ATP2B1 and blood pressure: from associations to pathophysiology

ATP2B1 gene polymorphisms associated with resistant hypertension in the Japanese population

Single-nucleotide polymorphisms (SNP) of ATP2B1 gene are associated with essential hypertension but their association with resistant hypertension (RHT) remains unexplored. The authors examined the relationship between ATP2B1 SNPs and RHT by genotyping 12 SNPs in ATP2B1 gene of 1124 Japanese individuals with lifestyle-related diseases. Patients with RHT had inadequate blood pressure (BP) control using three antihypertensive drugs or used ≥4 antihypertensive drugs. Patients with controlled hypertension had BP controlled using ≤3 antihypertensive drugs. The association between each SNP and RHT was analyzed by logistic regression. The final cohort had 888 (79.0%) and 43 (3.8%) patients with controlled hypertension and RHT, respectively. Compared with patients homozygous for the minor allele of each SNP in ATP2B1, a significantly higher number of patients carrying the major allele at 10 SNPs exhibited RHT (most significant at rs1401982: 5.8% vs. 0.8%, p = .014; least significant at rs11105378: 5.7% vs. 0.9%, p = .035; most nonsignificant at rs12817819: 5.1% vs. 10%, p = .413). After multivariate adjustment for age, sex, systolic BP, and other confounders, the association remained significant for rs2681472 and rs1401982 (OR: 7.60, p < .05 and OR: 7.62, p = .049, respectively). Additionally, rs2681472 and rs1401982 were in linkage disequilibrium with rs11105378. This study identified two ATP2B1 SNPs associated with RHT in the Japanese population. rs1401982 was most closely associated with RHT, and major allele carriers of rs1401982 required significantly more antihypertensive medications. Analysis of ATP2B1 SNPs in patients with hypertension can help in early prediction of RHT and identification of high-risk patients who are more likely to require more antihypertensive medications.

Association between polymorphism and haplotype of ATP2B1 gene and skeletal fluorosis in Han population

To evaluate the association between ATP2B1 gene polymorphisms and skeletal fluorosis, a cross-sectional study was conducted. In China, 962 individuals were recruited, including 342 cases of skeletal fluorosis. Four TP2BA1 polymorphisms (rs2070759, rs12817819, rs17249754, and rs7136259) were analysed. The results suggested that rs17249754 and rs7136259 were associated with skeletal fluorosis. After controlling confounders, the protective effect of GG genotype in rs17249754 was apparent in individuals over 45 years old, female, with urine fluoride concentration below 1.6 mg/L, serum calcium above 2.25 mmol/L or serum phosphorus between 1.1 and 1.3. Heterozygote TC in rs7136259 increased the risk of skeletal fluorosis in subjects who are elderly, female, with urinary fluoride more than 1.6 mg/L, serum calcium more than 2.25 mmol/L and blood phosphorus between 1.1 and 1.3 mmol/L. Four loci were found to be tightly related by linkage disequilibrium analysis, and the frequency of distribution of haplotype GCGT was lower in the skeletal fluorosis group.

ATP2B1 genotypes rs2070759 and rs2681472 polymorphisms and risk of hypertension in Saudi population

