An NPPB Promoter Polymorphism Associated With Elevated N-Terminal pro-B-Type Natriuretic Peptide and Lower Blood Pressure, Hypertension, and Mortality

Sex-based differences in metabolic protection by the ANP genetic variant rs5068 in the general population

Atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) are produced in the heart and secreted into the circulation. As hormones, both peptides activate the guanylyl cyclase receptor A (GC-A), playing a role in blood pressure (BP) regulation. A significant role for ANP and BNP includes favorable actions in metabolic homeostasis. Sex-based high prevalence of risk factors for cardiovascular disease in males compared with females is well established, but sex-based differences on cardiometabolic protection have not been investigated in relation to ANP (NPPA) and BNP (NPPB) gene variants. We included 1,146 subjects in the general population from Olmsted County, Minnesota. Subjects were genotyped for the ANP gene variant rs5068 and BNP gene variant rs198389. Cardiometabolic parameters and medical records were reviewed. In the presence of the minor allele of rs5068, diastolic BP, creatinine, body mass index (BMI), waist measurement, insulin, and prevalence of obesity and metabolic syndrome were lower, whereas HDL was higher in males with only trends observed in females. We observed no associations of the minor allele with echocardiographic parameters in either males or females. Regarding rs198389 genotype, the minor allele was not associated with any BP, metabolic, renal, or echocardiographic parameters in either sex. In the general community, the minor allele of the ANP gene variant rs5068 is associated with a favorable metabolic phenotype in males. No associations were observed with the BNP gene variant rs198389. These studies support a protective role of the ANP pathway on metabolic function and underscore the importance of sex in relationship to natriuretic peptide responses.NEW & NOTEWORTHY Males are characterized by lower ANP and BNP with greater prevalence of cardiometabolic disease. The ANP genetic variant rs5068 was associated with less metabolic dysfunction in males, whereas no metabolic profile was related to the BNP genetic variant rs198389 in the general population. ANP may play a more biological role in metabolic homeostasis compared with BNP in the general population with greater physiological metabolic actions in males compared with females.

The underlying mechanism of transcription factor IRF1, PRDM1, and ZNF263 involved in the regulation of NPPB rs3753581 on pulse pressure hypertension

To investigate the correlation between NPPB gene variants and pulse pressure hypertension and the underlying regulatory mechanisms and try to confirm that NPPB may be a potential molecular target of gene therapy for pulse pressure hypertension. A total of 898 participants were recruited from the First Affiliated Hospital of Fujian Medical University and the plasmids with differential expression of NPPB were constructed. Genotype distribution of NPPB(rs3753581, rs198388, and rs198389)was analyzed and the expression of N-terminal pro-B-type natriuretic peptide(NT-proBNP) and renin-angiotensin -aldosterone system(RAAS) related indicators were identified in the groups studied. According to a genotype analysis, there was a significant difference in the genotype distribution of NPPB rs3753581 among the groups (P=0.034). In logistic regression analysis, NPPB rs3753581 TT was associated with a 1.8-fold greater risk of pulse pressure hypertension than NPPB rs3753581 GG (odds ratio = 1.801; 95% confidence interval: 1.070-3.032; P=0.027). The expression of NT-proBNP and RAAS related indicators in clinical and laboratory samples showed striking differences. The activity of firefly and Renilla luciferase in pGL-3-NPPB-luc (-1299G) was higher than pGL-3-NPPBmut-luc(-1299T)(P<0.05). The binding of NPPB gene promoter rs3753581 (-1299G) with transcription factors IRF1, PRDM1, and ZNF263 was predicted and validated by the bioinformatics software TESS and chromatin immunoprecipitation(P<0.05). NPPB rs3753581 was correlated with genetic susceptibility to pulse pressure hypertension and the transcription factors IRF1, PRDM1, and ZNF263 may be involved in the regulation of NPPB rs3753581 promoter (-1299G) on the expression of NT-proBNP/RAAS.

Phenomapping in heart failure with preserved ejection fraction: insights, limitations, and future directions

Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous entity with complex pathophysiology and manifestations. Phenomapping is the process of applying statistical learning techniques to patient data to identify distinct subgroups based on patterns in the data. Phenomapping has emerged as a technique with potential to improve the understanding of different HFpEF phenotypes. Phenomapping efforts have been increasing in HFpEF over the past several years using a variety of data sources, clinical variables, and statistical techniques. This review summarizes methodologies and key takeaways from these studies, including consistent discriminating factors and conserved HFpEF phenotypes. We argue that phenomapping results to date have had limited implications for clinical care and clinical trials, given that the phenotypes, as currently described, are not reliably identified in each study population and may have significant overlap. We review the inherent limitations of aggregating and utilizing phenomapping results. Lastly, we discuss potential future directions, including using phenomapping to optimize the likelihood of clinical trial success or to drive discovery in mechanisms of the disease process of HFpEF.

The Predictive Value of A, B, and C-Type Natriuretic Peptides in People at Risk of Heart Disease: Protocol for a Longitudinal Observational Study

BACKGROUND

Heart disease and stroke are major and often unheralded causes of serious morbidity and premature death in middle age. Early detection of those most at risk is an urgent unmet need for instituting preventative measures. In an earlier community study (Canterbury Health, Ageing and Life Course [CHALICE]) of healthy people aged 50 years, contrary to previous reports, low levels of the heart hormone B-type natriuretic peptide (BNP) were associated with reduced measures of heart function and higher markers of vascular risk. A specific gene variant (rs198358) was found to be an independent contributor to higher BNP levels. A closely related vascular hormone (C-type natriuretic peptide [CNP]) showed opposite associations-higher levels were correlated with higher vascular risk and reduced cardiac function. To determine whether these novel findings predict serious heart or vascular disease in later life, this proposal re-examines the same CHALICE participants 15 years later.

OBJECTIVE

The primary objective is to determine the predictive value of (1) low plasma concentrations of the circulating cardiac hormones (atrial natriuretic peptide [ANP] and BNP) and (2) high levels of the vascular hormone CNP at age 50 years in detecting impaired cardiac and vascular function 15 years later. Secondary objectives are to determine specific associations of individual analytes (ANP, BNP, CNP, cyclic guanosine monophosphate [cGMP]) with echo-derived changes in cardiac performance at ages 50 years and 65 years.

METHODS

All of the 348 participants (205/348, 58.9% female; 53/348, 15.2% Māori or Pacifica ethnicity) participating in the original CHALICE study-free of history of heart or renal disease at age 50 years and who consented to further study-will be contacted, recruited, and restudied as previously described. Data will include intervening health history, physical examination, heart function (speckle-tracking echocardiography), vascular status (carotid intimal thickness), and genetic status (genome-wide genotyping). Laboratory measures will include fasting blood sampling and routine biochemistry, ANP, BNP, CNP, their downstream effector (cGMP), and their bio-inactive products. Humoral metabolic-cardiovascular risk factors will be measured after an overnight fast. Primary outcomes will be analyzed using multiple linear regression.

RESULTS

The study will commence in 2022 and be completed in 2024.

