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121 Telomere attrition is attenuated in ultra-marathon runners

- Denham, Joshua, Nankervis, Scott, Debiec, Radek, Harvey, Jack, Pascoe, Deborah, Marques, Francine, O’Brien, Brendan, Zukowska-Szczechowska, Ewa, Tomaszewski, Maciej, Charchar, Fadi

  • Authors: Denham, Joshua , Nankervis, Scott , Debiec, Radek , Harvey, Jack , Pascoe, Deborah , Marques, Francine , O’Brien, Brendan , Zukowska-Szczechowska, Ewa , Tomaszewski, Maciej , Charchar, Fadi
  • Date: 2012
  • Type: Text , Journal article
  • Relation: Journal of Hypertension Vol. 30, no. e-Supplement (September 2012), p. e37
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  • Description: Background: Leukocyte telomere length is a marker of biological ageing and its shortening is associated with cardiovascular disease. Engagement in regular moderate-intensity physical activity is a recognised method of cardiovascular disease prevention. However, it is not clear whether repeated exposure to ultra-strenuous physical exercise is beneficial long-term and whether it may attenuate biological ageing. Methods: We compared leukocyte telomere length in context of inflammation and endothelial dysfunction between 67 male ultra-marathon runners and 67 age-, sex- and BMI-matched apparently healthy controls. Genomic DNA was extracted from peripheral blood and leukocyte telomere length was measured by quantitative polymerase chain reaction assays. Adhesion molecules (sICAM-1, sE-selectin) and inflammatory markers (IL-6, C-reactive protein) concentrations were measured in 67 ultra-marathon runners by quantitative sandwich enzyme immunoassay technique, high-sensitive immunoassay and ultra-sensitive double antibody sandwich ELISA, respectively. Results: Adjusted (for age, BMI, blood pressure and lipids) leukocyte telomere length was approximately 13.8% greater in the ultra-marathon runners than in the controls (P<0.001). This translates into approximately 32.9 years difference in age-related telomere length attrition. There was a strong negative linear correlation between sICAM-1 and leukocyte telomere length in the ultra-marathon runners (r=-0.33; P=0.007) and this association retained its statistical significance after adjustment for age, BMI, blood pressure and lipids in multiple regression (P=0.026). Conclusion: Prolonged, intense physical exercise may attenuate cellular ageing possibly through a protective effect on endothelial function.
  • Description: C1

A MicroRNA Guide for Clinicians and Basic Scientists : Background and Experimental Techniques

- Bernardo, Bianca, Charchar, Fadi, Lin, Ruby, McMullen, Julie

  • Authors: Bernardo, Bianca , Charchar, Fadi , Lin, Ruby , McMullen, Julie
  • Date: 2012
  • Type: Text , Journal article
  • Relation: Heart Lung and Circulation Vol. 21, no. 3 (2012), p. 131-142
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  • Description: MicroRNAs (miRNAs) are short non-coding RNA molecules that are approximately 22 nucleotides in length. In the last 10. years, miRNA research and discovery has advanced at a rapid rate. This review provides a brief overview of the discovery and biology of miRNAs, and summarises some of the experimental techniques used for isolation, detection, target prediction, and regulation of miRNAs. We also outline experimental workflows for investigators new to the field, and discuss the diagnostic and therapeutic application of miRNAs. © 2011 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ).

Abnormal microRNA expression in cardiac hypertrophy and the regulation of the Endog gene

- Quarrell, Sean, Marques, Francine, Jayaswal, Vivek, Curl, Claire, Nankervis, Scott, Yang, Jean, Delbridge, Lea, Harrap, Stephen, Charchar, Fadi

  • Authors: Quarrell, Sean , Marques, Francine , Jayaswal, Vivek , Curl, Claire , Nankervis, Scott , Yang, Jean , Delbridge, Lea , Harrap, Stephen , Charchar, Fadi
  • Date: 2012
  • Type: Text , Journal article
  • Relation: Heart, Lung and Circulation Vol. 21, no. Supplement 1 (2012), p. s7
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  • Description: A deficiency in the gene for endonuclease G (Endog) was recently described as a genetic determinant of cardiac hypertrophy. The mechanisms involved in the regulation of Endog, however, are still to be elucidated. Therefore we hypothesised that Endog, being regulated by small regulatory non-coding RNAs called microRNAs (miRNAs), could contribute to the cardiac hypertrophy of the Hypertrophic Heart Rat (HHR), a human polygenic model of cardiac hypertrophy. From birth the HHR has less and smaller cardiomyocytes, which leads to hypertrophy and cardiac failure later in life. In this study, we examined genome-wide miRNA expression by Agilent Rat miRNA Microarray Kit Release 16.0 and Endog mRNA levels by real-time PCR in the left ventricle of neonatal HHR compared to age-matched rats from its authentic control, the Normal Heart Rat (NHR). Endog mRNA was significantly under-expressed in the HHR (fold change=−4.7; P=0.0001). Sixty-seven miRNAs (FDR P<0.05 and fold change>1.1) were differentially expressed between HHR and NHR (n=16). We then performed an in silico analysis to predict the miRNAs that are able to bind to the 3′ untranslated region of Endog mRNA, and therefore could regulate Endog levels. We discovered that the miRNAs let-7b, miR-338 and miR-347 are predicted to bind to Endog mRNA. Functional studies are being undertaken to determine whether these miRNAs can regulate Endog mRNA levels in vitro and their role in the pathological processes leading to cardiac hypertrophy. These miRNAs could be a new target for the prevention and treatment of cardiac hypertrophy in humans