This study examined an association of ATP2B1 gene polymorphism and hypertension in the Saudi population. The 246 hypertensive cases and 300 healthy human controls were genotyped. The results showed that genotypes rs.207075 (CA + AA) [p = 0.05; OR: 95% CI, 1.5:(1.0 to 2.4) and p = 0.001, OR: 95% CI, 2.4: (1.5 to 4.0) and rs2681472 (CT + TT) [p = 0.05; OR: 95% CI, 1.5 (1.0 to 2.4) and p = 0.006 OR: 95% CI, 2.0 (1.2 to 3.1) respectively] associated with the risk of hypertension. Cases carrying the recessive models: [(CA + AA)/(CT + TT)] and [(AA)/(TT)] genotypes confer a strong susceptibility risk of hypertension [p = 0.002; OR: (95%CI) 1.8 (1.2 to 2.6) and p = 0.001; OR: (95%CI) 2.6 (1.5 to 4.7) respectively]. However, cases with body-mass-index (BMI)<25, carrying homozygous mutant genotypes [AA, rs2070759, p = 0.007; OR: (95%CI) 2.75(1.37 to 5.5) and (TT, rs2681472, p = 0.05; OR: (95%CI) 1.96 (1.03 to 3.72)] as well as A allele of rs2070759 [p = 0.006; OR: (95%CI) 1.62 (1.16 to 2.25)] and T allele of rs2681472, p = 0.04, 1.43(1.03 to 1.98)] showed a significant association with high risk of hypertension. In short, a significant association between ATP2B1 gene polymorphism and risk of hypertension was noticed. In addition, individuals carrying recessive genotypes have greater risk in developing hypertension than those carrying dominant genotypes. Moreover, cases with high-risk BMI associated with ATP2B1 variants may play a critical role in developing hypertension.Supplemental data for this article is available online at https://doi.org/10.1080/15257770.2021.1973034 .

ATP2B1 gene polymorphisms rs2681472 and rs17249754 are associated with susceptibility to hypertension and blood pressure levels: A systematic review and meta-analysis

OBJECTIVE

The present study aimed to conduct a systematic review and meta-analysis to evaluate the relationships between ATP2B1 gene polymorphisms with blood pressure (BP) level and susceptibility to hypertension.

METHODS

PubMed, Web of Science, Embase and China National Knowledge Infrastructure (CNKI) Databases were systematically searched by 2 independent researchers to screen studies on ATP2B1 gene polymorphisms and BP related phenotypes. The records retrieval period was limited from the formation of the database to March 4, 2021. Pooled odds rations (ORs) or β and their 95% confidence intervals (95%CI) were calculated to assess the association between ATP2B1 gene polymorphisms and the risk of hypertension or BP levels. Publication bias and sensitivity analysis were conducted to find potential bias. All the statistical analysis were conducted with Stata version 11.0 software.

RESULTS

A total of 15 articles were ultimately included in the present study, including 15 polymorphisms of ATP2B1 gene. Nine articles (N = 65,362) reported the polymorphism rs17249754, and 7 articles(N = 91,997) reported rs2681472 (both loci were reported in 1 article). Meta-analysis showed that rs17249754 (G/A) and rs2681472 (A/G) were associated with the susceptibility to hypertension (rs17249754: OR = 1.19, 95%CI: 1.10-1.28; rs2681472: OR = 1.15, 95%CI: 1.12-1.17), and were positively associated with systolic BP (SBP) and diastolic blood pressure (DBP) (rs17249754: SBP, β=1.01, 95%CI: 0.86-1.16, DBP, β=0.48, 95%CI: 0.30-0.66; rs2681472: SBP, β=0.92, 95%CI: 0.77-1.07, DBP, β=0.50, 95%CI: 0.42-0.58) in the additive genetic model. Subgroup analysis stratified by race, population, sample size, and BP measurement method revealed that the association between A allele in rs2681472 polymorphism and risk of hypertension was slightly stronger in European (EUR) populations (OR = 1.16, 95%CI: 1.13-1.20) than in East Asians (OR = 1.14, 95%CI: 1.10-1.17). While in East Asians, relation between rs17249754 with risk of hypertension (OR = 1.19, 95%CI: 1.10-1.28) is stronger than rs2681472 (OR = 1.14, 95%CI: 1.10-1.17).

CONCLUSIONS

Our study demonstrated that ATP2B1 gene polymorphism rs2681472 and rs17249754 were associated with BP levels and the susceptibility to hypertension.

A genome-wide association and replication study of blood pressure in Ugandan early adolescents

BACKGROUND

Genetic association studies of blood pressure (BP) have mostly been conducted in non-African populations. Using the Entebbe Mother and Baby Study (EMaBS), we aimed to identify genetic variants associated with BP among Ugandan adolescents.