CONCLUSIONS

Proving our hypothesis-that low BNP and high CNP at any age in healthy people predict premature aging of heart and blood vessels, respectively-opens the way to early detection and improved outcomes for those most at risk. Confirmation of our hypotheses would improve current methods of screening and, in appropriate cases, enable interventions aimed at increasing natriuretic hormones and reducing risk of serious cardiovascular complications using drugs already available. Such advances in detection, and from interventional corrections, have the potential to not only improve health in the community but also reduce the high costs inevitably associated with heart failure.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/37011.

Role of Cardiac Natriuretic Peptides in Heart Structure and Function

Cardiac natriuretic peptides (NPs), atrial NP (ANP) and B-type NP (BNP) are true hormones produced and released by cardiomyocytes, exerting several systemic effects. Together with C-type NP (CNP), mainly expressed by endothelial cells, they also exert several paracrine and autocrine activities on the heart itself, contributing to cardiovascular (CV) health. In addition to their natriuretic, vasorelaxant, metabolic and antiproliferative systemic properties, NPs prevent cardiac hypertrophy, fibrosis, arrhythmias and cardiomyopathies, counteracting the development and progression of heart failure (HF). Moreover, recent studies revealed that a protein structurally similar to NPs mainly produced by skeletal muscles and osteoblasts called musclin/osteocrin is able to interact with the NPs clearance receptor, attenuating cardiac dysfunction and myocardial fibrosis and promoting heart protection during pathological overload. This narrative review is focused on the direct activities of this molecule family on the heart, reporting both experimental and human studies that are clinically relevant for physicians.

Developmental Toxicity of Surface-Modified Gold Nanorods in the Zebrafish Model

BACKGROUND

nanotechnology is one of the fastest-growing areas, and it is expected to have a substantial economic and social impact in the upcoming years. Gold particles (AuNPs) offer an opportunity for wide-ranging applications in diverse fields such as biomedicine, catalysis, and electronics, making them the focus of great attention and in parallel necessitating a thorough evaluation of their risk for humans and ecosystems. Accordingly, this study aims to evaluate the acute and developmental toxicity of surface-modified gold nanorods (AuNRs), on zebrafish (Danio rerio) early life stages.

METHODS

in this study, zebrafish embryos were exposed to surface-modified AuNRs at concentrations ranging from 1 to 20 μg/mL. Lethality and developmental endpoints such as hatching, tail flicking, and developmental delays were assessed until 96 h post-fertilization (hpf).

RESULTS

we found that AuNR treatment decreases the survival rate in embryos in a dose-dependent manner. Our data showed that AuNRs caused mortality with a calculated LC50 of EC_50,24hpf of AuNRs being 9.1 μg/mL, while a higher concentration of AuNRs was revealed to elicit developmental abnormalities. Moreover, exposure to high concentrations of the nanorods significantly decreased locomotion compared to untreated embryos and caused a decrease in all tested parameters for cardiac output and blood flow analyses, leading to significantly elevated expression levels of cardiac failure markers ANP/NPPA and BNP/NPPB.

CONCLUSIONS

our results revealed that AuNR treatment at the EC₅₀ induces apoptosis significantly through the P53, BAX/BCL-2, and CASPASE pathways as a suggested mechanism of action and toxicity modality.

Natriuretic peptide pathways in heart failure: further therapeutic possibilities

The discovery of the heart as an endocrine organ resulted in a remarkable recognition of the natriuretic peptide system (NPS). Specifically, research has established the production of atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) from the heart, which exert pleiotropic cardiovascular, endocrine, renal, and metabolic actions via the particulate guanylyl cyclase A receptor (GC-A) and the second messenger, cGMP. C-type natriuretic peptide (CNP) is produced in the endothelium and kidney and mediates important protective auto/paracrine actions via GC-B and cGMP. These actions, in part, participate in the efficacy of sacubitril/valsartan in heart failure (HF) due to the augmentation of the NPS. Here, we will review important insights into the biology of the NPS, the role of precision medicine, and focus on the phenotypes of human genetic variants of ANP and BNP in the general population and the relevance to HF. We will also provide an update of the existence of NP deficiency states, including in HF, which provide the rationale for further therapeutics for the NPS. Finally, we will review the field of peptide engineering and the development of novel designer NPs for the treatment of HF. Notably, the recent discovery of a first-in-class small molecule GC-A enhancer, which is orally deliverable, will be highlighted. These innovative designer NPs and small molecule possess enhanced and novel properties for the treatment of HF and cardiovascular diseases.

Sex and Race Differences in N-Terminal Pro-B-type Natriuretic Peptide Concentration and Absolute Risk of Heart Failure in the Community

Importance

Sex- and race-based differences in N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentrations are poorly understood. Clinical decisions are often informed by absolute-as opposed to relative-risk, but absolute risk of incident heart failure (HF) associated with NT-proBNP concentration across these important demographic categories is unclear.

Objective

To determine whether physiologic determinants of NT-proBNP concentrations account for sex and race differences, and to more uniformly predict HF risk using NT-proBNP in these demographic subgroups.

Design, Setting, and Participants

In the longitudinal Atherosclerosis Risk in Communities epidemiologic prospective community-based cohort study, the association of NT-proBNP concentration with relative and absolute risk of HF by sex- and race-based categories was assessed at study visit 2 (1990-1992) and study visit 5 (2011-2013) using Cox and Poisson regression. These data were analyzed from June 2018 to October 2021. The contribution of clinical, anthropometric, echocardiographic, and laboratory parameters to sex- and race-based differences in NT-proBNP concentration was assessed at visit 5 using linear regression. Participants included were free of HF in midlife (visit 2; a total of 12 750 participants) and late life (visit 5; a total of 5191 participants).

Exposures

NT-proBNP concentration.

Main Outcomes and Measures

Incident HF or death.

Results

Among the 5191 HF-free participants at visit 5, the mean (SD) age was 76.0 (5.2) years, 2104 (41%) were male, 1043 (20%) were Black, and the median (IQR) NT-proBNP concentration was 124 (64-239) pg/. In both midlife and late life, NT-proBNP concentration was lowest in Black men (median [IQR] concentration: visit 2, 30 [14-67] pg/mL; visit 5, 74 [34-153] pg/mL) and highest in White women (median [IQR] concentration: visit 2, 70 [42-111] pg/mL; visit, 5, 154 [82-268] pg/mL). Sex and race differences in NT-proBNP concentration persisted after accounting for age, income, education, area deprivation index, cardiovascular diseases, left ventricular structure (LV), LV function, LV wall stress, weight and fat mass, and estimated glomerular filtration rate. Substantial differences in the absolute risk of incident HF or death existed across the sex- and race-based categories at any NT-proBNP concentration (eg, 7-fold [rate ratio, 6.7; 95% CI, 4.6-9.9] and 3-fold [rate ratio, 2.7; 95% CI, 1.7-4.1] difference at visit 2 and visit 5, respectively, at guideline-recommended thresholds) with higher risk consistently observed among Black men and lower risk in White women. Results were replicated in a cohort of participants from the Cardiovascular Health Study.

Conclusions and Relevance

In this study, sex- and race-based differences in NT-proBNP persisted after accounting for known physiologic determinants. Absolute risk associated with a given value of NT-proBNP varied substantially by sex and race. Consideration of NT-proBNP values in the context of sex and race allows for more uniform prediction of absolute risk across important demographic subgroups.