Council for high blood pressure research/InterAmerican Society of Hypertension/International Society of Hypertension: First new investigators symposium at the High Blood Pressure Research 2011 scientific sessions

- Veerabhadrappa, Praveen, Burger, Dylan, Charchar, Fadi, Tomaszewski, Maciej, Carlberg, Bo, Harrap, Stephen, Touyz, Rhian

Inheritance of coronary artery disease in men : An analysis of the role of the y chromosome

- Charchar, Fadi, Bloomer, Lisa, Barnes, Timothy, Cowley, Mark, Nelson, Christopher, Wang, Yanzhong, Denniff, Matthew, Debiec, Radoslaw, Christofidou, Paraskevi, Nankervis, Scott, Dominiczak, Anna, Bani-Mustafa, Ahmed, Balmforth, Anthony, Hall, Alistair, Erdmann, Jeanette, Cambien, Francois, Deloukas, Panos, Hengstenberg, Christian, Packard, Chris, Schunkert, Heribert, Ouwehand, Willem, Ford, Ian, Goodall, Alison, Jobling, Mark, Samani, Nilesh, Tomaszewski, Maciej

  • Authors: Charchar, Fadi , Bloomer, Lisa , Barnes, Timothy , Cowley, Mark , Nelson, Christopher , Wang, Yanzhong , Denniff, Matthew , Debiec, Radoslaw , Christofidou, Paraskevi , Nankervis, Scott , Dominiczak, Anna , Bani-Mustafa, Ahmed , Balmforth, Anthony , Hall, Alistair , Erdmann, Jeanette , Cambien, Francois , Deloukas, Panos , Hengstenberg, Christian , Packard, Chris , Schunkert, Heribert , Ouwehand, Willem , Ford, Ian , Goodall, Alison , Jobling, Mark , Samani, Nilesh , Tomaszewski, Maciej
  • Date: 2012
  • Type: Text , Journal article
  • Relation: The Lancet Vol. 379, no. 9819 (2012), p. 915-922
  • Relation: http://purl.org/au-research/grants/nhmrc/1009490
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  • Description: Background: A sexual dimorphism exists in the incidence and prevalence of coronary artery disease - men are more commonly affected than are age-matched women. We explored the role of the Y chromosome in coronary artery disease in the context of this sexual inequity. Methods: We genotyped 11 markers of the male-specific region of the Y chromosome in 3233 biologically unrelated British men from three cohorts: the British Heart Foundation Family Heart Study (BHF-FHS), West of Scotland Coronary Prevention Study (WOSCOPS), and Cardiogenics Study. On the basis of this information, each Y chromosome was tracked back into one of 13 ancient lineages defined as haplogroups. We then examined associations between common Y chromosome haplogroups and the risk of coronary artery disease in cross-sectional BHF-FHS and prospective WOSCOPS. Finally, we undertook functional analysis of Y chromosome effects on monocyte and macrophage transcriptome in British men from the Cardiogenics Study. Findings: Of nine haplogroups identified, two (R1b1b2 and I) accounted for roughly 90 of the Y chromosome variants among British men. Carriers of haplogroup I had about a 50 higher age-adjusted risk of coronary artery disease than did men with other Y chromosome lineages in BHF-FHS (odds ratio 1·75, 95 CI 1·20-2·54, p=0·004), WOSCOPS (1·45, 1·08-1·95, p=0·012), and joint analysis of both populations (1·56, 1·24-1·97, p=0·0002). The association between haplogroup I and increased risk of coronary artery disease was independent of traditional cardiovascular and socioeconomic risk factors. Analysis of macrophage transcriptome in the Cardiogenics Study revealed that 19 molecular pathways showing strong differential expression between men with haplogroup I and other lineages of the Y chromosome were interconnected by common genes related to inflammation and immunity, and that some of them have a strong relevance to atherosclerosis. Interpretation: The human Y chromosome is associated with risk of coronary artery disease in men of European ancestry, possibly through interactions of immunity and inflammation. Funding: British Heart Foundation; UK National Institute for Health Research; LEW Carty Charitable Fund; National Health and Medical Research Council of Australia; European Union 6th Framework Programme; Wellcome Trust. © 2012 Elsevier Ltd.

