregnancy, and have explored as a potential markers in maternal serum for pregnancy and placental pathologies, including miscarriage, Down's syndrome and pre-eclampsia. Finally, additional roles in immunomodulation at the materno-fetal interface, and in endometrial inflammatory events associated with menstruation and repair, are discussed.
Human CD56(bright) NK cells accumulate in the maternal decidua during pregnancy and are found in direct contact with fetal trophoblasts. Several mechanisms have been proposed to explain the inability of NK cells to kill the semiallogeneic fetal cells. However, the actual functions of decidual NK (dNK) cells during pregnancy are mostly unknown. Here we show that dNK cells, but not peripheral blood-derived NK subsets, regulate trophoblast invasion both in vitro and in vivo by production of the interleukin-8 and interferon-inducible protein-10 chemokines. Furthermore, dNK cells are potent secretors of an array of angiogenic factors and induce vascular growth in the decidua. Notably, such functions are regulated by specific interactions between dNK-activating and dNK-inhibitory receptors and their ligands, uniquely expressed at the fetal-maternal interface. The overall results support a 'peaceful' model for reproductive immunology, in which elements of innate immunity have been incorporated in a constructive manner to support reproductive tissue development.
During the invasive phase of implantation, trophoblasts and maternal decidual stromal cells secrete products that regulate trophoblast differentiation and migration into the maternal endometrium. Paracrine interactions between the extravillous trophoblast and the maternal decidua are important for successful embryonic implantation, including establishing the placental vasculature, anchoring the placenta to the uterine wall, and promoting the immunoacceptance of the fetal allograph. To our knowledge, global crosstalk between the trophoblast and the decidua has not been elucidated to date, and the present study used a functional genomics approach to investigate these paracrine interactions. Human endometrial stromal cells were decidualized with progesterone and further treated with conditioned media from human trophoblasts (TCM) or, as a control, with control conditioned media (CCM) from nondecidualized stromal cells for 0, 3, and 12 h. Total RNA was isolated and processed for analysis on whole-genome, high-density oligonucleotide arrays containing 54,600 genes. We found that 1374 genes were significantly upregulated and that 3443 genes were significantly downregulated after 12 h of coincubation of stromal cells with TCM, compared to CCM. Among the most upregulated genes were the chemokines CXCL1 (GRO1) and IL8,CXCR4, and other genes involved in the immune response (CCL8 [SCYA8], pentraxin 3 (PTX3), IL6, and interferon-regulated and -related genes) as well as TNFAIP6 (tumor necrosis factor alpha-induced protein 6) and metalloproteinases (MMP1, MMP10, and MMP14). Among the downregulated genes were growth factors, e.g., IGF1, FGF1, TGFB1, and angiopoietin-1, and genes involved in Wnt signaling (WNT4 and FZD). Real-time RT-PCR and ELISAs, as well as immunohistochemical analysis of human placental bed specimens, confirmed these data for representative genes of both up- and downregulated groups. The data demonstrate a significant induction of proinflammatory cytokines and chemokines, as well as angiogenic/static factors in decidualized endometrial stromal cells in response to trophoblast-secreted products. The data suggest that the trophoblast acts to alter the local immune environment of the decidua to facilitate the process of implantation and ensure an enriched cytokine/chemokine environment while limiting the mitotic activity of the stromal cells during the invasive phase of implantation.
Chorionic gonadotropin (CG) is an early embryo-derived signal that is known to support the corpus luteum. An in vivo baboon model was used to study the direct actions of human CG (hCG) on the endometrium, during the periimplantation period. Endometrial gene expression was analyzed using microarrays. The endometrial biopsies were taken from hCG-treated (n = 5) and control (n = 6) animals on d 10 after ovulation. Class comparison identified 61 genes whose transcript levels differed between control and hCG-treated samples (48 increased, 13 decreased in mean expression level more than 2.5-fold; P < 0.01). Real-time PCR of transcript abundance confirmed up-regulation of several of these, including SerpinA3, matrix metalloproteinase 7, leukemia inhibitory factor (LIF), IL-6, and Complement 3 (P </= 0.05). Analysis of protein abundance in endometrial flushings showed increased LIF and IL-6 protein in uterine flushings from hCG-treated animals compared with controls. Complement C3 and Superoxide dismutase 2 that were also up-regulated, were further evaluated by immunocytochemistry. Complement C3 showed a marked increase in stromal staining in response to hCG, whereas and superoxide dismutase 2 localization was most markedly increased in the glandular epithelial cells. Expression of Soluble Frizzled Related Protein 4, the most highly down-regulated gene, was also validated by PCR. Our experiments have shown that hCG induces alterations in the endometrial expression of genes that regulate embryo attachment, extracellular matrix remodeling and the modulation of the immune response around the implanting blastocyst. Several of these genes, including LIF and gp130, have been shown to be essential for implantation in other species. This study provides strong evidence that the preimplantation embryo itself influences the development of the receptive endometrium via secreted paracrine signals.
