Genome-Wide Association Study of Apparent Treatment-Resistant Hypertension in the CHARGE Consortium: The CHARGE Pharmacogenetics Working Group

Discovery of RXFP2 genetic association in resistant hypertensive men and RXFP2 antagonists for the treatment of resistant hypertension

Hypertension remains a leading cause of cardiovascular and kidney diseases. Failure to control blood pressure with ≥ 3 medications or control requiring ≥ 4 medications is classified as resistant hypertension (rHTN) and new therapies are needed to reduce the resulting increased risk of morbidity and mortality. Here, we report genetic evidence that relaxin family peptide receptor 2 (RXFP2) is associated with rHTN in men, but not in women. This study shows that adrenal gland gene expression of RXFP2 is increased in men with hypertension and the RXFP2 natural ligand, INSL3, increases adrenal steroidogenesis and corticosteroid secretion in human adrenal cells. To address the hypothesis that RXFP2 activation is an important mechanism in rHTN, we discovered and characterized small molecule and monoclonal antibody (mAb) blockers of RXFP2. The novel chemical entities and mAbs show potent, selective inhibition of RXFP2 and reduce aldosterone and cortisol synthesis and release. The RXFP2 mAbs have suitable rat pharmacokinetic profiles to evaluate the role of RXFP2 in the development and maintenance of rHTN. Overall, we identified RXFP2 activity as a potential new mechanism in rHTN and discovered RXFP2 antagonists for the future interrogation of RXFP2 in cardiovascular and renal diseases.

Whole genome sequence analysis of apparent treatment resistant hypertension status in participants from the Trans-Omics for Precision Medicine program

Introduction: Apparent treatment-resistant hypertension (aTRH) is characterized by the use of four or more antihypertensive (AHT) classes to achieve blood pressure (BP) control. In the current study, we conducted single-variant and gene-based analyses of aTRH among individuals from 12 Trans-Omics for Precision Medicine cohorts with whole-genome sequencing data. Methods: Cases were defined as individuals treated for hypertension (HTN) taking three different AHT classes, with average systolic BP ≥ 140 or diastolic BP ≥ 90 mmHg, or four or more medications regardless of BP (n = 1,705). A normotensive control group was defined as individuals with BP < 140/90 mmHg (n = 22,079), not on AHT medication. A second control group comprised individuals who were treatment responsive on one AHT medication with BP < 140/ 90 mmHg (n = 5,424). Logistic regression with kinship adjustment using the Scalable and Accurate Implementation of Generalized mixed models (SAIGE) was performed, adjusting for age, sex, and genetic ancestry. We assessed variants using SKAT-O in rare-variant analyses. Single-variant and gene-based tests were conducted in a pooled multi-ethnicity stratum, as well as self-reported ethnic/racial strata (European and African American). Results: One variant in the known HTN locus, KCNK3, was a top finding in the multi-ethnic analysis (p = 8.23E-07) for the normotensive control group [rs12476527, odds ratio (95% confidence interval) = 0.80 (0.74-0.88)]. This variant was replicated in the Vanderbilt University Medical Center's DNA repository data. Aggregate gene-based signals included the genes AGTPBP, MYL4, PDCD4, BBS9, ERG, and IER3. Discussion: Additional work validating these loci in larger, more diverse populations, is warranted to determine whether these regions influence the pathobiology of aTRH.

Role of the CASZ1 transcription factor in tissue development and disease

The zinc finger transcription factor gene, CASZ1/Castor (Castor zinc finger 1), initially identified in Drosophila, plays a critical role in neural, cardiac, and cardiovascular development, exerting a complex, multifaceted influence on cell fate and tissue morphogenesis. During neurogenesis, CASZ1 exhibits dynamic expression from early embryonic development to the perinatal period, constituting a key regulator in this process. Additionally, CASZ1 controls the transition between neurogenesis and gliomagenesis. During human cardiovascular system development, CASZ1 is essential for cardiomyocyte differentiation, cardiac morphogenesis, and vascular morphology homeostasis and formation. The deletion or inactivation of CASZ1 mutations can lead to human developmental diseases or tumors, including congenital heart disease, cardiovascular disease, and neuroblastoma. CASZ1 can be used as a biomarker for disease prevention and diagnosis as well as a prognostic indicator for cancer. This review explores the unique functions of CASZ1 in tissue morphogenesis and associated diseases, offering new insights for elucidating the molecular mechanisms underlying diseases and identifying potential therapeutic targets for disease prevention and treatment.

