First-trimester Decidual Cells Research Articles

Regulation of CX3CL1 Expression in Human First-Trimester Decidual Cells: Implications for Preeclampsia.

C-X3-C motif ligand 1 (CX3CL1) mediates migration, survival, and adhesion of natural killer (NK) cells, monocytes, and T-cells to endothelial/epithelial cells. Aberrant numbers and/or activation of these decidual immune cells elicit preeclampsia development. Decidual macrophages and NK cells are critical for implantation, while macrophage-derived tumor necrosis factor-α (TNF-α), interleukin-1 β (IL-1β), and NK cell-derived interferon-γ (IFN-γ) are associated with preeclampsia development. Thus, serum and decidual levels of CX3CL1 from first-trimester pregnancy and preeclampsia-complicated term pregnancy were examined by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry, respectively. The effects of incubating primary human first-trimester decidual cells (FTDCs) with estradiol + medroxyprogesterone acetate + either IL-1β or TNF-α and/or IFN-γ on CX3CL1 expression were also assessed by quantitative reverse transcription-polymerase chain reaction and ELISA. The inhibition of each signaling pathway with each kinase and nuclear factor κB (NFκB) inhibitors was evaluated by ELISA. Chemotaxis of CD56brightCD16- NK cells by various concentrations of CX3CL1 was evaluated. C-X3-C motif ligand 1 is expressed by both cytotrophoblasts and decidual cells in first-trimester decidua. C-X3-C motif ligand 1 expression is increased in term decidua but unchanged in first-trimester and term serum of patients with preeclampsia. Interferon-gamma and either IL-1β or TNF-α synergistically upregulated CX3CL1 expression in FTDCs. Coincubation with IL-1β or TNF-α or IFN-γ, mitogen-activated protein kinase kinase 1 and 2 (MEK1/2), c-JUN N-terminal kinase (JNK), and NFκB inhibitors suppressed CX3CL1 production. C-X3-C motif ligand 1 elicited concentration-dependent enhancement of CD56brightCD16- NK cell migration. In conclusion, the current study suggests that decidual cell-secreted CX3CL1 is involved in the later development of preeclampsia, whereas circulating CX3CL1 levels do not predict preeclampsia. Mitogen-activated protein kinase kinase 1 and 2, JNK, and NFκB signaling mediate IL-1β-, TNF-α-, and IFN-γ-induced CX3CL1 production by FTDCs.

Modulation of Decidual Macrophage Polarization by Macrophage Colony-Stimulating Factor Derived from First-Trimester Decidual Cells: Implication in Preeclampsia

During human pregnancy, immune tolerance of the fetal semiallograft occurs in the presence of abundant maternal leukocytes. At the implantation site, macrophages comprise approximately 20% of the leukocyte population and act as primary mediators of tissue remodeling. Decidual macrophages display a balance between anti-inflammatory and proinflammatory phenotypes. However, a shift to an M1 subtype is reported in preeclampsia. Granulocyte-macrophage colony-stimulating-factor (GM-CSF) and macrophage colony-stimulating factor (M-CSF) are major differentiating factors that mediate M1 and M2 polarization, respectively. Previously, we observed the following: i) the preeclamptic decidua contains an excess of both macrophages and GM-CSF, ii) the preeclampsia-associated proinflammatory cytokines, IL-1β and tumor necrosis factor-α, markedly enhance GM-CSF and M-CSF expression in cultured leukocyte-free first-trimester decidual cells (FTDCs), iii) FTDC-secreted GM-CSF polarizes macrophages toward an M1 subtype. The microenvironment is a key determinant of macrophage phenotype. Thus, we examined proinflammatory stimulation of FTDC-secreted M-CSF and its role in macrophage development. Immunofluorescence staining demonstrated elevated M-CSF-positive decidual cell numbers in preeclamptic decidua. In FTDCs, IL-1β and tumor necrosis factor-α signal through the NF-κB pathway to induce M-CSF production, which does the following: i) enhances differentiation of and elevates CD163 expression in macrophages, ii) increases macrophage phagocytic capacity, and iii) inhibits signal-regulatory protein α expression by macrophages. These findings suggest that FTDC-secreted M-CSF modulates the decidual immune balance by inducing M2 macrophage polarization and phagocytic capacity in response to proinflammatory stimuli.

