Project description:Analysis of genome-wide gene expression in placentas from women with preterm severe preeclampsia, with or without HELLP syndrome, compared to gestational age-matched controls. The hypothesis tested in the present study was that placental transcriptomic changes in preeclampsia are considerably different from controls. The results provide important information on placental transcriptomic changes in preeclampsia.
Project description:Preeclampsia (PE), which affects 4-8% of human pregnancies, causes significant maternal and neonatal morbidity and mortality. Within the basal plate, placental cytotrophoblasts (CTBs) of fetal origin invade the uterus and extensively remodel the maternal vasculature. In PE, CTB invasion is often shallow, and vascular remodeling is rudimentary. To better understand possible causes, we conducted a global analysis of gene expression at the maternal-fetal interface in placental samples from women with PE (n = 12; 24-36 wk) vs. samples from women who delivered due to preterm labor with no evidence of infection (n = 11; 24-36 wk), a condition that our previous work showed is associated with normal CTB invasion. Using the HG-U133A&B Affymetrix GeneChip platform, and statistical significance set at log odds-ratio of B >0, 55 genes were differentially expressed in PE. They encoded proteins previously associated with PE [e.g. Flt-1 (vascular endothelial growth factor receptor-1), leptin, CRH, and inhibin] and novel molecules [e.g. sialic acid binding Ig-like lectin 6 (Siglec-6), a potential leptin receptor, and pappalysin-2 (PAPP-A2), a protease that cleaves IGF-binding proteins]. We used quantitative PCR to validate the expression patterns of a subset of the genes. At the protein level, we confirmed PE-related changes in the expression of Siglec-6 and PAPP-A2, which localized to invasive CTBs and syncytiotrophoblasts. Notably, Siglec-6 placental expression is uniquely human, as is spontaneous PE. The functional significance of these novel observations may provide new insights into the pathogenesis of PE, and assaying the circulating levels of these proteins could have clinical utility for predicting and/or diagnosing PE. Keywords: disease state analysis Basal plate biopsies of preterm labor (24-36 weeks; n=11) and preterm severe preeclampsia (24-36 weeeks; n=12) were isolated and the global gene expression profiles determined using Affymetrix Human GeneChips. Comparisons between the preeclampsia samples and the preterm labor controls revealed genes differentially expressed in preeclampsia.
Project description:During human pregnancy, placental cytotrophoblasts invade the uterus and its blood vessels, anchoring the progeny and rerouting maternal blood to the embryo/fetus. In preeclampsia, cytotrophoblast invasion is restricted and blood flow to the placenta is reduced. The causes of restricted cytotrophoblast invasion are unknown. Here, preeclampsia and control cytotrophoblasts were cultured for 48 h to allow differentiation/invasion. In various severe forms of preeclampsia ± intrauterine growth restriction, global transcriptional profiling revealed common aberrations in cytotrophoblast gene expression that resolved with culture. Villous cytotrophoblasts were isolated from preeclampsia placentas (PRE, n=5) and placentas of preterm labor patients without signs of infection (PTL, n=5), which served as gestation-matched controls. To better understand the CTB phenotype in the context of PE variants, we included patients with the most clinically significant forms of this condition that necessitated preterm delivery: women with severe PE ± intrauterine growth restrictions, PE with superimposed hypertension and HELLP syndrome (hemolysis, elevated liver enzymes; low platelet count). RNA was purified immediately after the cells were isolated (0 h) and after 12, 24 and 48 h in culture. The relative gene expression across the whole genome was profiled using the Affymetrix HG-U133Plus 2.0 GeneChip platform. Array quality was assesed using RMAExpress. One sample of preterm labor collected at 48h was omitted (39 arrays total). We used both LIMMA and maSigPro (R/Bioconductor) to determine differentially expressed genes.
Project description:Bronchopulmonary dysplasia (BPD) continues to impact the health of preterm infants worldwide. Preeclampsia (PE), a placental-driven pregnancy disorder, has a strong clinical association with BPD risk. We hypothesize that preeclampsia causes a unique type of developmental lung injury that predisposes infants to an increased risk of BPD. Research on human placental tissues is needed to more clearly define the role of PE in developmental lung injury. A new approach to human placental analysis is spatial transcriptomics (Sp-Tr), a technique which produces spatially oriented gene expression data from cells in their native tissue environment.
