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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

Kidney omics in hypertension: from statistical associations to biological mechanisms and clinical applications

- Tomaszewski, Maciej, Morris, Andrew, Howson, Joanna, Franceschini, Nora, Eales, James, Xu, Xiaoguang, Dikalov, Sergey, Guzik, Tomasz, Humphreys, Benjamin, Harrap, Stephen, Charchar, Fadi

  • Authors: Tomaszewski, Maciej , Morris, Andrew , Howson, Joanna , Franceschini, Nora , Eales, James , Xu, Xiaoguang , Dikalov, Sergey , Guzik, Tomasz , Humphreys, Benjamin , Harrap, Stephen , Charchar, Fadi
  • Date: 2022
  • Type: Text , Journal article , Review
  • Relation: Kidney International Vol. 102, no. 3 (2022), p. 492-505
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  • Description: Hypertension is a major cardiovascular disease risk factor and contributor to premature death globally. Family-based investigations confirmed a significant heritable component of blood pressure (BP), whereas genome-wide association studies revealed >1000 common and rare genetic variants associated with BP and/or hypertension. The kidney is not only an organ of key relevance to BP regulation and the development of hypertension, but it also acts as the tissue mediator of genetic predisposition to hypertension. The identity of kidney genes, pathways, and related mechanisms underlying the genetic associations with BP has started to emerge through integration of genomics with kidney transcriptomics, epigenomics, and other omics as well as through applications of causal inference, such as Mendelian randomization. Single-cell methods further enabled mapping of BP-associated kidney genes to cell types, and in conjunction with other omics, started to illuminate the biological mechanisms underpinning associations of BP-associated genetic variants and kidney genes. Polygenic risk scores derived from genome-wide association studies and refined on kidney omics hold the promise of enhanced diagnostic prediction, whereas kidney omics-informed drug discovery is likely to contribute new therapeutic opportunities for hypertension and hypertension-mediated kidney damage. © 2022 International Society of Nephrology

Genetics of blood pressure : Time to curate the collection

- Harrap, Stephen, Charchar, Fadi

  • Authors: Harrap, Stephen , Charchar, Fadi
  • Date: 2017
  • Type: Text , Journal article , Editorial
  • Relation: Journal of Hypertension Vol. 35, no. 7 (2017), p. 1360-1362
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  • Description: The genetics of blood pressure (BP) is all about discovery and understanding, but it is certainly not for the faint hearted. Despite heroic effort, the question we posed nearly 15 years ago [1] regarding the whereabouts of BP genes remains largely unanswered.

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.

Tripartite motif-containing 55 identified as functional candidate for spontaneous cardiac hypertrophy in the rat locus cardiac mass 22

- Prestes, Priscilla, Marques, Francine, Lopez-Campos, Guillermo, Booth, Scott, McGlynn, Maree, Lewandowski, Paul, Delbridge, Lea, Harrap, Stephen, Charchar, Fadi

  • Authors: Prestes, Priscilla , Marques, Francine , Lopez-Campos, Guillermo , Booth, Scott , McGlynn, Maree , Lewandowski, Paul , Delbridge, Lea , Harrap, Stephen , Charchar, Fadi
  • Date: 2016
  • Type: Text , Journal article
  • Relation: Journal of Hypertension Vol. 34, no. 5 (May 2016), p. 950-958
  • Relation: http://purl.org/au-research/grants/nhmrc/1034371
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  • Description: Background:Left ventricular (LV) hypertrophy is a risk factor for cardiovascular death, but the genetic factors determining LV size and predisposition to hypertrophy are not well understood. We have previously linked the quantitative trait locus cardiac mass 22 (Cm22) on chromosome 2 with cardiac hypertrophy independent of blood pressure in the spontaneously hypertensive rat. From an original cross of spontaneously hypertensive rat with F344 rats, we derived a normotensive polygenic model of spontaneous cardiac hypertrophy, the hypertrophic heart rat (HHR) and its control strain, the normal heart rat (NHR).Methods and results:To identify the genes and molecular mechanisms underlying spontaneous LV hypertrophy we sequenced the HHR genome with special focus on quantitative trait locus Cm22. For correlative analyses of function, we measured global RNA transcripts in LV of neonatal HHR and NHR and 198 neonatal rats of an HHRxNHR F2 crossbred population. Only one gene within locus Cm22 was differentially expressed in the parental generation: tripartite motif-containing 55 (Trim55), with mRNA downregulation in HHR (P<0.05) and reduced protein expression. Trim55 mRNA levels were negatively correlated with LV mass in the F2 cross (r=-0.16, P=0.025). In exon nine of Trim55 in HHR, we found one missense mutation that functionally alters protein structure. This mutation was strongly associated with Trim55 mRNA expression in F2 rats (F=10.35, P<0.0001). Similarly, in humans, we found reduced Trim55 expression in hearts of subjects with idiopathic dilated cardiomyopathy.Conclusion:Our study suggests that the Trim55 gene, located in Cm22, is a novel candidate gene for polygenic LV hypertrophy independent of blood pressure.

