The natriuretic peptide system in heart failure: Diagnostic and therapeutic implications

Jin-Xin-Kang alleviates heart failure by mitigating mitochondrial dysfunction through the Calcineurin/Dynamin-Related Protein 1 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Chronic heart failure (CHF) is a severe consequence of cardiovascular disease, marked by cardiac dysfunction. Jin-Xin-Kang (JXK) is a traditional Chinese herbal formula used for the treatment of CHF. This formula consists of seven medicinal herbs, including Ginseng (Ginseng quinquefolium (L.) Alph.Wood), Astragali Radix (Astragalus membranaceus (Fisch.) Bunge), Salvia miltiorrhiza (Salvia miltiorrhiza Bunge), Descurainiae Semen Lepidii Semen (Descurainia sophia (L.) Webb ex Prantl), Leonuri Herba (Leonurus japonicus Houtt.), Cinnamomi Ramulus (Cinnamomum cassia (L.) J.Presl), and Ilex pubescens (Ilex pubescens Hook. & Arn.). Its clinical efficacy has been validated through prospective randomized controlled studies. However, the specific mechanisms of action for this formula have yet to be elucidated.

AIM OF THE STUDY

This study aimed to investigate the effect of JXK on mitochondrial function and its mechanism in the treatment of CHF.

METHODS

JXK components were qualitatively analyzed using UPLC-Q-Orbitrap-MS. HF was induced in mice via transverse aortic constriction (TAC). After successful model establishment, lyophilized JXK-L (4.38 g/kg) and JXK-H (13.14 g/kg) were administered for 8 weeks. In vitro, hypertrophic myocardium was induced using angiotensin II (Ang II) for 48 h, followed by JXK-L and JXK-H treatment. Network pharmacology and molecular docking techniques were used to predict the relevant targets of JXK. Cardiac function, serum markers, and histopathological changes were evaluated to assess cardiac function. Immunofluorescence of Tomm20, mitochondrial membrane potential, and ROS were measured to assess mitochondrial dysfunction. Protein expression of calcineurin (CaN) and Drp1 in the myocardium was assessed by Western blot analysis.

RESULTS

We detected that the active components of JXK include terpenes, glycosides, flavonoids, amino acids, and alkaloids, among others. In mice with CHF, JXK improved cardiac function and reversed ventricular remodeling. Network pharmacology indicated that JXK can inhibit the calcium signaling pathway. The molecular docking results demonstrated that the active components of JXK effectively bind with CaN. Both in vitro and in vivo experiments confirmed that JXK regulated the CaN/Drp1 pathway and alleviated mitochondrial dysfunction.

CONCLUSION

JXK can inhibit the CaN/Drp1 pathway to improve mitochondrial function, and consequently treat CHF.

Utility of Point-of-Care Diagnosis of Chronic Heart Failure Using an Express Test for Semi-Quantitative Determination of NT-proBNP Levels

AIM

To evaluate the accuracy of a rapid test for semi-quantitative determination of NT-proBNP levels in the diagnosis of CHF in comparison with quantitative assessment; to study the strength of the association of the results of this NT-proBNP test with indicators of the CHF severity.

MATERIAL AND METHODS

The concentration of NT-proBNP was determined in 44 patients at bedside both semi-quantitatively using an express test (BioTest, Novosibirsk) and quantitatively in a laboratory. In 11 patients, the severity of CHF was assessed with the CHF Clinical Status Scale (CSS). Echocardiography was performed in all patients.

RESULTS

The sensitivity of the quantitative and semi-quantitative tests coincided and was 95%. The specificity of the quantitative test was 100% in our study, whereas the semi-quantitative test showed a specificity of 92%. The negative predictive value of either test was 96%. The diagnostic accuracy was 98% and 93%, respectively. In patients with significantly high NT-proBNP concentrations, the semi-quantitative test demonstrated a reduced ability to verify values above 1800 pg/ml; in patients with threshold concentrations, the semi-quantitative test showed an increased subthreshold sensitivity. Increases in the NT-proBNP concentration correlated with the severity of CHF according to the stage of the disease.

CONCLUSION

Due to the sufficiently high sensitivity, specificity, ease of use, and speed of obtaining results, the rapid test for semi-quantitative measuring NT-proBNP is promising for outpatient screening bedside diagnosis of CHF and in the emergency room to confirm or exclude CHF. When determining the dynamics of NT-proBNP during the treatment of CHF, the use of the semi-quantitative rapid test with visual assessment of the results may produce an error compared to the quantitative assessment, which will probably not allow tracking the effect of therapy or predicting exacerbation of the disease.

SCD4 deficiency decreases cardiac steatosis and prevents cardiac remodeling in mice fed a high-fat diet

Stearoyl-CoA desaturase (SCD) is a lipogenic enzyme that catalyzes formation of the first double bond in the carbon chain of saturated fatty acids. Four isoforms of SCD have been identified in mice, the most poorly characterized of which is SCD4, which is cardiac-specific. In the present study, we investigated the role of SCD4 in systemic and cardiac metabolism. We used WT and global SCD4 KO mice that were fed standard laboratory chow or a high-fat diet (HFD). SCD4 deficiency reduced body adiposity and decreased hyperinsulinemia and hypercholesterolemia in HFD-fed mice. The loss of SCD4 preserved heart morphology in the HFD condition. Lipid accumulation decreased in the myocardium in SCD4-deficient mice and in HL-1 cardiomyocytes with knocked out Scd4 expression. This was associated with an increase in the rate of lipolysis and, more specifically, adipose triglyceride lipase (ATGL) activity. Possible mechanisms of ATGL activation by SCD4 deficiency include lower protein levels of the ATGL inhibitor G0/G1 switch protein 2 and greater activation by protein kinase A under lipid overload conditions. Moreover, we observed higher intracellular Ca2+ levels in HL-1 cells with silenced Scd4 expression. This may explain the activation of protein kinase A in response to higher Ca2+ levels. Additionally, the loss of SCD4 inhibited mitochondrial enlargement, NADH overactivation, and reactive oxygen species overproduction in the heart in HFD-fed mice. In conclusion, SCD4 deficiency activated lipolysis, resulting in a reduction of cardiac steatosis, prevented the induction of left ventricular hypertrophy, and reduced reactive oxygen species levels in the heart in HFD-fed mice.

miPEP31 alleviates Ang II-induced hypertension in mice by occupying Cebpα binding sites in the pri-miR-31 promoter

BACKGROUND

Previous studies have shown that peptides encoded by noncoding RNAs (ncRNAs) can be used as peptide drugs to alleviate diseases. We found that microRNA-31 (miR-31) is involved in the regulation of hypertension and that the peptide miPEP31, which is encoded by the primary transcript of miR-31 (pri-miR-31), can inhibit miR-31 expression. However, the role and mechanism of miPEP31 in hypertension have not been elucidated.

METHODS

miPEP31 expression was determined by western blot analysis. miPEP31-deficient mice (miPEP31-/-) were used, and synthetic miPEP31 was injected into Ang II-induced hypertensive mice. Blood pressure was monitored through the tail-cuff method. Histological staining was used to evaluate renal damage. Regulatory T (Treg) cells were assessed by flow cytometry. Differentially expressed genes were analysed through RNA sequencing. The transcription factors were predicted by JASPAR. Luciferase reporter and electrophoretic mobility shift assays (EMSAs) were used to determine the effect of pri-miR-31 on the promoter activity of miPEP31. Images were taken to track the entry of miPEP31 into the cell.

RESULTS

miPEP31 is endogenously expressed in target organs and cells related to hypertension. miPEP31 deficiency exacerbated but exogenous miPEP31 administration mitigated the Ang II-induced systolic blood pressure (SBP) elevation, renal impairment and Treg cell decreases in the kidney. Moreover, miPEP31 deletion increased the expression of genes related to Ang II-induced renal fibrosis. miPEP31 inhibited the transcription of miR-31 and promoted Treg differentiation by occupying the Cebpα binding site. The minimal functional domain of miPEP31 was identified and shown to regulate miR-31.