Expression of Interferon γ by Decidual Cells and Natural Killer Cells at the Human Implantation Site: Implications for Preeclampsia, Spontaneous Abortion, and Intrauterine Growth Restriction.

Human first-trimester decidual cells (FTDCs) chemoattract CXCR3-expressing circulating CD56(bright)CD16(-) natural killer (NK) cells, which increase uteroplacental blood flow by remodeling spiral arteries and arterioles. This recruitment reflects elevated FTDC expression of NK cell-recruiting induced protein 10 and interferon (IFN)-inducible T-cell-α chemoattractant produced in response to the synergistic effects of tumor necrosis factor α (TNF-α) and IFN-γ stimulation. Decidual macrophages express TNF-α, whereas the cellular origin of IFN-γ is unclear. Therefore, this study aims to identify the cell source(s) of IFN-γ in human first trimester decidua. Immunostaining of decidual sections revealed that both FTDCs and decidual NK (dNK) cells express IFN-γ. Although individual dNK cells express higher IFN-γ levels, the more numerous FTDCs account for greater proportion of total IFN-γ immunostaining. Freshly isolated FTDCs express greater IFN-γ staining than dNK cells as measured by flow cytometry, whereas incubation of dNK cells with documented NK cell activators significantly increases IFN-γ above FTDC levels. Confluent FTDCs intrinsically produce, but paradoxically respond to, exogenous IFN-γ.

Pathological mechanisms of antiphospholipid antibodies in trophoblastic cell fusion

Pathological mechanisms of antiphospholipid antibodies in trophoblastic cell fusion

Pregnancy recall in decidual NK cells

Pregnancy recall in decidual NK cells

Interferon-γ Protects First-Trimester Decidual Cells against Aberrant Matrix Metalloproteinases 1, 3, and 9 Expression in Preeclampsia

Human extravillous trophoblast (EVT) invades the decidua via integrin receptors and subsequently degrades extracellular matrix proteins. In preeclampsia (PE), shallow EVT invasion elicits incomplete spiral artery remodeling, causing reduced uteroplacental blood flow. Previous studies show that preeclamptic decidual cells, but not interstitial EVTs, display higher levels of extracellular matrix-degrading matrix metalloproteinase (MMP)-9, but not MMP-2. Herein, we extend our previous PE-related assessment of MMP-2 and MMP-9 to include MMP-1, which preferentially degrades fibrillar collagens, and MMP-3, which can initiate a local proteolytic cascade. In human first-trimester decidual cells incubated with estradiol, tumor necrosis factor-α (TNF-α) significantly enhanced MMP-1, MMP-3, and MMP-9 mRNA and protein levels and activity measured by real-time quantitative RT-PCR, ELISA, immunoblotting, and zymography, respectively. In contrast, interferon γ (IFN-γ) reversed these effects and medroxyprogesterone acetate elicited further reversal. Immunoblotting revealed that p38 mitogen-activated protein kinase signaling mediated TNF-α enhancement of MMP-1, MMP-3, and MMP-9, whereas IFN-γ inhibited p38 mitogen-activated protein kinase phosphorylation. Unlike highly regulated MMP-1, MMP-3, and MMP-9, MMP-2 mRNA and protein expression was constitutive in decidual cells. Because inflammation underlies PE-associated shallow EVT invasion, these results suggest that excess macrophage-derived TNF-α augments expression of MMP-1, MMP-3, and MMP-9 in decidual cells tointerfere with normal stepwise EVT invasion of the decidua. In contrast, decidual natural killer cell-derived IFN-γ reverses such TNF-α-induced MMPs to protect against PE.