MicroRNA-34a and tert act as epi-drivers of cardiac telomere length and polygenic cardiac hypertrophy

- Booth, Scott, Marques, Francine, Prestes, Priscilla, Curl, Claire, Delbridge, Lea, Lewandowski, Paul, Harrap, Stephen, Charchar, Fadi

  • Authors: Booth, Scott , Marques, Francine , Prestes, Priscilla , Curl, Claire , Delbridge, Lea , Lewandowski, Paul , Harrap, Stephen , Charchar, Fadi
  • Date: 2015
  • Type: Text , Journal article
  • Relation: Heart, Lung and Circulation Vol. 24, no. S3 (2015), p. S180-S181
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  • Description: Cardiac hypertrophy is one of the main risk factors forheart failure. Here we aimed to investigate whether cardiactelomere length contributes to polygenic cardiac hypertro-phy independent of blood pressure. We also investigatedwhether changes in telomere length were due to the telomereregulators microRNA-34a,Ppp1r10(also known asPnuts)and telomerase. We used the hypertrophic heart rat (HHR),a normotensive model of polygenetic cardiac hypertrophy,and compared it to age-matched controls. Telomere length, microRNA levels, gene expression and telomerase activitywere measured in isolated cardiomyocytes and left ventricletissue using real-time PCR. Telomere length was significantlylonger in 2-day and 38-week-old HHR, but shorter at 4-and 13-week HHR. In the HHR, telomere length becameshorter early in development, while in the control straintelomere shortening was only observed in late adulthood.Telomere length was the main determinant of cardiac mass.

Measurement of absolute copy number variation reveals association with essential hypertension

- Marques, Francine, Prestes, Priscilla, Pinheiro, Leonardo, Scurrah, Katrina, Emslie, Kerry, Tomaszewski, Maciej, Harrap, Stephen, Charchar, Fadi

  • 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.

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

Dysregulation of c-kit expression parallels the development of spontaneous genetic cardiac hypertrophy

- Marques, Francine, Prestes, Priscilla, Lewandowski, Paul, Harrap, Stephen, Charchar, Fadi

  • Authors: Marques, Francine , Prestes, Priscilla , Lewandowski, Paul , Harrap, Stephen , Charchar, Fadi
  • Date: 2015
  • Type: Text , Conference paper
  • Relation: Cardiac Society of Australia and New Zealand Annual Scientific Meeting and the International Society for Heart Research Australasian Section Annual Scientific Meeting; Melbourne, Victoria, Australia; 13th-16th August 2016; published in Heart, Lung and Circulation. Vol. 24, p. S401-S401
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  • Description: Objective: The molecular processes associated with cardiac hypertrophy independent of blood pressure are still largely unknown. The hypertrophic heart rate (HHR) is normotensive and born with a reduced complement of cardiomyocytes that predisposes to cardiac hypertrophy and failure in later life. We investigated the expression of c-kit gene, a marker of cardiac stem cells and myocardial regeneration that could contribute to hypertrophy. Methods: Left ventricular c-kit mRNA expression was measured by real-time PCR in HHR and control strain in neonatal and 38-week old rats (n=7-12/group). We tested for linkage of c-kit expression with neonatal cardiac size in 197 second generation crosses (F2) of HHR and control strain. Results: c-kit mRNA was slightly up-regulated in neonatal (fold change +1.3, P=0.02) and markedly so in 38-week old HHR (+35.5, P=0.0003). Cardiac weight index was positively correlated with neonatal myocardial c-kit mRNA in the F2 population (r=0.19, P=0.007). Conclusions: In HHR hearts c-kit expression appears increased throughout life, but more so in the adult where cardiac hypertrophy is established and leading to failure. In aged hypertrophic hearts, over-expression of c-kit is likely a compensatory mechanism of the failing heart. Previous studies showed an activation of cardiac stem cells in the hypertrophic myocardium. Our study suggests that c-kit might be involved from an early age in mechanisms that lead to cardiac hypertrophy in adulthood.

