Association between genome-wide DNA methylation and all-cause mortality in nonagenarians
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE68194 | GEO | 2017/02/09
SECONDARY ACCESSION(S): PRJNA282024
REPOSITORIES: GEO
Similar Datasets
Project description:BACKGROUND: Prediction models for old-age mortality have generally relied upon conventional markers such as plasma-based factors and biophysiological characteristics. However, it is unknown whether the existing markers are able to provide the most relevant information in terms of old-age survival or whether predictions could be improved through the integration of whole-genome expression profiles. METHODS: We assessed the predictive abilities of survival models containing only conventional markers, only gene expression data or both types of data together in a Vitality 90+ study cohort consisting of n = 151 nonagenarians. The all-cause death rate was 32.5% (49 of 151 individuals), and the median follow-up time was 2.55 years. RESULTS: Three different feature selection models, the penalized Lasso and Ridge regressions and the C-index boosting algorithm, were used to test the genomic data. The Ridge regression model incorporating both the conventional markers and transcripts outperformed the other models. The multivariate Cox regression model was used to adjust for the conventional mortality prediction markers, i.e., the body mass index, frailty index and cell-free DNA level, revealing that 331 transcripts were independently associated with survival. The final mortality-predicting transcriptomic signature derived from the Ridge regression model was mapped to a network that identified nuclear factor kappa beta (NF-?B) as a central node. CONCLUSIONS: Together with the loss of physiological reserves, the transcriptomic predictors centered around NF-?B underscored the role of immunoinflammatory signaling, the control of the DNA damage response and cell cycle, and mitochondrial functions as the key determinants of old-age mortality. The study consisted of 151 nonagenarians who were analyzed for genome-wide transcriptomic mortality predictors in a longitudinal setting.
2015-01-22 | E-GEOD-65218 | biostudies-arrayexpress
Project description:BACKGROUND: Prediction models for old-age mortality have generally relied upon conventional markers such as plasma-based factors and biophysiological characteristics. However, it is unknown whether the existing markers are able to provide the most relevant information in terms of old-age survival or whether predictions could be improved through the integration of whole-genome expression profiles. METHODS: We assessed the predictive abilities of survival models containing only conventional markers, only gene expression data or both types of data together in a Vitality 90+ study cohort consisting of n = 151 nonagenarians. The all-cause death rate was 32.5% (49 of 151 individuals), and the median follow-up time was 2.55 years. RESULTS: Three different feature selection models, the penalized Lasso and Ridge regressions and the C-index boosting algorithm, were used to test the genomic data. The Ridge regression model incorporating both the conventional markers and transcripts outperformed the other models. The multivariate Cox regression model was used to adjust for the conventional mortality prediction markers, i.e., the body mass index, frailty index and cell-free DNA level, revealing that 331 transcripts were independently associated with survival. The final mortality-predicting transcriptomic signature derived from the Ridge regression model was mapped to a network that identified nuclear factor kappa beta (NF-κB) as a central node. CONCLUSIONS: Together with the loss of physiological reserves, the transcriptomic predictors centered around NF-κB underscored the role of immunoinflammatory signaling, the control of the DNA damage response and cell cycle, and mitochondrial functions as the key determinants of old-age mortality.
2015-01-22 | GSE65218 | GEO
Project description:Age predictors based on DNA methylation levels at a small set of CpG sites, DNAm clocks, have been developed for humans and extended to several other species. Three currently available versions of mouse DNAm clocks were either created for individual tissues or tuned towards young ages. Here, we constructed a robust multi-tissue age predictor based on 435 CpG sites, which covers the entire mouse lifespan and remains unbiased with respect to any particular age group. It can successfully detect the effects of several lifespan-modulating interventions on biological age as well as the rejuvenation effect related to the transition from fibroblasts to iPSCs. We have carried out comparative analyses of available mouse DNAm clocks, which revealed their broad applicability, but also certain limitations to the use of tissue-specific and multi-tissue age predictors. Together, these tools should help address diverse questions in aging research.