Endometrium is a dynamic tissue that responds on a cyclic basis to circulating levels of the ovarian-derived steroid hormones, estradiol and progesterone. Functional genomics has enabled a global approach to understanding gene regulation in whole endometrial tissue in the setting of a changing hormonal milieu. The proliferative phase of the cycle, under the influence of estradiol, has a preponderance of genes involved in DNA synthesis and cell cycle regulation. Interestingly, genes encoding ion channels and cell adhesion, as well as angiogenic factors, are also highly regulated in this phase of the cycle. After the LH surge, different gene expression profiles are uniquely observed in the early secretory, mid-secretory (window of implantation), and late secretory phases. The early secretory phase is notable for up-regulation of multiple genes and gene families involved in cellular metabolism, steroid hormone metabolism, as well as some secreted glycoproteins. The mid-secretory phase is characterized by multiple biological processes, including up-regulation of genes encoding secreted glycoproteins, immune response genes with a focus on innate immunity, and genes involved in detoxification mechanisms. In the late secretory phase, as the tissue prepares for desquamation, there is a marked up-regulation of an inflammatory response, along with matrix degrading enzymes, and genes involved in hemostasis, among others. This monograph reviews hormonal regulation of gene expression in this tissue and the molecular events occurring therein throughout the cycle derived from functional genomics analysis. It also highlights challenges encountered in using human endometrial tissue in translational research in this context.
Extravillous trophoblast cell (EVT) invasion of decidua and inner third of the myometrium is critical for a successful pregnancy. Many decidual factors are likely to play a role in regulating this process, including uterine natural killer (uNK) cell-derived cytokines.
1) uNK cells are a major source of IFN gamma (IFN-gamma) and 2) IFN-gamma inhibits EVT invasion via an increase in EVT apoptosis and/or a decrease in active protease levels.
Total decidual and uNK cells from 8-10 wk and 12-14 wk gestational age were cultured. IFN-gamma mRNA (real-time RT-polymerase chain reaction) and protein levels (FastQuant multicytokine analysis) were determined. EVT invasion in the presence of IFN-gamma or anti-IFN-gamma-neutralizing antibodies was assessed. Trophoblast apoptosis and proliferation was assessed in explants by immunohistochemistry for M30 and Ki67. Substrate zymography was performed to determine levels of secreted MMP2, MMP9, and uPA.
mRNA and protein for IFN-gamma was detected in both total decidual and uNK cell fractions. Trophoblast invasion was inhibited by IFN-gamma. The level of M30-positive EVT was increased in the presence of IFN-gamma whereas levels of secreted MMP2 were decreased.
uNK cells are a source of IFN-gamma within early human pregnancy decidua. Mechanisms of IFN-gamma inhibition of EVT invasion include both increased EVT apoptosis and reduced levels of active proteases.
Evidence suggests that chemokines, proteins involved in regulation of inflammation and immune response, may have a regulatory function in pregnancy. The authors hypothesized that circulating levels of chemokines are associated with increased risk of miscarriage. Serum samples were obtained from women in the Collaborative Perinatal Project cohort who had had a miscarriage (n=439) and controls (n=373) matched by gestational age at sample collection. Concentrations of interleukin 8, epithelial cell-derived neutrophil-activating peptide (ENA)-78, macrophage inhibitory protein (MIP)-1alpha, MIP-1beta, monocyte chemotactic protein 1, and RANTES (regulated upon activation, normal T-cell-expressed, and secreted) were determined by multiplex assays, and values were standardized using the standard deviation among controls. Conditional logistic regression was used to model the relation between chemokine levels and risk of miscarriage. In multivariable analysis using all available data, the authors did not observe significant associations between any of the evaluated chemokines and miscarriage risk. In analyses using subsets of the study population based on the collection-outcome interval, elevated ENA-78 levels were associated with increased risk of miscarriage as the collection-outcome interval increased; the adjusted odds ratio was 1.25 (95% confidence interval: 1.04, 1.49) for samples collected more than 35 days prior to pregnancy outcome. The observation regarding ENA-78, which has roles in regulation of angiogenesis and leukocyte recruitment, suggests a possible role for this chemokine as an early indicator of miscarriage risk.