CONCLUSION

miPEP31 was identified as a potential therapeutic peptide for treating hypertension by promoting Treg cell differentiation in vivo. Mechanistically, we found that miPEP31 acted as a transcriptional repressor to specifically inhibit miR-31 transcription by competitively occupying the Cebpα binding site in the pri-miR-31 promoter. Our study highlights the significant therapeutic effect of miPEP31 on hypertension and provides novel insight into the role and mechanism of miPEPs.

Challenging and target-based shifting strategies for heart failure treatment: An update from the last decades

Heart failure (HF) is a major global health problem afflicting millions worldwide. Despite the significant advances in therapies and prevention, HF still carries very high morbidity and mortality, requiring enormous healthcare-related expenditure, and the search for new weapons goes on. Following initial treatment strategies targeting inotropism and congestion, attention has focused on offsetting the neurohormonal overactivation and three main therapies, including angiotensin-converting enzyme inhibitors or angiotensin II type 1 receptor antagonists, β-adrenoceptor antagonists, and mineralocorticoid receptor antagonists, have been the foundation of standard treatment for patients with HF. Recently, a paradigm shift, including angiotensin receptor-neprilysin inhibitor, sodium glucose co-transporter 2 inhibitor, and ivabradine, has been added. Moreover, soluble guanylate cyclase stimulator, elamipretide, and omecamtiv mecarbil have come out as a next-generation therapeutic agent for patients with HF. Although these pharmacologic therapies have been significantly successful in relieving symptoms, there is still no complete cure for HF. We may be currently entering a new era of treatment for HF with animal experiments and human clinical trials assessing the value of antibody-based immunotherapy and gene therapy as a novel therapeutic strategy. Such tempting therapies still have some challenges to be addressed but may become a weighty option for treatment of HF. This review article will compile the paradigm shifts in HF treatment over the past dozen years or so and illustrate current landscape of antibody-based immunotherapy and gene therapy as a new therapeutic algorithm for patients with HF.

Sacubitril/valsartan ameliorates cardiac function and ventricular remodeling in CHF rats via the inhibition of the tryptophan/kynurenine metabolism and inflammation

Sacubitril/valsartan has been highly recognized as a treatment for Chronic heart failure (CHF). Its potential cardioprotective benefits and mechanisms, however, remain to be explored. Metabolomics can be used to identify the metabolic characteristics and related markers, as well as the influence of drugs, thereby opening up the new mechanism for sacubitril/valsartan therapy in CHF disease. In this study, the ligation of left anterior descending and exhaustive swimming were used to induce a rat model of CHF after myocardial infarction. The efficacy was appraised with echocardiography, serum NT-proBNP, and histopathologica. UPLC-Q/TOF-MS combined with multivariate statistical analysis approach were used to analyze the effect of sacubitril/valsartan on CHF rats. RT-qPCR and western blot were performed to investigate the tryptophan/kynurenine metabolism pathway. Accordingly, the basal cardiac function were increased, while the serum NT-proBNP and collagen volume fraction decreased in CHF rats with sacubitril/valsartan. Sacubitril/valsartan regulated the expression of kynurenine et.al 8 metabolomic biomarkers in CHF rats serum, and it contributed to the cardioprotective effects through tryptophan metabolism pathway. In addition, the mRNA and protein expression of the indoleamine 2,3-dioxygenase (IDO) in the myocardial tissue of CHF rats, were down-regulated by sacubitril/valsartan, which was the same with the IL-1β, IFN-γ, TNF-α, COX-2, and IL-6 mRNA expression, and IL-1β, IFN-γ, and TNF-α expression in serum. In conclusion, sacubitril/valsartan can ameliorate cardiac function and ventricular remodeling in CHF rats, at least in part through inhibition of tryptophan/kynurenine metabolism.

Plasma Biomarkers for Hypertension-Mediated Organ Damage Detection: A Narrative Review

Hypertension (HT) is a disease that poses a serious threat to human health, mediating organ damage such as the cardiovascular (CV) system, kidneys, central nervous system (CNS), and retinae, ultimately increasing the risk of death due to damage to the entire vascular system. Thus, the widespread prevalence of hypertension brings enormous health problems and socioeconomic burdens worldwide. The goal of hypertension management is to prevent the risk of hypertension-mediated organ damage and excess mortality of cardiovascular diseases. To achieve this goal, hypertension guidelines recommend accurate monitoring of blood pressure and assessment of associated target organ damage. Early identification of organ damage mediated by hypertension is therefore crucial. Plasma biomarkers as a non-invasive test can help identify patients with organ damage mediated by hypertension who will benefit from antihypertensive treatment optimization and improved prognosis. In this review, we provide an overview of some currently available, under-researched, potential plasma biomarkers of organ damage mediated by hypertension, looking for biomarkers that can be detected by simple testing to identify hypertensive patients with organ damage, which is of great significance in clinical work. Natriuretic peptides (NPs) can be utilized as a traditional biomarker to detect hypertension-mediated organ damage, especially for heart failure. Nevertheless, we additionally may need to combine two or more plasma biomarkers to monitor organ damage in the early stages of hypertension.

Sacubitril/Valsartan inhibits M1 type macrophages polarization in acute myocarditis by targeting C-type natriuretic peptide

Studies have shown that Sacubitril/valsartan (Sac/Val) can reduce myocardial inflammation in myocarditis mice, in addition to its the recommended treatment of heart failure. However, the underlying mechanisms of Sac/Val in myocarditis remain unclear. C-type natriuretic peptide (CNP), one of the targeting natriuretic peptides of Sac/Val, was recently reported to exert cardio-protective and anti-inflammatory effects in cardiovascular systems. Here, we focused on circulating levels of CNP in patients with acute myocarditis (AMC) and whether Sac/Val modulates inflammation by targeting CNP in experimental autoimmune myocarditis (EAM) mice as well as LPS-induced RAW 264.7 cells and bone marrow derived macrophages (BMDMs) models. Circulating CNP levels were higher in AMC patients compared to healthy controls, and these levels positively correlated with the elevated inflammatory cytokines IL-6 and monocyte count. In EAM mice, Sac/Val alleviated myocardial inflammation while augmenting circulating CNP levels rather than BNP and ANP, accompanied by reduction in intracardial M1 macrophage infiltration and expression of inflammatory cytokines IL-1β, TNF-α, and IL-6. Furthermore, Sac/Val inhibited CNP degradation and directly blunted M1 macrophage polarization in LPS-induced RAW 264.7 cells and BMDMs. Mechanistically, the effects might be mediated by the NPR-C/cAMP/JNK/c-Jun signaling pathway apart from NPR-B/cGMP/NF-κB pathway. In conclusion, Sac/Val exerts a protective effect in myocarditis by increasing CNP concentration and inhibiting M1 macrophages polarization.

