Project description:Genome wide DNA methylation profiling of normal and trisomic placentas, and maternal blood cell DNA. The aim of this study was to search for methylation differences between maternal and fetal(placenta) cell free DNA, and between normal and trisomic placentas for an optimized methylation based noninvasive prenatal diagnosis of fetal chromosomal aberations. The Illumina Infinium 450k Human DNA methylation Beadchip was used to obtain DNA methylation profiles across approximately 450,000 CpGs in DNA samples from Chorionic villus samples(CVS) and DNA samples from whole blood. Samples included 12 Maternal blood cell samples from normal pregnancies, 12 normal CVS, 12 Trisomy 21 CVS, 12 trisomy 18 CVS and 6 trisomy 13 CVS samples. Bisulphite converted DNA from the 54 samples were hybridized to the Illumina Infinium 450k Human Methylation Beadchip.
Project description:Comparative analysis of DNA methylation in 12 human chorionic villus samples and 12 human maternal blood cell samples We performed a genome wide analysis of DNA methylation first trimester CVS samples and gestational age matched MBCs. We analyzed DNA samples obtained from 12 CVS samples and 12 MBC samples. Data were generated using two high-throughput approaches: the Infinium “humanmethylation27” platform marketed by Illumina and a custom Agilent-based platform. We then compared these data with genome wide transcription data for the same tissues. This Series covers only the Illumina HumanMethylation27 part of the study.
Project description:Genome wide DNA methylation profiling of normal and trisomic placentas, and maternal blood cell DNA. The aim of this study was to search for methylation differences between maternal and fetal(placenta) cell free DNA, and between normal and trisomic placentas for an optimized methylation based noninvasive prenatal diagnosis of fetal chromosomal aberations. The Illumina Infinium 450k Human DNA methylation Beadchip was used to obtain DNA methylation profiles across approximately 450,000 CpGs in DNA samples from Chorionic villus samples(CVS) and DNA samples from whole blood. Samples included 12 Maternal blood cell samples from normal pregnancies, 12 normal CVS, 12 Trisomy 21 CVS, 12 trisomy 18 CVS and 6 trisomy 13 CVS samples.
Project description:Noninvasive prenatal diagnosis currently used does not achieve desirable levels of sensitivity and specificity. Recently, fetal methylated DNA biomarkers in maternal whole blood have been explored for noninvasive prenatal detection. However, such efforts cover only chromosomal aneuploidy; fetal methylated DNA biomarkers for detecting single-gene disease remain to be discovered. To address this issue, we systematically screened significantly hypermethylated genes in fetal tissues compared with maternal blood for noninvasive prenatal diagnosis of various inherited diseases. First, Methylated-CpG island recovery assay combined with CpG island array was performed in four maternal peripheral bloods and their corresponding placental tissues. Subsequently, direct bisulfite sequencing and combined bisulfite restriction analysis (COBRA) were carried out to validate the reliability of methylation microarray analysis. As results, 310 significantly hypermethylated genes in fetal tissues were detected by microarray. Two of five randomly selected hypermethylated genes detected by microarray were confirmed to be hypermethylated in fetal tissue samples by direct bisulfite sequencing. All four randomly selected hypermethylated genes detected by microarray were confirmed to be hypermethylated in five independent amniotic fluid samples and five independent chorionic villus samples from 10 pregnant women by CORBA. In conclusions, We found a lot of hypermethylated genes and methylation sites in fetal tissues, some of which have great potential to be developed into molecular markers for noninvasive prenatal diagnosis of monogenic disorders. Further clinical study is warranted to confirm these findings. Paired experiments, placental tissues vs. maternal peripheral bloods. Biological replicates: 4 placental tissues and 4 correspoding maternal peripheral bloods.