Genes, environment, and African ancestry in cardiometabolic disorders

The past two decades have been characterized by a substantial global increase in cardiometabolic diseases, but the prevalence and incidence of these diseases and related traits differ across populations. African ancestry populations are among the most affected yet least included in research. Populations of African descent manifest significant genetic and environmental diversity and this under-representation is a missed opportunity for discovery and could exacerbate existing health disparities and curtail equitable implementation of precision medicine. Here, we discuss cardiometabolic diseases and traits in the context of African descent populations, including both genetic and environmental contributors and emphasizing novel discoveries. We also review new initiatives to include more individuals of African descent in genomics to address current gaps in the field.

Primary Aldosteronism and Drug Resistant Hypertension: A "Chicken-Egg" Story

Drug-resistant arterial hypertension (RH) is a major risk factor for cardiovascular disease, often due to overlooked underlying causes. Identification of such causes poses significant clinical challenges. In this setting, primary aldosteronism (PA) is a frequent cause of RH and its prevalence in RH patients is likely higher than 20%.The pathophysiological link between PA and the development and maintenance of RH involves target organ damage and the cellular and extracellular effects of aldosterone excess that promote pro-inflammatory and pro-fibrotic changes in the kidney and vasculature.The feasibility of adrenal vein sampling in PA patients with RH, and the clinical benefit achieved by adrenalectomy, further emphasize the need to implement systematic screening for this common form of secondary hypertension in the management of a high-risk population as RH patients.: We herein review the current knowledge of the factors that contribute to the RH phenotype with a focus on PA and discuss the issues regarding the screening for PA in this setting and the therapeutic approaches (surgical and medical) aimed at resolving RH caused by PA.

Genome-wide Association Studies Categorized by Class of Antihypertensive Drugs Reveal Complex Pathogenesis of Hypertension with Drug Resistance

Resistant hypertension is defined as uncontrolled blood pressure (BP) despite the use of three or more antihypertensive drugs of different classes. Although genetic factors may greatly contribute to hypertension with resistance to multiple drug classes, more than for general hypertension, its pathogenesis remains unknown. To reveal the genetic background of resistant hypertension, we categorized 32,239 patients whose data were obtained from the BioBank Japan Project, by prescription of 7 classes of antihypertensive drugs and performed genome-wide association studies (GWAS). Our GWAS identified four loci with significant association (P < 5 × 10-8 ): rs6445583 in CACNA1D and rs12308051 in the intergenic region on chromosome 12 for angiotensin II receptor blockers, rs35497065 in FOXA3 for calcium channel blockers, and rs11066280 in HECTD4 for αβ-blockers. Because these loci are known to be susceptibility loci for hypertension and/or BP, our results indicate that resistant hypertension is caused by a combination of excessive BP and drug resistance to each antihypertensive pharmacological class. Furthermore, to investigate the genetic difference between BP traits and the treatment effectiveness of antihypertensive drugs, we performed gene-set analysis and calculated the genetic correlation continuously. Most of the genetic factors were in common between BP traits and antihypertensive effectiveness, but it seems that the genetic architecture of the drug response to antihypertensive treatment is more complicated than BP traits. This corresponds to the well-known mosaic theory of hypertension. Our findings reveal the complex pathogenesis of hypertension with resistance to multiple classes of antihypertensive drugs.