METHODS

Systolic and diastolic BP were measured among 10- and 11-year olds. Whole-genome genotype data were generated using Illumina omni 2.5M arrays and untyped variants were imputed. Genome-wide association study (GWAS) was conducted using linear mixed model regression to account for population structure. Linear regression analysis was used to assess whether variants previously associated with BP (p < 5.0 × 10-8 ) in published BP GWASs were replicated in our study.

RESULTS

Of the 14 million variants analyzed among 815 adolescents, none reached genome-wide significance (p < 5.0×10-8 ) for association with systolic or diastolic BP. The most strongly associated variants were rs181430167 (p = 6.8 × 10-7 ) for systolic BP and rs12991132 (p = 4.0 × 10-7 ) for diastolic BP. Thirty-three (17 single nucleotide polymorphisms (SNPs) for systolic BP, 15 SNPs for diastolic BP and one SNP for both) of 330 variants previously identified as associated with BP were replicated in this study, but none remained significant after accounting for multiple testing.

CONCLUSION

Variants showing suggestive associations are worthy of future investigation. Replication results suggest that variants influencing adolescent BP may overlap somewhat with those already established in previous studies, largely based on adults in Western settings.

Genetics of Human Primary Hypertension: Focus on Hormonal Mechanisms

Increasingly, primary hypertension is being considered a syndrome and not a disease, with the individual causes (diseases) having a common sign-an elevated blood pressure. To determine these causes, genetic tools are increasingly employed. This review identified 62 proposed genes. However, only 21 of them met our inclusion criteria: (i) primary hypertension, (ii) two or more supporting cohorts from different publications or within a single publication or one supporting cohort with a confirmatory genetically modified animal study, and (iii) 600 or more subjects in the primary cohort; when including our exclusion criteria: (i) meta-analyses or reviews, (ii) secondary and monogenic hypertension, (iii) only hypertensive complications, (iv) genes related to blood pressure but not hypertension per se, (v) nonsupporting studies more common than supporting ones, and (vi) studies that did not perform a Bonferroni or similar multiassessment correction. These 21 genes were organized in a four-tiered structure: distant phenotype (hypertension); intermediate phenotype [salt-sensitive (18) or salt-resistant (0)]; subintermediate phenotypes under salt-sensitive hypertension [normal renin (4), low renin (8), and unclassified renin (6)]; and proximate phenotypes (specific genetically driven hypertensive subgroup). Many proximate hypertensive phenotypes had a substantial endocrine component. In conclusion, primary hypertension is a syndrome; many proposed genes are likely to be false positives; and deep phenotyping will be required to determine the utility of genetics in the treatment of hypertension. However, to date, the positive genes are associated with nearly 50% of primary hypertensives, suggesting that in the near term precise, mechanistically driven treatment and prevention strategies for the specific primary hypertension subgroups are feasible.

ATP2B1 rs2681472 and STK39 rs35929607 polymorphisms and risk of Hypertension in Iranian Population

Background: ATP2B1 and STK39 have been introduced as essential hypertension candidate genes. The association of these genes' variations have not been studied in Iranian population yet. Here we aimed to investigate the association of ATP2B1 rs2681472 and STK39 rs35929607 polymorphisms with the risk of hypertension in an Iranian population. Methods: We included 400 individuals in our case-control study: 200 cases with essential hypertension and 200 healthy sex and age matched controls. All subjects were genotyped for rs2681472 and rs35929607 using a PCR-RFLP method. Genotype and allele frequencies were compared between the two groups using chi-squared test. The association was further assessed under log-additive, dominant and recessive genetic models. Results: There was no association between rs2681472 and rs35929607 polymorphisms and risk of essential hypertension in our population (p>0.05). There was also no association between the studied polymorphisms and hypertension under different genetic models. Conclusion: Our study indicated that rs2681472 of ATP2B1 and rs35929607 of STK39 may not have a significant effect on the risk of essential hypertension in Iranian population. More studies are still needed to validate our results.