Specific decidual CD14+ cells hamper cognate NK cell proliferation and cytolytic mediator expression after mucin 1 treatment in vitro

Mucin 1 (MUC1) forms a glycocalyx on the surface of decidual epithelial cells that needs to be removed for successful embryo attachment. We investigated whether MUC1 affects human early pregnancy decidual CD14+ cells and their interactions with cognate decidual natural killer (NK) cells. FITC-dextran internalisation, surface and intracellular antigen levels, and proliferation of CD14+ and/or CD56+ cells were analysed by flow cytometry. Magnetic separation was used to purify CD56+ and CD14+ cells. Uncultured CD14+ cells expressed a negligible percentage of CD1a and CD83 molecules. They expressed lower levels of CD16, and higher levels of endocytic mannose receptors (MR), dendritic cell-specific intercellular adhesion molecule grabbing non-integrin (DC-SIGN), proinflammatory chemokine CC receptor 5 (CCR5), and CD163 receptor, than their peripheral blood counterparts. Lipopolysaccharide stimulation did not affect FITC-dextran internalisation in CD14+ cells. MUC1 bound and internalised, in a dose-dependent manner, the carbohydrate recognition domain of MR, increasing the decoy IL-1 receptor type II and decreasing IL-15 expression in CD14+ cells. In the presence of MUC1-treated macrophages, the expression levels of the proliferation and cytotoxic mediators (perforin, Fas ligand and TNF-related activation-induced ligand or TRAIL) was attenuated, while that of the anti-inflammatory chemokine CCL17 was increased, in NK cells compared with untreated macrophages. In conclusion, MUC1 supports the alternative activation of tissue-specific CD14+ cells, and may restrict proliferation of NK cells and regulate their content of cytotoxic mediators. Based on the experiments with first-trimester decidual cells in vitro, we conclude that removing MUC1 from decidual tissue might help control trophoblast invasion by NK cells.

Decidual Cell‐expressed Tissue Factor in Human Pregnancy and Its Involvement in Hemostasis and Preeclampsia‐related Angiogenesis

During extravascular trophoblast (EVT) invasion of the decidua, thrombin generated from decidual cell-expressed tissue factor (TF) forms a "hemostatic envelope" that protects against hemorrhage during the initial breaching of capillaries by EVTs and subsequent invasion and remodeling of the spiral arteries and arterioles. Preeclampsia, the world's leading cause of fetal and maternal morbidity and mortality, stems from shallow trophoblast invasion leading to incomplete vascular remodeling that impairs uteroplacental blood flow. A considerable subset of cases of preeclampsia is associated with decidual hemorrhage and maternal thrombophilias, which form excess thrombin from decidual cell-expressed TF. Thrombin affects several cell functions by binding to protease-activated receptors. In first-trimester decidual cells, thrombin enhances expression of sFlt-1, which can block the angiogenic effects of vascular endothelial growth factor (VEGF) and placental growth factor. By contrast, thrombin does not affect decidual cell VEGF expression. Thrombin-enhanced sFlt-1 expression by decidual cells, the predominant cell type encountered by invading cytotrophoblasts, could promote preeclampsia by interfering with angiogenesis-dependent vascular remodeling to reduce uteroplacental blood flow.

Matrix Metalloproteinase 9 (MMP9) Expression in Preeclamptic Decidua and MMP9 Induction by Tumor Necrosis Factor Alpha and Interleukin 1 Beta in Human First Trimester Decidual Cells1

