Abstract P175: Discovery And Validation Of Unique Associations Of DNA Methylation Regions With 24-hour Blood Pressure Phenotypes In African Americans

Hypertension ◽  
2021 ◽  
Vol 78 (Suppl_1) ◽  
Author(s):  
Michelle L Roberts ◽  
Theodore A Kotchen ◽  
Xiaoqing Pan ◽  
Yingchuan Li ◽  
Chun Yang ◽  
...  
Keyword(s):  
Dna Methylation ◽  
African Americans ◽  
Cumulative Effect ◽  
Epigenetic Mark ◽  
Discovery Cohort ◽  
Reduced Representation ◽  
Specific Pcr ◽  
Reduced Representation Bisulfite Sequencing ◽  
Sequencing Method ◽  
Independent Cohort

DNA methylation, an epigenetic mark, may reflect the interactions between DNA, environment, and lifestyle. It has been implicated in the development and progression of hypertension, a risk factor for cardiovascular disease. We hypothesize that regions of DNA methylation in blood cells can explain 24h BP phenotypes in African Americans. We performed Reduced Representation Bisulfite Sequencing (RRBS) in a discovery cohort of 281 African Americans. Several DNA methylation regions (MRs) were significantly associated with continuously monitored 24-h, daytime, or nighttime SBP, DBP, PP, and MAP after adjustments for covariates age, sex, and body mass index (False Discovery Rate (FDR) = 0.013 - 0.050). Each of these MRs explained a substantial portion of 24h BP variance, ranging from 6.5% - 9.4%. After FDR adjustment, there were no MRs significantly associated with clinic BPs (FDR > 0.1374), calculated by the average of 4 resting measurements (2 per arm) by sphygmomanometer. To interrogate specific regions of DNA methylation, our lab developed a potentially clinically applicable, deep, and targeted methylation sequencing method called Bisulfite-Specific PCR ULtrapLEx Targeted Sequencing (BULLET-Seq), and tested it in two reference samples for three MRs of interest. BULLET-Seq is able to accurately quantify the 10% changes in the dilution series when methylation rates ranged from ~40% to 90% (a chr19 methylation region; R 2 = 0.95 - 0.97) and can modestly measure these changes when rates range from ~2% to 4% (a chr5 region, R 2 = 0.82), and is questionable when methylation rates are below 2% (a chr13 region, R 2 = 0.03 - 0.27). Validation of the chr19 MR in an independent cohort (n=117) was performed in a single BULLET-Seq run. After covariate adjustment, the chr19 region was significantly associated with 24h BPs (SBP, DBP, and MAP; FDR < 0.05), confirming the findings from the discovery cohort. The MR accounted for up to 1.75% of BP variance in the 24h phenotypes. In conclusion, the reported DNA MRs have potential to be excellent markers for the cumulative effect of factors that influence 24h BPs and the BULLET-Seq workflow can be applied in clinical and population settings to screen up to thousands of patients.

Unique Associations of DNA Methylation Regions With 24-Hour Blood Pressure Phenotypes in Blacks

Hypertension ◽  
2022 ◽  
Author(s):  
Michelle L. Roberts ◽  
Theodore A. Kotchen ◽  
Xiaoqing Pan ◽  
Yingchuan Li ◽  
Chun Yang ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Dna Methylation ◽  
Large Scale ◽  
Cumulative Effect ◽  
Targeted Sequencing ◽  
Reduced Representation ◽  
Gene Environment ◽  
Reduced Representation Bisulfite Sequencing ◽  
Sequencing Method ◽  
Hypertension Development

Background: Epigenetic marks (eg, DNA methylation) may capture the effect of gene-environment interactions. DNA methylation is involved in blood pressure (BP) regulation and hypertension development; however, no studies have evaluated its relationship with 24-hour BP phenotypes (daytime, nighttime, and 24-hour average BPs). Methods: We examined the association of whole blood DNA methylation with 24-hour BP phenotypes and clinic BPs in a discovery cohort of 281 Blacks using reduced representation bisulfite sequencing. We developed a deep and region-specific methylation sequencing method, Bisulfite ULtrapLEx Targeted Sequencing and utilized it to validate our findings in a separate validation cohort (n=117). Results: Analysis of 38 215 DNA methylation regions (MRs), derived from 1 549 368 CpG sites across the genome, identified up to 72 regions that were significantly associated with 24-hour BP phenotypes. No MR was significantly associated with clinic BP. Two to 3 MRs were significantly associated with various 24-hour BP phenotypes after adjustment for age, sex, and body mass index. Together, these MRs explained up to 16.5% of the variance of 24-hour average BP, while age, sex, and BMI explained up to 11.0% of the variance. Analysis of one of the MRs in an independent cohort using Bisulfite ULtrapLEx Targeted Sequencing confirmed its association with 24-hour average BP phenotype. Conclusions: We identified several MRs that explain a substantial portion of variances in 24-hour BP phenotypes, which might be excellent markers of cumulative effect of factors influencing 24-hour BP levels. The Bisulfite ULtrapLEx Targeted Sequencing workflow has potential to be suitable for clinical testing and population screenings on a large scale.