Systematic-analysis of mRNA expression profiles in skeletal muscle of patients with type II diabetes: The glucocorticoid was central in pathogenesis

Since the past 30 years, the prevalence of diabetes has more than doubled, making it an urgent challenge globally. We carried out systematic analysis with the public data of mRNA expression profiles in skeletal muscle to study the pathogenesis, since insulin resistance in the skeletal muscle is an early feature. We utilized three GEO datasets, containing total 60 cases and 63 normal samples. After the background removal, R package QC was utilized to finish the preprocessing of datasets. We obtained a dataset containing 2481 genes and 123 samples after the preprocessing. Quantitative quality control measures were calculated to represent the quality of these datasets. MetaDE package provides functions for conducting different systematic analysis methods for differential expression analysis. The GO term enrichment was carried out using PANTHER. Protein-protein interactions, drug-gene interactions, and genetic association of the identified differentially expressed genes were analyzed using STRING v10.0 online tool, DGIdb, and the Genetic Association Database, respectively. The datasets had good performances on IQC and EQC, which suggested that the datasets had good internal and external quality. Totally 96 differentially expressed genes were detected using 0.01 as cutoff of AW. The enriched GO terms were mainly associated with the response to glucocorticoid. There were seven genes involving in the gluconeogenesis were differentially expressed, which might be the potential treatment target for this disease. The closely connected networks and potential targets of existed drugs suggested that some of the drugs might be applied to the treatment of diabetes as well.

The effects of anti-hypertensive drugs and the mechanism of hypertension in vascular smooth muscle cell-specific ATP2B1 knockout mice

ATP2B1 is a gene associated with hypertension. We reported previously that mice lacking ATP2B1 in vascular smooth muscle cells (VSMC ATP2B1 KO mice) exhibited high blood pressure and increased intracellular calcium concentration. The present study was designed to investigate whether lack of the ATP2B1 gene causes a higher response to calcium channel blockers (CCBs) than to other types of anti-hypertensive drugs. Both VSMC ATP2B1 KO and control mice were administered anti-hypertensive drugs while monitoring blood pressure shifts. We also examined the association of nitric oxide synthase (NOS) activity in those mice to investigate whether another mechanism of hypertension existed. VSMC ATP2B1 KO mice exhibited significantly greater anti-hypertensive effects with a single injection of nicardipine, but the effects of an angiotensin II receptor blocker (ARB), an α-blocker and amlodipine on blood pressure were all similar to control mice. However, long-term treatment with amlodipine, but not an ARB, significantly decreased the blood pressure of KO mice compared with control mice. Both mRNA and protein expression levels of the L-type calcium channel were significantly upregulated in KO VSMCs. There were no alterations in neural NOS protein expression of VSMCs or in urinary NO production between the two groups. VSMC ATP2B1 KO mice had a higher response to CCBs for blood pressure-lowering effects than other anti-hypertensive drugs. These results mean that increased intracellular calcium concentration in VSMCs due to lack of ATP2B1 and subsequent activation of L-type calcium channels mainly affects blood pressure and suggests increased susceptibility to CCBs in this type of hypertension.

Consensus Genome-Wide Expression Quantitative Trait Loci and Their Relationship with Human Complex Trait Disease

Most of the risk loci identified from genome-wide association (GWA) studies do not provide direct information on the biological basis of a disease or on the underlying mechanisms. Recent expression quantitative trait locus (eQTL) association studies have provided information on genetic factors associated with gene expression variation. These eQTLs might contribute to phenotype diversity and disease susceptibility, but interpretation is handicapped by low reproducibility of the expression results. To address this issue, we have generated a set of consensus eQTLs by integrating publicly available data for specific human populations and cell types. Overall, we find over 4000 genes that are involved in high-confidence eQTL relationships. To elucidate the role that eQTLs play in human common diseases, we matched the high-confidence eQTLs to a set of 335 disease risk loci identified from the Wellcome Trust Case Control Consortium GWA study and follow-up studies for 7 human complex trait diseases-bipolar disorder (BD), coronary artery disease (CAD), Crohn's disease (CD), hypertension (HT), rheumatoid arthritis (RA), type 1 diabetes (T1D), and type 2 diabetes (T2D). The results show that the data are consistent with ∼50% of these disease loci arising from an underlying expression change mechanism.

