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:Vascular calcification is a hallmark of atherosclerosis and end-stage renal disease (ESRD). However, the molecular mechanism of vascular calcification is poorly understood. Diabetes mellitus is increasingly recognized as the most important cause for atherosclerosis and ESRD. Emerging evidence supports the concept that vascular calcification resembles the process of osteogenesis, in which the vascular smooth muscle cells (VSMC) undergo osteochondrogenic differentiation. Recently, we have established an in vitro calcification system with primary mouse VSMC. With the use of osteogenic stimuli, we induced trans-differentiation of primary mouse VSMC into bone-like cells. Interestingly stroptozotocin (STZ), O-GlcNAcase inhibitor and a drug that has been used to induce diabetes in mice, was able to induce calcification of VSMC and the expression of the osteogenic transcription factor Runx2, suggesting glycosylation may be involved in regulation of Runx2. We have reported an essential role of Runx2 in oxidative stress-induce VSMC calcification and have recently generated a tissue specific mouse with Runx2 ablation in smooth muscle cells. Therefore, we will use STZ and other relevant reagents in the glucose synthesis/metabolism pathways as stimuli for VSMC calcification to characterize the glycogene profiles during VSMC calcification. Results from VSMC of Runx2 knockout mice will be compared with those from control mice to determine the regulation of calcification-associated glycogenes by Runx2 in response to STZ. These studies will provide foundation for further mechanistic studies and may lead to identification of novel strategies and targets for diabetes-induced vascular calcification. To examine vascular smooth muscle cells (VSMC) under two conditions: 1) wild-type VSMC differentiated into bone-like cells with osteogenic media, 2) wild-type VSMC treated with STZ and osteogenic media
Project description:To better elucidate underlying mechanisms of circadian gene disruption on chronic kidney disease, we compared whole kidney transcriptome profiles between kidneys of WT and Bmal1 KO mice.
Project description:Incomplete repair after acute kidney injury (AKI) is associated with progressive loss of tubular cell function and development of chronic kidney disease (CKD). Here, we compared the kidney single-cell transcriptomes from the mice subjected to either unilateral ischemia-reperfusion kidney injury with contralateral nephrectomy (IRI/CL-NX, in which tubule repair predominates) or unilateral IRI with contralateral kidney intact (U-IRI, in which fibrosis and atrophy predominates) to investigate the mechanism(s) underlying transition to CKD following AKI.