Placental Malaria Induces a Unique Methylation Profile Associated with Fetal Growth Restriction
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ABSTRACT: Fetal growth restriction (FGR) is associated with perinatal death and adverse birth outcomes, as well as long-term complications, including increased childhood morbidity, abnormal neurodevelopment, and cardio-metabolic diseases in adulthood. Placental epigenetic reprogramming associated with FGR may mediate these long-term outcomes. Placental malaria (PM), characterized by sequestration of Plasmodium falciparum-infected erythrocytes in placental intervillous space, is the leading global cause of FGR, but its impact on placental epigenetics is unknown. We hypothesized that placental methylomic profiling would reveal common and distinct mechanistic pathways of non-malarial and PM-associated FGR. We analyzed placentas from a US cohort with no malaria exposure (n = 12) and a cohort from eastern Uganda, a region with a high prevalence of malaria (n = 12). From each site, 8 cases of FGR and 4 healthy controls were analyzed. PM was diagnosed by placental histopathology. We compared the methylation levels of over 850K CpGs of the placentas using Infinium MethylationEPIC v1 microarray. Non-malarial FGR was associated with 65 differentially methylated CpGs (DMCs), whereas PM-FGR was associated with 133 DMCs, compared to their corresponding controls without FGR. One DMC (cg16389901, located in the promoter region of BMP4) was commonly hypomethylated in both groups. We identified 522 DMCs between non-malarial FGR vs. PM-FGR placentas, independent of differing geographic location or cellular composition. Placentas with PM-associated FGR have distinct methylation profiles compared to placentas with non-malarial FGR, suggesting novel epigenetic reprogramming in response to malaria. Larger cohort studies are needed to determine the distinct long-term health outcomes in PM-associated FGR pregnancies.
Project description:Chronic inflammation during placental malaria (PM) caused by Plasmodium falciparum is most frequent in first-time mothers and is associated with poor maternal and fetal outcomes. In the first genome wide analysis of the local human response to sequestered malaria parasites, we identified genes associated with chronic PM, then localized the corresponding proteins and immune cell subsets in placental cryosections. Experiment Overall Design: Placental samples from twenty first-time mothers were selected based on placental malaria (PM) status and RNA quality. Ten had active PM-episodes, seven of which had inflammatory cells on histology. Of the ten PM-negative women, five had histological evidence of a past PM-episode, including one with inflammatory cells.
Project description:Chronic inflammation during placental malaria (PM) caused by Plasmodium falciparum is most frequent in first-time mothers and is associated with poor maternal and fetal outcomes. In the first genome wide analysis of the local human response to sequestered malaria parasites, we identified genes associated with chronic PM, then localized the corresponding proteins and immune cell subsets in placental cryosections. Keywords: Disease state analysis
Project description:Fetal growth restriction (FGR) develops when fetal nutrient availability is compromised and increases the risk for perinatal complications and predisposes for offspring obesity, diabetes and cardiovascular disease later in life. Emerging evidence implicates changes in placental function in altered fetal growth and the subsequent development of adult disease. The susceptibility for disease in response to an adverse intrauterine environment differs distinctly between boys and girls, with girls typically having better outcomes. Here, we test the hypothesis that regulation of the placental transcriptome by moderate nutrient reduction is dependent on fetal sex. We used a non-human primate model of FGR in which maternal global food intake is reduced by 30% starting at gestational day (GD) 30. At GD 165 (term = GD 183) placental genome expression profiling was carried out followed by bioinformatics including pathway and network analysis. Surprisingly, there was no coordinated placental molecular response to decreased nutrient availability when analyzing the data without accounting for fetal sex. In contrast, female placentas exhibited a highly coordinated response that included up-regulation of genes in networks, pathways and functional groups related to programmed cell death and down-regulation of genes in networks, pathways and functional groups associated with cell proliferation. These changes were not apparent in the male placentas. Our data support the concept that female placentas initiate complex adaptive responses to an adverse intrauterine environment, which may contribute to increased survival and better pregnancy outcomes in girls. Total RNA obtained from 165dGA control female (n=3), control male (n=3), nutrient restricted female (n=3), and nutrient restricted male (n=3) pregnancies.