Early growth response protein 1 regulates promoter activity of α-plasma membrane calcium ATPase 2, a major calcium pump in the brain and auditory system

BACKGROUND

Along with sodium/calcium (Ca2+) exchangers, plasma membrane Ca2+ ATPases (ATP2Bs) are main regulators of intracellular Ca2+ levels. There are four ATP2B paralogs encoded by four different genes. Atp2b2 encodes the protein pump with the fastest activation, ATP2B2. In mice, the Atp2b2 transcript has several alternate transcriptional start site variants: α, β, µ and δ. These variants are expressed in developmental and tissue specific manners. The α and β Atp2b2 transcripts are equally expressed in the brain. αAtp2b2 is the only transcript found in the outer hair cells of young mice (Silverstein RS, Tempel BL. in Neuroscience 141:245-257, 2006). Mutations in the coding region of the mouse Atp2b2 gene indicate a narrow window for tolerated dysfunction of the ATP2B2 protein, specifically in the auditory system. This highlights the necessity of tight regulation of this gene for normal cell physiology.

RESULTS

Although ATP2Bs are important regulators of Ca2+ in many cell types, little is known about their transcriptional regulation. This study identifies the proximal promoter of the αAtp2b2 transcript. Further investigations indicate that ATOH1 and EGR1 modulate promoter activity. Additionally, we report that EGR1 increases endogenous expression of Atp2b2 transcript in two cell lines. Electrophoretic mobility shift assays (EMSA) indicate that EGR1 binds to a specific site in the CpG island of the αAtp2b2 promoter.

CONCLUSION

This study furthers our understanding of Atp2b2 regulation by: (I) elucidating transcriptional regulatory mechanisms for Atp2b2, and (II) identifying transcription factors that modulate expression of Atp2b2 in the brain and peripheral auditory system and (III) allows for future studies modulating gene expression of Atp2b2.

Association of genetic variation with blood pressure traits among East Africans

INTRODUCTION

Genetic variation may play explain some of the disparity in prevalence and control of hypertension across Sub-Saharan Africa. However, there have been very few studies to characterize genetic variation of blood pressure traits.

AIM

To determine whether a set of blood pressure-associated genetic loci can be replicated among samples East African samples.

METHODS

Twenty-seven blood pressures (BP)-related single nucleotide polymorphisms (SNPs) were genotyped among 2881 samples from participants in the Medical Education Partnership Initiative for Cardiovascular Disease (MEPI-CVD) survey. Associations with known BP variants were evaluated for systolic blood pressure (SBP), diastolic blood pressure (DBP) and pulse pressure (PP) as continuous variables and for hypertension (HTN) as a binary variable.

RESULTS

Eleven SNPS were associated with at least 1 BP trait (P < .05). Four SNPs; rs2004776, rs7726475, rs11837544 and rs2681492, whose nearest genes are AGT, NPR3/SUB1, PLXNC1 and ATP2B1, respectively, were associated with SBP. Six SNPs, rs2004776, rs11977526, rs11191548, rs381815, rs2681492 and rs1327235, close to AGT, IGFBP3, CYP17A1, PLEKHA7, ATP2B1 and JAG, respectively, were associated with DBP while 2 SNPs located within AGT and IGFBP-3 genes associated with HTN. For PP, 4 variants rs1458038, rs11725861, rs7726475 and rs11953630 whose corresponding genes are FGF5, CHIC2, SUB1/NPR3 and EBF1 reached significance (P < .05). Eight SNPs were replicated in the same effect direction as the parent studies. Risk scores defined using published effect sizes were significantly associated with both SBP (P = .0026) and DBP (P = .0214).