Novel insights into essential hypertension etiology revealed by genome-wide gene expression profiling of human kidneys: evidence for renin involvement via a microRNA-mediated effect on expression

- Marques, Francine, Campain, Anna, Tomaszewski, Maciej, Zukowska-Szczechowska, Ewa, Yang, Yee, Charchar, Fadi, Morris, Brian

Report of the first International Society of Hypertension (ISH) Trainee/new investigator symposium : A global hypertension initiative

- Burger, Dylan, Veerabhadrappa, Praveen, Charchar, Fadi, Tomaszewski, Maciej, Harrap, Stephen, Carlberg, Bo, Touyz, Rhian

The acute effects of intense cardiorespiratory exercise on human telomerase reverse transcriptase and sirtuin 6 expression in white blood cells

- Chilton, Warrick, Marques, Francine, O'Brien, Brendan, Charchar, Fadi

  • Authors: Chilton, Warrick , Marques, Francine , O'Brien, Brendan , Charchar, Fadi
  • Date: 2012
  • Type: Text , Journal article
  • Relation: Journal of Hypertension Vol. 30, no. e-Supplement (September 2012), p. e49
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  • Description: Background: Compelling epidemiological data demonstrates that regular physical exercise reduces cardiovascular mortality. Telomeres are specialised DNA structures located at the end of linear chromosomes where they protect them from degradation during DNA replication. Telomerase reverse transcriptase (TERT) expression is essential for telomere length maintenance. Accelerated telomere shortening is associated with increased risk of cardiovascular disease (CVD). Sirtuin 6 (SIRT6) is associated with increased longevity and protection against cardiac hypertrophy. Importantly, SIRT6 maintains genomic stability by specifically associating with telomeric chromatin. We hypothesized that acute cardiorespiratory exercise will affect the immediate expression of TERT and SIRT6. Methods: Twenty four healthy adults (19-39 years old) undertook 30 minutes of continuous treadmill running at 80% of maximal oxygen uptake (VO2max). Blood samples were taken before and immediately after exercise. Total RNA was extracted from white blood cells using TRIzol(R) LS reagent. TERT and SIRT6 mRNA expression were measured by real-time PCR. Results: There was no difference in TERT (P = 0.13) and SIRT6 (P = 0.73) mRNA levels immediately after acute cardiorespiratory exercise. Resting TERT levels, however, were negatively correlated with body mass index (BMI) (P = 0.03), waist to hip ratio (P = 0.01) and diastolic blood pressure (BP) (P = 0.05), while a marginal negative correlation was observed with systolic BP (P = 0.07). Conclusions: The results indicate that intense cardiorespiratory exercise does not result in acute modulation of TERT and SIRT6 mRNA. The negative correlations between BP, BMI, waist to hip ratio and TERT levels may provide a mechanistic insight into the established negative correlations between telomere length, hypertension and obesity.
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Up-regulation of autophagic pathways early in life might contribute to cardiac hypertrophy in a heritable polygenic model

- Marques, Francine, Quarrell, Sean, Jayaswal, Vivek, Curl, Claire, Nankervis, Scott, Yang, Jean, Delbridge, Lea, Harrap, Stephen, Charchar, Fadi

Association of genetic variation with systolic and diastolic blood pressure among African Americans: the Candidate Gene Association Resource study

- Fox, Ervin, Young, J. Hunter, Li, Yali, Dreisbach, Albert, Charchar, Fadi

  • Authors: Fox, Ervin , Young, J. Hunter , Li, Yali , Dreisbach, Albert , Charchar, Fadi
  • Date: 2011
  • Type: Text , Journal article
  • Relation: Human molecular genetics Vol. 20, no. 11 (June 2011), p. 2273
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  • Description: The prevalence of hypertension in African Americans (AAs) is higher than in other US groups; yet, few have performed genome-wide association studies (GWASs) in AA. Among people of European descent, GWASs have identified genetic variants at 13 loci that are associated with blood pressure. It is unknown if these variants confer susceptibility in people of African ancestry. Here, we examined genome-wide and candidate gene associations with systolic blood pressure (SBP) and diastolic blood pressure (DBP) using the Candidate Gene Association Resource (CARe) consortium consisting of 8591 AAs. Genotypes included genome-wide single-nucleotide polymorphism (SNP) data utilizing the Affymetrix 6.0 array with imputation to 2.5 million HapMap SNPs and candidate gene SNP data utilizing a 50K cardiovascular gene-centric array (ITMAT-Broad-CARe [IBC] array). For Affymetrix data, the strongest signal for DBP was rs10474346 (P= 3.6 × 10−8) located near GPR98 and ARRDC3. For SBP, the strongest signal was rs2258119 in C21orf91 (P= 4.7 × 10−8). The top IBC association for SBP was rs2012318 (P= 6.4 × 10−6) near SLC25A42 and for DBP was rs2523586 (P= 1.3 × 10−6) near HLA-B. None of the top variants replicated in additional AA (n = 11 882) or European-American (n = 69 899) cohorts. We replicated previously reported European-American blood pressure SNPs in our AA samples (SH2B3, P= 0.009; TBX3-TBX5, P= 0.03; and CSK-ULK3, P= 0.0004). These genetic loci represent the best evidence of genetic influences on SBP and DBP in AAs to date. More broadly, this work supports that notion that blood pressure among AAs is a trait with genetic underpinnings but also with significant complexity.