CASZ1: Current Implications in Cardiovascular Diseases and Cancers

Castor zinc finger 1 (CASZ1) is a C2H2 zinc finger family protein that has two splicing variants, CASZ1a and CASZ1b. It is involved in multiple physiological processes, such as tissue differentiation and aldosterone antagonism. Genetic and epigenetic alternations of CASZ1 have been characterized in multiple cardiovascular disorders, such as congenital heart diseases, chronic venous diseases, and hypertension. However, little is known about how CASZ1 mechanically participates in the pathogenesis of these diseases. Over the past decades, at first glance, paradoxical influences on cell behaviors and progressions of different cancer types have been discovered for CASZ1, which may be explained by a "double-agent" role for CASZ1. In this review, we discuss the physiological function of CASZ1, and focus on the association of CASZ1 aberrations with the pathogenesis of cardiovascular diseases and cancers.

No association between genetic markers and hypertension control in multiple cross-sectional studies

We aimed to assess whether genetic markers are associated with hypertension control using two cross-sectional surveys conducted in Lausanne, Switzerland. Management of hypertension was assessed as per ESC guidelines using the 140/90 or the 130/80 mm Hg thresholds. One genetic risk score (GRS) for hypertension (18 SNPs) and 133 individual SNPs related to response to specific antihypertensive drugs were tested. We included 1073 (first) and 1157 (second survey) participants treated for hypertension. The prevalence of controlled participants using the 140/90 threshold was 58.8% and 63.6% in the first and second follow-up, respectively. On multivariable analysis, only older age was consistently and negatively associated with hypertension control. No consistent associations were found between GRS and hypertension control (140/90 threshold) for both surveys: Odds ratio and (95% confidence interval) for the highest vs. the lowest quartile of the GRS: 1.06 (0.71-1.58) p = 0.788, and 1.11 (0.71-1.72) p = 0.657, in the first and second survey, respectively. Similar findings were obtained using the 130/80 threshold: 1.23 (0.79-1.90) p = 0.360 and 1.09 (0.69-1.73) p = 0.717, in the first and second survey, respectively. No association between individual SNPs and hypertension control was found. We conclude that control of hypertension is poor in Switzerland. No association between GRS or SNPs and hypertension control was found.

New advances in endocrine hypertension: from genes to biomarkers

Hypertension (HT) is a major cardiovascular risk factor that affects 10% to 40% of the general population in an age-dependent manner. Detection of secondary forms of HT is particularly important because it allows the targeted management of the underlying disease. Among hypertensive patients, the prevalence of endocrine HT reaches up to 10%. Adrenal diseases are the most frequent cause of endocrine HT and are associated with excess production of mineralocorticoids (mainly primary aldosteronism), glucocorticoids (Cushing syndrome), and catecholamines (pheochromocytoma). In addition, a few rare diseases directly affecting the action of mineralocorticoids and glucocorticoids in the kidney also lead to endocrine HT. Over the past years, genomic and genetic studies have allowed improving our knowledge on the molecular mechanisms of endocrine HT. Those discoveries have opened new opportunities to transfer knowledge to clinical practice for better diagnosis and specific treatment of affected subjects. In this review, we describe the physiology of adrenal hormone biosynthesis and action, the clinical and biochemical characteristics of different forms of endocrine HT, and their underlying genetic defects. We discuss the impact of these discoveries on diagnosis and management of patients, as well as new perspectives related to the use of new biomarkers for improved patient care.

CASZ1: a promising factor modulating aldosterone biosynthesis and mineralocorticoid receptor activity

Hypertension is the definitive risk factor for cardiovascular disease. Primary aldosteronism (PA), a typical form of secondary hypertension, is responsible for treatment-resistant hypertension and carries an even higher risk of causing cardiovascular complications than essential hypertension. Several genes involved in the pathogenesis of hypertension have been identified recently using genome-wide association studies (GWASs). Among these, castor zinc finger 1(CASZ1) is considered to be involved in the pathophysiology of hypertension via modulation of aldosterone action. In 2021, using a biochemical approach with liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis, we identified CASZ1b, an isoform of CASZ1, as a novel mineralocorticoid receptor (MR) coregulator. Our further analysis revealed that CASZ1b is coexpressed with MR in MR targets such as kidney tubule cells, and that a decrease in CASZ1 protein levels promotes aldosterone-dependent transcriptional activity of MR. Further, a recent study of GWAS on PA identified CASZ1 to be a PA-related gene and demonstrated that overexpression of CASZ1 suppresses aldosterone biosynthesis in adrenal cells. These results suggest CASZ1 plays a pivotal role in the pathophysiology of hypertension and PA via dual mechanisms: aldosterone biosynthesis and transcriptional activity of MR.

