Genetic variation in the natriuretic peptide system and heart failure

The Role of Natriuretic Peptides in the Management of Heart Failure with a Focus on the Patient with Diabetes

Natriuretic peptides (NPs) are polypeptide hormones involved in the homeostasis of the cardiovascular system. They are produced by cardiomyocytes and regulate circulating blood volume and sodium concentration. Clinically, measurements of brain natriuretic peptide (BNP) and N-terminal pro-BNP (NT-proBNP) are recommended by international guidelines as evidence is accumulating on their usefulness. They have a high negative predictive value, and in the setting of low NPs, a diagnosis of heart failure (HF) can be safely excluded in both emergency (BNP < 100 pg/mL, NT-proBNP < 300 pg/mL) and outpatient settings (BNP < 35 pg/mL and NT-proBNP < 125 pg/mL). Moreover, the 2023 consensus from the European Society of Cardiology suggests threshold values for inclusion diagnosis. These values are also associated with increased risks of major cardiovascular events, cardiovascular mortality, and all-cause mortality whether measured in inpatient or outpatient settings. Among patients without known HF, but at high risk of developing it (e.g., in the setting of diabetes mellitus, hypertension, or atherosclerotic cardiovascular disease), NPs may be useful in stratifying cardiovascular risk, optimizing therapy, and reducing the risk of developing overt HF. In the diabetes setting, risk stratification with the use of these peptides can guide the physician to a more informed and appropriate therapeutic choice as recommended by guidelines. Notably, NP levels should be carefully interpreted in light of certain conditions that may affect their reliability, such as chronic kidney disease and obesity, as well as demographic variables, including age and sex. In conclusion, NPs are useful in the diagnosis and prognosis of HF, but they also offer advantages in the primary prevention setting.

The impact of serum BNP on retinal perfusion assessed by an AI-based denoising optical coherence tomography angiography in CHD patients

Background

To investigate the correlation between retinal vessel density (VD) parameters with serum B-type natriuretic peptide (BNP) in patients with coronary heart disease (CHD) using novel optical coherence tomography angiography (OCTA) denoising images based on artificial intelligence (AI).

Methods

OCTA images of the optic nerve and macular area were obtained using a Canon-HS100 OCT device in 176 patients with CHD. Baseline information and blood test results were recorded.

Results

Retinal VD parameters of the macular and optic nerves on OCTA were significantly decreased in patients with CHD after denoising. Retinal VD of the superficial capillary plexus (SCP), deep capillary plexus (DCP) and radial peripapillary capillary (RPC) was strongly correlated with serum BNP levels in patients with CHD. Significant differences were noted in retinal thickness and retinal VD (SCP, DCP and RPC) between the increased BNP and normal BNP groups in patients with CHD.

Conclusion

Deep learning denoising can remove background noise and smooth rough vessel surfaces. SCP,DCP and RPC may be potential clinical markers of cardiac function in patients with CHD. Denoising shows great potential for improving the sensitivity of OCTA images as a biomarker for CHD progression.

Racial and ethnic differences in circulating N-terminal pro-brain-type natriuretic peptide (NT-proBNP) in US adults

BACKGROUND

The presence and interpretation of racial and ethnic differences in circulating N-terminal pro-brain-type natriuretic peptide (NT-proBNP), a diagnostic biomarker for heart failure, are controversial.

OBJECTIVE

To examine racial and ethnic differences in NT-proBNP levels among the general US adult population.

METHODS

We performed a cross-sectional analysis of data from the 1999-2004 National Health and Nutrition Examination Survey (NHANES). We included 4717 non-Hispanic White, 1675 non-Hispanic Black, and 2148 Mexican American adults aged 20 years or older without a history of cardiovascular disease. We examined the associations of race and ethnicity with NT-proBNP using linear and logistic regression models in the overall population and in a younger, 'healthy' subsample.

RESULTS

The mean age was 45 years. Median NT-proBNP levels were significantly lower among Black (29.3 pg/mL) and Mexican American adults (28.3.4 pg/mL) compared to White adults (49.1pg/mL, P-values<0.001). After adjusting for sociodemographic factors and cardiovascular risk factors, NT-proBNP was 34.4% lower (95%CI -39.2 to -29.3%) in Black adults and 22.8% lower (95%CI -29.4 to -15.5) in Mexican American adults compared to White adults. Our findings were consistent in a young, healthy subsample, suggesting non-cardiometabolic determinants of these differences.