scholarly journals Characterization of Global DNA Methylation in Different Gene Regions Reveals Candidate Biomarkers in Pigs with High and Low Levels of Boar Taint

2020 ◽  
Vol 7 (2) ◽  
pp. 77 ◽  
Author(s):  
Xiao Wang ◽  
Haja N. Kadarmideen
Keyword(s):  
Dna Methylation ◽  
Cpg Island ◽  
Cpg Islands ◽  
Gene Interaction ◽  
Boar Taint ◽  
Reduced Representation ◽  
Gene Interaction Networks ◽  
Reduced Representation Bisulfite Sequencing ◽  
Pathways Analysis ◽  
Porcine Gene

DNA methylation of different gene components, including different exons and introns, or different lengths of exons and introns is associated with differences in gene expression. To investigate the methylation of porcine gene components associated with the boar taint (BT) trait, this study used reduced representation bisulfite sequencing (RRBS) data from nine porcine testis samples in three BT groups (low, medium and high BT). The results showed that the methylation levels of the first exons and first introns were lower than those of the other exons and introns. The first exons/introns of CpG island regions had even lower levels of methylation. A total of 123 differentially methylated promoters (DMPs), 194 differentially methylated exons (DMEs) and 402 differentially methylated introns (DMIs) were identified, of which 80 DMPs (DMP-CpGis), 112 DMEs (DME-CpGis) and 166 DMIs (DMI-CpGis) were discovered in CpG islands. Importantly, GPX1 contained one each of DMP, DME, DMI, DMP-CpGi, DME-CpGi and DMI-CpGi. Gene-GO term relationships and pathways analysis showed DMP-CpGi-related genes are mainly involved in methylation-related biological functions. In addition, gene–gene interaction networks consisted of nodes that were hypo-methylated GPX1, hypo-methylated APP, hypo-methylated ATOX1, hyper-methylated ADRB2, hyper-methylated RPS6KA1 and hyper-methylated PNMT. They could be used as candidate biomarkers for reducing boar taint in pigs, after further validation in large cohorts.

Preparation of reduced representation bisulfite sequencing libraries for genome-scale DNA methylation profiling

2011 ◽  
Vol 6 (4) ◽  
pp. 468-481 ◽  
Author(s):  
Hongcang Gu ◽  
Zachary D Smith ◽  
Christoph Bock ◽  
Patrick Boyle ◽  
Andreas Gnirke ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Bisulfite Sequencing ◽  
Reduced Representation ◽  
Reduced Representation Bisulfite Sequencing ◽  
Dna Methylation Profiling ◽  
Genome Scale ◽  
Methylation Profiling

scholarly journals DNA methylation landscapes of 1538 breast cancers reveal a replication-linked clock, epigenomic instability and cis-regulation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Rajbir Nath Batra ◽  
Aviezer Lifshitz ◽  
Ana Tufegdzic Vidakovic ◽  
Suet-Feung Chin ◽  
Ankita Sati-Batra ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Cpg Island ◽  
Cpg Islands ◽  
Tumor Grade ◽  
Normal Breast ◽  
Breast Cancers ◽  
Reduced Representation ◽  
Reduced Representation Bisulfite Sequencing ◽  
Transcriptional Changes ◽  
In Cis

AbstractDNA methylation is aberrant in cancer, but the dynamics, regulatory role and clinical implications of such epigenetic changes are still poorly understood. Here, reduced representation bisulfite sequencing (RRBS) profiles of 1538 breast tumors and 244 normal breast tissues from the METABRIC cohort are reported, facilitating detailed analysis of DNA methylation within a rich context of genomic, transcriptional, and clinical data. Tumor methylation from immune and stromal signatures are deconvoluted leading to the discovery of a tumor replication-linked clock with genome-wide methylation loss in non-CpG island sites. Unexpectedly, methylation in most tumor CpG islands follows two replication-independent processes of gain (MG) or loss (ML) that we term epigenomic instability. Epigenomic instability is correlated with tumor grade and stage, TP53 mutations and poorer prognosis. After controlling for these global trans-acting trends, as well as for X-linked dosage compensation effects, cis-specific methylation and expression correlations are uncovered at hundreds of promoters and over a thousand distal elements. Some of these targeted known tumor suppressors and oncogenes. In conclusion, this study demonstrates that global epigenetic instability can erode cancer methylomes and expose them to localized methylation aberrations in-cis resulting in transcriptional changes seen in tumors.

