Project description:Epidemiological studies indicate that adverse intrauterine and postnatal environment has a long-lasting role in chronic kidney disease (CKD) development. Epigenetic information can represent a plausible carrier for mediating this "programming" effect. Here we demonstrate that genome-wide cytosine methylation patterns of healthy and CKD tubule samples obtained from patients show significant differences. We rarely observed differentially methylated regions (DMR) on promoters. Histone modification-based kidney specific genome-wide gene regulatory region annotation maps (promoters, enhancers, transcribed and repressed regions) were generated. DMRs mostly overlapped with putative enhancer regions and were enriched in consensus binding sequences for important renal transcription factors, indicating their importance in gene expression regulation. A core set of genes, including transforming growth factors and collagens, showed cytosine methylation changes correlating with downstream transcript levels. Our report raises the possibility that epigenetic dysregulation plays a role in CKD development via influencing core profibrotic pathways. HG18_HELP array We used custom-commercial array to detail the differences of methylation regions of human tubule epithelial cells between chronic kidney disease and normal. We sought to decrease the cell type heterogeneity of kidney tissues to increase the resolution of methylation profiles. To that end, microdissected human kidney tissue from both chronic kidney disease patient and normal are used for the HELP-assay (HpaII tiny fragment Enrichment by Ligation-mediated PCR) and hybridization on Roche NimbleGen microarrays.
Project description:Epidemiological studies indicate that adverse intrauterine and postnatal environment has a long-lasting role in chronic kidney disease (CKD) development. Epigenetic information can represent a plausible carrier for mediating this programming effect. Here we demonstrate that genome-wide cytosine methylation patterns of healthy and CKD tubule samples obtained from patients show significant differences. Cytosine methylation changes showed high concordance (98%) with a large (n=87) replication dataset. We rarely observed differentially methylated regions (DMR) on promoters. Histone modification-based kidney specific genome-wide gene regulatory region annotation maps (promoters, enhancers, transcribed and repressed regions) were generated. DMRs mostly overlapped with putative enhancer regions and were enriched in consensus binding sequences for important renal transcription factors, indicating their importance in gene expression regulation. A core set of genes, including transforming growth factors and collagens, showed cytosine methylation changes correlating with downstream transcript levels. Our report raises the possibility that epigenetic dysregulation plays a role in CKD development via influencing core profibrotic pathways. We used microarrays to detail the differences of gene expression of human tubule epithelial cells between chronic kidney disease and normal. We sought to decrease the cell type heterogeneity of kidney tissues to increase the resolution of expression profiles. To that end, microdissected human kidney tissue from both chronic kidney disease patient and normal are used for RNA extraction and hybridization on Affymetrix microarrays.
Project description:Genome-wide association studies (GWAS) have identified hundreds of susceptibility loci for chronic and inflammatory disease phenotypes in humans. There is increasing evidence that chronic inflammation is a crucial driver in the pathogenesis of cardiovascular diseases (CVD), which may be genetically determined. To understand the genetic architecture underlying chronic inflammation and CVD we performed a systematic analysis of (1) common risk alleles coming from published GWAS, (2) of protein-protein interaction (PPI) networks informed by (3) gene expression data with a defined molecular target involved in the inflammatory processes promoting CVD, MRP8. (4) through analysis of integrated haplotype scores (iHS) and FST values in HapMap phase 2 data, we investigated whether recent selection pressure acting upon inflammatory genes affected CVD susceptibility loci. Our findings provide significant evidence for a PPI network, which connects inflammatory and cardiovascular susceptibility genes, and establish a genetic framework of inflammatory CVD. 41.59% of PPI genes are associated with immune functions. 28.3% of integrated genes can be linked to both, an inflammatory and cardiovascular disease phenotype. Interestingly, CDKN2B, and CELSR2/PSRC1/MYBPHL/SORT1, unequivocally replicated CVD loci, are integrated within this network as are several SNPs located in transcription factor recognition sequences, i.e. NFKB1, STAT3, which are key factors in inflammation. Finally, we observed a significant enrichment of inflammatory variants within CVD cluster loci that are targets of selection. Overall, 32 genes exhibit traces of selection, 16 of which are part of the PPI, further suggesting that recent selective sweeps may have affected the genomic architecture underlying CVD. 6 samples, no replicates.