Epigenetic modifications in essential hypertension
- Authors: Wise, Ingrid , Charchar, Fadi
- Date: 2016
- Type: Text , Journal article , Review
- Relation: International Journal of Molecular Sciences Vol. 17, no. 4 (2016), p. 1-14
- Relation: http://purl.org/au-research/grants/nhmrc/1009490
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- Description: Essential hypertension (EH) is a complex, polygenic condition with no single causative agent. Despite advances in our understanding of the pathophysiology of EH, hypertension remains one of the world’s leading public health problems. Furthermore, there is increasing evidence that epigenetic modifications are as important as genetic predisposition in the development of EH. Indeed, a complex and interactive genetic and environmental system exists to determine an individual’s risk of EH. Epigenetics refers to all heritable changes to the regulation of gene expression as well as chromatin remodelling, without involvement of nucleotide sequence changes. Epigenetic modification is recognized as an essential process in biology, but is now being investigated for its role in the development of specific pathologic conditions, including EH. Epigenetic research will provide insights into the pathogenesis of blood pressure regulation that cannot be explained by classic Mendelian inheritance. This review concentrates on epigenetic modifications to DNA structure, including the influence of non-coding RNAs on hypertension development. © 2016 by the authors; licensee MDPI, Basel, Switzerland.
Measurement of absolute copy number variation reveals association with essential hypertension
- Authors: Marques, Francine , Prestes, Priscilla , Pinheiro, Leonardo , Scurrah, Katrina , Emslie, Kerry , Tomaszewski, Maciej , Harrap, Stephen , Charchar, Fadi
- Date: 2014
- Type: Text , Journal article
- Relation: BMC Medical Genomics Vol. 7, no. (2014), p. 1-8
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- Description: Background: The role of copy number variation (CNV) has been poorly explored in essential hypertension in part due to technical difficulties in accurately assessing absolute numbers of DNA copies. Droplet digital PCR (ddPCR) provides a powerful new approach to CNV quantitation. The aim of our study was to investigate whether CNVs located in regions previously associated with blood pressure (BP) variation in genome-wide association studies (GWAS) were associated with essential hypertension by the use of ddPCR. Methods: Using a "power of extreme" approach, we quantified nucleic acids using ddPCR in white subjects from the Victorian Family Heart Study with extremely high (n = 96) and low (n = 92) SBP, providing power equivalent to 1714 subjects selected at random. Results: A deletion of the CNVs esv27061 and esv2757747 on chromosome 1p13.2 was significantly more prevalent in extreme high BP subjects after adjustment for age, body mass index and sex (12.6% vs. 2.2%; P = 0.013). Conclusions: Our data suggests that CNVs within regions identified in previous GWAS may play a role in human essential hypertension.
A meta-analysis of gene expression signatures of blood pressure and hypertension
- Authors: Charchar, Fadi
- Date: 2015
- Type: Text , Journal article
- Relation: PLoS Genetics Vol. 11, no. 3 (2015), p. 1-29
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- Description: Genome-wide association studies (GWAS) have uncovered numerous genetic variants (SNPs) that are associated with blood pressure (BP). Genetic variants may lead to BP changes by acting on intermediate molecular phenotypes such as coded protein sequence or gene expression, which in turn affect BP variability. Therefore, characterizing genes whose expression is associated with BP may reveal cellular processes involved in BP regulation and uncover how transcripts mediate genetic and environmental effects on BP variability. A meta-analysis of results from six studies of global gene expression profiles of BP and hypertension in whole blood was performed in 7017 individuals who were not receiving antihypertensive drug treatment. We identified 34 genes that were differentially expressed in relation to BP (Bonferroni-corrected p<0.05). Among these genes, FOS and PTGS2 have been previously reported to be involved in BP-related processes; the others are novel. The top BP signature genes in aggregate explain 5%–9% of inter-individual variance in BP. Of note, rs3184504 in SH2B3, which was also reported in GWAS to be associated with BP, was found to be a trans regulator of the expression of 6 of the transcripts we found to be associated with BP (FOS, MYADM, PP1R15A, TAGAP, S100A10, and FGBP2). Gene set enrichment analysis suggested that the BP-related global gene expression changes include genes involved in inflammatory response and apoptosis pathways. Our study provides new insights into molecular mechanisms underlying BP regulation, and suggests novel transcriptomic markers for the treatment and prevention of hypertension. **Please note that there are multiple authors for this article therefore only the name of the Federation University Australia affiliate is provided in this record**
Telomeres, aging and exercise : Guilty by association?
