RAS Genetic Variants in Interaction with ACE Inhibitors Drugs Influences Essential Hypertension Control

Sensitive detection of single-nucleotide polymorphisms by conjugated polymers for personalized treatment of hypertension

Genetic variants among individuals have been associated with ineffective control of hypertension. Previous work has shown that hypertension has a polygenic nature, and interactions between these loci have been associated with variations in drug response. Rapid detection of multiple genetic loci with high sensitivity and specificity is needed for the effective implementation of personalized medicine for the treatment of hypertension. Here, we used a cationic conjugated polymer (CCP)-based multistep fluorescence resonance energy transfer (MS-FRET) technique to qualitatively analyze DNA genotypes associated with hypertension in the Chinese population. Assessment of 10 genetic loci using this technique successfully identified known hypertensive risk alleles in a retrospective study of whole-blood samples from 150 patients hospitalized with hypertension. We then applied our detection method in a prospective clinical trial of 100 patients with essential hypertension and found that personalized treatment of patients with hypertension based on results from the MS-FRET technique could effectively improve blood pressure control rate (94.0% versus 54.0%) and shorten the time duration to controlling blood pressure (4.06 ± 2.10 versus 5.82 ± 1.84 days) as compared with conventional treatment. These results suggest that CCP-based MS-FRET genetic variant detection may assist clinicians in rapid and accurate classification of risk in patients with hypertension and improve treatment outcomes.

Tetra-ARMS-PCR assay development for genotyping of AGT rs699 T/C polymorphism, its comparison with PCR-RFLP and application in a case-control association study of cardiovascular disease patients

Genetic variations in the AGT gene play a significant role in controlling the plasma concentration of angiotensinogen (precursor protein of bioactive octapeptide angiotensin II) and the efficacy of antihypertensive drugs. In the current study, Tetra-Amplification Refractory Mutation System-Polymerase Chain Reaction (T-ARMS-PCR) was developed for genotyping of AGT rs699 T/C polymorphism and validated through Sanger DNA sequencing. Its efficiency was also tested using 474 human DNA samples [control, n = 181; cardiovascular disease (CVD) patients, n = 293]. Results showed that T-ARMS-PCR is superior to the commonly used PCR-Restriction Fragment Length Polymorphism (PCR-RFLP). Statistical analysis revealed that the AGT rs699 CC genotype is more prevalent in the CVD patient group (37% vs. 28%) and AGT rs699 C allele and CC genotype increased the risk of CVD by 1.4 and 1.9 fold, respectively. In summary, T-ARMS-PCR is the most suitable approach for quick and efficient genotyping of AGT rs699 T/C polymorphism in a large population in resource-limited countries, Furthermore, AGT rs699 T/C polymorphism is associated with the risk of CVD in the Punjabi Pakistani population.

Association between Interactions among ACE Gene Polymorphisms and Essential Hypertension in Patients in the Hefei Region, Anhui, China

Objective

Essential hypertension (EH) is a common cardiovascular disease that endangers human health. Its pathogenesis is complex and has not been fully elucidated. We explore the association between EH and interactions among polymorphisms of the angiotensin converting enzyme (ACE) gene in the Hefei region, Anhui, China.

Methods

A total of 500 participants (400 hypertensive and 100 normotensive) were included in this study. The polymorphisms were detected via improved multiple ligase detection reaction (iMLDR). To improve the accuracy of prediction, multifactor dimensionality reduction (MDR) was used to analyze the overall effect of interactions among seven loci on the incidence of EH.

Results

The frequencies of polymorphisms in the ACE genes rs12709426, rs4291, rs4309, rs4331, rs4343, rs4459609, and rs4461142 in the EH group were not statistically significantly different from those in the control group. We also found that the single nucleotide polymorphism (SNP) rs12709426 only had a homozygous AA genotype and no polymorphisms. There were no differences in the frequency of genetic polymorphisms between the EH and control groups. The best model explaining the EH group was the combined effect of ACE genes rs4291, rs4309, and rs4461142.

Conclusion

There is an interaction effect among ACE gene loci in EH patients in Hefei region, Anhui, China. Also, the ACE gene SNP rs12709426 only has a homozygous AA genotype and does not show an association with EH.