CONCLUSIONS

NT-proBNP levels are significantly lower among Black and Mexican American adults compared with White adults, independent of cardiometabolic risk. Although race/ethnicity is a poor proxy for genetic differences, our findings may have clinical implications for the management of HF. However, studies in diverse populations are needed to characterize the biological basis of NT-proBNP variation.

Clinical Phenotypes of Cardiovascular and Heart Failure Diseases Can Be Reversed? The Holistic Principle of Systems Biology in Multifaceted Heart Diseases

Recent advances in cardiology and biological sciences have improved quality of life in patients with complex cardiovascular diseases (CVDs) or heart failure (HF). Regardless of medical progress, complex cardiac diseases continue to have a prolonged clinical course with high morbidity and mortality. Interventional coronary techniques together with drug therapy improve quality and future prospects of life, but do not reverse the course of the atherosclerotic process that remains relentlessly progressive. The probability of CVDs and HF phenotypes to reverse can be supported by the advances made on the medical holistic principle of systems biology (SB) and on artificial intelligence (AI). Studies on clinical phenotypes reversal should be based on the research performed in large populations of patients following gathering and analyzing large amounts of relative data that embrace the concept of complexity. To decipher the complexity conundrum, a multiomics approach is needed with network analysis of the biological data. Only by understanding the complexity of chronic heart diseases and explaining the interrelationship between different interconnected biological networks can the probability for clinical phenotypes reversal be increased.

Pre-Conditioning Stem Cells in a Biomimetic Environment for Enhanced Cardiac Tissue Repair: In Vitro and In Vivo Analysis

Introduction

Stem cell-based therapies represent a valid approach to restore cardiac function due to their beneficial effect in reducing scar area formation and promoting angiogenesis. However, their translation into the clinic is limited by the poor differentiation and inability to secrete sufficient therapeutic factors. To address this issue, several strategies such as genetic modification and biophysical preconditioning have been used to enhance the efficacy of stem cells for cardiac tissue repair.

Methods

In this study, a biomimetic approach was used to mimic the natural mechanical stimulation of the myocardium tissue. Specifically, human adipose-derived stem cells (hASCs) were cultured on a thin gelatin methacrylamide (GelMA) hydrogel disc and placed on top of a beating cardiomyocyte layer. qPCR studies and metatranscriptomic analysis of hASCs gene expression were investigated to confirm the correlation between mechanical stimuli and cardiomyogenic differentiation. In vivo intramyocardial delivery of pre-conditioned hASCs was carried out to evaluate their efficacy to restore cardiac function in mice hearts post-myocardial infarction.

Results

The cyclic strain generated by cardiomyocytes significantly upregulated the expression of both mechanotransduction and cardiomyogenic genes in hASCs as compared to the static control group. The inherent angiogenic secretion profile of hASCs was not hindered by the mechanical stimulation provided by the designed biomimetic system. Finally, in vivo analysis confirmed the regenerative potential of the pre-conditioned hASCs by displaying a significant improvement in cardiac function and enhanced angiogenesis in the peri-infarct region.

Conclusion

Overall, these findings indicate that cyclic strain provided by the designed biomimetic system is an essential stimulant for hASCs cardiomyogenic differentiation, and therefore can be a potential solution to improve stem-cell based efficacy for cardiovascular repair.

Pharmacogenomics of the Natriuretic Peptide System in Heart Failure

PURPOSE OF REVIEW

Heart failure (HF) continues to be a public health burden despite advances in therapy, and the natriuretic peptide (NP) system is clearly of critical importance in this setting, spawning valuable diagnostic and prognostic testing, such as B-type natriuretic peptide (BNP) and N-terminal pro-BNP (NT-proBNP), as well as current and future therapeutics, including recombinant natriuretic peptides (e.g., carperitide, nesiritide) and recently sacubitril, which inhibits the key clearance mechanism for NPs. This article intends to summarize the existing evidence for the role of NP system genetic variation on cardiovascular phenotypes relevant to HF with particular focus on the potential impact on pharmacologic therapies.