Cardiac lipotoxicity and fibrosis underlie impaired contractility in a mouse model of metabolic dysfunction-associated steatotic liver disease

The leading cause of death among patients with metabolic dysfunction-associated steatotic liver disease (MASLD) is cardiovascular disease. A significant percentage of MASLD patients develop heart failure driven by functional and structural alterations in the heart. Previously, we observed cardiac dysfunction in hepatocyte-specific peroxisome proliferator-activated receptor alpha knockout (Ppara HepKO), a mouse model that exhibits hepatic steatosis independent of obesity and insulin resistance. The goal of the present study was to determine mechanisms that underlie hepatic steatosis-induced cardiac dysfunction in Ppara HepKO mice. Experiments were performed in 30-week-old Ppara HepKO and littermate control mice fed regular chow. We observed decreased cardiomyocyte contractility (0.17 ± 0.02 vs. 0.24 ± 0.02 μm, p < 0.05), increased cardiac triglyceride content (0.96 ± 0.13 vs. 0.68 ± 0.06 mM, p < 0.05), collagen type 1 (4.65 ± 0.25 vs. 0.31 ± 0.01 AU, p < 0.001), and collagen type 3 deposition (1.32 ± 0.46 vs. 0.05 ± 0.03 AU, p < 0.05). These changes were associated with increased apoptosis as indicated by terminal deoxynucleotidyl transferase dUTP nick end labeling staining (30.9 ± 4.7 vs. 13.1 ± 0.8%, p < 0.006) and western blots showing increased cleaved caspase-3 (0.27 ± 0.006 vs. 0.08 ± 0.01 AU, p < 0.003) and pro-caspase-3 (5.4 ± 1.5 vs. 0.5 ± 0.3 AU, p < 0.02), B-cell lymphoma protein 2-associated X (0.68 ± 0.07 vs. 0.04 ± 0.04 AU, p < 0.001), and reduced B-cell lymphoma protein 2 (0.29 ± 0.01 vs. 1.47 ± 0.54 AU, p < 0.05). We further observed elevated circulating natriuretic peptides and exercise intolerance in Ppara HepKO mice when compared to controls. Our data demonstrated that lipotoxicity, and fibrosis underlie cardiac dysfunction in MASLD.

Sorafenib reduces the production of epoxyeicosatrienoic acids and leads to cardiac injury by inhibiting CYP2J in rats

Sorafenib, an important cancer drug in clinical practice, has caused heart problems such as hypertension, myocardial infarction, and thrombosis. Although some mechanisms of sorafenib-induced cardiotoxicity have been proposed, there is still more research needed to reach a well-established definition of the causes of cardiotoxicity of sorafenib. In this report, we demonstrate that sorafenib is a potent inhibitor of the CYP2J enzyme. Sorafenib significantly inhibited the production of epoxyeicosatrienoic acids (EETs) in rat cardiac microsomes. The in vivo experimental results also showed that after the administration of sorafenib, the levels of 11,12-EET and 14,15-EET in rat plasma were significantly reduced, which was similar to the results of CYP2J gene knockout. Sorafenib decreased the levels of EETs, leading to abnormal expression of mitochondrial fusion and fission factors in heart tissue. In addition, the expression of mitochondrial energy metabolism factors (Pgc-1α, Pgc-1β, Ampk, and Sirt1) and cardiac mechanism factors (Scn5a and Prkag2) was significantly reduced, increasing the risk of arrhythmia and heart failure. Meanwhile, the increase in injury markers Anp, CK, and CK-MB further confirmed the cardiotoxicity of sorafenib. This study is of great significance for understanding the cardiotoxicity of sorafenib, and is also a model for studying the cardiotoxicity of other drugs that inhibit CYP2J activity.

Building Synthetic Biosensors Using Red Blood Cell Proteins

As the use of engineered cell therapies expands from pioneering efforts in cancer immunotherapy to other applications, an attractive but less explored approach is the use of engineered red blood cells (RBCs). Compared to other cells, RBCs have a very long circulation time and reside in the blood compartment, so they could be ideally suited for applications as sentinel cells that enable in situ sensing and diagnostics. However, we largely lack tools for converting RBCs into biosensors. A unique challenge is that RBCs remodel their membranes during maturation, shedding many membrane components, suggesting that an RBC-specific approach may be needed. Toward addressing this need, here we develop a biosensing architecture built on RBC membrane proteins that are retained through erythropoiesis. This biosensor employs a mechanism in which extracellular ligand binding is transduced into intracellular reconstitution of a split output protein (including either a fluorophore or an enzyme). By comparatively evaluating a range of biosensor architectures, linker types, scaffold choices, and output signals, we identify biosensor designs and design features that confer substantial ligand-induced signal in vitro. Finally, we demonstrate that erythroid precursor cells engineered with our RBC-protein biosensors function in vivo. This study establishes a foundation for developing RBC-based biosensors that could ultimately address unmet needs including noninvasive monitoring of physiological signals for a range of diagnostic applications.

Efficacy and safety of Shen Gui capsules for chronic heart failure: a systematic review and meta-analysis

Background

Although Shen Gui capsules (SGCP) are widely used as an adjuvant treatment for chronic heart failure (CHF), their clinical efficacy and safety remain controversial.

Purpose

To assess the efficacy and safety of SGCP in the treatment of CHF through a systematic review and meta-analysis, to provide high-quality evidence for evidence-based medicine.

Methods

Seven databases were searched for randomized controlled trials (RCTs) assessing SGCP for CHF, from inception to 9 January 2023. RCT quality of evidence was evaluated using the Cochrane Handbook for the Evaluation of Intervention Systems to assess risk of bias and Grading of Recommendations Assessment, Development, and Evaluation. A meta-analysis with subgroup and sensitivity analyses was performed using Review Manager 5.4 and Stata 12.

Results

Nine RCTs representing 888 patients with CHF were included in the review. Meta-analysis revealed that SGCP combined with conventional heart failure therapy is more advantageous for improving left ventricular ejection fraction [LVEF; mean difference (MD) = 5.26, 95% confidence interval (CI) (3.78, 6.74), p < 0.0000] and increasing effective rate [relative risk (RR) = 1.21, 95%CI (1.14, 1.29), p < 0.001] compared with conventional therapy alone. The experimental treatment also reduced brain natriuretic peptide [MD = -100.15, 95%CI (-157.83, -42.47), p = 0.0007], left ventricular end-diastolic diameter [MD = -1.93, 95%CI (-3.22, -0.64), p = 0.003], and hypersensitive C-reactive protein [MD = -2.70, 95%CI (-3.12,-2.28), p < 0.001] compared with the control group. However, there was not a statistically significant difference in tumor necrosis factor-α [MD = -14.16, 95%CI (-34.04, 5.73), p = 0.16] or left ventricular end-systolic diameter [MD = -1.56, 95%CI (-3.13, 0.01), p = 0.05]. Nor was there a statistically significant between-groups difference in incidence of adverse events (p > 0.05).

Conclusion

SGCP combined with conventional heart failure therapy can improve LVEF and increase the effective rate to safely treat patients with CHF. However, further high-quality studies are needed to confirm these findings, due to the overall low quality of evidence in this literature.

Clinical Trial Registration: https://www.crd.york.ac.uk/PROSPERO/logout.php, PROSPERO [CRD42023390409].

HAPLN1 knockdown inhibits heart failure development via activating the PKA signaling pathway

BACKGROUND

Heart failure (HF) is a heterogeneous syndrome that affects millions worldwide, resulting in substantial health and economic burdens. However, the molecular mechanism of HF pathogenesis remains unclear.

METHODS

HF-related key genes were screened by a bioinformatics approach.The impacts of HAPLN1 knockdown on Angiotensin II (Ang II)-induced AC16 cells were assessed through a series of cell function experiments. Enzyme-linked immunosorbent assay (ELISA) was used to measure levels of oxidative stress and apoptosis-related factors. The HF rat model was induced by subcutaneous injection isoprenaline and histopathologic changes in the cardiac tissue were assessed by hematoxylin and eosin (HE) staining and echocardiographic index. Downstream pathways regulated by HAPLN1 was predicted through bioinformatics and then confirmed in vivo and in vitro by western blot.

RESULTS

Six hub genes were screened, of which HAPLN1, FMOD, NPPB, NPPA, and COMP were overexpressed, whereas NPPC was downregulated in HF. Further research found that silencing HAPLN1 promoted cell viability and reduced apoptosis in Ang II-induced AC16 cells. HAPLN1 knockdown promoted left ventricular ejection fraction (LVEF) and left ventricular fraction shortening (LVFS), while decreasing left ventricular end-systolic volume (LVESV) in the HF rat model. HAPLN1 knockdown promoted the levels of GSH and suppressed the levels of MDA, LDH, TNF-α, and IL-6. Mechanistically, silencing HAPLN1 activated the PKA pathway, which were confirmed both in vivo and in vitro.

