scholarly journals 30 YEARS OF THE MINERALOCORTICOID RECEPTOR: Mineralocorticoid receptor mutations

2017 ◽  
Vol 234 (1) ◽  
pp. T93-T106 ◽  
Author(s):  
Maria-Christina Zennaro ◽  
Fabio Fernandes-Rosa

Aldosterone and the mineralocorticoid receptor (MR) are key elements for maintaining fluid and electrolyte homeostasis as well as regulation of blood pressure. Loss-of-function mutations of the MR are responsible for renal pseudohypoaldosteronism type 1 (PHA1), a rare disease of mineralocorticoid resistance presenting in the newborn with weight loss, failure to thrive, vomiting and dehydration, associated with hyperkalemia and metabolic acidosis, despite extremely elevated levels of plasma renin and aldosterone. In contrast, a MR gain-of-function mutation has been associated with a familial form of inherited mineralocorticoid hypertension exacerbated by pregnancy. In addition to rare variants, frequent functional single nucleotide polymorphisms of the MR are associated with salt sensitivity, blood pressure, stress response and depression in the general population. This review will summarize our knowledge on MR mutations in PHA1, reporting our experience on the genetic diagnosis in a large number of patients performed in the last 10 years at a national reference center for the disease. We will also discuss the influence of rare MR variants on blood pressure and salt sensitivity as well as on stress and cognitive functions in the general population.

Hypertension ◽  
2000 ◽  
Vol 36 (suppl_1) ◽  
pp. 717-717
Author(s):  
Frederick D Grant ◽  
Jose R Romero ◽  
Xavier Jeunemaitre ◽  
Steven C Hunt ◽  
Paul N Hopkins ◽  
...  

P133 Single nucleotide polymorphisms of the adducin genes have been associated with the development of elevated blood pressure in the rat. However, previous studies of the 460Trp polymorphism of human alpha-adducin have not clearly identified an association with the development of human hypertension. In this study, 281 hypertensive subjects were subgrouped by the intermediate phenotypes of plasma renin status and sensitivity of systolic blood pressure to dietary sodium. The frequency of the 460Trp allele was 19% and 9 of 281 subjects (3.2%) were homozygous (TT) for the 460Trp allele. The systolic blood pressure response to changes in dietary sodium (>150 meq/d vs. ≤30 meq/d) was significantly (p < 0.05) greater in TT subjects (25 ± 2 mmHg) compared to those heterozygous (GT) for the 460Trp allele (12 ± 2 mmHg) or homozygous (GG) for the 460Gly allele (14 ± 1 mmHg). There was a significant (p < 0.005) association between homozygosity for the 460Trp allele and low-renin hypertension. Six of 67 (9%) low-renin subjects, but only 3 of 214 (1.4%) normal- renin subjects had the TT genotype. Heterozygous (GT) subjects did not have increased salt-sensitivity of systolic blood pressure and did not have an increased frequency of low-renin hypertension. Erythrocyte sodium content was significantly (p < 0.01) less in subjects with the TT genotype (24.5 ± 1.0 mmol/kgHgb) compared to all subjects (33.2 ± 0.4 mmol/kgHgb). Subjects with the TT genotype had a significantly (p < 0.05) lower sodium-lithium countertransport (SLC) (0.16 ± 0.04 mmol/l/h) than other subjects (0.28 ± 0.01 mmol/l/h). However, the mean SLC of all low-renin hypertensive subjects (0.25 ± 0.02 mmol/l/h) was not significantly different than the mean SLC of normal-renin hypertensive subjects (0.26 ± 0.01 mmol/l/h). Thus, a decreased SLC is associated with the TT genotype and is not a characteristic of all individuals with low-renin hypertension. These findings suggest that homozygous expression of the 460Trp polymorphism of the alpha-adducin gene alters sodium handling in humans and may be an important contributor to the development of low-renin hypertension in some individuals.


BMJ Open ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. e023042 ◽  
Author(s):  
Han Qi ◽  
Bin Liu ◽  
Chunyue Guo ◽  
Zheng Liu ◽  
Han Cao ◽  
...  