Gene expression profiling reveals renin mRNA overexpression in human hypertensive kidneys and a role for microRNAs

- Marques, Francine, Campain, Anna, Tomaszewski, Maciej, Zukowska-Szczechowska, Ewa, Yang, Yee, Charchar, Fadi, Morris, Brian

  • Authors: Marques, Francine , Campain, Anna , Tomaszewski, Maciej , Zukowska-Szczechowska, Ewa , Yang, Yee , Charchar, Fadi , Morris, Brian
  • Date: 2011
  • Type: Text , Journal article
  • Relation: Hypertension Vol. 58, no. 6 (2011), p. 1093-1098
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  • Description: The kidney has long been invoked in the etiology of essential hypertension. This could involve alterations in expression of specific genes and microRNAs (miRNAs). The aim of the present study was to identify, at the transcriptome-wide level, mRNAs and miRNAs that were differentially expressed between kidneys of 15 untreated hypertensive and 7 normotensive white male subjects of white European ancestry. By microarray technology we found 14 genes and 11 miRNAs that were differentially expressed in the medulla. We then selected and confirmed by real-time quantitative PCR expression differences for NR4A1, NR4A2, NR4A3, PER1, and SIK1 mRNAs and for the miRNAs hsa-miR-638 and hsa-let-7c. Luciferase reporter gene experiments in human kidney (HEK293) cells confirmed the predicted binding of hsa-let-7c to the 3' untranslated region of NR4A2 mRNA. In the renal cortex we found differential expression of 46 genes and 13 miRNAs. We then confirmed expression differences for AIFM1, AMBP, APOE, CD36, EFNB1, NDUFAF1, PRDX5, REN, RENBP, SLC13A1, STX4, and TNNT2 mRNAs and for miRNAs hsa-miR-21, hsa-miR-126, hsa-miR-181a, hsa-miR-196a, hsa-miR-451, hsa-miR-638, and hsa-miR-663. Functional experiments in HEK293 cells demonstrated that hsa-miR-663 can bind to the REN and APOE 3' untranslated regions and can regulate REN and APOE mRNA levels, whereas hsa-miR-181a regulated REN and AIFM1 mRNA. Our data demonstrated for the first time that miRNAs can regulate renin expression. The observed downregulation of 2 miRNAs in hypertension could explain the elevation in intrarenal renin mRNA. Renin, CD36, and other mRNAs, as well as miRNAs and associated pathways identified in the present study, provide novel insights into hypertension etiology. © 2011 American Heart Association, Inc.

Genetic variants in novel pathways influence blood pressure and cardiovascular disease risk

- Charchar, Fadi

  • Authors: Charchar, Fadi
  • Date: 2011
  • Type: Text , Journal article
  • Relation: Nature Vol. 478, no. 7367 (2011), p. 103-109
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  • Description: Blood pressure is a heritable trait influenced by several biological pathways and responsive to environmental stimuli. Over one billion people worldwide have hypertension (≥140mmg Hg systolic blood pressure ≥90mmg Hg diastolic blood pressure). Even small increments in blood pressure are associated with an increased risk of cardiovascular events. This genome-wide association study of systolic and diastolic blood pressure, which used a multi-stage design in 200,000 individuals of European descent, identified sixteen novel loci: six of these loci contain genes previously known or suspected to regulate blood pressure (GUCY1A3 GUCY1B3, NPR3 C5orf23, ADM, FURIN FES, GOSR2, GNAS EDN3); the other ten provide new clues to blood pressure physiology. A genetic risk score based on 29 genome-wide significant variants was associated with hypertension, left ventricular wall thickness, stroke and coronary artery disease, but not kidney disease or kidney function. We also observed associations with blood pressure in East Asian, South Asian and African ancestry individuals. Our findings provide new insights into the genetics and biology of blood pressure, and suggest potential novel therapeutic pathways for cardiovascular disease prevention. © 2011 Macmillan Publishers Limited. All rights reserved. Please note that there are two hundred and six authors for this article therefore only the Federation University Australia affiliate is provided in this record.
  • Description: Blood pressure is a heritable trait influenced by several biological pathways and responsive to environmental stimuli. Over one billion people worldwide have hypertension (≥140mmg Hg systolic blood pressure ≥90mmg Hg diastolic blood pressure). Even small increments in blood pressure are associated with an increased risk of cardiovascular events. This genome-wide association study of systolic and diastolic blood pressure, which used a multi-stage design in 200,000 individuals of European descent, identified sixteen novel loci: six of these loci contain genes previously known or suspected to regulate blood pressure (GUCY1A3 GUCY1B3, NPR3 C5orf23, ADM, FURIN FES, GOSR2, GNAS EDN3); the other ten provide new clues to blood pressure physiology. A genetic risk score based on 29 genome-wide significant variants was associated with hypertension, left ventricular wall thickness, stroke and coronary artery disease, but not kidney disease or kidney function. We also observed associations with blood pressure in East Asian, South Asian and African ancestry individuals. Our findings provide new insights into the genetics and biology of blood pressure, and suggest potential novel therapeutic pathways for cardiovascular disease prevention. © 2011 Macmillan Publishers Limited. All rights reserved. Please note that there are two hundred and six authors for this article and we have included only the University of Ballarat Affiliate.