The process of implantation, necessary for all viviparous birth, consists of tightly regulated events, including apposition
of the blastocyst, attachment to the uterine lumen, and differentiation of the uterine stroma. In rodents and primates the
uterine stroma undergoes a process called decidualization. Decidualization, the process by which the uterine endometrial stroma
proliferates and differentiates into large epithelioid decidual cells, is critical to the establishment of fetal-maternal
communication and the progression of implantation. The role of bone morphogenetic protein 2 (Bmp2) in regulating the transformation of the uterine stroma during embryo implantation in the mouse was investigated by the conditional
ablation of Bmp2 in the uterus using the (PR-cre) mouse. Bmp2 gene ablation was confirmed by real-time PCR analysis in the PR-cre; Bmp2fl/fl (termed Bmp2d/d) uterus. While littermate controls average 0.9 litter of 6.2 ± 0.7 pups per month, Bmp2d/d females are completely infertile. Analysis of the infertility indicates that whereas embryo attachment is normal in the Bmp2d/d as in control mice, the uterine stroma is incapable of undergoing the decidual reaction to support further embryonic development.
Recombinant human BMP2 can partially rescue the decidual response, suggesting that the observed phenotypes are not due to
a developmental consequence of Bmp2 ablation. Microarray analysis demonstrates that ablation of Bmp2 leads to specific gene changes, including disruption of the Wnt signaling pathway, Progesterone receptor (PR) signaling, and the induction of prostaglandin synthase 2 (Ptgs2). Taken together, these data demonstrate that Bmp2 is a critical regulator of gene expression and function in the murine uterus.
In human endometrium, cytokines and growth factors that vary periodically during the menstrual cycles have been suggested to play various roles in uterine function. In the present study, differential gene expression in human endometrium between the proliferative and the secretory phases was investigated by using a human cDNA expression array system. Human interleukin (IL)-15 was identified as an up-regulated transcription product during the secretory phase, in comparison with the proliferative phase, and therefore its expression in human uterus was examined by Northern blot analysis. In human endometrium, expression of IL-15 mRNA significantly increased during the secretory phase compared with the proliferative phase (P < 0.01). The most abundant expression of IL-15 mRNA during the menstrual cycle was observed in the midsecretory phase. In the first trimester pregnancy, the expression of IL-15 mRNA in the decidua was significantly higher than that in the chorionic villi (P < 0.01). By using an in-vitro decidualization with human endometrial stromal cells, it was demonstrated that the expression of IL-15 mRNA is up-regulated during progesterone-induced decidualization. These results suggest that IL-15 plays a role in uterine function during pregnancy, as well as during the menstrual cycle.
During early pregnancy, in response to the implanting embryo, the surrounding uterine stroma undergoes a dramatic transformation into a specialized tissue known as the decidua. The decidua encapsulates the developing embryo, facilitating nutrient transfer and limiting trophoblast invasion. Here we show that female mice with a null mutation of the interleukin-11 receptor alpha chain are infertile because of defective decidualization. A temporal analysis revealed IL-11 expression is maximal in the normal pregnant uterus at the time of decidualization, and in situ hybridization studies showed expression of the IL-11 and the IL-11 receptor alpha chain in the developing decidual cells. These observations reveal a previously unrecognized critical role for IL-11 signaling in female reproduction.
During human pregnancy, the uterus is infiltrated by a population of maternal leukocytes that co-exist with fetal cytotrophoblasts occupying the decidua and uterine blood vessels. These immune cells, termed “decidual granulated leukocytes,” are composed predominately (70%) of the CD56bright subset of natural killer cells, accompanied by T cells (15%) and macrophages (15%). The mechanisms underlying the recruitment of these cells are unknown, but by analogy to other systems, chemokines are likely to be involved. We examined the expression patterns of 14 chemokines in the decidualized uterine wall by in situ hybridization, and the expression of chemokine receptors on decidual leukocytes by RNase protection. The striking concordance between the expression of chemokines in the uterus and their receptors on decidual leukocytes allowed us to identify numerous receptor-ligand pairs that may recruit the latter cells to the uterus during pregnancy. Additionally, chemokine expression patterns suggested other, nonimmune functions for these molecules, including a role in cytotrophoblast differentiation. Together, our results imply that chemokine networks serve important functions at the maternal-fetal interface.