Telomere dynamics during aging in polygenic left ventricular hypertrophy

- Marques, Francine, Booth, Scott, Prestes, Priscilla, Curl, Claire, Delbridge, Lea, Lewandowski, Paul, Harrap, Stephen, Charchar, Fadi

  • Authors: Marques, Francine , Booth, Scott , Prestes, Priscilla , Curl, Claire , Delbridge, Lea , Lewandowski, Paul , Harrap, Stephen , Charchar, Fadi
  • Date: 2016
  • Type: Text , Journal article
  • Relation: Physiological Genomics Vol. 48, no. 1 (2016), p. 42-49
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  • Description: Short telomeres are associated with increased risk of cardiovascular disease. Here we studied cardiomyocyte telomere length at key ages during the ontogeny of cardiac hypertrophy and failure in the hypertrophic heart rat (HHR) and compared these with the normal heart rat (NHR) control strain. Key ages corresponded with the pathophysiological sequence beginning with fewer cardiomyocytes (2 days), leading to left ventricular hypertrophy (LVH) (13 wk) and subsequently progression to heart failure (38 wk). We measured telomere length, tissue activity of telomerase, mRNA levels of telomerase reverse transcriptase (Tert) and telomerase RNA component (Terc), and expression of the telomeric regulator microRNA miR-34a. Cardiac telomere length was longer in the HHR compared with the control strain at 2 days and 38 wk, but shorter at 13 wk. Neonatal HHR had higher cardiac telomerase activity and expression of Tert and miR-34a. Telomerase activity was not different at 13 or 38 wk. Tert mRNA and Terc RNA were overexpressed at 38 wk, while miR-34a was overexpressed at 13 wk but downregulated at 38 wk. Circulating leukocytes were strongly correlated with cardiac telomere length in the HHR only. The longer neonatal telomeres in HHR are likely to reflect fewer fetal and early postnatal cardiomyocyte cell divisions and explain the reduced total cardiomyocyte complement that predisposes to later hypertrophy and failure. Although shorter telomeres were a feature of cardiac hypertrophy at 13 wk, they were not present at the progression to heart failure at 38 wk. © 2016 the American Physiological Society.

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

Early treatment to prevent hypertension: A laudable goal

- Harrap, Stephen, Charchar, Fadi

Experimental and human evidence for Lipocalin-2 (Neutrophil Gelatinase-Associated Lipocalin NGAL ) in the development of cardiac hypertrophy and heart failure

- Marques, Francine, Prestes, Priscilla, Byars, Sean, Ritchie, Scott, Wurtz, Peter, Patel, Sheila, Booth, Scott, Rana, Indrajeetsinh, Minoda, Yosuke, Berzins, Stuart, Curl, Claire, Bell, James, Wai, Bryan, Srivastava, Piyush, Kangas, Antti, Soininen, Pasi, Ruohonen, Saku, Kahonen, Mika, Lehtimaki, Terho, Raitoharju, Emma, Havulinna, Aki, Perola, Markus, Raitakari, Olli, Salomaa, Veikko, Ala-Korpela, Mika, Kettunen, Johannes, McGlynn, Maree, Kelly, Jason, Wlodek, Mary, Lewandowski, Paul, Delbridge, Lea, Burrell, Louise, Inouye, Michael, Harrap, Stephen, Charchar, Fadi