Genome-wide association study identifies loci influencing concentrations of liver enzymes in plasma

- Chambers, John, Zhang, Weihua, Sehmi, Joban, Li, Xinzhong, Wass, Mark N, van der Harst, Pim, Holm, Hilma, Sanna, Serena, Kavousi, Maryam, Charchar, Fadi

  • Authors: Chambers, John , Zhang, Weihua , Sehmi, Joban , Li, Xinzhong , Wass, Mark N , van der Harst, Pim , Holm, Hilma , Sanna, Serena , Kavousi, Maryam , Charchar, Fadi
  • Date: 2011
  • Type: Text , Journal article
  • Relation: Nature genetics Vol. 43, no. 11 (2011), p. 1131-1138
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  • Description: Concentrations of liver enzymes in plasma are widely used as indicators of liver disease. We carried out a genome-wide association study in 61,089 individuals, identifying 42 loci associated with concentrations of liver enzymes in plasma, of which 32 are new associations (P = 10−8 to P = 10−190). We used functional genomic approaches including metabonomic profiling and gene expression analyses to identify probable candidate genes at these regions. We identified 69 candidate genes, including genes involved in biliary transport (ATP8B1 and ABCB11), glucose, carbohydrate and lipid metabolism (FADS1, FADS2, GCKR, JMJD1C, HNF1A, MLXIPL, PNPLA3, PPP1R3B, SLC2A2 and TRIB1), glycoprotein biosynthesis and cell surface glycobiology (ABO, ASGR1, FUT2, GPLD1 and ST3GAL4), inflammation and immunity (CD276, CDH6, GCKR, HNF1A, HPR, ITGA1, RORA and STAT4) and glutathione metabolism (GSTT1, GSTT2 and GGT), as well as several genes of uncertain or unknown function (including ABHD12, EFHD1, EFNA1, EPHA2, MICAL3 and ZNF827). Our results provide new insight into genetic mechanisms and pathways influencing markers of liver function. 137 authors

ISH Hypertension Future Leaders Group : A network for new investigators run by new investigators

- Veerabhadrappa, Praveen, Burger, Dylan, Carlberg, Bo, Charchar, Fadi, Tomaszewski, Maciej, Harrap, Stephen, Horsfield, Helen

Pathway analysis shows association between FGFBP1 and hypertension

- Tomaszewski, Maciej, Charchar, Fadi, Nelson, Christopher, Barnes, Timothy, Denniff, Matthew, Kaiser, Michael, Debiec, Radoslaw, Christofidou, Paraskevi, Rafelt, Suzanne, Van Harst, Pim Der, Wang, William, Maric, Christine, Zukowska-Szczechowska, Ewa, Samani, Nilesh

  • Authors: Tomaszewski, Maciej , Charchar, Fadi , Nelson, Christopher , Barnes, Timothy , Denniff, Matthew , Kaiser, Michael , Debiec, Radoslaw , Christofidou, Paraskevi , Rafelt, Suzanne , Van Harst, Pim Der , Wang, William , Maric, Christine , Zukowska-Szczechowska, Ewa , Samani, Nilesh
  • Date: 2011
  • Type: Text , Journal article
  • Relation: Journal of the American Society of Nephrology Vol. 22, no. 5 (2011), p. 947-955
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  • Description: Variants in the gene encoding fibroblast growth factor 1 (FGF1) co-segregate with familial susceptibility to hypertension, and glomerular upregulation of FGF1 associates with hypertension. To investigate whether variants in other members of the FGF signaling pathway may also associate with hypertension, we genotyped 629 subjects from 207 Polish families with hypertension for 79 single nucleotide polymorphisms in eight genes of this network. Family-based analysis showed that parents transmitted the major allele of the rs16892645 polymorphism in the gene encoding FGF binding protein 1 (FGFBP1) to hypertensive offspring more frequently than expected by chance (P = 0.005). An independent cohort of 807 unrelated Polish subjects validated this association. Furthermore, compared with normotensive subjects, hypertensive subjects had approximately 1.5- and 1.4-fold higher expression of renal FGFBP1 mRNA and protein (P = 0.04 and P = 0.001), respectively. By immunohistochemistry, hypertensionrelated upregulation of FGFBP1 was most apparent in the glomerulus and juxtaglomerular space. Taken together, these data suggest that FGFBP1 associates with hypertension and that systematic analysis of signaling pathways can identify previously undescribed genetic associations. Copyright © 2011 by the American Society of Nephrology.