DNA Methylation of the Natriuretic Peptide System Genes and Ischemic Stroke: Gene-Based and Gene Set Analyses

Background and Objectives

The natriuretic peptide (NP) system has been considered an important regulator for ischemic stroke (IS) with a limited clinical implication. A better understanding of the underlying molecular mechanisms is urgent. Here, we aimed to examine the role of DNA methylation of NP system genes in IS.

Methods

DNA methylation at promoter regions of 4 core NP system genes, e.g., CORIN, FURIN, NPPA, and NPPB, was measured by targeted bisulfite sequencing in 853 patients with IS and 918 controls. We first examined the association between DNA methylation at each single CpG and IS, followed by gene-based and gene set analyses to examine the joint associations of DNA methylation at multiple CpGs in a gene or all 4 genes as a pathway with IS.

Results

After control of covariates and multiple testing, DNA methylation at 19 of the 36 assayed CpGs was individually associated with IS at q < 0.05. Higher average methylation levels at the targeted regions of CORIN (odds ratio [OR] = 0.64, 95% confidence interval [CI]: 0.56–0.73), FURIN (OR = 0.78, 95% CI: 0.69–0.88), and NPPA (OR = 0.78, 95% CI: 0.69–0.88) were associated with a lower odds of IS (all q < 0.05). The truncated product method revealed the same gene-based associations (all q < 0.05) and found that DNA methylation at all 4 NP system genes together was jointly associated with IS (p = 0.0001).

Discussion

DNA methylation at NP system genes was downregulated in patients with IS. Our results may unravel a molecular mechanism underlying the regulating effect of the NP system on IS and highlight the relevance of testing the joint effect of multiple CpGs in the epigenetic analysis.

ASA Status, NPPA/NPPB Haplotype and Coronary Artery Disease Have an Impact on BNP/NT-proBNP Plasma Levels

Plasma concentrations of natriuretic peptides (NP) contribute to risk stratification and management of patients undergoing non-cardiac surgery. However, genetically determined variability in the levels of these biomarkers has been described previously. In the perioperative setting, genetic contribution to NP plasma level variability has not yet been determined. A cohort of 427 patients presenting for non-cardiac surgery was genotyped for single-nucleotide polymorphisms (SNPs) from the NPPA/NPPB locus. Haplotype population frequencies were estimated and adjusted haplotype trait associations for brain natriuretic peptide (BNP) and amino-terminal pro natriuretic peptide (NT-proBNP) were calculated. Five SNPs were included in the analysis. Compared to the reference haplotype TATAT (rs198358, rs5068, rs632793, rs198389, rs6676300), haplotype CACGC, with an estimated frequency of 4%, showed elevated BNP and NT-proBNP plasma concentrations by 44% and 94%, respectively. Haplotype CGCGC, with an estimated frequency of 9%, lowered NT-proBNP concentrations by 28%. ASA classification status III and IV, as well as coronary artery disease, were the strongest predictors of increased NP plasma levels. Inclusion of genetic information might improve perioperative risk stratification of patients based on adjusted thresholds of NP plasma levels.

Natriuretic Peptides and Blood Pressure Homeostasis: Implications for MANP, a Novel Guanylyl Cyclase a Receptor Activator for Hypertension

The heart serves as an endocrine organ producing the hormones atrial natriuretic peptide (ANP) and b-type natriuretic peptide (BNP) which via the guanylyl cyclase A (GC-A) receptor and the second messenger cGMP participate in blood pressure homeostasis under physiologic conditions. Genetic models of the ANP gene or the GCA receptor together with genomic medicine have solidified the concept that both cardiac hormones are fundamental for blood pressure homeostasis and when deficient or disrupted they may contribute to human hypertension. Advances in peptide engineering have led to novel peptide therapeutics including the ANP-analog MANP for human hypertension. Most importantly a first in human study of MANP in essential hypertension has demonstrated its unique properties of aldosterone suppression and blood pressure reduction. Physiology and pharmacology ultimately lead us to innovative peptide-based therapeutics to reduce the burden of cardiovascular disease.

Large-Scale Plasma Protein Profiling of Incident Myocardial Infarction, Ischemic Stroke, and Heart Failure

Background

We recently reported a link between plasma levels of 2 of 84 cardiovascular disease (CVD)–related proteins and the 3 major CVDs, myocardial infarction, ischemic stroke, and heart failure. The present study investigated whether measurement of almost 10 times the number of proteins could lead to discovery of additional risk markers for CVD.

Methods and Results

We measured 742 proteins using the proximity extension assay in 826 male participants of ULSAM (Uppsala Longitudinal Study of Adult Men) who were free from CVD at the age of 70 years. Cox proportional hazards models were adjusted for age only, as well as all traditional risk factors. During a 12.5‐year median follow‐up (maximal, 22.0 years), 283 incident CVDs occurred. Forty‐one proteins were significantly (false discovery rate <0.05) related to the combined end point of incident CVD, with N‐terminal pro–brain natriuretic peptide as the top finding, while 53 proteins were related to incident myocardial infarction. A total of 13 and 16 proteins were significantly related to incident ischemic stroke and heart failure, respectively. Growth differentiation factor 15, 4‐disulfide core domain protein 2, and kidney injury molecule were related to all of the 3 major CVD outcomes. A lasso selection of 11 proteins improved discrimination of incident CVD by 5.0% (P=0.0038).

Conclusions

Large‐scale proteomics seem useful for the discovery of new risk markers for CVD and to improve risk prediction in an elderly population of men. Further studies are needed to replicate the findings in independent samples of both men and women of different ages.

Impact of natriuretic peptide polymorphisms on diastolic and metabolic function in a populational cohort: insights from the STANISLAS cohort

AIMS

Elevated brain natriuretic peptide (BNP) and the N-terminal fragment of its pro-hormone (NT-proBNP) have become established biomarkers for heart failure and are associated with cardiovascular morbidity and mortality. Investigating sources of inter-individual heterogeneity, particularly genetic factors, could help better identify patients at risk of future cardiovascular disease. The aim of this study was to estimate the heritability of circulating NT-proBNP levels, to perform a genome-wide association study (GWAS) and gene-candidate analysis focused on NPPB-NPPA genes on these levels, and to examine their association with cardiovascular or metabolic outcomes.

METHODS AND RESULTS

A total of 1555 individuals from the STANISLAS study were included. The heritability of circulating NT-proBNP levels was estimated at 15%, with seven single nucleotide polymorphisms (SNPs) reaching the significant threshold in the GWAS. All above SNPs were located on the same gene cluster constituted of MTHFR, CLCN6, NPPA, NPPB, and C1orf167. NPPA gene expression was also associated with NT-proBNP levels. Moreover, six other SNPs from NPPA-NPPB genes were associated with diastolic function (lateral e' on echocardiography) and metabolic features (glycated haemoglobin).

CONCLUSIONS

The heritability of natriuretic peptides appears relatively low (15%) and mainly based on the same gene cluster constituted of MTHFR, CLCN6, NPPA, NPPB, and C1orf167. Natriuretic peptide polymorphisms are associated with natriuretic peptide levels and diastolic function. These results suggest that natriuretic peptide polymorphisms may have an impact in the early stages of cardiovascular and metabolic disease.

