Project description:Placental insufficiency is implicated in the intrauterine infection-associated spontaneous preterm birth. Using a mouse model of LPS-induced intrauterine inflammation that leads to preterm delivery, RNA-seq study was performed in the placenta at gestational day 17 to assess the transcriptome changes.
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:Preterm birth is a main determinant of neonatal mortality and morbidity and a major contributor to the overall mortality and burden of disease. However, precise phenotyping of the preterm birth is hampered by the imprecise definition of the clinical phenotype and complexity of the molecular phenotype due to multiple pregnancy tissue types and molecular processes that may contribute to the preterm birth. The studyâ??s aim was to comprehensively evaluate the mRNA transcriptome that characterizes preterm and term labor using precisely phenotyped samples. Expression profiles of 73 genes and non-coding RNA sequences uniquely identified the four groups of patients: delivering preterm with (PL) and without labor (PNL), term with (TL) and without labor (TNL). The largest differences in gene expression among the four groups occurred in decidua, chorion and amnion. The gene expression profiles showed suppression of chemokines expression in TNL, withdrawal of this suppression in TL, activation of multiple pathways of inflammation in PL, and an immune rejection profile in PNL. The genes constituting expression signatures showed over-representation of three putative regulatory elements in their 5â?? and 3â??UTR regions. The results suggest that pregnancy is maintained by downregulation of chemokines at the maternal-fetal interface. Withdrawal of this downregulation results in the term birth and its overriding by the activation of multiple pathways of the immune system in the preterm birth. Complications of the pregnancy associated with impairment of placental function, which necessitated premature delivery of the fetus in the absence of labor, show gene expression patterns associated with immune rejection. 183 total RNA samples from 8 tissue types collected from 35 women grouped into six categories of pregnancy outcome. One microarray replicate per sample. Other Contributors: Radek Bukowski, Sam Parry and the NICHD Genomic and Proteomic Network for Preterm Birth Research
Project description:Preterm birth is a significant clinical problem and an enormous burden on society, affecting one in eight pregnant women and their newborns. Despite decades of research, its pathogenesis remains unclear. Many studies have shown that preterm birth is associated with health risks across the later life course. The “fetal origins” hypothesis postulates that adverse intrauterine exposures are associated with later disease susceptibility. Our recent studies have focused on the placental epigenome at term. We extended these studies to genome-wide placental DNA methylation across a wide range of gestational ages. We applied methylation dependent immunoprecipitation/DNA sequencing (MeDIP-seq) to 9 placentas with gestational age from 25 weeks to term to identify differentially methylated regions (DMRs). Enrichment analysis revealed 427 DMRs with nominally significant differences in methylation between preterm and term placentas (p<0.01) and 21 statistically significant DMRs after multiple comparison correction (FDR p<0.05), of which 62% were hypo-methylated in preterm placentas vs term placentas. The majority of DMRs were in distal intergenic regions and introns. Significantly enriched pathways identified by Ingenuity Pathway Analysis (IPA) included Citrulline-Nitric Oxide Cycle and Fcy Receptor Mediated Phagocytosis in macrophages. The DMR gene set overlapped placental gene expression data, genes and pathways associated evolutionarily with preterm birth. These studies form the basis for future studies on the epigenetics of preterm birth, "fetal programming” and the impact of environment exposures on this important clinical challenge.
Project description:Spontaneous preterm birth (PTB) is a major obstetrical problem around the globe and the mechanisms leading to PTB are unclear. Recently, changes in the circulating levels of placental extracellular vesicles (EVs) during pregnancy have been associated with various pregnancy complications. However, progress in the field is hindered by the inability to isolate placental EVs from the maternal circulation. A longitudinal study design was used to determine the protein cargo present in circulating placental EVs in maternal plasma of term and preterm birth across gestation (i.e. first, second and third trimester). Placental derived EVs were enriched from the total EVs population based on their expression of membrane bound placental alkaline phosphatase (PLAP). A quantitative, information-independent acquisition (Sequential Windowed Acquisition of All Theoretical Mass Spectra [SWATH]) approach identified and quantified the placental EV protein contents. PLAP+ EVs do not change in characteristics (size shape and markers) but did differ in numbers across gestation with low levels in PTB. A comparison analysis between the PLAP+ EV proteome from term and PTB revealed 96 proteins differing significantly (P<0.05, False Discovery Rate 1%) across gestation. Bioinformatics analysis of differentially expressed proteins revealed consistent upregulation of inflammatory pathways in both, upregulation of epithelial mesenchymal transition pathways at term and down regulation of coagulation/complement activation in preterm. Characterization of the proteomic profile in PLAP+ EVs across gestation demonstrates dramatic changes, which might be used to understand the biological process associated with early parturition and develop biomarkers for predicting high risk status for PTB.
Project description:Placental insufficiency is implicated in spontaneous preterm birth (SPTB). We performed RNA-seq study in male and female placentas from women (African American, self-identified) with SPTB (< 36 weeks gestation) compared to normal pregnancies (≥ 38 weeks gestation) to assess the alterations in gene expression profiles.
Project description:We compared fetal membrane tissue from preterm labor deliveries to fetal tissue from preterm labor with preterm prelabor rupture of membranes (PPROM) deliveries to further explore the concept that spontaneous preterm birth can result from the initializing of two separate but overlapping pathological events. Chorioamnion, separated into amnion and chorion, was collected from gestationally age-matched cases and controls within 15 minutes of birth, and analyzed using RNA sequencing. In our study, transcriptome analysis of preterm fetal membranes revealed distinct differentially expressed genes for PPROM, separate from preterm labor. This study is the first to report transcriptome data that reflects the individual pathophysiology of amnion and chorion tissue from PPROM deliveries.