The epithelial sodium channel y-subunit gene and blood pressure : Family based association, renal gene expression, and physiological analyses

- Büsst, Cara, Bloomer, Lisa, Scurrah, Katrina, Ellis, Justine, Barnes, Timothy, Charchar, Fadi, Braund, Peter, Hopkins, Paul, Samani, Nilesh, Hunt, Steven, Tomaszewski, Maciej, Harrap, Stephen

  • Authors: Büsst, Cara , Bloomer, Lisa , Scurrah, Katrina , Ellis, Justine , Barnes, Timothy , Charchar, Fadi , Braund, Peter , Hopkins, Paul , Samani, Nilesh , Hunt, Steven , Tomaszewski, Maciej , Harrap, Stephen
  • Date: 2011
  • Type: Text , Journal article
  • Relation: Hypertension Vol. 58, no. 6 (2011), p. 1073-1078
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  • Description: Variants in the gene encoding the y-subunit of the epithelial sodium channel (SCNN1G) are associated with both Mendelian and quantitative effects on blood pressure. Here, in 4 cohorts of 1611 white European families composed of a total of 8199 individuals, we undertook staged testing of candidate single-nucleotide polymorphisms for SCNN1G (supplemented with imputation based on data from the 1000 Genomes Project) followed by a meta-analysis in all of the families of the strongest candidate. We also examined relationships between the genotypes and relevant intermediate renal phenotypes, as well as expression of SCNN1G in human kidneys. We found that an intronic single-nucleotide polymorphism of SCNN1G (rs13331086) was significantly associated with age-, sex-, and body mass index-adjusted blood pressure in each of the 4 populations (P<0.05). In an inverse variance-weighted meta-analysis of this single-nucleotide polymorphism in all 4 of the populations, each additional minor allele copy was associated with a 1-mm Hg increase in systolic blood pressure and 0.52-mm Hg increase in diastolic blood pressure (SE=0.33, P=0.002 for systolic blood pressure; SE=0.21, P=0.011 for diastolic blood pressure). The same allele was also associated with higher 12-hour overnight urinary potassium excretion (P=0.04), consistent with increased epithelial sodium channel activity. Renal samples from hypertensive subjects showed a nonsignificant (P=0.07) 1.7-fold higher expression of SCNN1G compared with normotensive controls. These data provide genetic and phenotypic evidence in support of a role for a common genetic variant of SCNN1G in blood pressure determination. © 2011 American Heart Association, Inc.

FGF21 signalling pathway and metabolic traits - genetic association analysis

- Kaess, Bernhard, Barnes, Timothy, Stark, Klaus, Charchar, Fadi, Waterworth, Dawn, Song, Kijoung, Wang, William, Vollenweider, Peter, Waeber, Gerard, Mooser, Vincent, Zukowska-Szczechowska, Ewa, Samani, Nilesh, Hengstenberg, Christian, Tomaszewski, Maciej