The Association of Angiotensin-converting Enzyme I/D and Angiotensinogen M235T Polymorphism Genes with Essential Hypertension: A Meta-analysis

Objective:  Essential or primary hypertension in developing countries has become a major problem. Recent hypertension-related research has revealed susceptibility genes in genome-wide association studies. Several studies have associated angiotensin converting enzyme (ACE) I/D and angiotensinogen (AGT) M235T polymorphisms with essential hypertension, but results have been inconsistent. This meta-analysis aimed to clarify the association of AGT and ACE polymorphisms with the risk of primary hypertension. Methods: PubMed, Embase database, Medline, Goggle Scholar, Scopus.com, as well portal Garuda (www.garuda.ristekdikti.go.id) and Cochrane were used to retrieve all publications from 2006-2020 relating risk factors for hypertension with ACE I/D and AGT M235T polymorphisms. The meta-analysis was conducted from January –April 2020. All association studies were identified and data extracted from each study. Revman 5.3 software was used for meta-analysis to estimate odds ratios (OR) after extracting data and evaluating the quality of the enrolled studies. Results: A total of 27 studies (totaling 5,105 patients and 5196 controls) were identified. The overall effect suggested ACE I/D was significantly associated with primary hypertension (OR: 95%CI=1.51[1.29-1.77], p=0.004). There was no association between AGT M235T with risk of essential hypertension. Conclusion: This meta-analysis found significant association between ACE I/D gene polymorphisms with primary hypertension susceptibility. However, the AGT M235T gene had no association with the risk of primary hypertension. The Adrenoreceptor-beta/Renin Angiotensin System (ADRB/RAS) A allele should be considered a risk factor for essential hypertension.  

Association between angiotensin converting enzyme gene polymorphism and essential hypertension: A systematic review and meta-analysis

Background:

The current meta-analytic study explored the relation between ACE gene insertion/deletion (I/D), and the risk of EH by reviewing relevant trials so as to determine the association between Angiotensin Converting Enzyme (ACE) gene polymorphism and essential hypertension (EH) susceptibility.

Methods:

Relevant studies published before May 2019 were collected from the PubMed, Cochrane, Embase, CNKI, VANFUN, and VIP databases.

Results:

Fifty-seven studies involving a total of 32,862 patients were included. These studies found that ACE gene D allele was associated with higher EH susceptibility in allelic model, homozygote model, dominant model, and regressive model, and that Asian population with ACE gene D allele showed a higher EH susceptibility in all these models. Moreover, ACE gene D allele was found closely related to a higher EH susceptibility in the subgroups of HWE, NO HWE, Caucasian population, and Mixed population, with the majority being males in allelic model, homozygote model, and regressive model and the majority being females in allelic model.

Conclusion:

ACE gene D allele is associated with an overall higher EH susceptibility, which is confirmed in the subgroup analysis of Asian population, HWE, NO HWE, Caucasian population, and Mixed population.

miR-34a targets PAI-1 to regulate urinary microalbumin and renal function in hypertensive mice

Background

The aim of the study is to investigate the effects of miR-34a targeted at PAI-1 on urinary microalbumin and renal function in hypertensive mice.

Methods

Twenty specific-pathogen-free (SPF) BPN/3J mice were selected in normal group, and 120 SPF BPH/2J mice were evenly divided into model group, negative control group, miR-34a mimic group, miR-34a inhibitor group, Si-PAI-1 group, and miR-34a inhibitor + Si-PAI-1 group. qRT-PCR was used to detect the expression of miR-34a and PAI-1 mRNA. The protein expressions of PAI-1, angiotensin-converting enzyme (ACE) and ACE2 were detected by Western blot. Serum levels of AngII and Ang1-7 were detected by ELISA.

