Project description:Abnormal epigenetic gene regulation may play a pivotal role in atherogenesis. In particular, global DNA hypomethylation potentially leading to proatherogenic gene expression, occurs in atherosclerotic lesions in humans and animal models. In order to identify genomic sequences targeted for DNA hypomethylation in atherosclerosis, we analysed the methylation status of CpG islands (CGIs) in 45 human arteries with advanced atherosclerotic lesions and 16 normal counterparts by a microarray approach. Methylation data for 10,367 CGIs revealed that a subset (1.5%) of such sequences was hypermethylated in normal arteries, in accordance with data previously obtained in peripheral blood cells. Ninety-four per cent of this CGI subset was demethylated in atherosclerotic tissue, while only 17 of normally hypomethylated CGIs was hypermethylated in diseased tissue. A functional classification of genes physically associated with differentially methylated CGIs revealed a bias towards transcription factors (42%). The latter include HOX members, NOTCH1 and FOXP1, which are known to regulate angiogenesis, dedifferentiation, cell migration and macrophage function. The methylation status of selected CGIs was validated in further 10 subjects for either group. Expression patterns of these factors were compatible with the observed differential methylation. Our data suggest that one of the molecular changes associated with aberrant DNA methylation in advanced atherosclerosis is the regulation of critical transcription factor genes for the induction of a proatherogenic cellular phenotype. Two-condition experiment, i.e. normal vs. atherosclerotic arteries. 16 and 45 normal and atherosclerotic samples, respectively, were pooled and used to interrogate CpG island arrays in triplicate, for a total of six arrays. Each array was co-hybridized with untreated DNA (reference) and hypermethylated DNA obtained by biochemical filtration.
Project description:Abnormal epigenetic gene regulation may play a pivotal role in atherogenesis. In particular, global DNA hypomethylation potentially leading to proatherogenic gene expression, occurs in atherosclerotic lesions in humans and animal models. In order to identify genomic sequences targeted for DNA hypomethylation in atherosclerosis, we analysed the methylation status of CpG islands (CGIs) in 45 human arteries with advanced atherosclerotic lesions and 16 normal counterparts by a microarray approach. Methylation data for 10,367 CGIs revealed that a subset (1.5%) of such sequences was hypermethylated in normal arteries, in accordance with data previously obtained in peripheral blood cells. Ninety-four per cent of this CGI subset was demethylated in atherosclerotic tissue, while only 17 of normally hypomethylated CGIs was hypermethylated in diseased tissue. A functional classification of genes physically associated with differentially methylated CGIs revealed a bias towards transcription factors (42%). The latter include HOX members, NOTCH1 and FOXP1, which are known to regulate angiogenesis, dedifferentiation, cell migration and macrophage function. The methylation status of selected CGIs was validated in further 10 subjects for either group. Expression patterns of these factors were compatible with the observed differential methylation. Our data suggest that one of the molecular changes associated with aberrant DNA methylation in advanced atherosclerosis is the regulation of critical transcription factor genes for the induction of a proatherogenic cellular phenotype.
Project description:Using the Illumina Infinium Human Methylation27 BeadChip, we performed a genome-wide analysis of DNA methylation in right coronary artery in the area of advanced atherosclerotic plaques, atherosclerotic-resistant internal mammary arteries, and great saphenous veins obtained from same patients with coronary heart disease. The resulting DNA methylation patterns were markedly different between all the vascular tissues. The genes hypomethylated in athero-prone arteries to compare with atherosclerotic-resistant arteries were predominately involved in regulation of inflammation and immune processes, as well as development. The great saphenous veins exhibited an increase of the DNA methylation age in comparison to the internal mammary arteries. Gene ontology analysis for genes harboring hypermethylated CpG-sites in veins revealed the enrichment for biological processes associated with the development. Four CpG-sites located within the MIR10B gene sequence and about 1 Kb upstream of the HOXD4 gene were also confirmed as hypomethylated in the independent dataset of right coronary arteries in the area of advanced atherosclerotic plaques in comparison with the other vascular tissues. Bisulfite converted genomic DNA from 24 samples was denatured, whole-genome amplified, fragmented and subsequently hybridized to the Illumina Infinium 27k Human Methylation Beadchip.