CONCLUSION

HAPLN1 knockdown inhibited the progression of HF by activating the PKA pathway, which may provide novel perspectives on the management of HF.

Positive association between sodium-to-chloride ratio and in-hospital mortality of acute heart failure

Previous studies have suggested that levels of sodium and chloride in the blood may be indicative of the prognosis of different medical conditions. Nevertheless, the assessment of the prognostic significance of the sodium-to-chloride (Na/Cl) ratio in relation to in-hospital mortality among individuals suffering from acute heart failure (AHF) remains unexplored. In this study, the participants were selected from the Medical Information Mart for Intensive Care IV database and divided into three groups based on the Na/Cl ratio level upon admission. The primary results were the mortality rate within the hospital. Cox regression, Kaplan-Meier curves, receiver operator characteristic (ROC) curve analysis and subgroup analyses were utilized to investigate the correlation between the admission Na/Cl ratio and outcomes in critically ill patients with AHF. A total of 7844 patients who met the selection criteria were included in this study. After adjusting for confounders, the multivariable Cox regression analysis revealed that the baseline Na/Cl ratio significantly elevated the risk of in-hospital mortality among critically ill patients with AHF (HR = 1.34, 95% CI 1.21-1.49). Furthermore, when the Na/Cl ratio was converted into a categorical factor and the initial tertile was taken as a point of comparison, the hazard ratios (HRs) and 95% confidence intervals (CIs) for the second and third tertiles were 1.27 (1.05-1.54) and 1.53 (1.27-1.84), respectively. Additionally, a P value indicating a significant trend of < 0.001 was observed. ROC curve analysis showed that Na/Cl ratio had a more sensitive prognostic value in predicting in-hospital mortality of AHF than the sodium or chloride level alone (0.564 vs. 0.505, 0.544). Subgroup examinations indicated that the association between the Na/Cl ratio upon admission and the mortality rate of critically ill patients with AHF remained consistent in the subgroups of hyponatremia and hypochlorhydria (P for interaction > 0.05). The linear relationship between the Na/Cl ratio and in-hospital mortality in AHF patients indicates a positive association.

Pharmacodynamics and Mechanism of Astragali Radix and Anemarrhenae Rhizoma in Treating Chronic Heart Failure by Inhibiting Complement Activation

Astragali radix (AR) and anemarrhenae rhizoma (AAR) are used clinically in Chinese medicine for the treatment of chronic heart failure (CHF), but the exact therapeutic mechanism is unclear. In this study, a total of 60 male C57BL/6 mice were divided into 5 groups, namely sham, model, AR, AAR, and AR-AAR. In the sham group, the chest was opened without ligation. In the other groups, the chest was opened and the transverse aorta was ligated to construct the transverse aortic constriction model. After 8 weeks of feeding, mice were given medicines by gavage for 4 weeks. Left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) were detected by echocardiography. Heart weight index (HWI) and wheat germ agglutinin staining were used to evaluate cardiac hypertrophy. Hematoxylin-eosin staining was used to observe the pathological morphology of myocardial tissue. Masson staining was used to evaluate myocardial fibrosis. The content of serum brain natriuretic peptide (BNP) was detected by enzyme-linked immunosorbent assay kit. The content of serum immunoglobulin G (IgG) was detected by immunoturbidimetry. The mechanism of AR-AAR in the treatment of CHF was explored by proteomics. Western blot was used to detect the protein expressions of complement component 1s (C1s), complement component 9 (C9), and terminal complement complex 5b-9 (C5b-9). The results show that AR-AAR inhibits the expression of complement proteins C1s, C9, and C5b-9 by inhibiting the production of IgG antibodies from B cell activation, which further inhibits the complement activation, attenuates myocardial fibrosis, reduces HWI and cardiomyocyte cross-sectional area, improves cardiomyocyte injury, reduces serum BNP release, elevates LVEF and LVFS, improves cardiac function, and exerts myocardial protection.

Sacubitril/Valsartan Alleviates Cardiac Remodeling and Dysfunction in L-NAME-Induced Hypertension and Hypertensive Heart Disease

There is ample evidence on the benefit of angiotensin receptor-neprilysin inhibitors (ARNIs) in heart failure, yet data regarding the potential protective action of ARNIs in hypertensive heart disease are sparse. The aim of this study was to show whether an ARNI exerts a protective effect in a model of Nω-nitro-L-arginine methyl ester (L-NAME)-induced hypertension with a hypertensive heart and to compare this potential benefit with an angiotensin-converting enzyme inhibitor, captopril. Five groups of adult male Wistar rats were studied (14 per group) for four weeks: untreated controls; ARNI (68 mg/kg/day); L-NAME (40 mg/kg/day); L-NAME treated with ARNI; and L-NAME treated with captopril (100 mg/kg/day). L-NAME administration induced hypertension, accompanied by increased left ventricular (LV) weight and fibrotic rebuilding of the LV in terms of increased concentration and content of hydroxyproline in insoluble collagen and in total collagen and with a histological finding of fibrosis. These alterations were associated with a compromised systolic and diastolic LV function. Treatment with either an ARNI or captopril reduced systolic blood pressure (SBP), alleviated LV hypertrophy and fibrosis, and prevented the development of both systolic and diastolic LV dysfunction. Moreover, the serum levels of prolactin and prolactin receptor were reduced significantly by ARNI and slightly by captopril. In conclusion, in L-NAME-induced hypertension, the dual inhibition of neprilysin and AT1 receptors by ARNI reduced SBP and prevented the development of LV hypertrophy, fibrosis, and systolic and diastolic dysfunction. These data suggest that ARNI could provide protection against LV structural remodeling and functional disorders in hypertensive heart disease.

From Beats to Metabolism: the Heart at the Core of Interorgan Metabolic Cross Talk

The heart, once considered a mere blood pump, is now recognized as a multifunctional metabolic and endocrine organ. Its function is tightly regulated by various metabolic processes, at the same time it serves as an endocrine organ, secreting bioactive molecules that impact systemic metabolism. In recent years, research has shed light on the intricate interplay between the heart and other metabolic organs, such as adipose tissue, liver, and skeletal muscle. The metabolic flexibility of the heart and its ability to switch between different energy substrates play a crucial role in maintaining cardiac function and overall metabolic homeostasis. Gaining a comprehensive understanding of how metabolic disorders disrupt cardiac metabolism is crucial, as it plays a pivotal role in the development and progression of cardiac diseases. The emerging understanding of the heart as a metabolic and endocrine organ highlights its essential contribution to whole body metabolic regulation and offers new insights into the pathogenesis of metabolic diseases, such as obesity, diabetes, and cardiovascular disorders. In this review, we provide an in-depth exploration of the heart's metabolic and endocrine functions, emphasizing its role in systemic metabolism and the interplay between the heart and other metabolic organs. Furthermore, emerging evidence suggests a correlation between heart disease and other conditions such as aging and cancer, indicating that the metabolic dysfunction observed in these conditions may share common underlying mechanisms. By unraveling the complex mechanisms underlying cardiac metabolism, we aim to contribute to the development of novel therapeutic strategies for metabolic diseases and improve overall cardiovascular health.