A critical point during mammalian pregnancy is the implantation of the blastocyst when the embryo attaches to the wall of the uterus. The autonomously developing preimplantation embryo then becomes dependent on the maternal environment for its continued development. Little is known about the regulation of implantation, except that a complex interaction between peptide and steroid hormones synchronizes the preparation of the uterus for implantation with the development of the embryo. Whether the implantation event is under maternal or embryonic control is also unclear (reviewed in refs 1, 2). We have previously shown that a cytokine, leukaemia inhibitory factor (LIF), is expressed in the uterine endometrial glands specifically on the fourth day of pregnancy. This burst of expression is under maternal control and always precedes implantation of the blastocyst. Here we report that transient expression of LIF in mice is essential for implantation. Females lacking a functional LIF gene are fertile, but their blastocysts fail to implant and do not develop. The blastocysts, however, are viable and, when transferred to wild-type pseudopregnant recipients, they can implant and develop to term.
Leukaemia inhibitory factor (LIF) is a pleiotropic cytokine previously demonstrated to be essential for blastocyst implantation in mice. Samples of endometrium from normal cyclic women throughout the menstrual cycle were tested for LIF messenger RNA by Northern blot analysis and the corresponding protein was localised immunohistochemically with a polyclonal antibody to LIF. Western blot analysis detected a 45 kDa LIF protein in an extract from late secretory tissue. The expression of LIF messenger RNA transcript was detected only during the mid and late secretory phases of the cycle after day 20. Immunoreactive LIF was observed in all human endometrial samples. In the stroma there were moderate to high levels of immunohistochemical staining throughout the cycle with considerable variation between individuals but no cyclical variation. Epithelial staining, both luminal and glandular, was also present throughout the cycle but this was relatively low in the proliferative phase and strongest in the mid to late secretory phases. The marked cyclical changes of immunoreactive LIF in the human endometrial epithelium suggest a paracrine/autocrine role for LIF in endometrial function. Whether LIF is essential for implantation in the human remains to be established.
Journal of Endocrinology (1996) 148, 95–102
Recent findings suggest that coronary heart disease and stroke, and the associated conditions, hypertension and non-insulin dependent diabetes, originate through impaired growth and development during fetal life and infancy. These diseases may be consequences of 'programming', whereby a stimulus or insult at a critical, sensitive period of early life results in long-term changes in physiology or metabolism. Animal studies provide many examples of programming, which occurs because the systems and organs of the body mature during periods of rapid growth in fetal life and infancy. There are critical windows of time during which maturation must be achieved; and failure of maturation is largely irrecoverable.
This review examines evidence supporting the concept that menstruation occurs as a result of an inflammatory process. In the endometrium, leukocyte numbers rise in the late secretory phase following the fall in serum progesterone concentrations. It is postulated that products released following activation of these leukocytes are critically important for menstruation. Mast cells, eosinophils, neutrophils and macrophages in particular are involved. Endometrial granular lymphocytes may also play a role, although their increase in numbers is somewhat earlier during the menstrual cycle than that of the others, suggesting perhaps a primary role in embryo implantation. Leukocyte products include a range of proteases, chemokines and cytokines which in concert result in focal production and activation of matrix metalloproteinases by endometrial cells and the subsequent breakdown of tissue that characterizes menstruation. Regulation of leukocyte entry, proliferation, differentiation and activation within the endometrium is not yet well understood, although both chemokines and cytokines produced locally by endometrial cells are clearly implicated. The role of progesterone in regulating these events is still not understood although the lack of progesterone receptors on endometrial leukocytes suggests indirect actions.
Recombinant fractalkine possesses both chemoattractive and adhesive properties in vitro. Previous studies have demonstrated an upregulation of this molecule on the membranes of activated human endothelial cells and hypothesised that fractalkine plays a role in the recruitment and adherence of monocytes to the activated endothelium. Here we present data analysing both the adhesive and chemoattractive properties of this chemokine expressed by activated human umbilical vein endothelial cells. We demonstrate that both recombinant fractalkine and endogenously produced fractalkine function as adhesion molecules, tethering monocytes to the endothelium. However, our data demonstrate that although recombinant fractalkine has the potential to function as a potent monocyte chemoattractant, the endogenous fractalkine cleaved from activated human umbilical vein endothelial cells is not responsible for the observed chemotaxis in this model. Instead, we show that monocyte chemoattractant protein-1 (MCP-1), secreted from the activated human umbilical vein endothelial cells, is responsible for the chemotaxis of these monocytes.