A genome-wide association study identifies a novel association between SDC3 and apparent treatment-resistant hypertension

BACKGROUND

Compared with patients who require fewer antihypertensive agents, those with apparent treatment-resistant hypertension (aTRH) are at increased risk for cardiovascular and all-cause mortality, independent of blood pressure control. However, the etiopathogenesis of aTRH is still poorly elucidated.

METHODS

We performed a genome-wide association study (GWAS) in first cohort including 586 aTRHs and 871 healthy controls. Next, expression quantitative trait locus (eQTL) analysis was used to identify genes that are regulated by single nucleotide polymorphisms (SNPs) derived from the GWAS. Then, we verified the genes obtained from the eQTL analysis in the validation cohort including 65 aTRHs, 96 hypertensives, and 100 healthy controls through gene expression profiling analysis and real-time quantitative polymerase chain reaction (RT-qPCR) assay.

RESULTS

The GWAS in first cohort revealed four suggestive loci (1p35, 4q13.2-21.1, 5q22-23.2, and 15q11.1-q12) represented by 23 SNPs. The 23 significant SNPs were in or near LAPTM5, SDC3, UGT2A1, FTMT, and NIPA1. eQTL analysis uncovered 14 SNPs in 1p35 locus all had same regulation directions for SDC3 and LAPTM5. The disease susceptible alleles of SNPs in 1p35 locus were associated with lower gene expression for SDC3 and higher gene expression for LAPTM5. The disease susceptible alleles of SNPs in 4q13.2-21.1 were associated with higher gene expression for UGT2B4. GTEx database did not show any statistically significant eQTLs between the SNPs in 5q22-23.2 and 15q11.1-q12 loci and their influenced genes. Then, gene expression profiling analysis in the validation cohort confirmed lower expression of SDC3 in aTRH but no significant differences on LAPTM5 and UGT2B4, when compared with controls and hypertensives, respectively. RT-qPCR assay further verified the lower expression of SDC3 in aTRH.

CONCLUSIONS

Our study identified a novel association of SDC3 with aTRH, which contributes to the elucidation of its etiopathogenesis and provides a promising therapeutic target.

Identification of risk loci for primary aldosteronism in genome-wide association studies

Primary aldosteronism affects up to 10% of hypertensive patients and is responsible for treatment resistance and increased cardiovascular risk. Here we perform a genome-wide association study in a discovery cohort of 562 cases and 950 controls and identify three main loci on chromosomes 1, 13 and X; associations on chromosome 1 and 13 are replicated in a second cohort and confirmed by a meta-analysis involving 1162 cases and 3296 controls. The association on chromosome 13 is specific to men and stronger in bilateral adrenal hyperplasia than aldosterone producing adenoma. Candidate genes located within the two loci, CASZ1 and RXFP2, are expressed in human and mouse adrenals in different cell clusters. Their overexpression in adrenocortical cells suppresses mineralocorticoid output under basal and stimulated conditions, without affecting cortisol biosynthesis. Our study identifies the first risk loci for primary aldosteronism and highlights new mechanisms for the development of aldosterone excess.

Association between genetic risk of high SBP and hypertension control: the CoLaus|PsyColaus study

OBJECTIVE

To assess whether a genetic risk score (GRS) for high SBP is associated with poor control of hypertension.

METHODS

Data from the four waves of a population-based, prospective study conducted in Lausanne, Switzerland. Control of hypertension was defined based on SBP less than 140 mmHg and DBP less than 90 mmHg. A weighted GRS was computed from 362 SNPs.