Atrial natriuretic peptide T2238C gene polymorphism and the risk of cardiovascular diseases: A meta‑analysis

The present study aimed to investigate the association between atrial natriuretic peptide (ANP) T2238C (rs5065) gene polymorphism and the risk of cardiovascular disease. Relevant literature was obtained by searching databases. The odds ratios (ORs) of the ANP T2238C locus genotype distribution in the case group of cardiovascular diseases and the control group of a non-cardiovascular population were pooled using R software. Sensitivity analysis was used to verify the stability of the results. Egger's linear regression test was used to assess the publication bias of the included literature. Studies were classified according to quality assessment score of the Newcastle-Ottawa scale, year, region, sample size and underlying disease for subgroup analysis, and meta-regression analysis was performed. A total of 12 studies comprising 45,619 patients were included. ANP rs5065 mutant gene C allele was a significant risk factor for myocardial infarction relative to T allele (OR=2.55, 95% CI=1.47-4.43, P=0.0008), CC+CT genotype was a significant risk factor for cerebrovascular events relative to TT (OR=1.14, 95% CI=1.04-1.26, P=0.0048) and the mutant CC genotype was a potential risk factor for the composite cardio-cerebral vascular events (CVE) relative to CT+TT (OR=1.40, 95% CI=0.96-2.04, P=0.081). In studies fulfilling the Hardy-Weinberg equilibrium, the CC genotype was a significant risk factor for the composite CVE relative to TT (OR=2.39, 95% CI=1.40-4.10, P=0.0018) and the CC genotype was a significant risk factor for composite CVE relative to CT+TT (OR=2.41, 95% CI=1.41-4.13, P=0.0015). The P-value of the Egger's test for publication bias was 0.436, which was not statistically significant. The results of the sensitivity analysis were relatively stable. Subgroup analysis indicated that the publication year was a potential source of heterogeneity. Regression analysis was performed for the recessive model in the composite CVE and the results showed that the study region (Europe) was one of the sources of heterogeneity (P=0.016). In conclusion, ANP 2238T/C mutation may increase the risk of myocardial infarction, cerebrovascular events and composite CVE.

Identification of molecular markers for predicting the severity of heart failure after AMI: An Olink precision proteomic study

BACKGROUND

Acute myocardial infarction (AMI) still has a high incidence of varying degrees of heart failure (HF). The aim of this study is to identify new molecular markers for predicting the severity of HF after AMI.

METHODS

We analyzed demographic indicators, past medical history, clinical indicators, major adverse cardiac events (MACEs) and molecular markers in patients with different Killip classifications after AMI. Olink proteomics was used to explore new molecular markers for predicting different severity of HF after AMI.

RESULTS

Neutrophil count was the independent risk factors for in-hospital MACEs. Nineteen differentially expressed proteins (DEPs) increased significantly with increasing Killip classification. Five DEPs were also found to have an AUC (95 % CI) value greater than 0.8: GDF-15, NT-pro BNP, TNF-R2, TNF-R1 and TFF3.

CONCLUSIONS

Neutrophil count, GDF-15, TNF-R2, TNF-R1 and TFF3 were closely related to the Killip classification of HF after AMI, which suggests that the inflammatory response plays an important role in the severity of HF after AMI and that regulating inflammation might become a new target for controlling HF.

Brain natriuretic peptide in acute heart failure and its association with glomerular filtration rate: A systematic review and meta-analysis

BACKGROUND

Acute heart failure (AHF) is one of the most common cardiovascular diseases. Early diagnosis and prognosis are essential, as they can eventually lead to a fatal condition. Recently, brain natriuretic peptide (BNP) has been recognized as one of the most popular biomarkers for AHF. Changes in glomerular filtration rate (GFR) are often observed in AHF.

METHODS

We searched PubMed, Google Scholar, and ScienceDirect between March and June 2023. Original case control studies written in English that assessed levels oh BNP in AHF were included. Systematic reviews, letters to editor, correspondence, comprehensive reviews, and duplicated studies were excluded. Funnel plots were constructed to assess publication bias.

RESULTS

A total of 9 studies were selected and we obtained the mean difference (MD) of BNP level to be 2.57 (95% CI: 1.35, 3.78), and GFR to be -15.52, (95% CI: -23.35, -7.70) in AHF patients. Sensitivity analyses supported the robustness of the outcome.

CONCLUSION

Results indicated that BNP was a promising prognostic biomarker of AHF, whereas GFR was found to be negatively correlated with AHF.

Non-coding RNAs in the pathophysiology of heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) is the largest unmet clinical need in cardiovascular medicine. Despite decades of research, the treatment option for HFpEF is still limited, indicating our ongoing incomplete understanding on the underlying molecular mechanisms. Non-coding RNAs, comprising of microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), are non-protein coding RNA transcripts, which are implicated in various cardiovascular diseases. However, their role in the pathogenesis of HFpEF is unknown. Here, we discuss the role of miRNAs, lncRNAs and circRNAs that are involved in the pathophysiology of HFpEF, namely microvascular dysfunction, inflammation, diastolic dysfunction and cardiac fibrosis. We interrogated clinical evidence and dissected the molecular mechanisms of the ncRNAs by looking at the relevant in vivo and in vitro models that mimic the co-morbidities in patients with HFpEF. Finally, we discuss the potential of ncRNAs as biomarkers and potential novel therapeutic targets for future HFpEF treatment.

Cardiovascular dysfunction induced by combined exposure to nicotine inhalation and high-fat diet

Smoking and high-fat diet (HFD) consumption are two modifiable risk factors for cardiovascular (CV) diseases, and individuals who are overweight or obese due to unhealthy diet are more likely to use tobacco products. In this study, we aim to investigate the combined effects of nicotine (the addictive component of all tobacco products) and HFD on CV health, which are poorly understood. C57BL/6N male mice were placed on either HFD (60 kcal% fat) or regular diet (22 kcal% fat) and exposed to air or nicotine vapor for 10-12 wk. CV function was monitored by echocardiography and radiotelemetry, with left ventricular (LV) catheterization and aortic ring vasoreactivity assays performed at end point. Mice on HFD exhibited increased heart rate and impaired parasympathetic tone, whereas nicotine exposure increased sympathetic vascular tone as evidenced by increased blood pressure (BP) response to ganglionic blockade. Although neither nicotine nor HFD alone or in combination significantly altered BP, nicotine exposure disrupted circadian BP regulation with reduced BP dipping. LV catheterization revealed that combined exposure to nicotine and HFD led to LV diastolic dysfunction with increased LV end-diastolic pressure (LVEDP). Moreover, combined exposure resulted in increased inhibitory phosphorylation of endothelial nitric oxide synthase and greater impairment of endothelium-dependent vasodilation. Finally, a small cohort of C57BL/6N females with combined exposure exhibited similar increases in LVEDP, indicating that both sexes are susceptible to the combined effect of nicotine and HFD. In summary, combined exposure to nicotine and HFD leads to greater CV harm, including both additive and new-onset CV dysfunction.NEW & NOTEWORTHY Nicotine product usage and high-fat diet consumption are two modifiable risk factors for cardiovascular diseases. Here, we demonstrate that in mice, combined exposure to inhaled nicotine and high-fat diet results in unique cardiovascular consequences compared with either treatment alone, including left ventricular diastolic dysfunction, dysregulation of blood pressure, autonomic dysfunction, and greater impairment of endothelium-dependent vasorelaxation. These findings indicate that individuals who consume both nicotine products and high-fat diet have distinctive cardiovascular risks.

Building synthetic biosensors using red blood cell proteins

As the use of engineered cell therapies expands from pioneering efforts in cancer immunotherapy to other applications, an attractive but less explored approach is the use of engineered red blood cells (RBCs). Compared to other cells, RBCs have a very long circulation time and reside in the blood compartment, so they could be ideally suited for applications as sentinel cells that enable in situ sensing and diagnostics. However, we largely lack tools for converting RBCs into biosensors. A unique challenge is that RBCs remodel their membranes during maturation, shedding many membrane components, suggesting that an RBC-specific approach may be needed. Towards addressing this need, here we develop a biosensing architecture built on RBC membrane proteins that are retained through erythropoiesis. This biosensor employs a mechanism in which extracellular ligand binding is transduced into intracellular reconstitution of a split output protein (including either a fluorophore or an enzyme). By comparatively evaluating a range of biosensor architectures, linker types, scaffold choices, and output signals, we identify biosensor designs and design features that confer substantial ligand-induced signal in vitro. Finally, we demonstrate that erythroid precursor cells engineered with our RBC protein biosensors function in vivo. This study establishes a foundation for developing RBC-based biosensors that could ultimately address unmet needs including non-invasive monitoring of physiological signals for a range of diagnostic applications.