Results

miR-34a negatively regulated the expression of PAI-1. Compared with the normal group, mice in the other groups had significantly lower body weight, increased systolic blood pressure and 24-h urinary microalbumin content, decreased miR-34a expression, superoxide dismutase (SOD) and nitric oxide (NO) content, and ACE2 protein expression, and increased PAI-1 expression, serum creatinine (Scr), blood urea nitrogen (BUN) malondialdehyde (MDA), AngII and Ang1-7 levels, and ACE protein expression (all P < 0.05). Compared with the model group, mice in the miR-34a mimic group and Si-PAI-1 group had no significant changes in body weight (all P > 0.05), while they had significantly lower systolic blood pressure and 24-h urinary microalbumin content, increased SOD and NO levels and ACE2 protein expression, and decreased PAI-1 expression, Scr, BUN, MDA, AngII and Ang1-7 levels, and ACE protein expression (all P < 0.05). Compared with the miR-34a inhibitor group, symptoms in miR-34a inhibitor + Si-PAI-1 group were significantly improved (all P < 0.05).

Conclusions

miR-34a can inhibit the expression of PAI-1, thereby reducing urinary microalbumin content in hypertensive mice and protecting their renal function.

The Association Between Selected Molecular Biomarkers and Ambulatory Blood Pressure Patterns in African Chronic Kidney Disease and Hypertensive Patients Compared With Normotensive Controls: Protocol for a Longitudinal Study

Background

Chronic kidney disease (CKD) is a burgeoning epidemic in sub-Saharan Africa. Abnormal blood pressure variations are prevalent in CKD and potentiate the risk of cardiovascular morbidity and mortality. Certain genetic variants (angiotensin II receptor type 1 1166 A>C and angiotensin-converting enzyme insertion and deletion polymorphisms) and biomarkers such as interleukin–6, tumor necrosis factor, soluble (s) E-selectin, homocysteine, and highly sensitive C-reactive protein have been shown to affect blood pressure variability among non-African CKD, hypertensive. and nonhypertensive CKD population. However, the contributions of the pattern, genetic, and environmental determinants of ambulatory blood pressure in African CKD have not been characterized. Understanding these interactions may help to develop interventions to prevent major cardiovascular events among people with CKD.

Objective

The overarching objective of this study is to identify, document, and develop approaches to address related phenomic, genetic, and environmental determinants of ambulatory blood pressure patterns in African CKD and non-CKD hypertensive patients compared with normotensive controls.

Methods

This is a longitudinal short-term follow-up study of 200 adult subjects with CKD and 200 each of age-matched hypertensives without CKD and apparently healthy controls. Demographic information, detailed clinical profile, electrocardiography, echocardiography, and 24-hr ambulatory blood pressure measurements will be obtained. Blood samples will be collected to determine albumin-creatinine ratio, fasting plasma glucose, lipid profile, electrolytes, urea and creatinine, C-reactive protein, serum homocysteine, fibroblast growth factor–23, and complete blood count, while 2 mL blood aliquot will be collected in EDTA (ethylenediaminetetraacetic acid) tubes and mixed using an electronic rolling system to prevent blood clots and subsequently used for DNA extraction and genetic analysis.

Results

A total of 239 participants have been recruited so far, and it is expected that the recruitment phase will be complete in June 2020. The follow-up phase will continue with data analysis and publications of results.

Conclusions

This study will help stratify Nigerian CKD patients phenotypically and genotypically in terms of their blood pressure variations with implications for targeted interventions and timing of medications to improve prognosis.

International Registered Report Identifier (IRRID)

DERR1-10.2196/14820

Pharmacogenomics And Hypertension: Current Insights

Hypertension is a multifactorial disease that affects approximately one billion subjects worldwide and is a major risk factor associated with cardiovascular events, including coronary heart disease and cerebrovascular accidents. Therefore, adequate blood pressure control is important to prevent these events, reducing premature mortality and disability. However, only one third of patients have the effective control of blood pressure, despite several classes of antihypertensive drugs available. These disappointing outcomes may be at least in part explained by interpatient variability in drug response due to genetic polymorphisms. To address the effects of genetic polymorphisms on blood pressure responses to the antihypertensive drug classes, studies have applied candidate genes and genome wide approaches. More recently, a third approach that considers gene-gene interactions has also been applied in hypertension pharmacogenomics. In this article, we carried out a comprehensive review of recent findings on the pharmacogenomics of antihypertensive drugs, including diuretics, β-blockers, angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers, and calcium channel blockers. We also discuss the limitations and inconsistences that have been found in hypertension pharmacogenomics and the challenges to implement this valuable approach in clinical practice.