2018-11-20 | GSE121141 | GEO
Project description:By binding to specific DNA elements, known collectively as “κB sites”, contained within the promoters/enhancers of target genes, NF-κB regulates gene expression. We found that the identity of the central base pair (bp) of κB sites profoundly impacts the transcriptional activity of NF-κB dimers. RelA dimers prefer an A/T bp at this position for optimum transcriptional activation (A/T-centric) and discriminate against G/C-centric κB sites. The p52 homodimer, in contrast, activates transcription from G/C-centric κB sites in complex with Bcl3 but represses transcription from the A/T-centric sites. The p52:Bcl3 complex binds to these two classes of κB sites in distinct modes permitting recruitment of coactivator, corepressor, or both coactivator and corepressor complexes in promoters containing G/C, A/T or both G/C and A/T-centric sites. Therefore, through sensing of bp differences within κB sites, NF-κB dimers modulate biological programs by activating, repressing and altering expression of effector genes. Total RNA extracted from bone marrow derived macrophages (BMDMs) with Bcl3 siRNA knockdown or mouse scramble siRNA knockdown were subjected to LPS stimulation.
2012-08-06 | E-GEOD-39922 | biostudies-arrayexpress
Project description:Osteoporosis is an age-related metabolic bone disease. Hence, osteoporotic patients might suffer from molecular features of accelerated aging, which is generally reflected by specific age-associated DNA methylation (DNAm) changes. In this study, we analyzed genome wide DNAm profiles of peripheral blood from patients with manifest primary osteoporosis and non-osteoporotic controls. Statistical analysis did not reveal any individual CG dinucleotides (CpG sites) with significant aberrant DNAm in osteoporosis. Subsequently, we analyzed if age-associated DNAm patterns are increased in OP. Using three independent age-predictors we did not find any evidence for accelerated epigenetic age in blood of osteoporotic patients. Taken together, osteoporosis is not reflected by characteristic DNAm patterns of peripheral blood that might be used as biomarker for the disease. The prevalence of osteoporosis is age-associated – but it is not associated with premature epigenetic aging in peripheral blood.
2018-03-13 | GSE99624 | GEO
Project description:Background: Measurement of genome-wide DNA methylation (DNAm) has become an important avenue for investigating potentially functional changes in various pathological conditions. Illumina Infinium is a relatively inexpensive and user-friendly DNAm microarray platform used by many researchers to measure DNAm on a large scale. However it has been suggested that a subset of probes may give rise to misleading results due to issues related to probe design. To facilitate biologically significant data interpretation, we set out to enhance probe annotation of the newest HumanMethylation450 BeadChip array (with >485,000 probes covering 99% of RefSeq genes). Results: Annotation that was added or expanded on includes 1) SNPs documented in the probe target, 2) probe binding specificity, 3) CpG classification of target sites and 4) gene feature classification of target sites. Probes with documented SNPs within 10bp of the target site and especially those with documented SNPs at the target CpG, were associated with increased within-tissue variation in DNAm. An example of a probe with a SNP at the target CpG was used to demonstrate how sample genotype can confound the measurement of DNAm. 8.6% of probes were identified as non-specific, in other words, these probes map to multiple locations in silico. DNAm measured from these non-specific probes likely represents a combination of DNAm from multiple genomic sites. The expanded biological annotation demonstrated that based on DNAm, grouping probes by alternative CpG classes rather than UCSC islands provides a more distinctive classification system of CpG sites. Finally variable enrichment for tissue-specific differentially methylated probes was noted across CpG classes and gene feature groups, depending on the tissues that were compared. Conclusion: Probes containing SNPs and non-specific probes may affect the assessment of DNAm using the 450k array. Additionally CpG enrichment classes and to a lesser extent gene feature groups were associated with distinct patterns of DNAm. Thus, we recommend that confounded probes be removed from analyses and that genomic trends be considered in analyses of the Illumina HumanMethylation450 BeadChip. DNAm arrays offer a powerful approach for which thoughtful use of probe content can be utilized to better understand the biological processes affected. Bisulfite converted DNA from 4 buccal, 4 blood and 4 chorionic villus samples was hybridized to the Illumina Infinium HumanMethylation450 BeadChip array.
