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International Journal of Biological... 2022In some cases of spontaneous miscarriage (SM), the exact etiology cannot be determined. Autophagy, which is responsible for cellular survival under stress conditions,... (Review)
Review
In some cases of spontaneous miscarriage (SM), the exact etiology cannot be determined. Autophagy, which is responsible for cellular survival under stress conditions, has also been implicated in many diseases. Recently, it is also surmised to be correlated with SM. However, the detailed mechanism remains elusive. In fact, there are several essential steps during pregnancy establishment and maintenance: trophoblasts invasion, placentation, decidualization, enrichment and infiltration of decidua immune cells (e.g., natural killer, macrophage and T cells). Accordingly, upstream molecules and downstream effects of autophagy are discussed in these processes, respectively. Of note, autophagy regulates the crosstalk between these cells at the maternal-fetal interface as well. Aberrant autophagy is found in villi, decidual stromal cells, peripheral blood mononuclear cells in SM patients, although the findings are inconsistent among different studies. Furthermore, potential treatments targeting autophagy are included, during which rapamycin and vitamin D are hot-spots in recent literatures. To conclude, a moderately activated autophagy is deeply involved in pregnancy, suggesting that autophagy should be a regulator and promising target for treating SM.
Topics: Abortion, Spontaneous; Autophagy; Decidua; Female; Humans; Leukocytes, Mononuclear; Pregnancy; Trophoblasts
PubMed: 35173545
DOI: 10.7150/ijbs.68335 -
ELife Jul 2023Decidualization is a process in which endometrial stromal fibroblasts differentiate into specialized secretory decidual cells and essential for the successful...
Decidualization is a process in which endometrial stromal fibroblasts differentiate into specialized secretory decidual cells and essential for the successful establishment of pregnancy. The underlying mechanism during decidualization still remains poorly defined. Because decidualization and fibroblast activation share similar characteristics, this study was to examine whether fibroblast activation is involved in decidualization. In our study, fibroblast activation-related markers are obviously detected in pregnant decidua and under in vitro decidualization. ACTIVIN A secreted under fibroblast activation promotes in vitro decidualization. We showed that arachidonic acid released from uterine luminal epithelium can induce fibroblast activation and decidualization through PGI and its nuclear receptor PPARδ. Based on the significant difference of fibroblast activation-related markers between pregnant and pseudopregnant mice, we found that embryo-derived TNF promotes CPLA phosphorylation and arachidonic acid release from luminal epithelium. Fibroblast activation is also detected under human in vitro decidualization. Similar arachidonic acid-PGI-PPARδ-ACTIVIN A pathway is conserved in human endometrium. Collectively, our data indicate that embryo-derived TNF promotes CPLA phosphorylation and arachidonic acid release from luminal epithelium to induce fibroblast activation and decidualization.
Topics: Pregnancy; Female; Humans; Animals; Mice; Decidua; PPAR delta; Arachidonic Acid; Endometrium; Fibroblasts; Stromal Cells
PubMed: 37458359
DOI: 10.7554/eLife.82970 -
Frontiers in Immunology 2023One pivotal aspect of early pregnancy is decidualization. The decidualization process includes two components: the differentiation of endometrial stromal cells to... (Review)
Review
One pivotal aspect of early pregnancy is decidualization. The decidualization process includes two components: the differentiation of endometrial stromal cells to decidual stromal cells (DSCs), as well as the recruitment and education of decidual immune cells (DICs). At the maternal-fetal interface, stromal cells undergo morphological and phenotypic changes and interact with trophoblasts and DICs to provide an appropriate decidual bed and tolerogenic immune environment to maintain the survival of the semi-allogeneic fetus without causing immunological rejection. Despite classic endocrine mechanism by 17 β-estradiol and progesterone, metabolic regulations do take part in this process according to recent studies. And based on our previous research in maternal-fetal crosstalk, in this review, we elaborate mechanisms of decidualization, with a special focus on DSC profiles from aspects of metabolism and maternal-fetal tolerance to provide some new insights into endometrial decidualization in early pregnancy.
Topics: Pregnancy; Female; Humans; Decidua; Endometrium; Estradiol; Fetus; Energy Metabolism
PubMed: 37404833
DOI: 10.3389/fimmu.2023.1203719 -
Current Opinion in Immunology Feb 2022The human maternal-fetal interface is an immunologically complex environment that must balance the divergent demands of tolerance towards the developing fetus with... (Review)
Review
The human maternal-fetal interface is an immunologically complex environment that must balance the divergent demands of tolerance towards the developing fetus with anti-pathogen defense. The innate immune responses at the maternal-fetal interface that function in anti-microbial defense have been understudied to-date and how 'TORCH' pathogens evade maternal innate immunity to infect the fetus remains poorly understood. Herein, we discuss how newly described decidual innate lymphoid cells and maternal placenta-associated macrophage subsets may be involved in anti-pathogen defense. Moreover, we outline recent advances in our understanding of how placental trophoblasts and fetal-derived macrophages (Hofbauer cells) function in anti-microbial defense. In summary, we highlight current gaps in knowledge and describe novel experimental models of the human decidua and placenta that are poised to advance our knowledge of innate immune defenses at the maternal-fetal interface.