Micropeptides: origins, identification, and potential role in metabolism-related diseases

With the development of modern sequencing techniques and bioinformatics, genomes that were once thought to be noncoding have been found to encode abundant functional micropeptides (miPs), a kind of small polypeptides. Although miPs are difficult to analyze and identify, a number of studies have begun to focus on them. More and more miPs have been revealed as essential for energy metabolism homeostasis, immune regulation, and tumor growth and development. Many reports have shown that miPs are especially essential for regulating glucose and lipid metabolism and regulating mitochondrial function. MiPs are also involved in the progression of related diseases. This paper reviews the sources and identification of miPs, as well as the functional significance of miPs for metabolism-related diseases, with the aim of revealing their potential clinical applications.

Bioactive Peptides from Ruditapes philippinarum Attenuate Hypertension and Cardiorenal Damage in Deoxycorticosterone Acetate-Salt Hypertensive Rats

Hypertension is a common disease that affects human health and can lead to damage to the heart, kidneys, and other important organs. In this study, we investigated the regulatory effects of bioactive peptides derived from Ruditapes philippinarum (RPP) on hypertension and organ protection in deoxycorticosterone acetate (DOCA)-salt hypertensive rats. We found that RPPs exhibited significant blood pressure-lowering properties. Furthermore, the results showed that RPPs positively influenced vascular remodeling and effectively maintained a balanced water-sodium equilibrium. Meanwhile, RPPs demonstrated anti-inflammatory potential by reducing the serum levels of inflammatory cytokines (TNF-α, IL-2, and IL-6). Moreover, we observed the strong antioxidant activity of RPPs, which played a critical role in reducing oxidative stress and alleviating hypertension-induced damage to the aorta, heart, and kidneys. Additionally, our study explored the regulatory effects of RPPs on the gut microbiota, suggesting a possible correlation between their antihypertensive effects and the modulation of gut microbiota. Our previous studies have demonstrated that RPPs can significantly reduce blood pressure in SHR rats. This suggests that RPPs can significantly improve both essential hypertension and DOAC-salt-induced secondary hypertension and can ameliorate cardiorenal damage caused by hypertension. These findings further support the possibility of RPPs as an active ingredient in functional anti-hypertensive foods.

Long-term prognostic value of high-sensitivity cardiac troponin-I in patients with idiopathic dilated cardiomyopathy

Our objective was to evaluate the long-term prognostic value of high-sensitivity cardiac troponin-I (hs-cTn-I) in idiopathic dilated cardiomyopathy (DCM). First, patients were divided into an end-event group (n = 55) and a non-end-event group (n = 67). Then, patients were included in the subgroup analysis to compare the diagnostic value of brain natriuretic peptide (BNP) and hs-cTn-I in different populations. hs-cTn-I and BNP concentrations were higher in the end-event group. The Cox regression analysis indicated that high hs-cTn-I was a risk factor for poor long-term prognosis. Receiver operating characteristic analysis showed that the area under the curve (AUC) for hs-cTn-I to predict end events was 0.751, and the AUC for BNP was 0.742. The correlation analysis suggested that hs-cTn-I was related to the percentage change in left ventricular internal diameter at end-diastolic and left ventricular ejection fraction. Subgroup analysis showed that compared with BNP, hs-cTn-I was more suitable for predicting end events in patients with preserved renal function (AUC: 0.853 vs 0.712, P = 0.04). In conclusion, hs-cTn-I is a potential biomarker for evaluating long-term prognosis in idiopathic DCM, and its predictive value is higher than that of BNP in patients with preserved renal function.

Cellular Membrane-Engineered Nanovesicles as a Three-Stage Booster to Target the Lesion Core

The lesion core is the area with the most serious injury and vigorous repair. Existing nanocarriers are difficult to break through the targeted delivery to the lesion core for precise treatment in the intracellular and extracellular microenvironment. Herein, a cellular membrane-engineered nanovesicle (CMEV) with a hierarchical structure is constructed using the double emulsion-extrusion method by integrating a neutrophil membrane, functional antibody, and gelled drug-loaded core as a three-stage booster to target the lesion core and deliver catestatin (CST), a small therapeutic peptide, for ischemic cardiomyopathy therapy. By coating the neutrophil membrane outside the shell, CMEV is endowed with the function of neutrophil-like migration to achieve the first stage of tissue targeting. Based on the specific anchoring to injured myocardium, a myosin light chain 3 (MLC3) antibody is embedded to fulfill the second stage of CMEV accumulation in the lesion core. The gelled core containing CST-sodium alginate (NaAlg) with a pH-responsive shell is prepared by ionic cross-linking to accomplish the third stage of precise CST administration. Triggered by the microenvironment, NaAlg electrostatically adheres to the lesion core for sustained release, enhancing the efficacy of CST in improving cardiomyocyte apoptosis, excessive fibrosis, macrophage polarization, and angiogenesis. Thus, the "three-stage booster" nanovesicle significantly ameliorates cardiac function and adverse remodeling to treat ischemic cardiomyopathy.

Assessment of amino-terminal C-type natriuretic peptide serum level and its correlation with high-density lipoprotein structure and function in patients with end stage renal disease before and after kidney transplantation

We aimed to investigate serum amino-terminal C-type natriuretic peptide (NT-proCNP) and its relationship with quantitative and qualitative HDL-parameters in patients with end-stage renal disease (ESRD) before, then 1 and 6 months after kidney transplantation (TX). Seventy patients (47 males, 23 females, mean age 51.7 ± 12.4 years) were enrolled in a prospective follow-up study. We examined serum creatinine, C-reactive protein, procalcitonin, fasting glucose and lipid parameters before, then 1 and 6 months after TX. High-density lipoprotein- (HDL)-associated paraoxonase-1 (PON1) paraoxonase and arylesterase activities were measured spectrophotometrically. Lipoprotein subfractions were determined by Lipoprint. NT-proCNP and oxidized low-density lipoprotein (oxLDL) levels were measured by ELISA. Mean NT-proCNP was 45.8 ± 21.9 pmol/L before renal transplantation and decreased markedly 1 month and 6 months after transplantation (5.3 ± 2.5 and 7.7 ± 4.9 pmol/L, respectively, P = 1 × 10-4). During the 6 months' follow-up, PON1 arylesterase, paraoxonase and salt-stimulated paraoxonase activities improved. NT-proCNP positively correlated with procalcitonin and creatinine and negatively with GFR, LDL-cholesterol (LDL-C) and HDL-cholesterol (HDL-C). There was a negative correlation between serum NT-proCNP and PON1 arylesterase activity. According to the multiple regression analysis, the best predicting variables of NT-proCNP were serum procalcitonin, creatinine and PON1 arylesterase activity. NT-proCNP might be a novel link between HDL dysfunction and impaired vascular function in ESRD, but not after kidney transplantation. Further studies in larger populations are needed to clarify the exact role of NT-proCNP in the risk prediction for cardiovascular comorbidities and complications in ESRD.