RECENT FINDINGS

Several genes in NP system have been interrogated, in many cases genetic variation impacting protein quantity and function or related disease states. Recent data supports genetic variants potentially impacting pharmacokinetics or dynamics of medications targeting the pathway. Growing evidence indicates the importance of genetic variation to the functioning of the NP system and its pharmacologic manipulation.

Molecular Characterization of Pediatric Restrictive Cardiomyopathy from Integrative Genomics

Pediatric restrictive cardiomyopathy (RCM) is a genetically heterogeneous heart disease with limited therapeutic options. RCM cases are largely idiopathic; however, even within families with a known genetic cause for cardiomyopathy, there is striking variability in disease severity. Although accumulating evidence implicates both gene expression and alternative splicing in development of dilated cardiomyopathy (DCM), there have been no detailed molecular characterizations of underlying pathways dysregulated in RCM. RNA-Seq on a cohort of pediatric RCM patients compared to other forms of adult cardiomyopathy and controls identified transcriptional differences highly common to the cardiomyopathies, as well as those unique to RCM. Transcripts selectively induced in RCM include many known and novel G-protein coupled receptors linked to calcium handling and contractile regulation. In-depth comparisons of alternative splicing revealed splicing events shared among cardiomyopathy subtypes, as well as those linked solely to RCM. Genes identified with altered alternative splicing implicate RBM20, a DCM splicing factor, as a potential mediator of alternative splicing in RCM. We present the first comprehensive report on molecular pathways dysregulated in pediatric RCM including unique/shared pathways identified compared to other cardiomyopathy subtypes and demonstrate that disruption of alternative splicing patterns in pediatric RCM occurs in the inverse direction as DCM.

Genetic variability in the system of natriuretic B peptide and principal toxicological parameters in workers exposed to lead

The study was aimed at evaluating the influence of selected polymorphisms of natriuretic peptide B precursor (NPPB) and natriuretic peptide receptor C (NPR3) genes on blood lead concentration (Pb-B) and blood zinc protoporphyrin concentration (ZnPP) in persons occupationally exposed to lead. Investigations were conducted on 360 persons (mean age: 44.49±9.62years), workers exposed to lead compounds. The analysis examined four polymorphisms of BNP gene, i.e.,: rs198388, rs198389, rs632793, and rs6676300; as well as one polymorphism of receptor C for natriuretic peptides, i.e., rs1421811. Heterozygosity in locus rs632793 of NPPB gene may result in higher concentrations of Pb-B, while allele A in locus rs632793 of NPPB gene seems to determine higher concentrations of ZnPP in persons occupationally exposed to lead. Workers exposed to lead and carrying allele C in locus rs198388 of NPPB gene, particularly in the heterozygotic setup, seem to be predisposed to present higher concentrations of ZnPP. Carriership of A allele in locus rs198389 of NPPB gene probably determines higher concentrations of ZnPP in study group. In summary, among persons occupationally exposed to lead, certain relationships were demonstrated between rs632793, rs198388 and rs198389 polymorphisms of NPPB gene and principal toxicological parameters characterizing exposure to lead.

Molecular Physiology of Membrane Guanylyl Cyclase Receptors

cGMP controls many cellular functions ranging from growth, viability, and differentiation to contractility, secretion, and ion transport. The mammalian genome encodes seven transmembrane guanylyl cyclases (GCs), GC-A to GC-G, which mainly modulate submembrane cGMP microdomains. These GCs share a unique topology comprising an extracellular domain, a short transmembrane region, and an intracellular COOH-terminal catalytic (cGMP synthesizing) region. GC-A mediates the endocrine effects of atrial and B-type natriuretic peptides regulating arterial blood pressure/volume and energy balance. GC-B is activated by C-type natriuretic peptide, stimulating endochondral ossification in autocrine way. GC-C mediates the paracrine effects of guanylins on intestinal ion transport and epithelial turnover. GC-E and GC-F are expressed in photoreceptor cells of the retina, and their activation by intracellular Ca(2+)-regulated proteins is essential for vision. Finally, in the rodent system two olfactorial GCs, GC-D and GC-G, are activated by low concentrations of CO2and by peptidergic (guanylins) and nonpeptidergic odorants as well as by coolness, which has implications for social behaviors. In the past years advances in human and mouse genetics as well as the development of sensitive biosensors monitoring the spatiotemporal dynamics of cGMP in living cells have provided novel relevant information about this receptor family. This increased our understanding of the mechanisms of signal transduction, regulation, and (dys)function of the membrane GCs, clarified their relevance for genetic and acquired diseases and, importantly, has revealed novel targets for therapies. The present review aims to illustrate these different features of membrane GCs and the main open questions in this field.