B-Type Natriuretic Peptide Is Associated with Indices of Left Ventricular Dysfunction in Healthy Subjects from the General Population: The Akershus Cardiac Examination 1950 Study

BACKGROUND

Concentrations of B-type natriuretic peptide (BNP) reflect myocardial distension and stress, and are associated with poor prognosis in patients with cardiovascular disease. Accordingly, we hypothesized that concentrations of BNP would be associated with indices of adverse left ventricular (LV) remodeling and early stages of LV systolic and diastolic dysfunction in healthy participants from the general population.

METHODS

We measured BNP in 1757 women and 1677 men free from known coronary heart disease participating in the prospective observational Akershus Cardiac Examination 1950 Study. All study participants underwent extensive cardiovascular phenotyping at baseline, including detailed echocardiography with assessment of indexed LV mass (LVMI), diastolic [tissue Doppler e', E/e' ratio, indexed left atrial volume (LAVI), maximal tricuspid regurgitation velocity (TRVmax), and E/A ratio], and systolic [global longitudinal strain (GLS) and LV ejection fraction (LVEF)] function.

RESULTS

Study participants with the highest BNP concentrations had higher GLS, LVMI, e', E/e' ratio, LAVI, TRVmax, and E/A ratio. In adjusted analyses, both GLS and LVEF exhibited significant nonlinear associations with BNP, with reduced LV systolic function observed in both the low and high concentration range of BNP.

CONCLUSIONS

In healthy participants recruited from the general population, concentrations of BNP exhibit nonlinear associations with LV systolic function, and both low and high concentrations are associated with reduced LV systolic function. This supports the notion that natriuretic peptides are beneficial and elicit cardioprotective effects, and may have important implications for the interpretation of BNP measurements in the general population.

Identification of candidate biomarkers and therapeutic agents for heart failure by bioinformatics analysis

INTRODUCTION

Heart failure (HF) is a heterogeneous clinical syndrome and affects millions of people all over the world. HF occurs when the cardiac overload and injury, which is a worldwide complaint. The aim of this study was to screen and verify hub genes involved in developmental HF as well as to explore active drug molecules.

METHODS

The expression profiling by high throughput sequencing of GSE141910 dataset was downloaded from the Gene Expression Omnibus (GEO) database, which contained 366 samples, including 200 heart failure samples and 166 non heart failure samples. The raw data was integrated to find differentially expressed genes (DEGs) and were further analyzed with bioinformatics analysis. Gene ontology (GO) and REACTOME enrichment analyses were performed via ToppGene; protein-protein interaction (PPI) networks of the DEGs was constructed based on data from the HiPPIE interactome database; modules analysis was performed; target gene-miRNA regulatory network and target gene-TF regulatory network were constructed and analyzed; hub genes were validated; molecular docking studies was performed.

RESULTS

A total of 881 DEGs, including 442 up regulated genes and 439 down regulated genes were observed. Most of the DEGs were significantly enriched in biological adhesion, extracellular matrix, signaling receptor binding, secretion, intrinsic component of plasma membrane, signaling receptor activity, extracellular matrix organization and neutrophil degranulation. The top hub genes ESR1, PYHIN1, PPP2R2B, LCK, TP63, PCLAF, CFTR, TK1, ECT2 and FKBP5 were identified from the PPI network. Module analysis revealed that HF was associated with adaptive immune system and neutrophil degranulation. The target genes, miRNAs and TFs were identified from the target gene-miRNA regulatory network and target gene-TF regulatory network. Furthermore, receiver operating characteristic (ROC) curve analysis and RT-PCR analysis revealed that ESR1, PYHIN1, PPP2R2B, LCK, TP63, PCLAF, CFTR, TK1, ECT2 and FKBP5 might serve as prognostic, diagnostic biomarkers and therapeutic target for HF. The predicted targets of these active molecules were then confirmed.

CONCLUSION

The current investigation identified a series of key genes and pathways that might be involved in the progression of HF, providing a new understanding of the underlying molecular mechanisms of HF.

STOP-HF Trial: Higher Endogenous BNP and Cardiovascular Protection in Subjects at Risk for Heart Failure

•

Among subjects at risk for heart failure (Stage A and B), the minor C allele of the B-type natriuretic peptide (BNP) genetic variant rs198389 is associated with higher circulating levels of BNP.

•

Rs198389 C allele is also associated with lower risk of hypertension, new onset of left ventricular systolic dysfunction, and major adverse cardiovascular events.

•

These data support the role of BNP genetic testing and BNP-based therapy for the prevention of heart failure.

B-type natriuretic peptide (BNP) possesses blood-pressure–lowering, antifibrotic, and aldosterone-suppressing properties. In Stage A and B heart failure, the carriers of the minor C allele of the BNP genetic variant rs198389 have higher circulating levels of BNP and are at decreased risk of hypertension, new-onset left ventricular systolic dysfunction, and hospitalization for major adverse cardiovascular events. Future studies are warranted to investigate the role of BNP genetic testing and BNP-based therapy in the prevention of heart failure.

Plasma Protein Profile of Incident Myocardial Infarction, Ischemic Stroke, and Heart Failure in 2 Cohorts

Background The aim is to study common etiological pathways for 3 major cardiovascular diseases (CVD), as reflected in multiple proteins. Methods and Results Eighty-four proteins were measured using the proximity extension technique in 870 participants in the PIVUS (Prospective Investigation of Uppsala Seniors Study) cohort on 3 occasions (age 70, 75, and 80 years). The sample was followed for incident myocardial infarction, ischemic stroke or heart failure. The same proteins were measured in an independent validation sample, the ULSAM (Uppsala Longitudinal Study of Adult Men) cohort in 595 participants at age 77. During a follow-up of up to 15 years in PIVUS and 9 years in ULSAM, 222 and 167 individuals experienced a CVD. Examining associations with the 3 outcomes separately in a meta-analysis of the 2 cohorts, 6 proteins were related to incident myocardial infarction, 25 to heart failure, and 8 proteins to ischemic stroke following adjustment for traditional risk factors. Growth differentiation factor 15 and tumor necrosis factor-related apoptosis-inducing ligand receptor 2 were related to all 3 CVDs. Including estimated glomerular filtration rate in the models attenuated some of these relationships. Fifteen proteins were related to a composite of all 3 CVDs using a discovery/validation approach when adjusting for traditional risk factors. A selection of 7 proteins by lasso in PIVUS improved discrimination of incident CVD by 7.3% compared with traditional risk factors in ULSAM. Conclusions We discovered and validated associations of multiple proteins with incident CVD. Only a few proteins were associated with all 3 diseases: myocardial infarction, ischemic stroke, and heart failure.