Project description:Using the Illumina Infinium Human Methylation27 BeadChip, we performed a genome-wide analysis of DNA methylation in right coronary artery in the area of advanced atherosclerotic plaques, atherosclerotic-resistant internal mammary arteries, and great saphenous veins obtained from same patients with coronary heart disease. The resulting DNA methylation patterns were markedly different between all the vascular tissues. The genes hypomethylated in athero-prone arteries to compare with atherosclerotic-resistant arteries were predominately involved in regulation of inflammation and immune processes, as well as development. The great saphenous veins exhibited an increase of the DNA methylation age in comparison to the internal mammary arteries. Gene ontology analysis for genes harboring hypermethylated CpG-sites in veins revealed the enrichment for biological processes associated with the development. Four CpG-sites located within the MIR10B gene sequence and about 1 Kb upstream of the HOXD4 gene were also confirmed as hypomethylated in the independent dataset of right coronary arteries in the area of advanced atherosclerotic plaques in comparison with the other vascular tissues.
Project description:To globally define methylation-’prone’ and -’protected’ CpG islands in cancer, we analyzed the methylation status of 23,000 CpG islands of the human genome in 19 colorectal carcinoma samples as well as normal colon using our previously described methyl-CpG immunoprecipitation (MCIp) technique (Gebhard et al. 2006; Schilling and Rehli 2007). This method enriches for highly CpG methylated DNA that can be directly applied to fluorescent labeling and oligonucleotide microarray hybridization without an additional amplification step.
Project description:To globally define methylation-’prone’ and -’protected’ CpG islands in leukemia, we analyzed the methylation status of 23,000 CpG islands of the human genome in eight acute leukemia samples as well as normal blood monocytes using our previously described methyl-CpG immunoprecipitation (MCIp) technique (Gebhard et al. 2006; Schilling and Rehli 2007). This method enriches for highly CpG methylated DNA that can be directly applied to fluorescent labeling and oligonucleotide microarray hybridization without an additional amplification step. Keywords: MCIp-on-Chip; comparative genomic hybridization
Project description:To globally define methylation-’prone’ and -’protected’ CpG islands in leukemia, we analyzed the methylation status of 23,000 CpG islands of the human genome in two acute leukemia cell lines as well as normal blood monocytes using our previously described methyl-CpG immunoprecipitation (MCIp) technique (Gebhard et al. 2006; Schilling and Rehli 2007). This method enriches for highly CpG methylated DNA that can be directly applied to fluorescent labeling and oligonucleotide microarray hybridization without an additional amplification step. Keywords: MCIp-on-Chip; comparative genomic hybridization
Project description:To globally define methylation-’prone’ and -’protected’ CpG islands in colorectal carcinoma we analyzed the methylation status of 23,000 CpG islands of the human genome in ten coleorectal carcinoma samples as well as normal colon using our previously described methyl-CpG immunoprecipitation (MCIp) technique (Gebhard et al. 2006; Schilling and Rehli 2007). This method enriches for highly CpG methylated DNA that can be directly applied to fluorescent labeling and oligonucleotide microarray hybridization without an additional amplification step. Keywords: MCIp-on-Chip; comparative genomic hybridization
Project description:To globally define methylation-âproneâ and -âprotectedâ CpG islands in colorectal carcinoma we analyzed the methylation status of 23,000 CpG islands of the human genome in ten coleorectal carcinoma samples as well as normal colon using our previously described methyl-CpG immunoprecipitation (MCIp) technique (Gebhard et al. 2006; Schilling and Rehli 2007). This method enriches for highly CpG methylated DNA that can be directly applied to fluorescent labeling and oligonucleotide microarray hybridization without an additional amplification step. Keywords: MCIp-on-Chip; comparative genomic hybridization CpG-methylated genomic DNA was enriched using methyl-CpG immunoprecipitation (MCIp). On each microarray, the enriched material from colorectal carcinoma samples was compared to the enriched material from normal colon to identify aberrantly methylated regions.
Project description:To globally define methylation-M-bM-^@M-^YproneM-bM-^@M-^Y and -M-bM-^@M-^YprotectedM-bM-^@M-^Y CpG islands in cancer, we analyzed the methylation status of 23,000 CpG islands of the human genome in 19 colorectal carcinoma samples as well as normal colon using our previously described methyl-CpG immunoprecipitation (MCIp) technique (Gebhard et al. 2006; Schilling and Rehli 2007). This method enriches for highly CpG methylated DNA that can be directly applied to fluorescent labeling and oligonucleotide microarray hybridization without an additional amplification step. CpG-methylated genomic DNA was enriched using methyl-CpG immunoprecipitation (MCIp). On each microarray, the enriched material from colorectal carcinoma samples was compared to the enriched material from normal colon to identify aberrantly methylated regions.