Genetic Factors Influencing B-type Natriuretic Peptide-Mediated Production of Cyclic Guanosine Monophosphate and Blood Pressure Effects in Heart Failure Patients

Natriuretic peptides (NPs) represent a critical pathway in heart failure (HF). We explored genetic determinants of pharmacodynamic effects of B-type NP (BNP) and changes in plasma cyclic guanosine monophosphate (cGMP) and blood pressure (BP). HF patients (n = 135) received recombinant human BNP (nesiritide) at standard doses, and plasma cGMP levels were measured at baseline and during infusion. We tested the association of 119 single nucleotide polymorphisms (SNPs) in 4 candidate genes (NPR1, NPR2, NPR3, and membrane metallo-endopeptidase (MME)) with the change in cGMP and BP. Gene-based testing for association of genetic variation with endpoints was significant only for MME. Upon individual SNP testing, two loci in MME were associated with ΔcGMP; another (rs16824656) showed association with BP change. In summary, the pharmacodynamic effects of BNP vary substantially in HF patients and are associated with genetic variation in MME. MME genetic variation may be an important determinant of NP-mediated effects in humans.

Harnessing fetal and adult genetic reprograming for therapy of heart disease

Heart is the first organ formed during organogenesis. The fetal heart undergoes several structural and functional modifications to form the four-chambered mammalian heart. The adult heart shows different adaptations during compensatory and decompensatory heart failure. However, one common adaptation in the pathological heart is fetal reprogramming, where the adult heart expresses several genes and miRNAs which are active in the fetal stage. The fetal reprogramming in the failing heart raises several questions, such as whether the switch of adult to fetal genetic programming is an adaptive response to cope with adverse remodeling of the heart, does the expression of fetal genes protect the heart during compensatory and/or decompensatory heart failure, does repressing the fetal gene in the failing heart is protective to the heart? To answer these questions, we need to understand the expression of genes and miRNAs that are reprogrammed in the failing heart. In view of this, we provided an overview of differentially expressed genes and miRNAs, and their regulation in this review. Further, we elaborated novel strategies for a plausible future therapy of cardiovascular diseases.

Genetic and nongenetic factors influencing pharmacokinetics of B-type natriuretic peptide

BACKGROUND

Natriuretic peptides (NPs) represent a critical pathway in heart failure (HF). However, there is wide individual variability in NP system activity, which could be partly genetic in origin. We explored genetic and nongenetic contributions to B-type natriuretic peptide (BNP) inactivation.

METHODS

Chronic HF patients (n = 95) received recombinant human BNP (nesiritide) at standard doses, and BNP levels were measured at baseline, after 2 hours of infusion, and 30 minutes after discontinuation. Genomic DNA was genotyped for 91 single-nucleotide polymorphisms (SNP) in 2 candidate genes. We tested the association of patient characteristics and genotype with 5 pharmacokinetics (PK) parameters: elimination rate constant, ΔBNP, BNP clearance, adjusted BNP clearance, and half-life. Linear regression with pleiotropic analysis was used to test genotype associations with PK.

RESULTS

Participants' mean age was 63 years, 44% were female, and 46% were African American. PK parameters varied widely, some >10-fold. HF type (preserved vs reduced) was associated with PK (P < .01), whereas renal function, demographics, and body mass index and were not. Two SNPs in MME (rs989692, rs6798179) and 2 in NPR3 (rs6880564, rs2062708) also had associations with PK (P < .05).

CONCLUSIONS

The pharmacokinetics of BNP varies greatly in HF patients, differs by HF type, and possibly by MME or NPR3 genotype. Additional study is warranted.