PurposeThe systemic epidemiology of salt sensitivity (EpiSS) study aims to combine molecular biology, epidemiology and bioinformatics methods to discover the potential causes of salt sensitivity of blood pressure (SSBP) using single-nucleotide polymorphisms in the genome and non-coding RNAs in the transcriptome to uncover both the genetic and environmental factors of SSBP.ParticipantsBetween July 2014 and July 2016, we enrolled adults from 11 study centres in Beijing and Liaoning Province; participants were of the Han population and were 35–70 years of age. We collected blood samples, spot urine samples and 24-hour urine samples, in addition to baseline data on demographics, health-related lifestyle factors, chronic diseases, family history of illness and anthropometric information through face-to-face interviews using a standardised questionnaire. EpiSS uses the modified Sullivan’s acute oral saline load and diuresis shrinkage test (MSAOSL-DST) to evaluate the effects of salt on blood pressure.Findings to dateIn total, 2163 participants were included in the EpiSS, of which 2144 participants completed the questionnaire, 2120 (98.0%) completed the MSAOSL-DST and 2083 (96.3%) provided a 24-hour urine sample. A total of 2057 participants (1501 women and 556 men) completed all the steps of the investigation and were included in the analysis. Among them, 583 (28.3%) subjects were classified as having salt sensitivity of blood pressure, and 1061 (51.6%) had hypertension.Future plansThe next step of our study is to evaluate the incidence of cardiovascular disease in the participants. Biennial follow-up, including face-to-face questionnaire surveys, laboratory measurements of blood, urinary creatinine, glomerular filtration rate and anthropometric measurements, will occur two additional times. DNA and RNA will be collected for subsequent genetic biomarker studies. We plan on screening the salt-sensitive-related gene loci and non-coding RNAs based on relative environmental risk factors.Trial registration numberChiCTR-EOC-16009980; Pre-results.


Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
John J Gildea ◽  
Julia M Carlson ◽  
Tran T Hanh ◽  
Dora Bigler Wang ◽  
Peng Xu ◽  
...  

The sodium bicarbonate cotransporter NBCe2 (encoded by SLC4A5) partially regulates renal tubular sodium bicarbonate transport. Hypothesis: since SLC4A5 single nucleotide polymorphisms (SNPs, rs10177833 and rs7571842) are associated with salt sensitivity of blood pressure, the gene product, NBCe2, would be involved with the etiology of human salt sensitivity. NBCe2 was localized in freshly fixed renal tissue and in primary and immortalized RPT cell (RPTC) cultures from tissue or isolated from urine. Basal expression of NBCe2 mRNA and protein was not different between RPTCs carrying WT or HV SLC4A5 before or after dopaminergic or angiotensin (II and III) stimulation. However, total transcellular sodium transport, NHE3 protein expression, and Cl-/HCO3- exchanger activity were higher in SLC4A5 HV than WT RPTCs (WT: 8.6±1.2 mM NaCl n=6, 5207.1±386.4 RFU n=36, 0.265±0.006 pH unit/min, n=33 respectively; VS HV: 14.75±0.7 mM NaCl n=4, 6946.2±500.4 RFU n=48, 0.314±0.018 pH unit/min n=35 respectively, p<0.01). Aberrant sodium transport was even more evident after increasing intracellular sodium, which resulted in increased NBCe2 mRNA, NBCe2 protein and bicarbonate transport in HV RPTCs compared to WT (WT 146% ± 24% , 109% ± 4.7%, 89% ± 4.5%, respectively, VS HV 214% ± 23%, 128% ± 5.7%, 141% ± 4.8%, respectively N=8-12, p<0.05). RPTCs carrying HV variants showed increased binding of HNF4A to SLC4A5 DNA, which was blocked by two HNF4A antagonists. Assays in RPTCs isolated from urine showed increased bicarbonate-dependent pH recovery in RPTCs from salt-sensitive subjects who are HV for SLC4A5. NBCe2 under high sodium is hyper-responsive in RPTCs carrying SLC4A5 HV through an aberrant HNF4A-mediated mechanism.


Author(s):  
Wasita W Parksook ◽  
Mahyar Heydarpour ◽  
Shadi K Gholami ◽  
James M Luther ◽  
Paul N Hopkins ◽  
...  

Abstract: Context Salt sensitivity of blood pressure (SSBP) is associated with increased cardiovascular risk, especially in individuals of African descent, although underlying mechanisms remain obscure. Lysine-specific demethylase 1 (LSD1) is a salt-sensitive epigenetic regulator associated with SSBP and aldosterone dysfunction. An LSD1 risk allele in humans is associated with SSBP and lower aldosterone levels in hypertensive African but not European descent. Heterozygous knockout LSD1 mice display SSBP and aldosterone dysregulation, but this effect is modified by age and biological sex. This might explain differences in cardiovascular risk with aging and biological sex in humans. Objective To determine if LSD1 risk allele (rs587618) carriers of African descent display a sex-by-age interaction with SSBP and aldosterone regulation. Methods We analyzed 297 individuals of African and European descent from the HyperPATH cohort. We performed multiple regression analyses for outcome variables related to SSBP and aldosterone. Results LSD1 risk allele carriers of African (but not European) descent had greater SSBP than non-risk homozygotes. Female LSD1 risk allele carriers of African descent had greater SSBP, mainly relationship-driven by women of low estrogen (postmenopausal). There was a significant LSD1 genotype-sex interaction in aldosterone response to angiotensin II stimulation in individuals ≤50 years, with female carriers displaying decreased aldosterone responsiveness. Conclusions SSBP associated with LSD1 risk allele status is driven by women of deplete estrogen state. Mechanisms related to a resistance to develop SSBP in females are uncertain but may relate to an estrogen modulating effect on mineralocorticoid receptor activation and/or LSD1 epigenetic regulation of the mineralocorticoid receptor.