Topoisomeric Membrane-Active Peptides: A Review of the Last Two Decades

In recent decades, bioactive peptides have been gaining recognition in various biomedical areas, such as intracellular drug delivery (cell-penetrating peptides, CPPs) or anti-infective action (antimicrobial peptides, AMPs), closely associated to their distinct mode of interaction with biological membranes. Exploiting the interaction of membrane-active peptides with diverse targets (healthy, tumoral, bacterial or parasitic cell membranes) is opening encouraging prospects for peptides in therapeutics. However, ordinary peptides formed by L-amino acids are easily decomposed by proteases in biological fluids. One way to sidestep this limitation is to use topoisomers, namely versions of the peptide made up of D-amino acids in either canonic (enantio) or inverted (retroenantio) sequence. Rearranging peptide sequences in this fashion provides a certain degree of native structure mimicry that, in appropriate contexts, may deliver desirable biological activity while avoiding protease degradation. In this review, we will focus on recent accounts of membrane-active topoisomeric peptides with therapeutic applications as CPP drug delivery vectors, or as antimicrobial and anticancer candidates. We will also discuss the most common modes of interaction of these peptides with their membrane targets.

Phloretin ameliorates heart function after myocardial infarction via NLRP3/Caspase-1/IL-1β signaling

OBJECTIVES/AIMS

Inflammation is crucial in structural and electrical remodeling after myocardial infarction (MI), affecting cardiac pump function and conduction pathways. Phloretin possesses an anti-inflammation role by inhibiting the NLRP3/Caspase-1/IL-1β pathway. However, the effects of Phloretin on cardiac contractile and electrical conduction function after MI remained unclear. Therefore, we aimed to investigate the potential role of Phloretin in a rat model of MI.

METHODS

Rats were assigned into four groups: Sham, Sham+Phloretin, MI and MI+Phloretin, with ad libitum food and water. In the MI and MI+Phloretin groups, the left anterior descending coronary artery was occluded for 4 weeks, while the Sham and Sham+Phloretin groups received sham operation. The Sham+Phloretin group and the MI+Phloretin group received oral administration of Phloretin. In vitro, H9c2 cells were subjected to hypoxic conditions to simulate an MI model, with Phloretin for 24 h. Cardiac electrophysiological properties were assessed following MI, including the effective refractory period (ERP), action potential duration (APD)90 and ventricular fibrillation (VF) incidence. Echocardiography evaluated left ventricular ejection fraction (LVEF), left ventricular fraction shortening (LVFS), left ventricular internal diameter at end-diastole (LVIDd), left ventricular internal diameter at end-systole (LVIDs), left ventricular end-systolic volume (LVESV) and left ventricular end-diastolic volume (LVEDV) to assess cardiac function. Serum type B natriuretic peptide (BNP) level was applied to evaluate the degree of Heart failure (HF). The fibrosis area and severity were assessed by Masson staining and protein expression levels of collagen 3, collagen 1, TGF-β and α-SMA. Western blot analysis estimated the protein expression levels of NLRP3, Pro Caspase-1, Caspase-1, ASC, IL-18, IL-1β, pp38, p38, and Connexin43(Cx43) to elucidate the influence of inflammation on electrical remodeling after MI.

RESULTS

Our findings demonstrate that Phloretin inhibits the NLRP3/Caspase-1/IL-1β pathway, leading to the upregulation of Cx43 by limiting p38 phosphorylation, which further decreases susceptibility to ventricular arrhythmias (VAs). Additionally, Phloretin attenuated fibrosis by inhibiting inflammation to prevent HF. In vitro experiments also provided strong evidence supporting the inhibitory effects of Phloretin on the NLRP3/Caspase-1/IL-1β pathway.

CONCLUSION

Our results suggest that Phloretin could suppress the NLRP3/Caspase-1/IL-1β pathway to reverse structural and electrical remodeling after MI to prevent the occurrence of VAs and HF.

Corin deficiency impairs cardiac function in mouse models of heart failure

Introduction

Corin is a protease in the natriuretic peptide system. Deleterious CORIN variants are associated with hypertension and heart disease. It remains unclear if and to what extent corin deficiency may contribute to heart failure (HF).

Methods

Corin knockout (KO) mice were used as a model. Cardiac function was assessed by echocardiography and tissue analysis in Corin KO mice at different ages or subjected to transverse aortic constriction (TAC), which increased pressure overload. Heart and lung tissues were analyzed for cardiac hypertrophy and lung edema using wheat germ agglutinin, Sirius red, Masson's trichrome, and Prussian blue staining. Recombinant corin was tested for its effect on cardiac function in the TAC-operated Corin KO mice. Selected gene expression in the heart was examined by RT-PCR. ELISA was used to analyze factors in plasma.

Results

Corin KO mice had progressive cardiac dysfunction with cardiac hypertrophy and fibrosis after 9 months of age, likely due to chronic hypertension. When Corin KO mice were subjected to TAC at 10-12 weeks of age, cardiac function decreased more rapidly than in similarly treated wild-type mice. When the TAC-operated Corin KO mice were treated with recombinant corin protein, cardiac dysfunction, hypertrophy, and fibrosis were ameliorated. The corin treatment also decreased the gene expression associated with cardiac hypertrophy and fibrosis, increased plasma cGMP levels, lowered plasma levels of N-terminal pro-atrial natriuretic peptide, angiotensin II, and aldosterone, and lessened lung edema in the Corin KO mice subjected to TAC.

Conclusion

Corin deficiency impairs cardiac function and exacerbates HF development in mice. Corin protein may be used to reduce cardiac hypertrophy and fibrosis, suppress the renin-angiotensin-aldosterone system, and improve cardiac function in HF.

NPRC deletion mitigated atherosclerosis by inhibiting oxidative stress, inflammation and apoptosis in ApoE knockout mice

Previous studies suggested a beneficial effect of natriuretic peptides in animal models of cardiovascular disease, but the role of natriuretic peptide receptor C (NPRC) in the pathogenesis of atherosclerosis (AS) remains unknown. This study was designed to test the hypothesis that NPRC may promote AS lesion formation and instability by enhancing oxidative stress, inflammation, and apoptosis via protein kinase A (PKA) signaling. ApoE-/- mice were fed chow or Western diet for 12 weeks and NPRC expression was significantly increased in the aortic tissues of Western diet-fed mice. Systemic NPRC knockout mice were crossed with ApoE-/- mice to generate ApoE-/-NPRC-/- mice, and NPRC deletion resulted in a significant decrease in the size and instability of aortic atherosclerotic lesions in ApoE-/-NPRC-/- versus ApoE-/- mice. In addition, endothelial cell-specific NPRC knockout attenuated atherosclerotic lesions in mice. In contrast, endothelial cell overexpression of NPRC aggravated the size and instability of atherosclerotic aortic lesions in mice. Experiments in vitro showed that NPRC knockdown in human aortic endothelial cells (HAECs) inhibited ROS production, pro-inflammatory cytokine expression and endothelial cell apoptosis, and increased eNOS expression. Furthermore, NPRC knockdown in HAECs suppressed macrophage migration, cytokine expression, and phagocytosis via its effects on endothelial cells. On the contrary, NPRC overexpression in endothelial cells resulted in opposite effects. Mechanistically, the anti-inflammation and anti-atherosclerosis effects of NPRC deletion involved activation of cAMP/PKA pathway, leading to downstream upregulated AKT1 pathway and downregulated NF-κB pathway. In conclusion, NPRC deletion reduced the size and instability of atherosclerotic lesions in ApoE-/- mice via attenuating inflammation and endothelial cell apoptosis and increasing eNOS expression by modulating cAMP/PKA-AKT1 and NF-κB pathways. Thus, targeting NPRC may provide a promising approach to the prevention and treatment of atherosclerosis.