The influx of inflammatory cells to sites of injury is largely directed by signals from the epithelium, but how these cells form chemotactic gradients is not known. In matrilysin null mice, neutrophils remained confined in the interstitium of injured lungs and did not advance into the alveolar space. Impaired transepithelial migration was accompanied by a lack of both shed syndecan-1, a heparan sulfate proteoglycan, and KC, a CXC chemokine, in the alveolar fluid. KC was bound to shed syndecan-1, and it was not detected in the lavage of syndecan-1 null mice. In vitro, matrilysin cleaved syndecan-1 from the surface of cells. Thus, matrilysin-mediated shedding of syndecan-1/KC complexes from the mucosal surface directs and confines neutrophil influx to sites of injury.
Recent studies indicate that chemoattractant cytokines (chemokines), together with tissue-specific adhesion molecules, coordinate the migration of antibody-secreting cells (ASCs) from their sites of antigen-driven differentiation in lymphoid tissues to target effector tissues. Developing ASCs downregulate the expression of receptors for lymphoid tissue chemokines and selectively upregulate the expression of chemokine receptors that might target the migration of IgA ASCs to mucosal surfaces, IgG ASCs to sites of tissue inflammation and both types of ASC to the bone marrow - an important site for serum antibody production. By directing plasma-cell homing, chemokines might help to determine the character and efficiency of mucosal, inflammatory and systemic antibody responses.
The materno-foetal relationship is not simply maternal tolerance of a foreign tissue, but a series of intricate mutual cytokine interactions governing selective immune regulation and also control of the adhesion and vascularisation processes during this dialogue. There is strong evidence that locally secreted cytokines, such as interleukine 18 (IL18) control the implantation process and can cause implantation failure in case of absence or overactivation. Uterine flushing fluids may be analysed to determine the level of several cytokines. At the time of egg retrieval, the flushing procedure does not adversely affect pregnancy rates. We report a strong positive correlation between the presence of IL18 in the uterine flushing and bad implantation rates. The presence of IL18 in the lumina is the traduction of an overactivation of endometrial IL18 that should be diagnosed and treated. Moreover, endometrial biopsy could define which type of cytokinic dysregulation is implicated in repeated implantation failure and define which type of treatment need to be introduced.
Chemokines are multifunctional molecules initially described as having a role in leukocyte trafficking and later found to participate in developmental processes such as differentiation and directed migration. Similar events occur in pregnancy during development of the fetal-maternal interface, where there is extensive leukocyte trafficking and tissue morphogenesis, and this is accompanied by abundant chemokine expression. The relationship between chemokines, leukocytes and placental development is beginning to be delineated. During pregnancy a specialised population of maternal leukocytes infiltrates the implantation site. These leukocytes are thought to sustain the delicate balance between protecting the developing embryo/fetus and tolerating its hemiallogeneic tissues. A network of chemokine expression by both fetal and maternal components in the pregnant uterus functions in establishing this leukocyte population. Intriguingly, experiments investigating immune cell recruitment revealed the additional possibility that chemokines influence aspects of placental development. Specifically, cytotrophoblasts, the effector cells of the placenta, express chemokine receptors that can bind ligands found at key locations, implicating chemokines as regulators of cytotrophoblast differentiation and migration. Thus, as in other systems, at the fetal-maternal interface chemokines might regulate multiple functions.
Leukocytes are critical mediators of endometrial remodeling, but the mechanisms by which leukocyte subpopulations enter the uterus are currently unknown. Endometrial leukocytes have no genomic progesterone receptors; thus, we hypothesized that leukocyte migration is induced indirectly by progesterone-regulated chemokines. Fractalkine (CX3CL1), a chemotactic membrane-bound adhesion factor, and its receptor (CX3CR1) were assessed by immunohistochemistry in endometrial samples across the menstrual cycle, in early pregnancy, and in women using progestin-only contraceptives. Fractalkine was localized predominantly to glandular epithelial and decidualized stromal cells, with the highest staining intensity in the secretory phase and early pregnancy. It was also detected in subpopulations of endometrial leukocytes (macrophages and uterine NK cells), with maximal numbers during the proliferative phase and early pregnancy. CX3CR1 was similarly colocalized to the glandular epithelium and decidualized stromal cells, with the highest expression in the secretory phase. CX3CR1-positive leukocytes (macrophages and neutrophils) were in greatest abundance during the menstrual phase. In the endometrium of women using progestin-only contraceptives, immunoreactive fractalkine was markedly reduced in the glandular epithelium, but was increased in decidualized stroma and infiltrating leukocytes. These findings support a number of roles for fractalkine in the endometrium, in the secretory phase, in early pregnancy, and when influenced by progestin-only contraceptives.
To determine whether primary human uterine epithelial cells in culture are able to influence monocyte chemotaxis and to establish whether the causal agent of chemotaxis is monocyte chemotactic protein (MCP)-1.
Tissue culture study.
University medical center.