2018 ◽  
Vol 50 (9) ◽  
pp. 724-725 ◽  
Author(s):  
Xiaoling Zhang ◽  
Alissa A. Frame ◽  
Jonathan S. Williams ◽  
Richard D. Wainford

Salt sensitivity of blood pressure (BP) increases hypertension risk and associated adverse cardiovascular outcomes. At present, there are no validated rapid tests or diagnostic markers to identify salt sensitivity of BP in clinical practice. Based on our prior animal studies that report a role for brain Gαi2 proteins in the salt sensitivity of BP and evidence that GNAI2 single nucleotide polymorphisms (SNPs) associate with hypertension risk, we investigated the hypothesis that GNAI2 SNPs associate with salt sensitivity of BP in humans. Our data provide the first evidence that a GNAI2 SNP ( rs10510755 ) positively associates with salt sensitivity of BP in the Genetic Epidemiology of Salt Sensitivity data set (continuous phenotype P = 0.049, case-control phenotype P = 0.039; n = 968), independently of subject sex or age. These observations suggest that genotyping at GNAI2 may be a useful biomarker in identifying individuals at risk for developing salt-sensitive BP and related complications or in identifying salt sensitivity within the hypertensive population.


1999 ◽  
Vol 84 (10) ◽  
pp. 3745-3749
Author(s):  
Emanuela Lovati ◽  
Paolo Ferrari ◽  
Bernhard Dick ◽  
Kristin Jostarndt ◽  
Brigitte M. Frey ◽  
...  

Abstract Salt-sensitive subjects (SS) increase their blood pressure with increasing salt intake. Because steroid hormones modulate renal sodium retention, we hypothesize that the activity of the 11β-hydroxy-steroid dehydrogenase type 2 (11βHSD2) enzyme is impaired in SS subjects as compared with salt-resistant (SR) subjects. The 11βHSD2 enzyme inactivates 11-hydroxy steroids in the kidney, thus protecting the nonselective mineralocorticoid receptor from occupation by glucocorticoids. We performed an association study using a recently identified single AluI polymorphism in exon 3 and a polymorphic microsatellite marker of the HSD11B2 gene in 149 normotensive white males (37 SS and 112 SR). The activity of the enzyme 11βHSD2 was assessed by determining the urinary ratio of cortisol (THF+5αTHF) to cortisone (THE) metabolites by gas chromatography in all the 37 SS subjects and in 37 age- and body habitus-matched SR volunteers. Mean (THF+5αTHF)/THE ratio was markedly elevated in SS subjects compared with SR subjects (1.51 ± 0.34 vs. 1.08 ± 0.26, P &lt; 0.00001), indicating enhanced access of glucocorticoids to the mineralocorticoid receptor in SS subjects. In 58% of SS subjects this ratio was higher than the maximum levels in SR subjects. The salt-induced elevation in arterial pressure increased with increasing (THF+5αTHF)/THE ratio (r2 = 0.51, P &lt; 0.0001). A total of 12 alleles of the polymorphic microsatellite marker were detected. Homozygosity for the allele A7 was higher in SS subjects than in SR subjects (41 vs. 28%, P &lt; 0.005), whereas the occurrence of the allele A7 with allele A8 was lower in SS subjects than in SR subjects (8 vs. 15%, P&lt; 0.03). The prevalence of salt sensitivity was 35% in subjects with allele A7/A7, whereas salt sensitivity was present in only 9% of the subjects with allele A7/A8. The (THF+5αTHF)/THE ratio was higher in subjects homozygous for the A7 microsatellite allele as compared with the corresponding control subjects. The prevalence of the AluI allele was 8.0% in SR subjects and 5.4% in SS subjects and did not correlate with blood pressure. The decreased activity of the 11βHSD2 in SS subjects indicates that this enzyme is involved in salt-sensitive blood pressure response in humans. The association of a polymorphic microsatellite marker of the gene with a reduced 11βHSD2 activity suggests that variants of the HSD11B2 gene contribute to enhanced blood pressure response to salt in humans.


Circulation ◽  
2012 ◽  
Vol 125 (suppl_10) ◽  
Author(s):  
Tanika N Kelly ◽  
Casey M Rebholz ◽  
Dongfeng Gu ◽  
James E Hixson ◽  
Dabeeru C Rao ◽  
...  