  • Authors: Kaess, Bernhard , Barnes, Timothy , Stark, Klaus , Charchar, Fadi , Waterworth, Dawn , Song, Kijoung , Wang, William , Vollenweider, Peter , Waeber, Gerard , Mooser, Vincent , Zukowska-Szczechowska, Ewa , Samani, Nilesh , Hengstenberg, Christian , Tomaszewski, Maciej
  • Date: 2010
  • Type: Text , Journal article
  • Relation: European Journal of Human Genetics Vol. 18, no. 12 (2010), p. 1344-1348
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  • Description: Fibroblast growth factor 21 (FGF21) is a novel master regulator of metabolic profile. The biological actions of FGF21 are elicited upon its klotho beta (KLB)-facilitated binding to FGF receptor 1 (FGFR1), FGFR2 and FGFR3. We hypothesised that common polymorphisms in the FGF21 signalling pathway may be associated with metabolic risk. At the screening stage, we examined associations between 63 common single-nucleotide polymorphisms (SNPs) in five genes of this pathway (FGF21, KLB, FGFR1, FGFR2, FGFR3) and four metabolic phenotypes (LDL cholesterol-LDL-C, HDL-cholesterol-HDL-C, triglycerides and body mass index) in 629 individuals from Silesian Hypertension Study (SHS). Replication analyses were performed in 5478 unrelated individuals of the Swiss CoLaus cohort (imputed genotypes) and in 3030 directly genotyped individuals of the German Myocardial Infarction Family Study (GerMIFS). Of 54 SNPs that met quality control criteria after genotyping in SHS, 4 (rs4733946 and rs7012413 in FGFR1; rs2071616 in FGFR2 and rs7670903 in KLB) showed suggestive association with LDL-C (P=0.0006, P=0.0013, P=0.0055, P=0.011, respectively) and 1 (rs2608819 in KLB) was associated with body mass index (P=0.011); all with false discovery rate q<0.5. Of these, only one FGFR2 polymorphism (rs2071616) showed replicated association with LDL-C in both CoLaus (P=0.009) and men from GerMIFS (P=0.017). The direction of allelic effect of rs2071616 upon LDL-C was consistent in all examined populations. These data show that common genetic variations in FGFR2 may be associated with LDL-C in subjects of white European ancestry

Fibroblast growth factor binding protein 1 gene (FGFBP1) and hypertension d from pathway analysis to renal glomerulus

- Tomaszewski, Maciej, Charchar, Fadi, Barnes, Timothy, Maric, Christine, Zukowska-Szczechowska, Ewa, Samani, Nilesh

  • Authors: Tomaszewski, Maciej , Charchar, Fadi , Barnes, Timothy , Maric, Christine , Zukowska-Szczechowska, Ewa , Samani, Nilesh
  • Date: 2010
  • Type: Text , Conference paper
  • Relation: Paper presented at British Cardiovascular Society Annual Conference 2010, Manchester Central, Manchester, UK : 7th-9th June 2010
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  • Description: Essential hypertension is a complex, multifactorial disease with a strong genetic component. Fibroblast growth factor 1 gene (FGF1) is one of the most relevant candidates having been associated not only with familial susceptibility to hypertension but also with up-regulation within the glomerulus of the human hypertensive kidney/Circulation 2007;116:1915e24/. We have hypothesised that systematic analysis of genes interacting with FGF1 may uncover novel variants underlying essential hypertension. Seventy-nine common (minor allele frequency$0.1) tagging (r2$0.8) and functional single nucleotide polymorphisms (SNPs) spanning eight critical components of the FGF (fibroblast growth factor) pathway (FGF2, FGFR1, FGFR2, FGFR3, FGFR4, FGFBP1, FIBP, SPRY1) were genotyped by MALDI-TOF mass spectrometry in 629 subjects from 207 Polish hypertensive families (Silesian Hypertension Study d SHS). 83.5% of genotyped SNPs that passed quality control filters provided 92.9% genetic coverage of FGF pathway loci. Family-based analysis in SHS revealed that alleles of three SNPs (rs2956724, rs2245964 and rs16892645) in two loci (FGFR1 and FGFBP1) were transmitted to hypertensive offspring more frequently than expected by chance. However, only one association survived correction for multiple testing e major allele of rs16892645 in FGFBP1 was over-transmitted from heterozygous parents to hypertensive offspring more frequently than expected by chance (p¼0.0048, false discovery rate<0.25). The association between rs16892645 and hypertension was replicated in an independent cohort of 807 Polish subjects from Silesian Cardiovascular Study d each major allele copy of rs16892645 increased the odds of hypertension approximately by 1.5 (odds ratio: 1.5; 95% CI: 1.1 to to 2.2, p¼0.04). Association between FGFBP1 and hypertension was also apparent at the protein expression level d compared with normotensive patients, hypertensives from Silesian Renal Tissue Bank showed approximately 1.4-fold higher renal abundance of FGFBP1 in Western blotting (p¼0.001). Immunohistochemical analysis revealed that hypertension-related up-regulation of FGFBP1 was exclusive to renal glomeruli. These data show that FGFBP1da gene that encodes a carrier protein for FGF1 d is associated with human hypertension. We also reveal that up-regulation of FGFBP1 maps to the same histological compartment where FGF1 was shown to be most abundant (renal glomeruli). Our study also proves that systematic genetic analysis of signalling pathways is a strategy with a potential to identify novel molecular mechanisms underlying blood pressure elevation.