Topics: Decidua; Female; Humans; Immunity, Innate; Lymphocytes; Placenta; Pregnancy; Trophoblasts
PubMed: 34768027
DOI: 10.1016/j.coi.2021.10.007 -
International Journal of Medical... 2023Recurrent miscarriage (RM) is a pregnancy complication associated with dysregulation of the maternal-fetal interface. We aimed to identify dysfunctional interactions...
Recurrent miscarriage (RM) is a pregnancy complication associated with dysregulation of the maternal-fetal interface. We aimed to identify dysfunctional interactions between trophoblast cells and decidual immune cells in RM. We downloaded single-cell RNA sequencing (scRNA-seq) datasets (GSE214607) from the Gene Expression Omnibus (GEO) datasets for further analysis using the R software. The data comprised of paired placental and decidual tissues, including those from patients diagnosed with RM and matched healthy controls. A total of 22976 cells were identified in 11 cell types, including trophoblasts, immune cells, and other cells. We divided trophoblast cells into three types and analyzed their interactions with decidual immune cells. Additionally, we re-clustered NK&T cells and macrophages, identified differentially expressed genes (DEGs), enriched their functions, and compared the cell interactions with trophoblast cells in each cell type. Our single-cell atlas of the maternal-fetal interface revealed alterations in the cellular organization of the decidua and placenta, cell type-specific transcriptome, and cell communication between immune and non-immune cells in RM, which are critical for illuminating the pathophysiology of RM.
Topics: Pregnancy; Humans; Female; Placenta; Trophoblasts; Decidua; Abortion, Habitual; Pregnancy Trimester, First
PubMed: 37575278
DOI: 10.7150/ijms.86533 -
Journal of Reproductive Immunology Feb 2021A successful pregnancy requires that the maternal immune system recognizes and tolerates the semi-allogeneic fetus without compromising the capability of protecting both... (Review)
Review
A successful pregnancy requires that the maternal immune system recognizes and tolerates the semi-allogeneic fetus without compromising the capability of protecting both mother and fetus from various pathogens. Decidual macrophages present unique phenotypes to play a key role in the establishment of the immunological aspects of maternal-fetal interaction. Dysfunction of decidual macrophages gives rise to pregnancy complications such as preeclampsia, recurrent spontaneous miscarriage, preterm labor and fetal growth restriction. Here, we reviewed the latest knowledge on the origin, differentiation, unique phenotype and function of macrophages in normal pregnancy and in pregnancy complications. We mainly focused on the significant roles of decidual macrophages in the process of extravillous trophoblast invasion, spiral arterial remodeling, decidual stromal cells cultivation and immune tolerance maintenance in normal pregnancy, and their pathological roles in pregnancy-related complications, offering more integrated information in maternal-fetal immunity.
Topics: Decidua; Female; Histocompatibility, Maternal-Fetal; Humans; Immune Tolerance; Macrophages; Pregnancy; Pregnancy Complications; Trophoblasts
PubMed: 33360717
DOI: 10.1016/j.jri.2020.103264 -
Annual Review of Immunology Apr 2023The presence of granulated lymphocytes in the human uterine mucosa, known as decidua during pregnancy, or endometrium otherwise, was first noted in the nineteenth... (Review)
Review
The presence of granulated lymphocytes in the human uterine mucosa, known as decidua during pregnancy, or endometrium otherwise, was first noted in the nineteenth century, but it was not until 1990 that these cells were identified as a type of natural killer (NK) cell. From the outset, uterine NK (uNK) cells were found to be less cytotoxic than their circulating counterparts, peripheral NK (pNK) cells. Recently, unbiased approaches have defined three subpopulations of uNK cells, all of which cluster separately from pNK cells. Here, we review the history of research into uNK cells, including their ability to interact with placental extravillous trophoblast cells and their potential role in regulating placental implantation. We go on to review more recent advances that focus on uNK cell development and heterogeneity and their potential to defend against infection and to mediate memory effects. Finally, we consider how a better understanding of these cells could be leveraged in the future to improve outcomes of pregnancy for mothers and babies.
Topics: Humans; Pregnancy; Female; Animals; Placenta; Uterus; Killer Cells, Natural; Mucous Membrane; Decidua
PubMed: 36630598
DOI: 10.1146/annurev-immunol-102119-075119 -
Environmental Research Jul 2023Placenta mediates the transfer of nutrients, oxygen and drugs from mother to fetus. It is constituted by two cellular layers separated by the intervillous space: the...