A robust machine learning framework to identify signatures for frailty: a nested case-control study in four aging European cohorts

Phenotype-specific omic expression patterns in people with frailty could provide invaluable insight into the underlying multi-systemic pathological processes and targets for intervention. Classical approaches to frailty have not considered the potential for different frailty phenotypes. We characterized associations between frailty (with/without disability) and sets of omic factors (genomic, proteomic, and metabolomic) plus markers measured in routine geriatric care. This study was a prevalent case control using stored biospecimens (urine, whole blood, cells, plasma, and serum) from 1522 individuals (identified as robust (R), pre-frail (P), or frail (F)] from the Toledo Study of Healthy Aging (R=178/P=184/F=109), 3 City Bordeaux (111/269/100), Aging Multidisciplinary Investigation (157/79/54) and InCHIANTI (106/98/77) cohorts. The analysis included over 35,000 omic and routine laboratory variables from robust and frail or pre-frail (with/without disability) individuals using a machine learning framework. We identified three protective biomarkers, vitamin D3 (OR: 0.81 [95% CI: 0.68-0.98]), lutein zeaxanthin (OR: 0.82 [95% CI: 0.70-0.97]), and miRNA125b-5p (OR: 0.73, [95% CI: 0.56-0.97]) and one risk biomarker, cardiac troponin T (OR: 1.25 [95% CI: 1.23-1.27]). Excluding individuals with a disability, one protective biomarker was identified, miR125b-5p (OR: 0.85, [95% CI: 0.81-0.88]). Three risks of frailty biomarkers were detected: pro-BNP (OR: 1.47 [95% CI: 1.27-1.7]), cardiac troponin T (OR: 1.29 [95% CI: 1.21-1.38]), and sRAGE (OR: 1.26 [95% CI: 1.01-1.57]). Three key frailty biomarkers demonstrated a statistical association with frailty (oxidative stress, vitamin D, and cardiovascular system) with relationship patterns differing depending on the presence or absence of a disability.

Biomarkers for the diagnosis and management of heart failure

Heart failure (HF) is a significant cause of morbidity and mortality worldwide. Circulating biomarkers reflecting pathophysiological pathways involved in HF development and progression may assist clinicians in early diagnosis and management of HF patients. Natriuretic peptides (NPs) are cardioprotective hormones released by cardiomyocytes in response to pressure or volume overload. The roles of B-type NP (BNP) and N-terminal pro-B-type NP (NT-proBNP) for diagnosis and risk stratification in HF have been extensively demonstrated, and these biomarkers are emerging tools for population screening and as guides to the start of treatment in subclinical HF. On the contrary, conflicting evidence exists on the role of NPs as a guide to HF therapy. Among the other biomarkers, high-sensitivity troponins and soluble suppression of tumorigenesis-2 are the most promising biomarkers for risk stratification, with independent value to NPs. Other biomarkers evaluated as predictors of adverse outcome are galectin-3, growth differentiation factor 15, mid-regional pro-adrenomedullin, and makers of renal dysfunction. Multi-marker scores and genomic, transcriptomic, proteomic, and metabolomic analyses could further refine HF management.

Genetic association analysis of the cardiovascular biomarker: N-terminal fragment of pro-B-type natriuretic peptide (NT-proBNP)

BACKGROUND

NT-proBNP is a biomarker of cardiovascular disease (CVD). Little is known about the heritability and genetic variants associated with NT-proBNP. Therefore, we estimated the heritability of and examined genetic associations of SNPs in the BNP gene region with circulating NT-proBNP and prevalent CVD in 4,331 participants from the Long Life Family Study (LLFS).

METHODS AND RESULTS

Genotypes of 10 SNPs from the NPPB and NPPA regions that encode BNP and A-type natriuretic peptide, respectively, were tested for association with NT-proBNP and prevalent cardiovascular disease and risk factors. We performed analyses using the Sequential Oligogenic Linkage Analysis (SOLAR) program to account for family relatedness, and adjusted all models for age, sex, and field center. The mean age of the LLFS was 69.8 years (range 24-110) with 55.4% females. NT-proBNP was significantly heritable (h2 = 0.21; P = 4x10-14), and the minor alleles of rs632793 (p<0.001) and rs41300100 (p = 0.05) were independently associated with higher serum NT-proBNP levels. Additionally, the minor allele of rs632793 was significantly and consistently associated with lower prevalent CVD, including blood pressures, independent of NT-proBNP level (all P<0.05). Results for prevalent CVD, but not NT-proBNP levels, showed significant interaction by familial generation.

CONCLUSION

In this family-based study of subjects with exceptional longevity, we identified several allelic variants in the BNP gene region associated with NT-pro-BNP levels and prevalent CVD.

Gastric bypass surgery is associated with reduced subclinical myocardial injury and greater activation of the cardiac natriuretic peptide system than lifestyle intervention

AIMS

Morbid obesity is a risk factor for cardiovascular disease. The relative effects of Roux-en-Y gastric bypass surgery (GBS) and intensive lifestyle intervention (ILI) on subclinical myocardial injury, the activity of the cardiac natriuretic system, and systemic inflammation remain unclear.

METHODS

In a 59-week non-randomized clinical trial that included 131 patients with morbid obesity, we compared the effects ofGBS and ILI on concentrations of cardiac troponin T (cTnT) and I (cTnI), N-terminal pro-B-type natriuretic peptide (NT-proBNP) and C-reactive protein (CRP).

RESULTS

In the GBS and ILI group, median body mass index (BMI) was reduced by 14.4 kg/m² versus 3.9 kg/m², respectively (p value < 0.001). Cardiac troponins decreased after GBS, p = 0.014 (cTnT) and p = 0.065 (cTnI) and increased significantly in those treated with ILI (p values ≤ 0.021) (between-group differences for deltas: p ≤ 0.003). NT-proBNP increased in both groups, but significantly more in the GBS than in the ILI group (between-group differences for deltas: p = 0.008). CRP decreased significantly within the GBS and the ILI group, with this change significantly greater in the GBS group (between-group differences for deltas p < 0.001). The dominating mediator of the biomarker changes was weight loss. Prior coronary artery disease and diabetes were predictive of the magnitude of the changes in cTnI and NT-proBNP, respectively.

CONCLUSION

Compared to ILI, GBS was associated with reduced subclinical myocardial injury and systemic inflammation, and enhancement of the cardiac natriuretic peptide system. The biomarker changes were predominantly mediated by weight loss.

Associations of B-Type Natriuretic Peptide and Its Coding Gene Promoter Methylation With Functional Outcome of Acute Ischemic Stroke: A Mediation Analysis

Background

The prognostic role of B‐type natriuretic peptide (BNP) in stroke has been suggested, but limited studies have shown mixed results and unknown underlying mechanisms. DNA methylation, a molecular modification that alters gene expression, may represent a candidate mechanism for this purpose. We aimed to examine the associations of BNP and methylation of its coding gene (natriuretic peptide B [NPPB]) with the functional outcome in a large sample of patients with acute ischemic stroke from CATIS (China Antihypertensive Trial in Acute Ischemic Stroke).

Methods and Results

Leveraging participants from CATIS with available specimens, serum proBNP (equimolarly produced with BNP) was measured in 3216 patients (mean age, 62 years; 64% men), and peripheral blood DNA methylation of the NPPB promoter was quantified by targeted bisulfite sequencing in 806 patients (mean age, 62 years; 54% men). The functional outcome was defined as an ordered modified Rankin Scale score assessed at 14 days or hospital discharge after stroke onset. Mediation analysis was conducted to test the potential mediating effect of proBNP on the relationship between NPPB methylation and functional outcome. The results showed that a higher level of proBNP was significantly associated with a higher risk of having a poorer functional outcome (odds ratio [OR], 1.14; P=0.006). Every 5% of hypermethylation at 2 (Chr1:11919160 [OR, 0.93; P=0.022] and Chr1:11918989 [OR, 0.92; P=0.032]) of 11 CpG loci assayed was associated with 7% and 8% lower risk, respectively, of having a poor functional outcome. In addition, proBNP was negatively correlated to hypermethylation at 1 CpG (Chr1:11918989 [β=−0.029; P=0.009]) and mediated approximately 7.69% (95% CI, 2.50%–13.82%) of the association between this CpG methylation and the functional outcome.