Women aged 23 to 53 years who were undergoing hysterectomy (n=7).
Primary human endometrial epithelial cells were acquired from surgical specimens and grown to confluence and high transepithelial resistance. Conditioned media from epithelial cultures were analyzed for the presence of MCP-1 and for capacity to affect monocyte chemotaxis using the THP-1 monocyte line. Antibody neutralization of conditioned media was used to establish the role of MCP-1 in chemotaxis.
Assay of conditioned media for MCP-1, quantitative measurement of monocyte chemotaxis to conditioned media, and inhibition of chemotaxis by antibody neutralization of MCP-1.
Primary endometrial epithelial cells in monolayer culture secrete MCP-1 to both the apical and basolateral compartments. Monocyte chemotactic protein-1 was identified as the primary agent of monocyte chemotaxis by antibody neutralization.
These findings suggest that biologically active MCP-1 is secreted into both the uterine lumen as well as the underlying stroma and that it mediates the presence of monocytes, macrophages, and other immune cells in the uterine endometrium.
Enrichment of uterine natural killer (uNK) cells occurs during pregnancy in many species. However, functions of uNK cells and regulation of their uterine homing are not fully defined. In mice and women, uNK cells contribute to angiogenesis, a role reviewed here and now addressed in a mammal with an alternative placental type.
To address lymphocyte functions, RNA from murine or porcine endometrium and lymphocytes purified from endometrium were analyzed using real-time or reverse transcription PCR. To address homing potential, human blood CD56(+) lymphocytes were evaluated using both RNA and functional adhesion to endothelium presented under shear force in frozen sections of gestation day 7 C57Bl/6J implantation sites. Women were serially sampled over a menstrual cycle or a clinical preparatory cycle for embryo transfer.
Activation of murine uNK cells is associated with much greater increases in transcription for Eomes than for T-bet (Tbx21). Lymphocytes from normal porcine implantation sites transcribe vascular endothelial growth factor, placental growth factor, interferon-gamma and hypoxia-inducible factor (HIF)-1alpha. In fertile women, increases in L-selectin- and alpha4-integrin-mediated interactions between CD56(+) cells and endothelium occur at luteinizing hormone (LH) surge (cycling women) to oocyte pick up or embryo transfer, then return to pre-LH levels.
Uterine lymphocytes may universally promote pregnancy-associated endometrial angiogenesis. Recruitment of uNK precursor cells from blood appears to occur in a window promoted by rising plasma estrogen and LH and limited by rising progesterone.
The current study describes a statistically significant increase in macrophages (CD68-positive cells) in the decidua of preeclamptic patients. To elucidate the regulation of this monocyte infiltration, expression of monocyte chemoattractant protein-1 (MCP-1) was assessed in leukocyte-free first trimester decidual cells. Confluent decidual cells were primed for 7 days in either estradiol or estradiol plus medroxyprogesterone acetate to mimic the decidualizing steroidal milieu of the luteal phase and early pregnancy. The medium was exchanged for a serum-free defined medium containing corresponding steroids +/- tumor necrosis factor (TNF)-alpha or interleukin (IL)-1beta. After 24 hours, enzyme-linked immunosorbent assay measurements indicated that the addition of medroxyprogesterone acetate did not affect MCP-1 output, whereas 10 ng/ml of TNF-alpha or IL-1beta increased output by 83.5-fold +/- 20.6 and 103.1-fold +/- 14.7, respectively (mean +/- SEM, n = 8, P < 0.05). Concentration-response comparisons revealed that even 0.01 ng/ml of TNF-alpha or IL-1beta elevated MCP-1 output by more than 15-fold. Western blotting confirmed the enzyme-linked immunosorbent assay results, and quantitative reverse transcriptase-polymerase chain reaction confirmed corresponding effects on MCP-1 mRNA levels. The current study demonstrates that TNF-alpha and IL-1beta enhance MCP-1 in first trimester decidua. This finding suggests a mechanism by which recruitment of excess macrophages to the decidua impairs endovascular trophoblast invasion, the primary placental defect of preeclampsia.
