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: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.
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.
Project description:Retinopathy of prematurity (ROP), a blinding condition affecting preterm infants, accounts for up to 40% of all childhood blindness worldwide. ROP is an interruption of retinal vascular maturation, which is physiologically complete at full term and thus ongoing at the time of preterm birth. Although ROP demonstrates delayed onset following preterm birth, representing a window for therapeutic intervention, we cannot cure or prevent this disease. The in-utero environment, including placental function, is increasingly recognized for contributions to preterm infant disease risk. Herein, we examine the clinical associations between presence and severity of acute placental inflammation to ROP risk. Using logistic regression, we find a protective relationship between presence and severity of acute placental inflammation and preterm infant development of ROP. This is most significant for infants born in the absence of maternal preeclampsia. Further, we examine the underlying molecular mediators that may inform this protective paradigm. Adopting a candidate approach analyzing proteins with described ROP risk associations, we find that placental HTRA1 and FABP4 protein expression is significantly decreased within placental tissues characterized by acute inflammation. Additionally, HTRA1 and VEGFA demonstrate inverse longitudinal trends within the peripheral circulation for infants born in the presence compared to absence of acute placental inflammation. An agnostic approach, including whole transcriptome and differential methylation placental analysis, identifies novel mediators and pathways that may underly protection. Taken together, these data build on emerging literature showing disparate associations between acute placental inflammation and ROP development within preeclamptic or non-preeclamptic preterm infant populations and identifies novel placental mechanisms that may inform postnatal risk associations in preterm infants.
Project description:Background: Early-onset preeclampsia (EOPE) and late-onset preeclampsia (LOPE) has been regarded as two different phenotypes with heterogeneous manifestation. The underlying mechanisms remain elusive. Aim to gain insight into the pathogenesis of the two traits, we analyzed the placental gene expression profiles in preeclampsia placentas. Methods: Whole genome-wide microarray was used to describe the gene expression profiles in the placenta tissues from patients with early-(n=7; <34 weeks), late-onset(n=8; >36 weeks) PE and their controls who delivered preterm (n=5;<34 weeks) or at term(n=5; >36 weeks) Genes were selected as differentially expressed upon a fold-changeâ?¥2 and q-value<0.05. qRT-PCR was undertaken to verify the results. Western blot was further performed to verify secreted genes at the protein level. Results: A total of 627 genes were differentially expressed in early-compared with late-onset PE. Of these, 177 genes were up-regulated and 450 genes down-regulated in early-onset PE. Go analysis showed significant alteration in several biological processes, in addition to the processes which have been found before, such as immune and inflammatory response, cell adhension, female pregnancy and blood vessel development. We also found alteration in G-protein coupled receptor protein signaling pathway, G protein-coupled receptor 124 (GPR124) (P=0.0064) and MAS-related GPR, member F (MRGPRF)(P=0.0155 ) were both down-regulated obviously in early-onset PE. Conclusion: The different gene expression profiles suggested early- and late-onset PE are separate disease entities. Moreover, G-protein coupled receptor protein signaling pathway may contribute to the mechanism underlying early- and late-onset preeclampsia. Whole genome-wide microarray was used to describe the gene expression profiles in the placenta tissues from patients with early-(n=7; <34 weeks), late-onset (n=8; >36 weeks) PE and their controls who delivered preterm(n=5;<34 weeks) or at term(n=5; >36 weeks). Pooled controls who delivered at term were labled with cy5.