Conclusions

Hypermethylation at the NPPB promoter is associated with the functional outcome after ischemic stroke, at least partially by suppressing BNP expression or excretion.

Cardiac natriuretic peptides

Investigations into the mixed muscle-secretory phenotype of cardiomyocytes from the atrial appendages of the heart led to the discovery that these cells produce, in a regulated manner, two polypeptide hormones - the natriuretic peptides - referred to as atrial natriuretic factor or atrial natriuretic peptide (ANP) and brain or B-type natriuretic peptide (BNP), thereby demonstrating an endocrine function for the heart. Studies on the gene encoding ANP (NPPA) initiated the field of modern research into gene regulation in the cardiovascular system. Additionally, ANP and BNP were found to be the natural ligands for cell membrane-bound guanylyl cyclase receptors that mediate the effects of natriuretic peptides through the generation of intracellular cGMP, which interacts with specific enzymes and ion channels. Natriuretic peptides have many physiological actions and participate in numerous pathophysiological processes. Important clinical entities associated with natriuretic peptide research include heart failure, obesity and systemic hypertension. Plasma levels of natriuretic peptides have proven to be powerful diagnostic and prognostic biomarkers of heart disease. Development of pharmacological agents that are based on natriuretic peptides is an area of active research, with vast potential benefits for the treatment of cardiovascular disease.

Research Priorities for Heart Failure With Preserved Ejection Fraction: National Heart, Lung, and Blood Institute Working Group Summary

Heart failure with preserved ejection fraction (HFpEF), a major public health problem that is rising in prevalence, is associated with high morbidity and mortality and is considered to be the greatest unmet need in cardiovascular medicine today because of a general lack of effective treatments. To address this challenging syndrome, the National Heart, Lung, and Blood Institute convened a working group made up of experts in HFpEF and novel research methodologies to discuss research gaps and to prioritize research directions over the next decade. Here, we summarize the discussion of the working group, followed by key recommendations for future research priorities. There was uniform recognition that HFpEF is a highly integrated, multiorgan, systemic disorder requiring a multipronged investigative approach in both humans and animal models to improve understanding of mechanisms and treatment of HFpEF. It was recognized that advances in the understanding of basic mechanisms and the roles of inflammation, macrovascular and microvascular dysfunction, fibrosis, and tissue remodeling are needed and ideally would be obtained from (1) improved animal models, including large animal models, which incorporate the effects of aging and associated comorbid conditions; (2) repositories of deeply phenotyped physiological data and human tissue, made accessible to researchers to enhance collaboration and research advances; and (3) novel research methods that take advantage of computational advances and multiscale modeling for the analysis of complex, high-density data across multiple domains. The working group emphasized the need for interactions among basic, translational, clinical, and epidemiological scientists and across organ systems and cell types, leveraging different areas or research focus, and between research centers. A network of collaborative centers to accelerate basic, translational, and clinical research of pathobiological mechanisms and treatment strategies in HFpEF was discussed as an example of a strategy to advance research progress. This resource would facilitate comprehensive, deep phenotyping of a multicenter HFpEF patient cohort with standardized protocols and a robust biorepository. The research priorities outlined in this document are meant to stimulate scientific advances in HFpEF by providing a road map for future collaborative investigations among a diverse group of scientists across multiple domains.

Do the Natriuretic Peptides Cause Atrial Fibrillation or is it Not So Black and White?

See Article by Whitman et al

Cyclic Guanosine Monophosphate and Risk of Incident Heart Failure and Other Cardiovascular Events: the ARIC Study

Background

Cyclic guanosine monophosphate (cGMP) is a second messenger regulated through natriuretic peptide and nitric oxide pathways. Stimulation of cGMP signaling is a potential therapeutic strategy for heart failure with preserved ejection fraction (HFpEF) and atherosclerotic cardiovascular disease (ASCVD). We hypothesized that plasma cGMP levels would be associated with lower risk for incident HFpEF, any HF, ASCVD, and coronary heart disease (CHD).

Methods and Results

We conducted a case–cohort analysis nested in the ARIC (Atherosclerosis Risk in Communities) study. Plasma cGMP was measured in 875 participants at visit 4 (1996–1998), with oversampling of incident HFpEF cases. We used Cox proportional hazard models to assess associations of cGMP with incident HFpEF, HF, ASCVD (CHD+stroke), and CHD. The mean (SD) age was 62.4 (5.6) years and median (interquartile interval) cGMP was 3.4 pmol/mL (2.4–4.6). During a median follow‐up of 9.9 years, there were 283 incident cases of HFpEF, 329 any HF, 151 ASCVD, and 125 CHD. In models adjusted for CVD risk factors, the hazard ratios (95% CI) associated with the highest cGMP tertile compared with lowest for HFpEF, HF, ASCVD, and CHD were 1.88 (1.17–3.02), 2.18 (1.18–4.06), 2.84 (1.44–5.60), and 2.43 (1.19–5.00), respectively. In models further adjusted for N‐terminal‐proB‐type natriuretic peptide, associations were attenuated for HFpEF and HF but remained statistically significant for ASCVD (2.56 [1.26–5.20]) and CHD (2.25 [1.07–4.71]).

Conclusions

Contrary to our hypothesis, higher cGMP levels were associated with incident CVD in a community‐based cohort. The associations of cGMP with HF or HFpEF may be explained by N‐terminal‐proB‐type natriuretic peptide, but not for ASCVD and CHD.

Identification of Circulating Proteins Associated With Blood Pressure Using Mendelian Randomization

BACKGROUND

Hypertension is a common modifiable risk factor for cardiovascular disease and mortality. Pathophysiological mechanisms leading to hypertension remain incompletely understood. Mendelian randomization (MR) allows the evaluation of the causal role of markers by minimizing the risk of biases such as reverse causation and confounding. We aimed to identify novel circulating proteins associated with blood pressure through a comprehensive screen of 227 blood biomarkers using MR.

METHODS

Genetic determinants of 227 biomarkers were identified in ORIGIN (Outcome Reduction With Initial Glargine Intervention; URL: http://www.clinicaltrials.gov. Unique identifier: NCT00069784) participants (N=4147) and combined with genetic effects on systolic blood pressure, diastolic blood pressure, mean arterial pressure, and pulse pressure from the International Consortium for Blood Pressure (74 064 individuals) using MR. Results were replicated in the UK Biobank (up to 319 103 individuals) and using another biomarker dataset (N=3301). MR analyses with cardiovascular risk factors and outcomes as well as other biomarkers were performed to further evaluate the mechanisms involved.