Project description:We present a detailed structural and functional analysis of the placental epigenome at its maternal interface. Specifically, we analyzed the DNA methylation pattern of chromsomes 13, 18, and 21 in samples of chorionic villus (CVS) and maternal blood cells (MBC) using custom designed microarrays. We then compared these data with transcription data for the same tissues. In addition to the discovery that CVS genomes are significantly more hypomethylated than their MBC counterparts, we identified numerous tissue-specific differentially methylated regions (T-DMRs). We further discovered that these T-DMRs are clustered spatially along the genome and are enriched for genes with tissue-specific biological functions. We identified unique patterns of DNA methylation associated with distinct genomic structures such as gene bodies, promoters and CpG islands and identified both direct and inverse relationships between DNA methylation levels and gene expression levels in gene bodies and promoters respectively. Furthermore, we found that these relationships were significantly associated with CpG content. We conclude that the early gestational placental DNA methylome is highly organized and is significantly associated with transcription. These data provide a unique insight into the structural and regulatory characteristics of the placental epigenome at its maternal interface and will drive future analyses of the role of placental dysfunction in gestational disease.
Project description:We present a detailed structural and functional analysis of the placental epigenome at its maternal interface. Specifically, we analyzed the DNA methylation pattern of chromsomes 13, 18, and 21 in samples of chorionic villus (CVS) and maternal blood cells (MBC) using custom designed microarrays. We then compared these data with transcription data for the same tissues. In addition to the discovery that CVS genomes are significantly more hypomethylated than their MBC counterparts, we identified numerous tissue-specific differentially methylated regions (T-DMRs). We further discovered that these T-DMRs are clustered spatially along the genome and are enriched for genes with tissue-specific biological functions. We identified unique patterns of DNA methylation associated with distinct genomic structures such as gene bodies, promoters and CpG islands and identified both direct and inverse relationships between DNA methylation levels and gene expression levels in gene bodies and promoters respectively. Furthermore, we found that these relationships were significantly associated with CpG content. We conclude that the early gestational placental DNA methylome is highly organized and is significantly associated with transcription. These data provide a unique insight into the structural and regulatory characteristics of the placental epigenome at its maternal interface and will drive future analyses of the role of placental dysfunction in gestational disease. Two-condition experiment, CVS vs. MBC cells. Biological replicates: 2 pooled CVS samples, 2 pooled MBC samples, collected from different patients. Each sample is divided into two parts, one part treated with HpaII enzyme, one part without. The two parts then are hybridized to the two channels of the same array. Two arrays for each sample, with dye swap to remove dye bias.
Project description:Noninvasive prenatal diagnosis currently used does not achieve desirable levels of sensitivity and specificity. Recently, fetal methylated DNA biomarkers in maternal whole blood have been explored for noninvasive prenatal detection. However, such efforts cover only chromosomal aneuploidy; fetal methylated DNA biomarkers for detecting single-gene disease remain to be discovered. To address this issue, we systematically screened significantly hypermethylated genes in fetal tissues compared with maternal blood for noninvasive prenatal diagnosis of various inherited diseases. First, Methylated-CpG island recovery assay combined with CpG island array was performed in four maternal peripheral bloods and their corresponding placental tissues. Subsequently, direct bisulfite sequencing and combined bisulfite restriction analysis (COBRA) were carried out to validate the reliability of methylation microarray analysis. As results, 310 significantly hypermethylated genes in fetal tissues were detected by microarray. Two of five randomly selected hypermethylated genes detected by microarray were confirmed to be hypermethylated in fetal tissue samples by direct bisulfite sequencing. All four randomly selected hypermethylated genes detected by microarray were confirmed to be hypermethylated in five independent amniotic fluid samples and five independent chorionic villus samples from 10 pregnant women by CORBA. In conclusions, We found a lot of hypermethylated genes and methylation sites in fetal tissues, some of which have great potential to be developed into molecular markers for noninvasive prenatal diagnosis of monogenic disorders. Further clinical study is warranted to confirm these findings.
Project description:Using the Illumina HumanMethylation450 BeadChip platform, we profiled the genome-wide DNA methylation of villous cytotrophoblasts samples isolated ex vivo from placental chorionic villi before they first come into contact with maternal blood (8-10 weeks of gestation, n = 9) and after (12-14 weeks of gestation, n = 10).