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.

Hypertension: a new treatment for an old disease? Targeting the immune system

Arterial hypertension represents a serious public health problem, being a major cause of morbidity and mortality worldwide. The availability of many antihypertensive therapeutic strategies still fails to adequately treat around 20% of hypertensive patients, who are considered resistant to conventional treatment. In the pathogenesis of hypertension, immune system mechanisms are activated and both the innate and adaptive immune responses play a crucial role. However, what, when and how the immune system is triggered during hypertension development is still largely undefined. In this context, this review highlights scientific advances in the manipulation of the immune system in order to attenuate hypertension and end-organ damage. Here, we discuss the potential use of immunosuppressants and immunomodulators as pharmacological tools to control the activation of the immune system, by non-specific and specific mechanisms, to treat hypertension and improve end-organ damage. Nevertheless, more clinical trials should be performed with these drugs to establish their therapeutic efficacy, safety and risk-benefit ratio in hypertensive conditions. LINKED ARTICLES: This article is part of a themed section on Immune Targets in Hypertension. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.12/issuetoc.

Association study of M235T and A-6G polymorphisms in angiotensinogen gene with risk of developing preeclampsia in Iranian population

OBJECTIVE

Preeclampsia (PE) is a life-threatening complication of pregnancy that accounts for 12% of all maternal deaths worldwide. The aim of this study is to investigate the relationships between the polymorphisms of angiotensinogen (AGT) gene and preeclampsia.

MATERIAL AND METHODS

In this study, 240 unrelated preeclampsia patients and 178 normotensive women were examined. Genomic DNA was extracted then we assessed M235T(C/T) and A-6G polymorphisms of the AGT gene. Genotyping of M235T and A-6G polymorphisms were performed using SSP-PCR and MS-PCR, respectively.

RESULTS

A significant protective association was observed between A-6G G allele, A-6G A/G heterozygote genotype (OR = 0.6, p = 0.007 and OR = 0.6, p = 0.04) against PE. Furthermore, it was shown that two copies of A-6G A allele would increase PE risk (OR: 0.62, p = 0.04). Our results did not show a significant association for M235T polymorphism and PE. However, the combinations of A-6G A/A genotype and M235T T/C genotype (OR = 0.4, p = 0.02) and also A-6G A/G genotype and M235T T/C genotype (OR = 0.5, p = 0.04) in controls represented a significant protective association against PE.

CONCLUSION

According to the existence of significant correlation between two candidate polymorphisms, A-6G and M235T polymorphisms, with PE disease in our study, they may be considered as valuable factors in susceptibility to PE disease in Iranian women.

Identification and Molecular Docking Study of a Novel Angiotensin-I Converting Enzyme Inhibitory Peptide Derived from Enzymatic Hydrolysates of Cyclina sinensis

Marine-derived angiotensin-I converting enzyme (ACE) inhibitory peptides have shown potent ACE inhibitory activity with no side effects. In this study, we reported the discovery of a novel ACE-inhibitory peptide derived from trypsin hydrolysates of Cyclina sinensis (CSH). CSH was separated into four different molecular weight (MW) fractions by ultrafiltration. Fraction CSH-I showed the strongest ACE inhibitory activity. A peptide was purified by fast protein liquid chromatography (FPLC) and reversed-phase high-performance liquid chromatography (RP-HPLC) and its sequence was determined to be Trp-Pro-Met-Gly-Phe (WPMGF, 636.75 Da). The Lineweaver-Burk plot showed that WPMGF was a competitive inhibitor of ACE. WPMGF showed a significant degree of stability at varying temperatures, pH, and simulated gastrointestinal environment conditions. We investigated the interaction between this pentapeptide and ACE by means of a flexible molecular docking tool. The results revealed that effective interaction between WPMGF and ACE occurred mainly through hydrogen bonding, hydrophobic interactions, and coordination bonds between WPMGF and Zn(II). In conclusion, our study indicates that a purified extract derived from Cyclina sinensis or the WPMGF peptide could potentially be incorporated in antihypertensive functional foods or dietary supplements.