RESULTS

Six biomarkers were associated with blood pressure using MR after adjustment for multiple hypothesis testing. Relationships between NT-proBNP (N-terminal Pro-B-type natriuretic peptide), systolic blood pressure, and diastolic blood pressure confirmed previous reports. Novel circulating proteins associated with blood pressure were also identified. uPA (urokinase-type plasminogen activator) was related to systolic blood pressure; ADM (adrenomedullin) was related to systolic blood pressure and pulse pressure; IL (interleukin) 16 was related to diastolic blood pressure; cFn (cellular fibronectin) and IGFBP3 (insulin-like growth factor-binding protein 3) were related to pulse pressure. With the exception of IL16 and diastolic blood pressure (P=0.58), these relationships were validated in the UK Biobank (P<0.0001). Further MR analyses with cardiovascular risk factors and outcomes showed relationships between NT-proBNP and large-artery atherosclerotic stroke, IGFBP3 and diabetes mellitus as well as cFn and body mass index.

CONCLUSIONS

We identified novel biomarkers associated with blood pressure using MR. These markers could prove useful for risk assessment and as potential therapeutic targets.

20th Annual Feigenbaum Lecture: Echocardiography for Precision Medicine-Digital Biopsy to Deconstruct Biology

Heart failure with preserved ejection fraction (HFpEF) is a complex, heterogeneous syndrome in need of improved classification given its high morbidity and mortality and few effective treatment options. HFpEF represents an ideal setting to examine the utility and feasibility of a precision medicine approach. This article (based on the 20th annual Feigenbaum Lecture, presented at the 2019 American Society of Echocardiography Scientific Sessions) describes the utility of echocardiography as a "digital biopsy" and how deep quantitative echocardiographic phenotyping, coupled with machine learning, can be used to identify novel HFpEF phenotypes. The cellular and ultrastructural basis of abnormal speckle-tracking echocardiography- (STE-) based measurements of cardiac mechanics can provide a window into cardiomyocyte calcium homeostasis. STE-based measurements of longitudinal strain can thus inform the extent of myocardial involvement in patients with HFpEF, which may help to determine responsiveness to cardiac-specific HF medications. However, classifying the complex, systemic, multiorgan nature of HFpEF appropriately likely requires more advanced methods. Using unsupervised machine learning, HFpEF can be classified into three distinct phenogroups with differing clinical and echocardiographic characteristics and outcomes: (1) natriuretic peptide deficiency syndrome; (2) extreme cardiometabolic syndrome; and (3) right ventricle-cardio-abdomino-renal syndrome. Each can be probed to determine their biological basis. The goal of improved classification of HFpEF is to match the right patient with the right treatment, with the hope of improving the track record of HFpEF clinical trials. This article emphasizes the central role of echocardiography in advancing precision medicine and illustrates the integration of basic, translational, clinical, and population research in echocardiography with the goal of better understanding the pathobiology of a complex cardiovascular syndrome.

Association of Natriuretic Peptides With Cardiovascular Prognosis in Heart Failure With Preserved Ejection Fraction: Secondary Analysis of the TOPCAT Randomized Clinical Trial

Importance

Contemporary clinical trials of heart failure with preserved ejection fraction (HFpEF) apply natriuretic peptide (NP) thresholds to identify patients who are more likely to have the disease of interest and to enrich the baseline risk of the enrolled cohort.

Objective

To determine whether age, race/ethnicity, obesity, renal function, and atrial fibrillation (AF) affect the levels of NPs in HFpEF and whether the prognostic significance of NPs varies in these clinically important subgroups.

Design, Setting, and Participants

This secondary analysis of the Treatment of Preserved Cardiac Function Heart Failure With an Aldosterone Antagonist Trial (TOPCAT) evaluated the distribution and prognostic significance of NPs across 6 subgroups comprising 1057 adult patients (60%) in the Americas region of TOPCAT with symptomatic heart failure (HF) and a left ventricular ejection fraction of 45% or more with available NPs at baseline.

Exposures

Natriuretic peptides were log-transformed and standardized (expressed per 1 SD, z score) and assessed in 6 subgroups: age (cutoff, 70 years), black race, body mass index (BMI; calculated as weight in kilograms divided by height in meters squared; cutoff, 30 kg/m2), waist circumference (cutoff, 102 cm for men, 88 cm for women), estimated glomerular filtration rate (cutoff, 60 mL/min/1.73 m2), and a history of AF.

Main Outcomes and Measures

Time to composite cardiovascular death, hospitalization for HF, or aborted cardiac arrest at mean (SD) 2.4-year (1.5) follow-up.

Results

Of 1057 participants, the mean (SD) age was 72 (10) years, 183 (17.3%) were black, the mean (SD) BMI was 33.4 (8.6) kg/m2, the mean (SD) estimated glomerular filtration rate was 64.6 (21.8) mL/min/1.73 m2, and 472 (45%) had a history of AF. Median B-type NP (n = 698) and N-terminal pro-B-type NP concentrations (n = 359) were 257 (interquartile range, 149-443) ng/L and 959 (interquartile range, 554-2015) ng/L, respectively. Natriuretic peptide concentrations varied by up to 0.5 SD within the 6 subgroups, being higher in older patients with nonblack race, a lower BMI, a lower waist circumference, a lower estimated glomerular filtration rate, and a history of AF. Elevated NP levels (per 1-SD increase) were independently associated with an increased risk of the primary outcome (adjusted hazard ratio, 1.36; 95% CI, 1.22-1.54; P < .001) consistently across all investigated subgroups (interaction P > .05). In TOPCAT Americas (n = 1767), 791 (45%) were enrolled based on elevated NP levels as the qualifying criterion (as opposed to a history of HF hospitalization). This proportion was 31% (93 of 302), 34% (258 of 760), and 39% (443 of 1144) for black race, younger than 70 years, and a BMI of 30 kg/m2 or greater, respectively.

Conclusions and Relevance

Natriuretic peptides remain important biomarkers of prognosis in HFpEF, even in subgroups who tend to have lower NP levels. A single, absolute NP threshold for inclusion in contemporary HFpEF trials may lead to an underrepresentation of certain demographic and clinical subgroups.

Trial Registration

ClinicalTrials.gov Identifier: NCT00094302.

Contrasting signals of cardiovascular health among natriuretic peptides in subjects without heart disease

Natriuretic Peptides (NP) are important in maintaining normal cardiac and metabolic status and have been used to predict cardiovascular events. Whether plasma concentrations of NP products within the normal range reflect cardio-metabolic health is unknown. Plasma NTproANP, NTproBNP and NTproCNP and their bioactive counterparts were measured in a random sample of 348 community dwellers aged 49-51 yr without heart disease and associations sought with established vascular risk factors, echocardiographic indices and a genetic variant previously linked with BNP. Stratified by sex, each of ten vascular risk factors were positively associated with NTproCNP whereas associations with NTproBNP and NTproANP were all negative. In both sexes, higher plasma NTproCNP was associated with higher arterial elastance, lower LV stroke volume and lower LV end diastolic volume. Exactly opposite associations were found with plasma NTproBNP or NTproANP. Sex specific differences were identified: positive association of NTproBNP with LV end systolic volume and the negative association with LV elastance were found only in males. The genetic variant rs198358 was independently associated with NTproBNP but not with NTproANP. In conclusion, higher NTproCNP is likely to be an adaptive response to impaired LV relaxation whereas genetic factors likely contribute to higher NTproBNP and improved cardio-metabolic health at midlife.