RESULTS

Overall, 1097 (51% men, mean age 61 years), 1126 (53% men, age 65 years), 1020 (52% men, age 69 years) and 809 (50% men, age 71 years) participants treated for hypertension were selected from the baseline (2003-2006), first (2009-2012), second (2014-2017) and third (2018-2021) surveys. Hypertension control rates were 50, 58, 52 and 59% for the baseline, first, second and third surveys, respectively. No association was found between GRS and hypertension control: multivariate-adjusted mean ± standard error for controlled vs. uncontrolled participants: 9.30 ± 0.09 vs. 9.50 ± 0.09 ( P  = 0.12); 9.32 ± 0.08 vs. 9.53 ± 0.10 ( P  = 0.10); 9.17 ± 0.08 vs. 9.34 ± 0.11 ( P  = 0.22), and 9.18 ± 0.09 vs. 9.46 ± 0.11 ( P  = 0.07) for the baseline, first, second and third surveys, respectively. Power analysis showed that a minimum of 3410 people treated for hypertension would be necessary to detect an association between the GRS and hypertension control rates. Notably, positive associations between the GRS and SBP levels were found among participants not treated for hypertension, with Spearman correlations ranging between 0.05 and 0.09 (all P  < 0.05).

CONCLUSION

Using a GRS associated with SBP levels is not predictive of hypertension control. The use of GRS for hypertension management is not warranted in clinical practice.

http://links.lww.com/HJH/C26.

Hypertension genetics past, present and future applications

Essential hypertension is a complex trait where the underlying aetiology is not completely understood. Left untreated it increases the risk of severe health complications including cardiovascular and renal disease. It is almost 15 years since the first genome-wide association study for hypertension, and after a slow start there are now over 1000 blood pressure (BP) loci explaining ∼6% of the single nucleotide polymorphism-based heritability. Success in discovery of hypertension genes has provided new pathological insights and drug discovery opportunities and translated to the development of BP genetic risk scores (GRSs), facilitating population disease risk stratification. Comparing highest and lowest risk groups shows differences of 12.9 mm Hg in systolic-BP with significant differences in risk of hypertension, stroke, cardiovascular disease and myocardial infarction. GRSs are also being trialled in antihypertensive drug responses. Drug targets identified include NPR1, for which an agonist drug is currently in clinical trials. Identification of variants at the PHACTR1 locus provided insights into regulation of EDN1 in the endothelin pathway, which is aiding the development of endothelin receptor EDNRA antagonists. Drug re-purposing opportunities, including SLC5A1 and canagliflozin (a type-2 diabetes drug), are also being identified. In this review, we present key studies from the past, highlight current avenues of research and look to the future focusing on gene discovery, epigenetics, gene-environment interactions, GRSs and drug discovery. We evaluate limitations affecting BP genetics, including ancestry bias and discuss streamlining of drug target discovery and applications for treating and preventing hypertension, which will contribute to tailored precision medicine for patients.

A genome-wide association study identifies a novel candidate locus at the DLGAP1 gene with susceptibility to resistant hypertension in the Japanese population

Numerous genetic variants associated with hypertension and blood pressure are known, but there is a paucity of evidence from genetic studies of resistant hypertension, especially in Asian populations. To identify novel genetic loci associated with resistant hypertension in the Japanese population, we conducted a genome-wide association study with 2705 resistant hypertension cases and 21,296 mild hypertension controls, all from BioBank Japan. We identified one novel susceptibility candidate locus, rs1442386 on chromosome 18p11.3 (DLGAP1), achieving genome-wide significance (odds ratio (95% CI) = 0.85 (0.81–0.90), P = 3.75 × 10⁻⁸) and 18 loci showing suggestive association, including rs62525059 of 8q24.3 (CYP11B2) and rs3774427 of 3p21.1 (CACNA1D). We further detected biological processes associated with resistant hypertension, including chemical synaptic transmission, regulation of transmembrane transport, neuron development and neurological system processes, highlighting the importance of the nervous system. This study provides insights into the etiology of resistant hypertension in the Japanese population.