- Authors: Chilton, Warrick , O’Brien, Brendan , Charchar, Fadi
- Date: 2017
- Type: Text , Journal article , Review
- Relation: International Journal of Molecular Sciences Vol. 18, no. 12 (2017), p. 1-32
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- Description: Telomeres are repetitive tandem DNA sequences that cap chromosomal ends protecting genomic DNA from enzymatic degradation. Telomeres progressively shorten with cellular replication and are therefore assumed to correlate with biological and chronological age. An expanding body of evidence suggests (i) a predictable inverse association between telomere length, aging and age-related diseases and (ii) a positive association between physical activity and telomere length. Both hypotheses have garnered tremendous research attention and broad consensus; however, the evidence for each proposition is inconsistent and equivocal at best. Telomere length does not meet the basic criteria for an aging biomarker and at least 50% of key studies fail to find associations with physical activity. In this review, we address the evidence in support and refutation of the putative associations between telomere length, aging and physical activity. We finish with a brief review of plausible mechanisms and potential future research directions. © 2017 by the authors. Licensee MDPI, Basel, Switzerland.
A guide to the short, long and circular RNAs in hypertension and cardiovascular disease
- Authors: Prestes, Priscilla , Maier, Michelle , Woods, Bradley , Charchar, Fadi
- Date: 2020
- Type: Text , Journal article , Review
- Relation: International Journal of Molecular Sciences Vol. 21, no. 10 (2020)
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- Description: Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in adults in developed countries. CVD encompasses many diseased states, including hypertension, coronary artery disease and atherosclerosis. Studies in animal models and human studies have elucidated the contribution of many genetic factors, including non-coding RNAs. Non-coding RNAs are RNAs not translated into protein, involved in gene expression regulation post-transcriptionally and implicated in CVD. Of these, circular RNAs (circRNAs) and microRNAs are relevant. CircRNAs are created by the back-splicing of pre-messenger RNA and have been underexplored as contributors to CVD. These circRNAs may also act as biomarkers of human disease, as they can be extracted from whole blood, plasma, saliva and seminal fluid. CircRNAs have recently been implicated in various disease processes, including hypertension and other cardiovascular disease. This review article will explore the promising and emerging roles of circRNAs as potential biomarkers and therapeutic targets in CVD, in particular hypertension. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.
The y chromosome : A blueprint for men's health?
- Authors: Maan, Akhlaq , Eales, James , Akbarov, Artur , Rowland, Joshua , Xu, Xiaoguang , Jobling, Mark , Charchar, Fadi , Tomaszewski, Maciej
- Date: 2017
- Type: Text , Journal article , Review
- Relation: European Journal of Human Genetics Vol. 25, no. 11 (2017), p. 1181-1188
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- Description: The Y chromosome has long been considered a genetic wasteland' on a trajectory to completely disappear from the human genome. The perception of its physiological function was restricted to sex determination and spermatogenesis. These views have been challenged in recent times with the identification of multiple ubiquitously expressed Y-chromosome genes and the discovery of several unexpected associations between the Y chromosome, immune system and complex polygenic traits. The collected evidence suggests that the Y chromosome influences immune and inflammatory responses in men, translating into genetically programmed susceptibility to diseases with a strong immune component. Phylogenetic studies reveal that carriers of a common European lineage of the Y chromosome (haplogroup I) possess increased risk of coronary artery disease. This occurs amidst upregulation of inflammation and suppression of adaptive immunity in this Y lineage, as well as inferior outcomes in human immunodeficiency virus infection. From structural analysis and experimental data, the UTY (Ubiquitously Transcribed Tetratricopeptide Repeat Containing, Y-Linked) gene is emerging as a promising candidate underlying the associations between Y-chromosome variants and the immunity-driven susceptibility to complex disease. This review synthesises the recent structural, experimental and clinical insights into the human Y chromosome in the context of men's susceptibility to disease (with a particular emphasis on cardiovascular disease) and provides an overview of the paradigm shift in the perception of the Y chromosome. © 2017 The Author(s).