Natriuretic Peptides in Heart Failure with Preserved Left Ventricular Ejection Fraction: From Molecular Evidences to Clinical Implications

The incidence of heart failure with preserved ejection fraction (HFpEF) is increasing and its challenging diagnosis and management combines clinical, imagistic and biological data. Natriuretic peptides (NPs) are hormones secreted in response to myocardial stretch that, by increasing cyclic guanosine monophosphate (cGMP), counteract myocardial fibrosis and hypertrophy, increase natriuresis and determine vasodilatation. While their role in HFpEF is controversial, most authors focused on b-type natriuretic peptides (BNPs) and agreed that patients may show lower levels. In this setting, newer molecules with an increased specificity, such as middle-region pro-atrial natriuretic peptide (MR-proANP), emerged as promising markers. Augmenting NP levels, either by NP analogs or breakdown inhibition, could offer a new therapeutic target in HFpEF (already approved in their reduced EF counterparts) by increasing the deficient cGMP levels found in patients. Importantly, these peptides also retain their prognostic value. This narrative review focuses on NPs' physiology, diagnosis, therapeutic and prognostic implication in HFpEF.

Design, Synthesis, and Actions of an Innovative Bispecific Designer Peptide

Despite optimal current therapies, cardiovascular disease remains the leading cause for death worldwide. Importantly, advances in peptide engineering have accelerated the development of innovative therapeutics for diverse human disease states. Additionally, the advancement of bispecific therapeutics targeting >1 signaling pathway represents a highly innovative strategy for the treatment of cardiovascular disease. We, therefore, engineered a novel, designer peptide, which simultaneously targets the pGC-A (particulate guanylyl cyclase A) receptor and the MasR (Mas receptor), potentially representing an attractive cardiorenoprotective therapeutic for cardiovascular disease. We engineered a novel, bispecific receptor activator, NPA7, that represents the fusion of a 22-amino acid sequence of BNP (B-type natriuretic peptide; an endogenous ligand of pGC-A) with Ang 1-7 (angiotensin 1-7)-the 7-amino acid endogenous activator of MasR. We assessed NPA7's dual receptor activating actions in vitro (second messenger production and receptor interaction). Further, we performed an intravenous peptide infusion comparison study in normal canines to study its biological actions in vivo, including in the presence of an MasR antagonist. Our in vivo and in vitro studies demonstrate the successful synthesis of NPA7 as a bispecific receptor activator targeting pGC-A and MasR. In normal canines, NPA7 possesses enhanced natriuretic, diuretic, systemic, and renal vasorelaxing and cardiac unloading properties. Importantly, NPA7's actions are superior to that of the individual native pGC-A or MasR ligands. These studies advance NPA7 as a novel, bispecific designer peptide with potential cardiorenal therapeutic benefit for the treatment of cardiovascular disease, such as hypertension and heart failure.

Molecular Implications of Natriuretic Peptides in the Protection from Hypertension and Target Organ Damage Development

The pathogenesis of hypertension, as a multifactorial trait, is complex. High blood pressure levels, in turn, concur with the development of cardiovascular damage. Abnormalities of several neurohormonal mechanisms controlling blood pressure homeostasis and cardiovascular remodeling can contribute to these pathological conditions. The natriuretic peptide (NP) family (including ANP (atrial natriuretic peptide), BNP (brain natriuretic peptide), and CNP (C-type natriuretic peptide)), the NP receptors (NPRA, NPRB, and NPRC), and the related protease convertases (furin, corin, and PCSK6) constitute the NP system and represent relevant protective mechanisms toward the development of hypertension and associated conditions, such as atherosclerosis, stroke, myocardial infarction, heart failure, and renal injury. Initially, several experimental studies performed in different animal models demonstrated a key role of the NP system in the development of hypertension. Importantly, these studies provided relevant insights for a better comprehension of the pathogenesis of hypertension and related cardiovascular phenotypes in humans. Thus, investigation of the role of NPs in hypertension offers an excellent example in translational medicine. In this review article, we will summarize the most compelling evidence regarding the molecular mechanisms underlying the physiological and pathological impact of NPs on blood pressure regulation and on hypertension development. We will also discuss the protective effect of NPs toward the increased susceptibility to hypertensive target organ damage.

Increased Levels of Cardiac Troponin I in Subjects with Extremely Low B-type Natriuretic Peptide Levels

Because of the lack of studies focused on the biological implications of extremely low B-type natriuretic peptide (BNP) levels, we investigated whether extremely low BNP levels could be harmful to the cardiovascular system due to compromised cardio-protection. By using cardiac troponin I (cTnI) as an indicator of cardiovascular disorder, we assessed whether cTnI was inversely associated with BNP in populations with low BNP levels. A total of 2,001 apparently healthy subjects older than 38 years were included in this study. We defined subgroups from this population by limiting the maximum BNP level with cut-off values ranging from 1 through 20 pg/mL and performed covariance structure analyses by comparing log(BNP) with log(cTnI) in each subgroup. The beta values between log(BNP) and log(cTnI) sharply decreased as the BNP cut-off was reduced from 20 pg/mL (beta = 0.04) to 1 pg/mL (beta = −0.29) and became significant when the BNP cut-off levels were lower than 4 pg/mL (p < 0.005). In subgroups with BNP levels lower than 4 pg/mL, elevation in cTnI level was inversely associated with BNP (p < 0.005), which suggests that insufficient BNP may play a pathogenic role in the occurrence of cardiovascular abnormalities.

Sustained Activation of Guanylate Cyclase-A with TDT, a Natriuretic Peptide Derivative, Exhibits Cardiorenal Protection in Dahl Salt-Sensitive Hypertensive Rats

Heart failure often presents with prognosis-relevant impaired renal function. To investigate whether the chronic activation of guanylate cyclase-A (GC-A) protects both heart and kidney, we examined the effects of TDT, a neprilysin (NEP)-resistant natriuretic peptide (NP) derivative, on cardiac and renal dysfunction in Dahl salt-sensitive hypertensive (DS) rats. Pretreatment with NEP or NEP inhibitor did not influence GC-A activation by TDT both in vitro and in vivo, resulting in a long-acting profile of TDT compared with native human atrial NP (hANP). The repeated administration of TDT to DS rats suppressed the progress of cardiac hypertrophy, systolic/diastolic dysfunction, and proteinuria in a dose-dependent manner. Compared with vehicle and hANP, salt diet-induced podocyte injury was reduced by TDT, as analyzed by urinary podocalyxin concentration, renal expression of nephrin mRNA, and glomerular expression of desmin protein. Since glomerular TRPC6 plays detrimental roles in podocyte homeostasis, we examined the renal expression of TRPC6 in DS rats and found that salt diet upregulated the expression of TRPC6. Importantly, TRPC6 induction was significantly decreased in TDT-treated rats, compared with vehicle and hANP. Consistently, in primary-culture podocytes from DS rats, TDT inhibited ATP-induced calcium influx, similar to TRPC inhibitor SKF96365. Finally, TDT-mediated protection of podocytes was abolished by protein kinase G inhibitor KT5823. In conclusion, TDT treatment attenuated heart and kidney dysfunction, accompanied by podocyte protection through inhibition of TRPC6. Thus, long-acting NPs could be a new avenue for treatment of heart failure.