Natriuretic peptides: molecular biology, pathophysiology and clinical implications for the cardiologist

Natriuretic peptides (NPs) counter the effects of volume overload or adrenergic activation of the cardiovascular system. They are able to induce arterial vasodilatations, natriuresis and diuresis, and they reduce the activities of the renin-angiotensin-aldosterone system and the sympathetic nervous system. However, in addition to wall stress, other factors have been associated with elevated natriuretic peptide levels. Since 2000, because of their characteristics, NPs have become quantitative plasma biomarkers of heart failure. Nowadays, NPs play an important role not only in the diagnosis of heart failure, but also for a prognostic purpose and a guide to medical therapy. Finally, a new drug that modulates the NP system or recombinant analogs of NPs are now available in patients with heart failure.

Weighted gene coexpression network analysis of human left atrial tissue identifies gene modules associated with atrial fibrillation

BACKGROUND

Genetic mechanisms of atrial fibrillation (AF) remain incompletely understood. Previous differential expression studies in AF were limited by small sample size and provided limited understanding of global gene networks, prompting the need for larger-scale, network-based analyses.

METHODS AND RESULTS

Left atrial tissues from Cleveland Clinic patients who underwent cardiac surgery were assayed using Illumina Human HT-12 mRNA microarrays. The data set included 3 groups based on cardiovascular comorbidities: mitral valve (MV) disease without coronary artery disease (n=64), coronary artery disease without MV disease (n=57), and lone AF (n=35). Weighted gene coexpression network analysis was performed in the MV group to detect modules of correlated genes. Module preservation was assessed in the other 2 groups. Module eigengenes were regressed on AF severity or atrial rhythm at surgery. Modules whose eigengenes correlated with either AF phenotype were analyzed for gene content. A total of 14 modules were detected in the MV group; all were preserved in the other 2 groups. One module (124 genes) was associated with AF severity and atrial rhythm across all groups. Its top hub gene, RCAN1, is implicated in calcineurin-dependent signaling and cardiac hypertrophy. Another module (679 genes) was associated with atrial rhythm in the MV and coronary artery disease groups. It was enriched with cell signaling genes and contained cardiovascular developmental genes including TBX5.

CONCLUSIONS

Our network-based approach found 2 modules strongly associated with AF. Further analysis of these modules may yield insight into AF pathogenesis by providing novel targets for functional studies.

Association of genetic variation with gene expression and protein abundance within the natriuretic peptide pathway

The natriuretic peptide (NP) system is a critical physiologic pathway in heart failure with wide individual variability in functioning. We investigated the genetic component by testing the association of single nucleotide polymorphisms (SNP) with RNA and protein expression. Samples of DNA, RNA, and tissue from human kidney (n = 103) underwent genotyping, RT-PCR, and protein quantitation (in lysates), for four candidate genes [NP receptor 1 (NPR1), NPR2, and NPR3 and membrane metalloendopeptidase]. The association of genetic variation with expression was tested using linear regression for individual SNPs, and a principal components (PC) method for overall gene variation. Eleven SNPs in NPR2 were significantly associated with protein expression (false discovery rate ≤0.05), but not RNA quantity. RNA and protein quantity correlated poorly with each other. The PC analysis showed only NPR2 as significant. Assessment of the clinical impact of NPR2 genetic variation is needed.

Systems biology and biomechanical model of heart failure

Heart failure is seen as a complex disease caused by a combination of a mechanical disorder, cardiac remodeling and neurohormonal activation. To define heart failure the systems biology approach integrates genes and molecules, interprets the relationship of the molecular networks with modular functional units, and explains the interaction between mechanical dysfunction and cardiac remodeling. The biomechanical model of heart failure explains satisfactorily the progression of myocardial dysfunction and the development of clinical phenotypes. The earliest mechanical changes and stresses applied in myocardial cells and/or myocardial loss or dysfunction activate left ventricular cavity remodeling and other neurohormonal regulatory mechanisms such as early release of natriuretic peptides followed by SAS and RAAS mobilization. Eventually the neurohormonal activation and the left ventricular remodeling process are leading to clinical deterioration of heart failure towards a multi-organic damage. It is hypothesized that approaching heart failure with the methodology of systems biology we promote the elucidation of its complex pathophysiology and most probably we can invent new therapeutic strategies.