Project description:Preeclampsia is a serious pregnancy-induced disorder unique to humans affecting 4.6% of pregnancies worldwide. Advances in the detection, prevention and treatment of preeclampsia have been poor due to our inadequate understanding of its pathogenesis. Here, we perform a multiomics study on early pregnancy placental biopsies (chorionic villus samples) from pregnancies that developed preterm and term preeclampsia compared to normotensive controls. Using an integrative statistical approach we discovered preterm preeclampsia was highly associated with lipoprotein metabolism whereas term preeclampsia was associated with inflammatory pathways and notch signaling. Melanophilin was identified as significantly reduced in early pregnancy placenta from term preeclampsia. Loss of melanophilin was required for syncytialization but excess loss disrupts syncytiotrophoblast function driving the production of antiangiogenic factors known to drive preeclampsia. Our study challenges the dogma that term preeclampsia is not associated with early placental pregnancy dysfunction and provides critical insight into the early pregnancy dysfunction underlying preeclampsia, opening up new avenues for predictive biomarker and preventative treatment discovery.
Project description:Preeclampsia is a serious pregnancy-induced disorder unique to humans affecting 4.6% of pregnancies worldwide. Advances in the detection, prevention and treatment of preeclampsia have been poor due to our inadequate understanding of its pathogenesis. Here, we perform a multiomics study on early pregnancy placental biopsies (chorionic villus samples) from pregnancies that developed preterm and term preeclampsia compared to normotensive controls. Using an integrative multivariate approach, we uncovered distinct molecular signatures: preterm preeclampsia was strongly associated with dysregulated lipoprotein metabolism, while term preeclampsia exhibited alterations in inflammatory pathways, notch signaling and ribosome assembly. These results challenge the prevailing notion that term preeclampsia is unrelated to early placental pregnancy dysfunction. Our study provides critical insights into the early pregnancy aberrations underlying both preterm and term preeclampsia, paving the way for novel predictive biomarker and targeted preventative treatments. This work represents a significant step towards unravelling the complex etiology of preeclampsia and improving maternal and perinatal health outcomes.
Project description:Preeclampsia (PE), a hypertensive disorder of pregnancy, is hypothesized to be associated with, if not mechanistically related to abnormal placental function. However, the exact mechanisms regulating the pathogenesis of PE remain unclear. While many studies have investigated changes in gene expression in the PE placenta, the role of epigenetics in PE associated placental dysfunction remains unclear. Using the genome-wide Illumina Infinium Methylation 450 BeadChip array, we analyzed gene-specific alterations in DNA methylation in placental biopsies collected from normal pregnant women delivering at term (n=14), with term PE (≥37 weeks; n=19) or with preterm PE (<37 weeks, n=12). Of the 485,582 gene loci on the array, compared to controls, 229 loci were differentially methylated in PE placentas and 3411 loci were differentially methylated in preterm PE (step up p-value <0.05 and >5% methylation difference). Functional annotation of the differentially methylated genes in preterm PE placentas revealed a 32 gene cluster in the cadherin and cell adhesion functional groups (Benjamini p<0.00001). Hypermethylation of CDH11 (p=0.0143), COL5A1 (p=0.0127) and TNF (p=0.0098) and hypomethylation of NCAM1 (p=0.0158) was associated with altered mRNA expression in preterm PE placentas. These studies demonstrate aberrant methylation, correlating with disease severity, in PE placentas. Bisulphite converted DNA from the 45 samples were hybridised to the Illumina Infinium 450k Human Methylation Beadchip v1.2
Project description:The placental microvasculature of the human fetus is essential for the efficient transfer of gases, nutrients and waste between the mother and fetus. Microvascular hypoplasia of the terminal villi is associated with the placental pathology observed in cases of severe Intra Uterine Growth Restriction (IUGR). We used novel methods to isolate a pure population of placental microvascular endothelial cells from control preterm placentas (n=3) and placenta complicated by severe IUGR (n=6) with superimposed preeclampsia (n=5). Distal placental villous tissue was collected to enrich for terminal villi. Tissue was minced, digested and placental microvascular endothelial cells (PlMEC) were positively selected using tocosylated magnetic Dynabeads labeled with Human Endothelial Antigen lectin. The purity of the PlMEC (95%) was assessed by CD31 immunocytochemistry. RNA was extracted from the PlMEC samples and also from 3 term placenta and subjected to Affymetrix microarray analysis (U133Plus2 array chips). Data from the 3 term placentas and 3 preterm PlMEC arrays was used to generate an endothelial cell specific gene profile. This profile was used to identify the endothelial genes differentially regulated in all 6 IUGR cases. BTNL9 and NTRK2 transcripts were upregulated and SAA1, GNAS and SLAMF1 transcripts were downregulated as relative to the preterm controls. These changes were validated by Real time PCR in the PlMEC samples. This novel study is the first to identify endothelial candidate genes that may play a role in the villous hypoplasia of severe IUGR. This work advances our understanding of the molecular defects in placental microvascular endothelial cells in normal and pathologic pregnancies.