Human embryo implantation is a complex process involving blastocyst attachment to the endometrial epithelium and subsequent trophoblast invasion of the decidua. Chemokines, critical regulators of leukocyte migration, are abundant in endometrial epithelial and decidual cells at this time. We hypothesized that endometrial chemokines stimulate trophoblast invasion. Chemokine receptors CX3CR1 and CCR1 were immunolocalized in human first-trimester implantation sites, specifically to endovascular extravillous trophoblasts, but not to the invading interstitial EVTs (iEVTs), with weak staining also on syncytium. CCR3 was localized to invading iEVTs and to microvilli on the syncytial surface. Expression of CX3CL1 (fractalkine), CCL7 (MCP-3), and their receptors (CX3CR1, CCR1, CCR2, CCR3, and CCR5) mRNA was examined in cellular components of the maternal-embryonic interface by RT-PCR. Both chemokines were abundant in entire endometrium and placenta, endometrial cells (primary cultures and HES, a human endometrial epithelial cell line) and trophoblast cell lines (JEG-3, ACIM-88, and ACIM-32). Chemokine receptor mRNA was expressed by placenta and trophoblast cell lines: CCR1 by all trophoblast cell types, whereas CCR2, CCR3, and CX3CR1 were more variable. CX3CR1, CCR1, CCR2, and CCR5 were also expressed by endometrial cells. Migration assays used the trophoblast cell line most closely resembling extravillous cytotrophoblast (AC1M-88). Trophoblast migration occurred in response to CX3CL1, CCL14, and CCL4, but not CCL7. Endometrial cell-conditioned media also stimulated trophoblast migration; this was attenuated by neutralizing antibodies to CX3CL1 and CCL4. Thus, chemokines are expressed by maternal and embryonic cells during implantation, whereas corresponding receptors are on trophoblast cells. Promotion of trophoblast migration by chemokines and endometrial cell conditioned medium indicates an important involvement of chemokines in maternal-fetal communication.
Remodelling of the human endometrium occurs during the normal menstrual cycle. This process involves the disintegration of the superficial or functionalis layer of the endometrium following the fall in progesterone resulting from the demise of the corpus luteum and the reconstruction of a new layer without scarring. The degradative properties of matrix metalloproteinases (MMP) and their presence in the endometrium during remodelling events suggests that they are effector molecules in this process. The features of menstruation parallel those of an inflammatory response and the abundance of leukocytes in the endometrium prior to the onset of menstruation indicates a role for these cells in the remodelling process. This review examines the relationship between leukocytes and the local production and activation of MMP within the endometrium.
Impaired implantation in assisted reproduction cycles with high serum estradiol (E2) concentrations may be related to abnormal endometrial functions.
The in vivo expression of T helper type 2 (Th2) cytokines in the periimplantation endometrium of infertile patients was compared between natural and stimulated cycles.
Uterine flushings and endometrial biopsies were collected 7 d after the LH surge in natural cycles or after human chorionic gonadotropin injection in stimulated cycles. Th2 cytokines were determined by immunolocalization and by ELISA. Natural cycles were in group A, whereas stimulated cycles with peak serum E2 of no more than 20,000 pmol/liter (moderate responders) and more than 20,000 pmol/liter (excessive responders) were classified as group B and group C, respectively.
Higher E2 had a negative effect on IL-11 and IL-6 expression in the endometrium and IL-11 concentration in the uterine flushing. In endometrial biopsies, a significantly lower immunostaining of stromal IL-11 (P < 0.001) and glandular IL-6 (P < 0.05) was detected in group C compared with that of groups A and B. IL-11 concentration by ELISA was significantly lower in group C (P < 0.05). Endometrial leukemia inhibitory factor and IL-4 expression was similar in the three groups. In uterine flushings, a significantly higher percentage of women in group C had undetectable IL-11 and a lower IL-11 concentration (P < 0.01) compared with group A, whereas no difference in IL-6 concentration was noted in the three groups.
Reduced expression of IL-11 and IL-6 in periimplantation endometrium may account for lower implantation in excessive responders.