Natriuretic peptides in therapy for decompensated heart failure

Congestive heart failure (CHF) is the most frequent cause of hospitalization for patients >65 years of age and continues to be a major public health burden among the ageing population. Unlike therapy for chronic CHF, there has been only modest progress in medical treatment for acutely decompensated CHF over the past several decades. Moreover, current treatment-consisting generally of diuretic, inotropic, and vasodilatory agents-is associated with many limitations in clinical practice. Natriuretic peptides provide a promising mechanism of action in the pathophysiologic background for CHF treatment based on their vasodilatory and diuretic properties and effective inhibition of the renin-angiotensin-aldosterone system, which is activated early in the course of CHF. Nesiritide (Natrecor® or Noratak®) is a recombinant natriuretic peptide that has the same 32 amino-acid sequence as human B-type natriuretic peptide. Nesiritide has been shown to improve dyspnea and hemodynamic parameters in patients with decompensated heart failure. Ularitide is a synthetic form of urodilatin, a natriuretic peptide hormone secreted by the kidney. Recent clinical studies suggest that ularitide may play a role in managing decompensated heart failure. This review provides an update on natriuretic peptides and their therapeutic potential in advanced CHF.

Systems biology and heart failure: concepts, methods, and potential research applications

Dramatic advances in molecular biology dominated twentieth century biomedical science and delineated the function of individual genes and molecules in exquisite detail. However, biological processes cannot be fully understood based on the properties of individual genes and molecules alone, since these elements act in concert to enable the specific functions that make for living cells and organisms. The discipline of systems biology provides a novel conceptual framework for understanding biological phenomenon. Systems biology synthesizes information concerning the interactions of genes and molecules and allows characterization of the supramolecular networks and functional modules that represent the most essential aspects of cell organization and physiology.

Progress toward genetic tailoring of heart failure therapy

Heart failure (HF) is a modern epidemic and a heterogeneous disorder with many therapeutic options. While the average response to each individual treatment is favorable, significant interindividual variation exists in the response to HF therapeutics. As a result, the optimal regimen for an individual patient or subgroup of patients is elusive, with current treatment being mainly empirical. Pharmacogenetic customization of HF therapy may provide an important opportunity to improve the treatment of HF. Common genetic variations exist in genes related to most classes of HF drugs, many of which have known functional consequences for or established relationships with drug response. This review summarizes the current understanding of the pharmacogenetics of HF therapeutics, including angiotensin-converting enzyme inhibitors and beta-blockers, and focuses on recent advances and medium-term expectations for the field.

Biosynthesis of cardiac natriuretic peptides

Cardiac-derived peptide hormones were identified more than 25 years ago. An astonishing amount of clinical studies have established cardiac natriuretic peptides and their molecular precursors as useful markers of heart disease. In contrast to the clinical applications, the biogenesis of cardiac peptides has only been elucidated during the last decade. The cellular synthesis including amino acid modifications and proteolytic cleavages has proven considerably more complex than initially perceived. Consequently, the elimination phase of the peptide products in circulation is not yet well characterized. An ongoing characterization of the molecular heterogeneity will help appreciate the biosynthetic capacity of the endocrine heart and could introduce new diagnostic possibilities. Notably, different biosynthetic products may not be equal markers of the same pathophysiological processes. An inefficient post-translational prohormone maturation will also affect the biology of the cardiac natriuretic peptide system. This review aims at summarizing the myocardial synthesis of natriuretic peptides focusing on B-type natriuretic peptide, where new data has disclosed cardiac myocytes as highly competent endocrine cells. The structurally related atrial natriuretic peptide will be mentioned where appropriate, whereas C-type natriuretic peptide will not be considered as a cardiac peptide of relevance in mammalian physiology.

Myocardial adaptations in the failing heart: cause or consequence?

Many changes in morphology, biochemical properties and myocyte function occur during development to heart failure. Most changes may be compensatory, yet unable to prevent cardiac dysfunction in the long run. This illustrates that it is important to carefully dissect the disease causing modifications from cardiac adaptation, in order to obtain a better understanding of the pathophysiological processes leading to heart failure.