5 Gene expression analysis and DNA methylation patterns of porcine somatic cell nuclear transfer blastocysts with high and low incidence of apoptosis

2019 ◽  
Vol 31 (1) ◽  
pp. 128
Author(s):  
L. Moley ◽  
R. Jones ◽  
R. Kaundal ◽  
A. Thomas ◽  
A. Benninghoff ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Enrichment Analysis ◽  
Epigenetic Reprogramming ◽  
Reduced Representation ◽  
False Discovery ◽  
Reduced Representation Bisulfite Sequencing ◽  
Methylation Patterns ◽  
Dna Methylation Analysis ◽  
Go Terms

Somatic cell NT (SCNT) efficiency remains poor, preventing the technology from being regularly used in the agricultural industry. It is believed that faulty epigenetic reprogramming of SCNT embryos leads to the low overall success. A clear apoptotic signature is associated with inappropriate gene expression and epigenomic aberrancies in many experimental cell culture systems, and we hypothesised that an apoptosis biomarker could be used to effectively separate properly reprogrammed porcine SCNT embryos from those that are destined to fail due to incomplete reprogramming. Therefore, our objective was to evaluate global gene expression and DNA methylation patterns in high- and low-apoptosis individual embryos in an effort to characterise the extent of genomic reprogramming that had taken place. Porcine SCNT blastocysts on Day 6 of development were stained with a nontoxic, noninvasive caspase activity reporter, and the top and bottom 20% of detected caspase activity were classified as high and low apoptosis, respectively (3 replicate cloning sessions; n=13 embryos per group). Genomic DNA and total RNA were isolated from each individual blastocyst. The RNA sequencing libraries were prepared using the Ovation SoLo RNA-Seq system (NuGen, San Carlos, CA, USA). Reduced representation bisulfite sequencing libraries were prepared for DNA methylation analysis using a modification of the single-cell reduced representation bisulfite sequencing global DNA methylation analysis approach detailed by Guo et al. (2015 Nat. Protoc. 10, 645-59). The RNA sequencing analysis using EdgeR (https://bioconductor.org/packages/release/bioc/html/edgeR.html) revealed 175 total differentially expressed genes (fold change ≥1.5; false discovery rate ≤0.05) between the high- and low-apoptosis SCNT embryos. This list of differentially expressed genes was used to perform enrichment analysis to identify overrepresented Gene Ontology (GO) terms or Kyoto Encyclopedia of Genes and Genomes pathways (DAVID Ease version 6.8 (https://david.ncifcrf.gov/) against the Sus scrofa background genome). However, no significantly enriched GO terms or pathways were identified (false discovery rate P&gt;0.05). Analysis of global DNA methylation patterns between high- and low-apoptosis SCNT embryos using MethylKit (Akalin et al. 2012Genome Biol. 13, R87) revealed 335 differentially methylated 100-bp regions with at least 25% difference in methylation (adjusted P ≤ 0.01). Gene transcription start sites associated with these regions were used for enrichment analysis; again, no significant enrichment of GO terms or Kyoto Encyclopedia of Genes and Genomes pathways was identified. Principal component analysis of CpG methylation showed the low-apoptosis embryos clustering more tightly than the high-apoptosis embryos, which were highly scattered. Ongoing comparisons of high- and low-apoptosis cloned embryos with naturally fertilized embryos produced invivo may provide more information about which embryos were properly reprogrammed. Although we are still pursuing a link between reprogramming and gene expression in high- and low-apoptosis embryos, we conclude that these data support a model of stochastic epigenetic reprogramming following SCNT and reinforce the necessity of identifying embryos most likely to be successful due to proper epigenetic reprogramming in order to increase SCNT efficiency.

scholarly journals DNA methylation assessment from human slow- and fast-twitch skeletal muscle fibers

2017 ◽  
Vol 122 (4) ◽  
pp. 952-967 ◽  
Author(s):  
Gwénaëlle Begue ◽  
Ulrika Raue ◽  
Bozena Jemiolo ◽  
Scott Trappe
Keyword(s):  
Skeletal Muscle ◽  
Human Skeletal Muscle ◽  
Bisulfite Sequencing ◽  
Fiber Type ◽  
Muscle Fibers ◽  
Methylation Data ◽  
Reduced Representation ◽  
Reduced Representation Bisulfite Sequencing ◽  
Sequencing Method ◽  
Fast Twitch

A new application of the reduced representation bisulfite sequencing method was developed using low-DNA input to investigate the epigenetic profile of human slow- and fast-twitch skeletal muscle fibers. Successful library construction was completed with as little as 15 ng of DNA, and high-quality sequencing data were obtained with 32 ng of DNA. Analysis identified 143,160 differentially methylated CpG sites across 14,046 genes. In both fiber types, selected genes predominantly expressed in slow or fast fibers were hypomethylated, which was supported by the RNA-sequencing analysis. These are the first fiber type-specific methylation data from human skeletal muscle and provide a unique platform for future research. NEW & NOTEWORTHY This study validates a low-DNA input reduced representation bisulfite sequencing method for human muscle biopsy samples to investigate the methylation patterns at a fiber type-specific level. These are the first fiber type-specific methylation data reported from human skeletal muscle and thus provide initial insight into basal state differences in myosin heavy chain I and IIa muscle fibers among young, healthy men.

Sign in / Sign up

Export Citation Format

Share Document