Genetic architecture of ambulatory blood pressure in the general population insights from cardiovascular gene-centric array

- Tomaszewski, Maciej, Debiec, Radoslaw, Braund, Peter, Nelson, Christopher, Hardwick, Robert, Christofidou, Paraskevi, Denniff, Matthew, Codd, Veryan, Rafelt, Suzanne, van der Harst, Pim, Waterworth, Dawn, Song, Kijoung, Vollenweider, Peter, Waeber, Gerard, Zukowska-Szczechowska, Ewa, Burton, Paul, Mooser, Vincent, Charchar, Fadi, Thompson, John, Tobin, Martin, Samani, Nilesh

  • Authors: Tomaszewski, Maciej , Debiec, Radoslaw , Braund, Peter , Nelson, Christopher , Hardwick, Robert , Christofidou, Paraskevi , Denniff, Matthew , Codd, Veryan , Rafelt, Suzanne , van der Harst, Pim , Waterworth, Dawn , Song, Kijoung , Vollenweider, Peter , Waeber, Gerard , Zukowska-Szczechowska, Ewa , Burton, Paul , Mooser, Vincent , Charchar, Fadi , Thompson, John , Tobin, Martin , Samani, Nilesh
  • Date: 2010
  • Type: Text , Journal article
  • Relation: Hypertension Vol. 56, no. 6 (2010), p. 1069-U146
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  • Reviewed:
  • Description: Genetic determinants of blood pressure are poorly defined. We undertook a large-scale, gene-centric analysis to identify loci and pathways associated with ambulatory systolic and diastolic blood pressure. We measured 24-hour ambulatory blood pressure in 2020 individuals from 520 white European nuclear families (the Genetic Regulation of Arterial Pressure of Humans in the Community Study) and genotyped their DNA using the Illumina HumanCVD BeadChip array, which contains approximate to 50 000 single nucleotide polymorphisms in >2000 cardiovascular candidate loci. We found a strong association between rs13306560 polymorphism in the promoter region of MTHFR and CLCN6 and mean 24-hour diastolic blood pressure; each minor allele copy of rs13306560 was associated with 2.6 mm Hg lower mean 24-hour diastolic blood pressure (P=1.2 x 10(-8)). rs13306560 was also associated with clinic diastolic blood pressure in a combined analysis of 8129 subjects from the Genetic Regulation of Arterial Pressure of Humans in the Community Study, the CoLaus Study, and the Silesian Cardiovascular Study (P=5.4 x 10(-6)). Additional analysis of associations between variants in gene ontology-defined pathways and mean 24-hour blood pressure in the Genetic Regulation of Arterial Pressure of Humans in the Community Study showed that cell survival control signaling cascades could play a role in blood pressure regulation. There was also a significant overrepresentation of rare variants (minor allele frequency: <0.05) among polymorphisms showing at least nominal association with mean 24-hour blood pressure indicating that a considerable proportion of its heritability may be explained by uncommon alleles. Through a large-scale gene-centric analysis of ambulatory blood pressure, we identified an association of a novel variant at the MTHFR/CLNC6 locus with diastolic blood pressure and provided new insights into the genetic architecture of blood pressure.

Whole genome survey of copy number variation in the spontaneously hypertensive rat relationship to quantitative trait loci, gene expression, and blood pressure

- Charchar, Fadi, Kaiser, Michael, Bingham, Andrew, Fotinatos, Nina, Ahmady, Fahima, Tomaszewski, Maciej, Samani, Nilesh

  • Authors: Charchar, Fadi , Kaiser, Michael , Bingham, Andrew , Fotinatos, Nina , Ahmady, Fahima , Tomaszewski, Maciej , Samani, Nilesh
  • Date: 2010
  • Type: Text , Journal article
  • Relation: Hypertension Vol. 55, no. 5 (2010), p. 1231-1238
  • Full Text: false
  • Reviewed:
  • Description: Copy number variation has emerged recently as an important genetic mechanism leading to phenotypic heterogeneity. The aim of our study was to determine whether copy number variants (CNVs) exist between the spontaneously hypertensive rat (SHR) and its control strain, the Wistar-Kyoto rat, whether these map to quantitative trait loci in the rat and whether CNVs associate with gene expression or blood pressure differences between the 2 strains. We performed a comparative genomic hybridization assay between SHR and Wistar-Kyoto strains using a whole-genome array. In total, 16 CNVs were identified and validated (6 because of a relative loss of copy number in the SHR and 10 because of a relative gain). CNVs were present on rat autosomes 1, 3, 4, 6, 7, 10, 14, and 17 and varied in size from 10.0 kb to 1.6 Mb. Most of these CNVs mapped to chromosomal regions within previously identified quantitative trait loci, including those for blood pressure in the SHR. Transcriptomic experiment! s confirmed differences in the renal expression of several genes (including Ms4a6a, Ndr3, Egln1, Cd36, Sema3a, Ugt2b, and Idi21) located in some of the CNVs between STIR and Wistar-Kyoto rats. In F-2 animals derived from an SHRXWistar-Kyoto cross, we also found a significant increase in blood pressure associated with an increase in copy number in the Egln1 gene. Our findings suggest that, CNVs may play a role in the susceptibility to hypertension and related trails in the SHR. (Hypertension. 2010;55:1231-1238.)