Investigating the interaction of human endometrium and trophoblast during implantation is difficult in vitro and impossible in vivo. This study was designed to analyze the effect of trophoblast on endometrial stromal cells during implantation by comprehensive gene profiling. An in vitro coculture system of endometrial stromal cells with first-trimester trophoblast explants was established. Trophoblast and endometrial stromal cells were separated after 24 h. Gene expression of endometrial stromal cells after coculture was compared with the gene expression of endometrial stromal cells cultured alone by microarray analysis. We confirmed the expression of distinct genes using real-time PCR. Genes up-regulated included those for inflammatory response, immune response, and chemotaxis (pentraxin-related gene 3, chemokine ligands, IL-8, IL-1 receptors, IL-18 receptor, IL-15, IL-15 receptor, TNF-alpha-induced protein 6, and IL-6 signal transducer), regulators of cell growth (IGF-binding proteins 1 and 2) and signal transduction. Also up-regulated were genes for growth and development, glucose metabolism, and lipid metabolism: DKK-1, WISP, IGF-II, hydroxysteroid 11beta-dehydrogenase 1, hydroxyprostaglandin dehydrogenase 15, prostaglandin E synthase, prostaglandin F receptor, aldehyde dehydrogenase 1 family, member A3 and phosphatidic acid phosphatase type 2B. Other genes included genes for cell-cell signaling (pre-B-cell colony-enhancing factor 1), proteolysis, calcium ion binding, regulation of transcription, and others. Down-regulated genes included genes for proteolysis (MMP-11 and mitochondrial intermediate peptidase), genes for cell death (caspase 6, death-associated protein kinase 1, and histone deacetylase 5), transcription factors (sex determining region Y-box 4, dachshund homolog 1, ets variant gene 1, and zinc finger protein 84 and 435), and genes for humoral immune response (CD24 antigen). Trophoblast has a significant impact on endometrial stromal cell gene expression. Some of the genes regulated by trophoblast in endometrial stromal cells are already known to be regulated by progesterone and show the endocrine function of trophoblast during pregnancy. Others are genes so far unknown to play a role in endometrial-trophoblast interaction and open a wide field of investigation.
A diverse array of cytokines is implicated in regulating the immune adaptation and endometrial tissue remodelling events that facilitate successful embryo implantation and early placental development. The aim of this study was to evaluate expression of mRNAs encoding a panel of immunoregulatory cytokines in the endometrium of fertile women and women experiencing recurrent miscarriage using highly sensitive, quantitative RT-PCR assays. Endometrial biopsies were collected during the mid-secretory phase of the menstrual cycle from women classified as proven fertile (control; n=12) and women experiencing unexplained recurrent miscarriage (RM; n=9). Reduced IL-6 mRNA and reduced IL-1alpha mRNA were independently associated with recurrent miscarriage. Altered expression was evident after accounting for variation in the composition of endometrial biopsies by normalization of data to epithelial and mesenchymal cell-specific transcripts, cytokeratin-18 mRNA and vimentin mRNA, respectively. The relative abundance of mRNAs encoding LIF, GM-CSF, IFNgamma, IL-1beta, IL-4, IL-5, IL-10, IL-12p40, TNFalpha, TGFbeta1, TGFbeta2 and TGFbeta3 were not altered in recurrent miscarriage tissue. Associations between expression of IL-10, LIF, GM-CSF and TGFbeta2 suggest that regulatory circuits link the transcription of these cytokine genes. Inadequate expression of IL-6 and IL-1alpha mRNAs in endometrial tissue may predispose to recurrent miscarriage through a perturbed maternal immune response, effects on decidual tissue remodeling and angiogenesis, or dysregulated trophoblast differentiation and invasion. Quantitative RT-PCR assays for these cytokines in endometrial biopsies may be a realistic strategy for development of novel diagnostics for predisposition to recurrent miscarriage.
Chemokines are well known for their roles in the immune system; convincing evidence has emerged demonstrating a broader role for chemokines in the endometrium, particularly during embryo implantation. This review highlights the evidence on newly defined roles for chemokines in the endometrium during embryo implantation, with particular focus on those chemokines expressed by the endometrium.
The highly regulated temporal and spatial expression of chemokines in the endometrium leads not only to specific recruitment and activation of appropriate leucocytes but also coordinates the precisely orchestrated invasion of trophoblasts through the decidua and maternal vasculature. Results to date implicate chemokine signalling at the maternal-foetal interface in important processes during implantation and placentation, such as leucocyte recruitment and controlled trophoblast invasion. Unravelling such actions of chemokines in the endometrium has provided new insights into these complex processes.
Disturbances of chemokine production, processing, or actions are likely to contribute to dysfunction of implantation and placentation, with implications for early pregnancy loss and disturbed placental and foetal development. More research into altered chemokine function in such conditions may provide leads for new clinical interventions.
The reproductive tissues undergo profound structural changes and major immune adaptation to accommodate pregnancy. Granulocyte-macrophage colony-stimulating factor (GM-CSF) is one of an array of cytokines with pivotal roles in embryo implantation and subsequent development. Several cell lineages in the reproductive tract and gestational tissues synthesise GM-CSF under direction by ovarian steroid hormones and signalling agents originating in male seminal fluid and the conceptus. The pre-implantation embryo, invading placental trophoblast cells and the abundant populations of leukocytes controlling maternal immune tolerance are all subject to GM-CSF regulation. GM-CSF deficiency in pregnancy adversely impacts fetal and placental development, as well as progeny viability and growth after birth, highlighting this cytokine as a central maternal determinant of pregnancy outcome with clinical relevance in human fertility.