Project description:We used trophoblast organoids differentiating to extravillous trophoblast (EVT) to study the effects of key cytokines secreted by uterine Natural Killer (uNK) cells on EVT behaviour. Specifically, we exposed the organoids to four uNK-derived cytokines (CSF1, CSF2, XCL1, CCL5) and collected cells at different time points along the EVT differentiation pathway for scRNA-seq. We observe enhanced EVT differentiation in cytokine-treated organoids demonstrated by the increased proportion of late EVT subtypes and regulation of related pathways such as epithelial-mesenchymal transition. Moreover, uNK cytokines affect other processes important during early pregnancy including dampening of inflammatory and adaptive immune responses, regulation of blood flow, and placental access to nutrients.
Project description:An allorecognition system depending on interactions between uterine Natural Killer (uNK) cells and placental extravillous trophoblast (EVT) during early pregnancy influences reproductive outcomes in humans. Our previous immunogenetic studies show that particular combinations of maternal Killer Immunoglobulin-like Receptors (KIR) in uNK cells with fetal HLA-C variants on EVT are associated with disorders of pregnancy, especially pre-eclampsia. To identify responses stimulated in uNK cells specifically when activating KIR (KIR2DS1) binds to C2+HLA-C, a combination protective against pre-eclampsia, we modelled KIR-HLA interactions by co-culturing uNK cells with the 721.221 HLA-null cell line transfected to express either C1+ or C2+HLA-C molecules, followed by transcriptome profiling by RNA sequencing. We detect the secretion of key cytokines by uNK cells under the protective combination between KIR2DS1 and C2+HLA-C.
Project description:Uterine Natural Killer (uNK) cells regulate essential developmental processes at the maternal-fetal interface during early pregnancy. Uterine NK cell functions are tightly regulated during early placentation to stimulate trophoblast invasion and remodel uterine spiral arteries. Access to human 1st and 2nd trimester uterine tissues allowed us to investigate the transcriptional changes in uNK cells during the early stages of early human pregnancy. Microarray analysis identified 97 upregulated genes in 2nd compared to 1st trimester purified uNK cells of which the majority (61%) clustered as interferon-stimulated-genes (ISG), with ISG15 and ISG20 being upregulated profoundly. Type I interferons (IFNα/β), but not type II interferon (IFNɣ) increased expression of the identified interferon target genes ISG15 and ISG20 in uNK cells in vitro. Moreover, the cytokine-like protein ISG15 stimulated in vitro trophoblast invasion. Second trimester uNK cells promoted trophoblast invasion in vitro, whereas both 1st and 2nd trimester uNK cells stimulated endothelial tube formation. IFNα but not IFNβ stimulation of 1st trimester uNK cells enhanced their capacity to promote trophoblast invasion. In conclusion, the uNK cell interferon transcriptome is upregulated during the 2nd trimester allowing uNK cells to promote trophoblast invasion. Type I interferon signaling regulates uNK cell-induced trophoblast invasion via induction of effector molecules like ISG15. First trimester uNK cells can be induced to act like second trimester uNK cells by IFNα with respect to promotion of trophoblast invasion. Key words: Gene expression profiling ■ uterine natural killer cells ■ extravillous trophoblast invasion ■ interferon alpha ■ ISG15
Project description:Decidual spiral arteriole (SpA) remodelling is essential to ensure optimal uteroplacental blood flow during human pregnancy. Decidual uterine natural killer cells and macrophages infiltrate the SpA and are proposed to initiate remodelling before colonisation by extravillous trophoblasts. Microarrays were used to measure the effect of extravillous trophoblasts conditioned medium on the transcriptome of human uterine microvascular endothelial cells.
Project description:Cell-to-cell communication is essential for the spiral artery (SpA) remodeling and required for maternal transfer of nutrient and oxygen to the fetus. Extravillous trophoblast invade the uterine arteries to remodel the SpA during the first 20 weeks of gestation. Interestingly, oxygen tenstion in the uterine environment changes with the progression of pregnancies and damage in the SpA remodelling can lead to preeclampsia and pther pregnancy complications. Recently, our understanding of how cells communicate has undergone a paradigm shift since the recognition of the role of exosomes on intercellular signaling. Here, we investigated whether oxygen tension alters the exosome release and miRNA profile from extravillous trophoblast (EVT), modifying their bioactivity on endothelial cells. Furthermore, we have established the exosomal miRNA profile at early gestation in women who develop pre-eclampsia (PE) and spontaneous preterm birth (SPTB). The effect of oxygen tension (i.e. 8% and 1% oxygen) on exosome release was quantified using nanocrystals (Qdot®) coupled to CD63 by fluorescence NTA. A real-time, live-cell imaging system (Incucyte™) was used to establish the effect of exosomes on endothelial cells. Plasma samples were obtained at early gestation (<18 weeks) and classified according to pregnancy outcomes. An Illumina TrueSeq Small RNA kit was used to construct a small RNA library from exosomal RNA obtained from EVT and plasma samples. The number of exosomes was significantly hifger in EVT culturedunder 1% compared to 8% oxygen. In total, 741 miRNA were identified in exosomes from EVT. Bioinformatic analysis revealed that these miRNA were associated with cell migration and cytokine production. Interestingly, exosomes isolated from EVT cultured at 8% oxygen increased EC migration, while exosomes from 1% oxygen decrease EC migration. These changes were inversely proportional to TNF-α released from EC. Finally, we have identified a set of uniques miRNA in exosomes from EVT cultured at 1% oxygen and exosomes isolated from maternal at early gestation, who developed PE and SPTB later in pregnancy. We suggest that aberrant exosomal signalling by placental cells is a common aetiological factor in pregnancy complications characterised by incomplete SpA remodeling and is therefore a clinically useful biomarker of pregnancy complications.