Project description:Fetal growth restriction (FGR) affects between 5-10% of all live births. Placental insufficiency is a leading cause of FGR, resulting in reduced nutrient and oxygen delivery to the fetus. Currently, there is no effective in utero treatment options for FGR, or placental insufficiency. We have developed a gene therapy to deliver human insulin-like 1 growth factor (hIGF1) to the placenta via a non-viral nanoparticle delivery mechanism as potential treatment of FGR. Using a guinea pig maternal nutrient restriction (MNR) model of FGR, we aimed to understand the transcriptional changes within the placenta associated with placental insufficiency that occur at the beginning stages of FGR (mid-pregnancy), and the immediate impact of hIGF1 nanoparticle treatment on the placental transcriptome. Using RNAsequencing, we analyzed protein coding genes of three experimental groups: Control dams and MNR receiving a sham treatment, and MNR dams receiving hIGF1 nanoparticle treatment. Pathway enrichment analysis comparing MNR placentas to Control revealed upregulation of pathways associated with degradation and repair of genetic information and downregulation of pathways associated with transmembrane transport. Similarly, differentially expressed genes that were decreased in MNR + hIGF1 placentas compared to Control demonstrated downregulation in pathways relating to transporter activities, but upregulation in pathways associated with positive regulation of phosphorylation and kinase activity. When compared to MNR placentas, MNR + hIGF1 placentas demonstrated changes to genes associated with transmembrane transporter activity including ion, vitamin and solute carrier (SLC-mediated) transport. Overall, this study identifies the key signaling and metabolic changes occurring in the placenta that contribute to placental insufficiency, and increases our understanding of the pathways that increasing placental IGF1 expression acts on and corrects.
Project description:Malaria in pregnancy remains a substantial public health concern in malaria-endemic areas. Accumulation of maternal immune cells in the placenta and increased levels of inflammatory cytokines caused by sequestration of Plasmodium falciparum-infected erythrocytes (IE) in the placental intervillous blood spaces have been associated to poor neonatal outcomes, including low birth weight due to fetal growth restriction. However, little is known about the molecular changes occurring in the placenta in past-stages of P. falciparum infection when the hemozoin pigment is present in the absence of parasites. We conducted an integrated proteome, phosphoproteome and glycoproteome analysis in P. falciparum infected and non-infected placentas aiming to find molecular changes occurring in past-stage infection. A total of 2946 proteins, 1733 glycosites and 4100 phosphosites were identified and quantified in this study, disclosing overrepresented processes related to oxidative stress, protein folding and regulation of apoptosis, as well as AKT and ERK signaling pathways activation, which together with clinical data and literature-based information were further correlated to an increased apoptosis in infected placentas. This study showed apoptosis-related mechanisms associated with past-stage of malaria infection that can be further explored as therapeutic target against adverse pregnancy outcomes in placental malaria.
Project description:Fetal growth restriction (FGR) develops when fetal nutrient availability is compromised and increases the risk for perinatal complications and predisposes for offspring obesity, diabetes and cardiovascular disease later in life. Emerging evidence implicates changes in placental function in altered fetal growth and the subsequent development of adult disease. The susceptibility for disease in response to an adverse intrauterine environment differs distinctly between boys and girls, with girls typically having better outcomes. Here, we test the hypothesis that regulation of the placental transcriptome by moderate nutrient reduction is dependent on fetal sex. We used a non-human primate model of FGR in which maternal global food intake is reduced by 30% starting at gestational day (GD) 30. At GD 165 (term = GD 183) placental genome expression profiling was carried out followed by bioinformatics including pathway and network analysis. Surprisingly, there was no coordinated placental molecular response to decreased nutrient availability when analyzing the data without accounting for fetal sex. In contrast, female placentas exhibited a highly coordinated response that included up-regulation of genes in networks, pathways and functional groups related to programmed cell death and down-regulation of genes in networks, pathways and functional groups associated with cell proliferation. These changes were not apparent in the male placentas. Our data support the concept that female placentas initiate complex adaptive responses to an adverse intrauterine environment, which may contribute to increased survival and better pregnancy outcomes in girls.
