The epithelial sodium channel y-subunit gene and blood pressure : Family based association, renal gene expression, and physiological analyses
- 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
- Full Text: false
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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.
Gene expression profiling reveals renin mRNA overexpression in human hypertensive kidneys and a role for microRNAs
- 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
- Full Text: false
- Reviewed:
- 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.
β-Adrenergic signaling regulates NR4A nuclear receptor and metabolic gene expression in multiple tissues
- Authors: Myers, Stephen , Eriksson, Natalie , Burow, Rachel , Wang, Mary Shu-Ching , Muscat, George
- Date: 2009
- Type: Text , Journal article
- Relation: Molecular and Cellular Endocrinology Vol. 309, no. 1-2 (2009), p. 101-108
- Full Text: false
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- Description: The nuclear hormone receptor (NR) 4A subgroup of orphan nuclear receptors includes three members, Nur77 (NR4A1), Nurr1 (NR4A2) and Nor-1 (NR4A3). Previously we have identified the rapid and robust (in vitro and in vivo) induction of the NR4A subgroup following β-adrenergic stimulation in mouse skeletal muscle. This was concomitant with changes in the expression of genes involved in the regulation of nutrient metabolism. We have isolated mouse tissue of cardiovascular, endocrine and gastrointestinal origin at 1, 4, 8 and 24 h after a single intraperitoneal injection of the β-adrenergic agonist, isoprenaline. We similarly identified the significant induction (between 1 and 4 h) of the NR4A genes in many of these tissues. Moreover, we have utilized TaqMan ® Low Density Arrays to determine the β-adrenergic-sensitive metabolic gene expression in liver, white adipose and heart. In summary, cross-talk between β-adrenergic and NR4A signaling occurs in several tissues, and is accompanied by modulation of metabolic gene expression. © 2009 Elsevier Ireland Ltd. All rights reserved.
AtNPF5.5, a nitrate transporter affecting nitrogen accumulation in Arabidopsis embryo
- Authors: Leran, Sophie , Garg, Bharti , Boursiac, Yann , Corratge-Failli, Claire , Brachet, Chantal , Tillard, Pascal , Gojon, Alain , Lacombe, Benoit
- Date: 2015
- Type: Text , Journal article
- Relation: Scientific Reports Vol. 5, no. (2015), p. 1-7
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- Description: Dipeptide (Leu-Leu) and nitrate transport activities of 26 Arabidopsis NPF (NRT1/PTR Family) proteins were screened in Saccharomyces cerevisiae and Xenopus laevis oocytes, respectively. Dipeptide transport activity has been confirmed for 2 already known dipeptide transporters (AtNPF8.1 and AtNPF8.3) but none of the other tested NPFs displays dipeptide transport. The nitrate transport screen resulted in the identification of two new nitrate transporters, AtNPF5.5 and AtNPF5.10. The localization of the mRNA coding for NPF5.5 demonstrates that it is the first NPF transporter reported to be expressed in Arabidopsis embryo. Two independent homozygous npf5.5 KO lines display reduced total nitrogen content in the embryo as compared to WT plants, demonstrating an effect of NPF5.5 function on the embryo nitrogen content. Finally, NPF5.5 gene produces two different transcripts (AtNPF5.5a and AtNPF5.5b) encoding proteins with different N-terminal ends. Both proteins are able to transport nitrate in xenopus oocytes.