CONCLUSION

The replication of multiple BP variants among East Africans suggests that these variants may have universal effects across ethnic populations.

Gender-Specific Association of ATP2B1 Variants with Susceptibility to Essential Hypertension in the Han Chinese Population

Previous genome-wide association studies (GWASs) found that several ATP2B1 variants are associated with essential hypertension (EHT). But the "genome-wide significant" ATP2B1 SNPs (rs2681472, rs2681492, rs17249754, and rs1105378) are in strong linkage disequilibrium (LD) and are located in the same LD block in Chinese populations. We asked whether there are other SNPs within the ATP2B1 gene associated with susceptibility to EHT in the Han Chinese population. Therefore, we performed a case-control study to investigate the association of seven tagSNPs within the ATP2B1 gene and EHT in the Han Chinese population, and we then analyzed the interaction among different SNPs and nongenetic risk factors for EHT. A total of 902 essential hypertensive cases and 902 normotensive controls were involved in the study. All 7 tagSNPs within the ATP2B1 gene were retrieved from HapMap, and genotyping was performed using the Tm-shift genotyping method. Chi-squared test, logistic regression, and propensity score analysis showed that rs17249754 was associated with EHT, particularly in females. The MDR analysis demonstrated that the interaction of rs2070759, rs17249754, TC, TG, and BMI increased the susceptibility to hypertension. Crossover analysis and stratified analysis indicated that BMI has a major effect on the development of hypertension, while ATP2B1 variants have a minor effect.

Impaired nitric oxide production and increased blood pressure in systemic heterozygous ATP2B1 null mice

BACKGROUND

In the 'Millennium Genome Project', we identified ATP2B1 as a gene responsible for hypertension through single-nucleotide polymorphism analysis. The ATP2B1 gene encodes the plasma membrane calcium ATPase isoform 1, which contributes to the maintenance of intracellular calcium homeostasis by removing calcium ions.

METHOD

Since ATP2B1 knockout mice are reported to be embryo-lethal, we generated systemic heterozygous ATP2B1 null (ATP2B1(+/-)) mice, and evaluated the implication of ATP2B1 in blood pressure.

RESULTS

ATP2B1(+/-) mice revealed significantly higher SBP as measured by a radiotelemetric method. Phenylephrine-induced vasoconstriction was significantly increased in vascular rings from ATP2B1(+/-) mice, and the difference in this contraction disappeared in the presence of a nitric oxide synthase (NOS) inhibitor. Vasorelaxation to acetylcholine was significantly attenuated in vascular rings from ATP2B1(+/-) mice. In addition, cultured endothelial cells of ATP2B1(+/-) mice showed that the phosphorylation (Ser-1177) level of endothelial NOS protein was significantly lower, and nitric oxide production in endothelial cells and aorta was lower compared with those in control mice. In contrast, neural NOS expression in vascular smooth muscle cells from ATP2B1(+/-) mice and control mice were not significantly different.

CONCLUSION

These results suggest that decreased ATP2B1 gene expression is associated with impaired endothelial NOS activity and nitric oxide production, and the ATP2B1 gene plays a crucial role in the regulation of blood pressure.

Genetic determinants of arterial stiffness

Stiffness of large arteries (called arteriosclerosis) is an independent predictor of cardiovascular morbidity and mortality. Although previous studies have shown that arterial stiffness is moderately heritable, genetic factors contributing to arterial stiffness are largely unknown. In this paper, we reviewed the available literature on genetic variants that are potentially related to arterial stiffness. Most variants have shown mixed depictions of their association with arterial stiffness across multiple studies. Various methods to measure arterial stiffness at different arterial sites can contribute to these inconsistent results. In addition, studies in patient populations with hypertension or atherosclerosis may overestimate the impact of genetic variants on arterial stiffness. Future studies are recommended to standardize current measures of arterial stiffness in different age groups. Studies conducted in normal healthy subjects may also provide better opportunities to find novel genetic variants of arterial stiffness.