Project description:Introduction: Maternal immune activation (MIA), characterized by increased circulating inflammatory mediators during pregnancy, is associated with adverse pregnancy outcomes and neurodevelopmental deficits in offspring. These health outcomes often manifest differently depending on fetal-placental sex. A well-established model of MIA involves administration of a viral mimetic, polyinosinic:polycytidilic acid (PolyI:C), to pregnant rodents. Placental responses to PolyI:C contribute to the detrimental effects of MIA on offspring, but these responses have not yet been well characterized. In the present study, we profiled acute gene expression changes in male and female placentas following PolyI:C administration to pregnant rats. Methods: Pregnant rats received 4 mg/kg PolyI:C or saline intravenously on gestational day 18.5, and tissues were harvested 4-5 hours later. Gene expression profiling on placental tissue was performed. Enzyme immunoassays and immunohistochemistry were conducted to determine levels of select proteins in maternal blood and placental tissue, respectively. Results: Maternal PolyI:C exposure caused a robust increase in levels of inflammatory markers in maternal blood and placental tissue. There were more genes differentially expressed in female placentas after PolyI:C exposure (765) than male placentas (221), including reduced expression of genes associated with maternal-fetal communication. Placentas also had increased expression of genes linked with vascular dysfunction after PolyI:C-induced MIA. Discussion: PolyI:C elicited a powerful inflammatory response in the placenta along with vascular dysfunction, likely contributing to the adverse pregnancy outcomes triggered by MIA. Female placentas responded to PolyI:C more vigorously than male placentas, which could underlie the differential outcomes of MIA depending on sex.
Project description:Fetal growth restriction (FGR) is a heterogeneous disorder of pregnancy associated with pathologically low fetal and neonatal weights. We hypothesized that FGR consists of multiple placental subtypes, similar to what we have observed in preeclampsia. To address this hypothesis, we assembled a fetal growth-focused human placental microarray data set (N=97) consisting of 20 new normotensive suspected FGR samples (below), in addition to term controls (N=26) and hypertensive suspected FGR samples (N=51) from GSE75010.
Project description:Early-onset preeclampsia (EOPE) is a severe hypertensive disorder of pregnancy, frequently associated with fetal growth restriction (FGR) and reduced estrogen levels due to placental dysfunction. We employed single-cell RNA sequencing (scRNA-seq) to profile placental trophoblasts from EOPE patients complicated by FGR.
Project description:Malaria continues to pose a significant public health threat, with millions of cases and hundreds of thousands of deaths reported annually, primarily in sub-Saharan Africa. The disease disproportionally affects children under five years of age residing in holoendemic Plasmodium falciparum transmission regions, who account for 94% of the cases and 80% of the mortality. Young children are highly vulnerable to developing life-threatening severe malarial anemia [SMA, hemoglobin (Hb)<5.0 g/dL]. The overall goal of the project was to identify critical gene pathways within the transcriptome that mediate disease severity and then target these specific genes with compounds that elicit expression profiles witnessed in children with milder forms of disease. To achieve this goal, we are investing the following specific aims: 1) Determine how changing temporal dynamics of gene pathways in the Malarial Immunity Transcriptome promote SMA during acute disease; 2) Determine how changes in gene pathways in the Malarial Immunity Transcriptome mediate malarial severity throughout the development of naturally acquired immunity; and 3) Identify immunotherapeutic targets in the Malarial Immunity Transcriptome that can be used to reduce malaria disease severity and improve clinical outcomes in future trials. To successfully complete these aims, we are determining how host profiles impact on acute disease over 14 days. We will utilize Ex vivo samples from the cohort to test the effect of immunotherapeutic compounds on host expression profiles. Accomplishing these goals will have broad reaching translational implications for: (1) identifying at-risk groups, and (2) prioritizing compounds that can be used to improve clinical outcomes in future immunotherapy trials.