2013-03-04 | E-GEOD-42409 | biostudies-arrayexpress
Project description:TNFα has an evolutionary conserved role in mediating inflammation via activation of the transcription factor NF-κB. The functions of individual NF-κB binding sites are not well understood. To identify conserved and functionally important NF-κB binding sites in mammals, we performed ChIP-seq to map the genome-wide binding of RELA and select histone modifications in primary vascular endothelial cells (ECs) isolated from the aortas of human (HAEC), mouse (MAEC) and cow (BAEC), before and after TNFα. The conserved RELA binding sites show strong epigenetic changes in response to TNFα and enrich near genes controlling vascular development and pro-inflammatory responses. Our method identifies novel modes of RELA-chromatin interactions that are conserved in mammals and shared between multiple cell-types. Particularly, genomic regions bound by RELA prior to stimulation are important responders during TNFα stimulation. We use CRISPR/Cas9 genome editing to validate the roles of the conserved RELA pre-bound sites near pro-inflammatory genes such as CCL2 and PLK2. Our evolutionary approach describes new aspects of mammalian NF-κB biology including its role within super-enhancers and relevance in inflammatory disorders.
2020-10-03 | E-MTAB-7889 | biostudies-arrayexpress
Project description:To identify conserved TNFα-induced changes in chromatin-accessibility in mammals, we performed ATAC-seq in primary vascular endothelial cells (ECs) isolated from the aortas of human (HAEC), mouse (MAEC) and cow (BAEC), before and after TNFα. We overlay our data with multi-species NF-κB binding data and identify multiple modes of NF-κB-chromatin interactions that are conserved during mammalian TNFα response. Our cross-species approach identifies conserved changes in chromatin-accessibility at NF-κB binding sites that are disease-relevant and essential during mammalian acute inflammation.
2020-06-01 | E-MTAB-7878 | biostudies-arrayexpress
Project description:****************************************************************** 450k ARRAY EXPANDED ANNOTATION PLATFORM: SEARCH GPL16304 ****************************************************************** Background: Measurement of genome-wide DNA methylation (DNAm) has become an important avenue for investigating potentially functional changes in various pathological conditions. Illumina Infinium is a relatively inexpensive and user-friendly DNAm microarray platform used by many researchers to measure DNAm on a large scale. However it has been suggested that a subset of probes may give rise to misleading results due to issues related to probe design. To facilitate biologically significant data interpretation, we set out to enhance probe annotation of the newest HumanMethylation450 BeadChip array (with >485,000 probes covering 99% of RefSeq genes). Results: Annotation that was added or expanded on includes 1) SNPs documented in the probe target, 2) probe binding specificity, 3) CpG classification of target sites and 4) gene feature classification of target sites. Probes with documented SNPs within 10bp of the target site and especially those with documented SNPs at the target CpG, were associated with increased within-tissue variation in DNAm. An example of a probe with a SNP at the target CpG was used to demonstrate how sample genotype can confound the measurement of DNAm. 8.6% of probes were identified as non-specific, in other words, these probes map to multiple locations in silico. DNAm measured from these non-specific probes likely represents a combination of DNAm from multiple genomic sites. The expanded biological annotation demonstrated that based on DNAm, grouping probes by alternative CpG classes rather than UCSC islands provides a more distinctive classification system of CpG sites. Finally variable enrichment for tissue-specific differentially methylated probes was noted across CpG classes and gene feature groups, depending on the tissues that were compared. Conclusion: Probes containing SNPs and non-specific probes may affect the assessment of DNAm using the 450k array. Additionally CpG enrichment classes and to a lesser extent gene feature groups were associated with distinct patterns of DNAm. Thus, we recommend that confounded probes be removed from analyses and that genomic trends be considered in analyses of the Illumina HumanMethylation450 BeadChip. DNAm arrays offer a powerful approach for which thoughtful use of probe content can be utilized to better understand the biological processes affected.
2013-03-04 | GSE42409 | GEO
Project description:By binding to specific DNA elements, known collectively as “κB sites”, contained within the promoters/enhancers of target genes, NF-κB regulates gene expression. We found that the identity of the central base pair (bp) of κB sites profoundly impacts the transcriptional activity of NF-κB dimers. RelA dimers prefer an A/T bp at this position for optimum transcriptional activation (A/T-centric) and discriminate against G/C-centric κB sites. The p52 homodimer, in contrast, activates transcription from G/C-centric κB sites in complex with Bcl3 but represses transcription from the A/T-centric sites. The p52:Bcl3 complex binds to these two classes of κB sites in distinct modes permitting recruitment of coactivator, corepressor, or both coactivator and corepressor complexes in promoters containing G/C, A/T or both G/C and A/T-centric sites. Therefore, through sensing of bp differences within κB sites, NF-κB dimers modulate biological programs by activating, repressing and altering expression of effector genes.
2012-08-07 | GSE39922 | GEO