Project description:Analysis of gene expression in uterine natural killer cells purified from control, diet-induced obese and diet-induced obese resistant female mice. The aim of the study is to identify differentially expressed genes and pathways in uterine natural killer cells affected by maternal diet and obesity in pregnancy.
Project description:The placenta an essential extra-embryonic organ that supports the fetus throughout gestation. The interactions between the placenta and the maternal immune system during the first trimester have not been completely characterized, despite their close physical association and hem-allogeneic relationship to each other. The most abundant type of immune cell found in the uterus in the first trimester is the decidual natural killer cell (dNK). Despite their name, dNKs play supportive roles during pregnancy by remodelling uterine spiral arteries. We present evidence suggesting that the matrix metalloproteinases (MMPs) that dNKs secrete to promote this remodelling also drive placental development. This study was performed using a novel co-culture system of dNKs and trophoblast organoids, which are mini-organs that represent two to three different cell types of the human placenta. We found that co-cultures for one week led to significant (p=0.020) increases in organoid area. Through bulk RNA sequencing and immunohistochemical examinations we also observed significant decreases in trophoblast stemness markers, and upregulation of gene sets associated with extravillous trophoblast (EVT) development. These changes were accompanied by significant (p<0.001) increases in collagen subunit gene expression in the organoids, with simultaneous significant decreases (p<0.001) in the proportion of organoid area occupied by collagen as determined through Masson’s Trichrome. Cultures containing dNKs also contained significantly higher levels of MMP1, 3, 9, and 10 in their culture media, each of which can break down collagen. Collectively, these findings demonstrate that dNKs promote changes concordant with trophoblast differentiation towards EVTs and villous branching morphogenesis.
Project description:Invasive extravillous trophoblasts (EVTs) of the human placenta are critically involved in successful pregnancy outcome since they remodel the uterine spiral arteries to increase blood flow and oxygen delivery to the placenta and the developing fetus. To gain more insights into their biological role different primary cell culture models are commonly utilised. However, access to early placental tissue may be limited and primary trophoblasts rapidly cease proliferation in vitro impairing genetic manipulation. Hence, trophoblastic cell lines have been widely used as surrogates to study EVT function. Although the cell lines share some molecular marker expression with their primary counterpart, it is unknown to what extent they recapture the invasive phenotype of EVT. Therefore, we here report the first thorough GeneChip analyses of SGHPL-5, HTR-8/SVneo, BeWo, JEG-3 and the novel ACH-3P trophoblast cells in comparison to previously analysed primary villous cytrophoblasts and extravillous trophoblasts. To identify EVT-specific gene expression signatures in trophoblast cell lines, we calcuted differentially expressed genes between pre-defined groups based on the distinct origins of the five trophoblast cell lines under investigation. Comparison 1 comprised EVT, HTR-8/Svneo and SGHPL-5 vs choriocarcinoma cells (ACH-3P, BeWo, JEG-3). Comparison 2 comprised EVT, ACH-3P, BeWo, JEG-3 vs extravillous trophoblast cell lines (HTR-8/SVneo, SGHPL-5).
Project description:The hemochorial placentation site is characterized by a dynamic interplay between trophoblast cells and maternal cells. These cells cooperate to establish an interface required for nutrient delivery to promote fetal growth. In the human, trophoblast cells penetrate deep into the uterus. This is not a consistent feature of hemochorial placentation and has hindered the establishment of suitable animal models. The rat represents an intriguing model for investigating hemochorial placentation with deep trophoblast cell invasion. In this study, we used single cell RNA sequencing to characterize the transcriptome of the invasive trophoblast cell lineage, as well as other cell populations within the rat uterine-placental interface during early (gestation day, gd, 15.5) and late (gd 19.5) stages of intrauterine trophoblast cell invasion. We identified a robust set of transcripts that define invasive trophoblast cells, as well as transcripts that distinguished endothelial, smooth muscle, natural killer, and macrophage cells. Invasive trophoblast, immune, and endothelial cell populations exhibited distinct spatial relationships within the uterine-placental interface. Furthermore, the maturation stage of invasive trophoblast cell development could be determined by assessing gestation-stage dependent changes in transcript expression. Finally, and most importantly, expression of a prominent subset of rat invasive trophoblast cell transcripts is conserved in the invasive extravillous trophoblast cell lineage of the human placenta. These findings provide foundational data to identify and interrogate key conserved regulatory mechanisms essential for development and function of an important compartment within the hemochorial placentation site that is essential for a healthy pregnancy.