Previous reports have documented increased blood pressure (BP) salt-sensitivity in women compared to men, suggesting that genes encoding sex hormones could influence BP response to sodium. In the current study, we examined the association between 799 single nucleotide polymorphisms (SNPs) in 44 genes involved in sex hormone biosynthesis, bioavailability and metabolism for their association with BP responses to sodium intervention separately in men and women. A 7-day low-sodium (51.3 mmol sodium/day) followed by a 7-day high-sodium feeding-study (307.8 mmol sodium/day) was conducted among 1,906 participants from 633 Han Chinese families. Nine BP measurements were obtained at baseline and the end of each intervention period using a random-zero sphygmomanometer. Additive associations between each SNP and BP responses to low and high-sodium interventions were assessed using a mixed linear regression model to account for familial dependencies. Among men, absolute BP responses to sodium interventions decreased with the number of minor alleles of estrogen receptor 1 (ESR1) markers rs9340844, rs9397453 and rs9383951. For example, men with genotypes C/C, C/T, and T/T of rs9397453 had respective mean DBP responses [95% confidence intervals (CI)] of: -2.67 (-3.13, -2.22), -1.23 (-1.98, -0.48), and 0.08 (-2.31, 2.47) mmHg to low-sodium intervention [p=1×10 -4 ; false discovery rate (FDR)-q=0.04]; and 1.46 (1.03, 1.89), 0.19 (-0.54, 0.91), and -1.10 (-2.82, 0.61) mmHg to high-sodium intervention (p=2×10 -4 ; FDR-q=0.04). In addition, mean SBP responses (95% CI) were: -5.70 (-6.19, -5.20), -4.34 (-5.37, -3.31), and -2.65 (-5.15, -0.16) mmHg, respectively, for low-sodium intervention (p=2×10 -3 ; FDR-q=0.17); and 4.56 (4.12, 4.99), 3.47 (2.63, 4.30), and 1.97 (-0.49, 4.43) mmHg, respectively, for high-sodium intervention (p=3×10 -3 ; FDR-q=0.40). ESR1 variants were not associated with BP responses in women, with highly significant genotype-gender interactions noted. In summary, we identified strong, consistent associations between genetic variants in the ESR1 gene and decreased salt-sensitivity in men. Although replication of these findings is needed, our results support a role for sex-hormones in the etiology of this complex trait. Funding(This research has received full or partial funding support from the American Heart Association, National Center)


Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Peng Xu ◽  
John J Gildea ◽  
Pedro A Jose ◽  
Robert M Carey ◽  
Robin A Felder

Our previous studies of salt sensitivity of blood pressure have demonstrated that approximately 11% of study participants have a paradoxical increase in blood pressure (> or = to 7-mm Hg) on a low NaCl diet (defined as inverse salt sensitivity (ISS)). However the mechanisms responsible for this effect are not known. We demonstrated that single nucleotide polymorphisms (SNPs) in the dopamine type 2 receptor (D 2 R) (RS6276 and 6267) are highly associated with ISS ( P values of 1.0х10 –2 and 3.8х10 –2 with odds ratios of 0.32 and 0.48 in unadjusted regression models, respectively). The C allele at both sites confers protection. The D 2 R is strongly expressed throughout the cytoplasm of proximal tubule cells in human kidney tissue slices. We also cultured RPTC from the urine from 4 salt resistant (SR) and 3 ISS participants enrolled in our clinical salt sensitivity studies. We hypothesize that D 2 R containing SNPs have altered receptor expression, and altered signaling compared to wild type controls. ISS participants were homozygous variant for the two D 2 R alleles and showed more D 2 R expression than SR RPTC heterozygous variant (HV) for the two alleles (ISS: 1.166±0.059 n=3 vs SR: 0.969±0.024 n=4, P<0.05, t-test). D 2 R expression was increased when the ISS cells were stimulated by a non-selective D 2 R agonist bromocriptine to a greater extent in the D 2 R SNP cell lines (ISS: VEH 1.166±0.059, vs bromocriptine 1.474 ± 0.040, n=3, P<0.05, t-test). Using the ROS reagent assay, dihydroethidium, there was found to be more ROS products in ISS cells than SR cells when stimulated under low salt (ISS: 1.145 ± 0.053, n=3 vs SR: 0.722 ± 0.101, n=4, P<0.05, t-test). We used a highly selective D 2 R agonist (sumanirole) to stimulate wild-type and SNPed cells, and the results demonstrated no effect in the cells with wild type D 2 R but an increase in ROS in cells heterozygous for the D 2 R SNPs (SNP: VEH 38,364±1,266, sumanirole 50,926 ± 3,310, VS WT: VEH 34,562±1,831 sumanirole 34,435 ± 1,614 RFU n=12, P<0.05, t-test) consistent with the higher expression of D 2 R found in ISS urine cells. We hypothesize that SNPs in the D 2 R lead to increased reactive oxygen species which has previously been associated with renal fibrosis and hypertension.


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