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

Involvement of human monogenic cardiomyopathy genes in experimental polygenic cardiac hypertrophy

- Prestes, Priscilla, Marques, Francine, Lopez-Campos, Guillermo, Lewandowski, Paul, Delbridge, Lea, Charchar, Fadi, Harrap, Stephen

  • Authors: Prestes, Priscilla , Marques, Francine , Lopez-Campos, Guillermo , Lewandowski, Paul , Delbridge, Lea , Charchar, Fadi , Harrap, Stephen
  • Date: 2018
  • Type: Text , Journal article
  • Relation: Physiological Genomics Vol. 50, no. 9 (2018), p. 680-687
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  • Description: Hypertrophic cardiomyopathy thickens heart muscles, reducing functionality and increasing risk of cardiac disease and morbidity. Genetic factors are involved, but their contribution is poorly understood. We used the hypertrophic heart rat (HHR), a unique normotensive polygenic model of cardiac hypertrophy and heart failure, to investigate the role of genes associated with monogenic human cardiomyopathy. We selected 42 genes involved in monogenic human cardiomyopathies to study: 1) DNA variants, by sequencing the whole genome of 13-wk-old HHR and age-matched normal heart rat (NHR), its genetic control strain; 2) mRNA expression, by targeted RNA-sequencing in left ventricles of HHR and NHR at 5 ages (2 days old and 4, 13, 33, and 50 wk old) compared with human idiopathic dilated cardiomyopathy data; and 3) microRNA expression, with rat microRNA microarrays in left ventricles of 2-day-old HHR and age-matched NHR. We also investigated experimentally validated microRNA-mRNA interactions. Whole-genome sequencing revealed unique variants mostly located in noncoding regions of HHR and NHR. We found 29 genes differentially expressed in at least 1 age. Genes encoding desmoglein 2 (Dsg2) and transthyretin (Ttr) were significantly differentially expressed at all ages in the HHR, but only Ttr was also differentially expressed in human idiopathic cardiomyopathy. Lastly, only two microRNAs differentially expressed in the HHR were present in our comparison of validated microRNA-mRNA interactions. These two microRNAs interact with five of the genes studied. Our study shows that genes involved in monogenic forms of human cardiomyopathies may also influence polygenic forms of the disease.

Renal Mechanisms of Association between Fibroblast Growth Factor 1 and Blood Pressure

- Tomaszewski, Maciej, Eales, James, Denniff, Matthew, Myers, Stephen, Chew, Guatsiew, Nelson, Christopher, Christofidou, Paraskevi, Desai, Aishwarya, Büsst, Cara, Wojnar, Lukasz, Musialik, Katarzyna, Jozwiak, Jacek, Debiec, Radoslaw, Dominiczak, Anna, Navis, Gerjan, van Gilst, Wiek, van der Harst, Pim, Samani, Nilesh, Harrap, Stephen, Bogdanski, Pawel, Zukowska-Szczechowska, Ewa, Charchar, Fadi

Cardiomyocyte functional etiology in heart failure with preserved ejection fraction is distinctive - A new preclinical model

- Curl, Claire, Danes, Vennetia, Bell, James, Raaijmakers, Antonia, Ip, Wendy, Chandramouli, Chanchal, Harding, Tristan, Porrello, Enzo, Erickson, Jeffrey, Charchar, Fadi, Kompa, Andrew, Edgley, Amanda, Crossman, David, Soeller, Christian, Mellor, Kimberley, Kalman, Jonathan, Harrap, Stephen, Delbridge, Lea