Placenta mediates the transfer of nutrients, oxygen and drugs from mother to fetus. It is constituted by two cellular layers separated by the intervillous space: the outer is in direct contact with maternal blood (decidua placenta), and the inner (villi) directly in contact with the fetus. Environmental contaminants, such as per- and polyfluoroalkyl substances (PFAS) also demonstrated the ability to cross the tissue multiple layers, posing at risk the health of the fetus. The aim of the present study was to analyse the PFAS amount in decidua and villi placenta explants and to study differences in their distribution among the two side of this organ. The determination of 23 PFAS was carried out by liquid chromatography coupled to high-resolution accurate mass spectrometry (LC-HRAM). Our research included women who delivered at term between 2021 and 2022. Our data indicated that all samples contained at least one PFAS, demonstrating the ubiquitarian presence of these compounds in our population. A high occurrence of PFOS, PFOA and PFHxS, followed by PFHxA, PFBS and PFUnA was found. The fluorotelomer 6:2 FTS was also present in more than 40% of samples and this represent the first data on placenta explants. Mean and median PFAS values for decidual explants were 0.5 ng/g and 0.4 ng/g (SD 0.3), while for villi explants mean and median values were 0.6 ng/g and 0.4 ng/g (SD 0.4). A different pattern of accumulation was observed between villi and decidual explants for PFOS, PFOA and PFUnA (villi > decidua) and PFHxA, PFHxS, PFBS and 6:2 FTS (decidua > villi). Even if the mechanism of this selectively accumuation is not yet understood, molecular degree of ionization and its lipophilicity could at least in part explain this difference. This study expands the limited data describing PFAS levels in the placenta and pose attention on PFAS exposure during pregnancy.
Topics: Pregnancy; Humans; Female; Placenta; Fluorocarbons; Mothers; Decidua; Alkanesulfonic Acids; Environmental Pollutants
PubMed: 37119845
DOI: 10.1016/j.envres.2023.115955 -
Frontiers in Immunology 2022The maternal-fetal immune disorder is considered to be an important factor of preterm birth (PTB); however, the underlying mechanism is still not fully understood. This...
The maternal-fetal immune disorder is considered to be an important factor of preterm birth (PTB); however, the underlying mechanism is still not fully understood. This study was designed to explore the innate and adaptive immune features in the decidua during term and preterm labor. Women delivered at term or preterm were classified into four groups: term not in labor (TNL, N=19), term in labor (TL, N=17), preterm not in labor (PNL, N=10), and preterm in labor (PIL, N=10). Decidua basalis and parietalis were collected and analyzed for macrophage subtypes (M1 and M2) as well as T helper 1 (Th1), Th2, Th17 and regulatory T (Treg) cells by flow cytometry and immunohistochemistry. Our results demonstrated significantly decreased frequencies of M2 cells and elevated M1/M2 ratio in the PIL group compared to that in the PNL group in both decidua basalis and parietalis, whereas no significant differences were found between the above two groups in both sites in terms of the polarization status of Th cells. On the contrary, macrophage subsets were comparable in the TL and TNL groups, whereas elevated Th1 percentages and Th1/Th2 ratio were observed in TL women compared to that in TNL women in the decidua. Interestingly, although the frequencies and ratios of Th17 and Treg were comparable among the four groups, the Th17/Treg ratios of these groups were significantly increased in decidua basalis than that in decidua parietalis. Collectively, the M1/M2 imbalance is associated with the breakdown of maternal-fetal immune tolerance during PTB, whereas the aberrant Th1/Th2 profile plays an important role in immune disorder during term labor. Moreover, Th17/Treg deviation is more remarkable in decidua basalis than in decidua parietalis.
Topics: Decidua; Female; Flow Cytometry; Humans; Infant, Newborn; Labor, Obstetric; Obstetric Labor, Premature; Pregnancy; Premature Birth
PubMed: 35757768
DOI: 10.3389/fimmu.2022.877314 -
Nature Reviews. Immunology Apr 2023The role of the maternal immune system in reproductive success in humans remains controversial. Here we focus on the events that occur in the maternal decidua during the... (Review)
Review
The role of the maternal immune system in reproductive success in humans remains controversial. Here we focus on the events that occur in the maternal decidua during the first few weeks of human pregnancy, because this is the site at which maternal leukocytes initially interact with and can recognize fetal trophoblast cells, potentially involving allorecognition by both T cells and natural killer (NK) cells. NK cells are the dominant leukocyte population in first-trimester decidua, and genetic studies point to a role of allorecognition by uterine NK cells in establishing a boundary between the mother and the fetus. By contrast, definitive evidence that allorecognition by decidual T cells occurs during the first trimester is lacking. Thus, our view is that during the crucial period when the placenta is established, damaging T cell-mediated adaptive immune responses towards placental trophoblast are minimized, whereas NK cell allorecognition contributes to successful implantation and healthy pregnancy.
Topics: Pregnancy; Humans; Female; Trophoblasts; Placenta; Decidua; Pregnancy Trimester, First; Killer Cells, Natural
PubMed: 36192648
DOI: 10.1038/s41577-022-00777-2