Extravillous trophoblasts (EVTs) invade human decidua via sequential integrin-mediated binding and proteolysis of basement membrane proteins in the extracellular matrix (ECM). In preeclampsia, shallow EVT invasion impairs spiral artery and arteriole remodeling to reduce uteroplacental blood flow. Excess decidual cell-expressed matrix metalloproteinases (MMPs) 2 and 9, in response to preeclampsia-related interleukin 1 beta (IL1B) and tumor necrosis factor alpha (TNF), may inappropriately degrade these basement membrane proteins and impede EVT invasion. This study found significantly higher immunohistochemical MMP9 levels in decidual cells and adjacent interstitial trophoblasts in placental sections of preeclamptic versus gestational age-matched control women. In contrast, immunostaining for MMP2 and tissue inhibitor of matrix metalloproteinases 1 and 2 (TIMP1 and TIMP2) were similar in preeclamptic and control groups. First-trimester decidual cells were incubated with estradiol (E(2)) or E(2) + medroxyprogesterone acetate (MPA), with or without TNF or IL1B. As measured by ELISA, both cytokines elicited concentration-dependent increases in secreted MMP9 levels that were unaffected by MPA. In contrast, secreted levels of MMP2, TIMP1, and TIMP2 were unchanged in all treatment groups. Substrate gel zymography and Western blotting confirmed that each cytokine increased secreted levels of MMP9 but not MMP2. Similarly, quantitative RT-PCR found that TNF and IL1B enhanced MMP9, but not MMP2, mRNA levels. At the implantation site, inflammatory cytokine-enhanced MMP9 may promote preeclampsia by disrupting the decidual ECM to interfere with normal stepwise EVT invasion.

Pre‐eclampsia is associated with dendritic cell recruitment into the uterine decidua

Pre-eclampsia is a leading cause of fetal and maternal morbidity and mortality that preferentially affects primiparous patients. It is associated with systemic inflammation and impaired trophoblast invasion of the decidua. Decidual cells are the major cell type of the pregnant endometrium. Macrophages and dendritic cells are major specialized antigen-presenting cells that promote both innate immunity and immune tolerance. Macrophage infiltration is implicated in impaired trophoblast invasion that leads to pre-eclampsia. By contrast, the potential modulating role of decidual dendritic cells in the genesis of pre-eclampsia has not been investigated. Interleukin-1beta (IL-1beta), a pro-inflammatory cytokine, has been implicated in the genesis of pre-eclampsia. Thus, we postulate that pre-eclampsia would be associated with enhanced decidual dendritic cells infiltration and that IL-1beta would enhance the production of relevant dendritic cell-recruiting chemokines. We used immunohistochemistry to demonstrate a marked infiltrate of immature and mature dendritic cells in pre-eclamptic decidua. Further, immunohistochemistry and immunoassays of placental bed biopsies revealed that pre-eclamptic decidua displays elevated levels of several monocyte- and dendritic cell-recruiting chemokines. Leukocyte-free first-trimester decidual cells were then treated with IL-1beta, which enhanced the mRNA and protein expression of these chemokines. The current study also confirmed previous reports that macrophages directly impaired trophoblast invasion and that this inhibitory effect is augmented by the conditioned medium of IL-1beta-treated first-trimester decidual cells. However, unlike macrophages, dendritic cells did not directly impede trophoblast invasion. This study demonstrates that the inflammatory milieu of pre-eclampsia induces decidual cells to promote dendritic cell infiltration. Given their unusual versatility in mediating both immunity and tolerance, these novel findings suggest that dendritic cells may play a critical role either in the pathogenesis of pre-eclampsia or its prevention in subsequent pregnancies.

Production of Prolactin by Cultures of Isolated Cells From Human First-Trimester Decidua

An enriched fraction of first-trimester decidual cells that synthesize and release prolactin (PRL) was obtained by discontinuous Percoll gradient (20-50%) centrifugation of collagenase type I- and deoxyribonuclease I-dispersed cells (3 mg/mL and 50 micrograms/mL, respectively). Centrifugation of the cell suspension yielded three major bands aggregating at the density interfaces. The fraction of the 30-40% Percoll interface contained enlarged decidual cells and constantly secreted significant amounts of PRL into the medium for at least 10 days. The fraction of the 40-50% Percoll interface contained fibroblastic cells and secreted a small amount of PRL into the medium. Cells in the other fractions did not attach to the plastic dishes in 48 hours. Under the influence of progesterone (100 ng/mL), the cultured decidual cells retained their capability of PRL production for at least 10 days because no decline of the secretion rate was observed. The culture system established by the present study is satisfactory for investigating decidual cell functions, including the regulatory mechanisms of PRL production.