  • Authors: Curl, Claire , Danes, Vennetia , Bell, James , Raaijmakers, Antonia , Ip, Wendy , Chandramouli, Chanchal , Harding, Tristan , Porrello, Enzo , Erickson, Jeffrey , Charchar, Fadi , Kompa, Andrew , Edgley, Amanda , Crossman, David , Soeller, Christian , Mellor, Kimberley , Kalman, Jonathan , Harrap, Stephen , Delbridge, Lea
  • Date: 2018
  • Type: Text , Journal article
  • Relation: Journal of the American Heart Association Vol. 7, no. 11 (2018), p. 1-32
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  • Description: Background--Among the growing numbers of patients with heart failure, up to one half have heart failure with preserved ejection fraction (HFpEF). The lack of effective treatments for HFpEF is a substantial and escalating unmet clinical need-and the lack of HFpEF-specific animal models represents a major preclinical barrier in advancing understanding of HFpEF. As established treatments for heart failure with reduced ejection fraction (HFrEF) have proven ineffective for HFpEF, the contention that the intrinsic cardiomyocyte phenotype is distinct in these 2 conditions requires consideration. Our goal was to validate and characterize a new rodent model of HFpEF, undertaking longitudinal investigations to delineate the associated cardiac and cardiomyocyte pathophysiology. Methods and Results--The selectively inbred Hypertrophic Heart Rat (HHR) strain exhibits adult cardiac enlargement (without hypertension) and premature death (40% mortality at 50 weeks) compared to its control strain, the normal heart rat. Hypertrophy was characterized in vivo by maintained systolic parameters (ejection fraction at 85%-90% control) with marked diastolic dysfunction (increased E/E'). Surprisingly, HHR cardiomyocytes were hypercontractile, exhibiting high Ca

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

Four-week inhibition of the renin-angiotensin system in spontaneously hypertensive rats results in persistently lower blood pressure with reduced kidney renin and changes in expression of relevant gene networks

- Byars, Sean, Prestes, Priscilla, Suphapimol, Varaporn, Takeuchi, Fumihiko, De Vries, Nathan, Maier, Michelle, Melo, Mariana, Balding, David, Samani, Nilesh, Allen, Andrew, Kato, Norihiro, Wilkinson-Berka, Jennifer, Charchar, Fadi, Harrap, Stephen

  • Authors: Byars, Sean , Prestes, Priscilla , Suphapimol, Varaporn , Takeuchi, Fumihiko , De Vries, Nathan , Maier, Michelle , Melo, Mariana , Balding, David , Samani, Nilesh , Allen, Andrew , Kato, Norihiro , Wilkinson-Berka, Jennifer , Charchar, Fadi , Harrap, Stephen
  • Date: 2024
  • Type: Text , Journal article
  • Relation: Cardiovascular Research Vol. 120, no. 7 (2024), p. 769-781
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  • Description: Aims: Prevention of human hypertension is an important challenge and has been achieved in experimental models. Brief treatment with renin-angiotensin system (RAS) inhibitors permanently reduces the genetic hypertension of the spontaneously hypertensive rat (SHR). The kidney is involved in this fascinating phenomenon, but relevant changes in gene expression are unknown. Methods and results: In SHR, we studied the effect of treatment between 10 and 14 weeks of age with the angiotensin receptor blocker, losartan, or the angiotensin-converting enzyme inhibitor, perindopril [with controls for non-specific effects of lowering blood pressure (BP)], on differential RNA expression, DNA methylation, and renin immunolabelling in the kidney at 20 weeks of age. RNA sequencing revealed a six-fold increase in renin gene (Ren) expression during losartan treatment (P < 0.0001). Six weeks after losartan, arterial pressure remained lower (P = 0.006), yet kidney Ren showed reduced expression by 23% after losartan (P = 0.03) and by 43% after perindopril (P = 1.4 × 10-6) associated with increased DNA methylation (P = 0.04). Immunolabelling confirmed reduced cortical renin after earlier RAS blockade (P = 0.002). RNA sequencing identified differential expression of mRNAs, miRNAs, and lncRNAs with evidence of networking and co-regulation. These included 13 candidate genes (Grhl1, Ammecr1l, Hs6st1, Nfil3, Fam221a, Lmo4, Adamts1, Cish, Hif3a, Bcl6, Rad54l2, Adap1, Dok4), the miRNA miR-145-3p, and the lncRNA AC115371. Gene ontogeny analyses revealed that these networks were enriched with genes relevant to BP, RAS, and the kidneys. Conclusion: Early RAS inhibition in SHR resets genetic pathways and networks resulting in a legacy of reduced Ren expression and BP persisting for a minimum of 6 weeks. © 2024 The Author(s). Published by Oxford University Press on behalf of the European Society of Cardiology.
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