Natriuretic Peptide Signaling in Uterine Biology and Preeclampsia

Endometrial decidualization is a uterine process essential for spiral artery remodeling, embryo implantation, and trophoblast invasion. Defects in endometrial decidualization and spiral artery remodeling are important contributing factors in preeclampsia, a major disorder in pregnancy. Atrial natriuretic peptide (ANP) is a cardiac hormone that regulates blood volume and pressure. ANP is also generated in non-cardiac tissues, such as the uterus and placenta. In recent human genome-wide association studies, multiple loci with genes involved in natriuretic peptide signaling are associated with gestational hypertension and preeclampsia. In cellular experiments and mouse models, uterine ANP has been shown to stimulate endometrial decidualization, increase TNF-related apoptosis-inducing ligand expression and secretion, and enhance apoptosis in arterial smooth muscle cells and endothelial cells. In placental trophoblasts, ANP stimulates adenosine 5'-monophosphate-activated protein kinase and the mammalian target of rapamycin complex 1 signaling, leading to autophagy inhibition and protein kinase N3 upregulation, thereby increasing trophoblast invasiveness. ANP deficiency impairs endometrial decidualization and spiral artery remodeling, causing a preeclampsia-like phenotype in mice. These findings indicate the importance of natriuretic peptide signaling in pregnancy. This review discusses the role of ANP in uterine biology and potential implications of impaired ANP signaling in preeclampsia.

CYP2J deficiency leads to cardiac injury and presents dual regulatory effects on cardiac function in rats

Cytochrome P450 2 J2 (CYP2J2) enzyme is widely expressed in aortic endothelial cells and cardiac myocytes and affects cardiac function, but the underlying mechanism is still unclear. Based on CYP2J knockout (KO) rats, we have directly studied the metabolic regulation of CYP2J on cardiac function during aging. The results showed that CYP2J deficiency significantly reduced the content of epoxyeicosatrienoic acids (EETs) in plasma, aggravated myocarditis, myocardial hypertrophy, as well as fibrosis, and inhibited the mitochondrial energy metabolism signal network Pgc-1α/Ampk/Sirt1. With the increase of age, the levels of 11,12-EET and 14,15-EET in plasma of KO rats decreased significantly, and the heart injury was more serious. Interestingly, we found that after CYP2J deletion, the heart initiated a self-protection mechanism by upregulating cardiac mechanism factors Myh7, Dsp, Tnni3, Tnni2, and Scn5a, as well as mitochondrial fusion factors Mfn2 and Opa1. However, this protective effect disappeared with aging. In conclusion, CYP2J deficiency not only reduces the amount of EETs, but also plays a dual regulatory role in cardiac function.

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.

Efficacy of a growth hormone-releasing hormone agonist in a murine model of cardiometabolic heart failure with preserved ejection fraction

Heart failure (HF) with preserved ejection fraction (HFpEF) represents a major unmet medical need owing to its diverse pathophysiology and lack of effective therapies. Potent synthetic, agonists (MR-356 and MR-409) of growth hormone-releasing hormone (GHRH) improve the phenotype of models of HF with reduced ejection fraction (HFrEF) and in cardiorenal models of HFpEF. Endogenous GHRH exhibits a broad range of regulatory influences in the cardiovascular (CV) system and aging and plays a role in several cardiometabolic conditions including obesity and diabetes. Whether agonists of GHRH can improve the phenotype of cardiometabolic HFpEF remains untested and unknown. Here we tested the hypothesis that MR-356 can mitigate/reverse the cardiometabolic HFpEF phenotype. C57BL6N mice received a high-fat diet (HFD) plus the nitric oxide synthase inhibitor (l-NAME) for 9 wk. After 5 wk of HFD + l-NAME regimen, animals were randomized to receive daily injections of MR-356 or placebo during a 4-wk period. Control animals received no HFD + l-NAME or agonist treatment. Our results showed the unique potential of MR-356 to treat several HFpEF-like features including cardiac hypertrophy, fibrosis, capillary rarefaction, and pulmonary congestion. MR-356 improved cardiac performance by improving diastolic function, global longitudinal strain (GLS), and exercise capacity. Importantly, the increased expression of cardiac pro-brain natriuretic peptide (pro-BNP), inducible nitric oxide synthase (iNOS), and vascular endothelial growth factor-A (VEGF-A) was restored to normal levels suggesting that MR-356 reduced myocardial stress associated with metabolic inflammation in HFpEF. Thus, agonists of GHRH may be an effective therapeutic strategy for the treatment of cardiometabolic HFpEF phenotype.NEW & NOTEWORTHY This randomized study used rigorous hemodynamic tools to test the efficacy of a synthetic GHRH agonist to improve cardiac performance in a cardiometabolic HFpEF. Daily injection of the GHRH agonist, MR-356, reduced the HFpEF-like effects as evidenced by improved diastolic dysfunction, reduced cardiac hypertrophy, fibrosis, and pulmonary congestion. Notably, end-diastolic pressure and end-diastolic pressure-volume relationship were reset to control levels. Moreover, treatment with MR-356 increased exercise capacity and reduced myocardial stress associated with metabolic inflammation in HFpEF.

Single-nucleus ribonucleic acid-sequencing and spatial transcriptomics reveal the cardioprotection of Shexiang Baoxin Pill (SBP) in mice with myocardial ischemia-reperfusion injury

Aim: The Shexiang Baoxin Pill (SBP) has been extensively used to treat cardiovascular diseases in China for four decades, and its clinical efficacy has been widely approved. However, the mechanism by which this is achieved remains largely unexplored. Research attempting to understand the underlying mechanism is ongoing, but the findings are controversial. Here, we aimed to explore the possible mechanism of SBP in myocardial ischemia-reperfusion (I/R) injury using heart single-nucleus and spatial ribonucleic acid (RNA) sequencing. Methods: We established a murine myocardial I/R injury model in C57BL/6 mice by ligating and recanalizing the left coronary artery anterior descending branch. Subsequently, single-nucleus RNA-seq and spatial transcriptomics were performed on mice cardiac tissue. We initially assessed the status of cell types and subsets in the model administered with or without SBP. Results: We used single-nucleus RNA sequencing to comprehensively analyze cell types in the cardiac tissue of sham, I/R, and SBP mice. Nine samples from nine individuals were analyzed, and 75,546 cells were obtained. We classified the cells into 28 clusters based on their expression characteristics and annotated them into seven cell types: cardiomyocytes, endothelial cells, fibroblasts, myeloid cells, smooth muscle cells, B cells, and T cells. The SBP group had distinct cellular compositions and features than the I/R group. Furthermore, SBP-induced cardioprotection against I/R was associated with enhanced cardiac contractility, reduced endocardial cell injury, increased endocardial-mediated angiogenesis, and inhibited fibroblast proliferation. In addition, macrophages had active properties. Conclusion: SBP improves the early LVEF of I/R mice and has a cardioprotective effect. Through sequencing analysis, we observed that SBP can increase the gene expression of Nppb and Npr3 in the infarct area of the heart. Npr3 is related to vascular generation mediated by endocardial cells and requires further research. In addition, SBP increases the number of fibroblasts, inhibits the expression of genes related to fibroblast activation and proliferation, and increases the transformation of endothelial cells into fibroblasts. These findings will help to indicate directions for further research.

Effect of the structural modification of Candesartan with Zinc on hypertension and left ventricular hypertrophy

Hypertension is the most common cause of left ventricular hypertrophy, contributing to heart failure progression. Candesartan (Cand) is an angiotensin receptor antagonist widely used for hypertension treatment. Structural modifications were previously performed by our group using Zinc (ZnCand) as a strategy for improving its pharmacological properties. The measurements showed that ZnCand exerts a stronger interaction with the angiotensin II receptor, type 1 (AT1 receptor), reducing oxidative stress and intracellular calcium flux, a mechanism implied in cell contraction. These results were accompanied by the reduction of the contractile capacity of mesangial cells. In vivo experiments showed that the complex causes a significant decrease in systolic blood pressure after 8 weeks of treatment in spontaneously hypertensive rats (SHR). The reduction of heart hypertrophy was evidenced by echocardiography, the histologic cross-sectional area of cardiomyocytes, collagen content, the B-type natriuretic peptide (BNP) marker and connective tissue growth factor (CTGF) and the matrix metalloproteinase 2 (MMP-2) expression. Besides, the complex restored the redox status. In this study, we demonstrated that the complexation with Zn(II) improves the antihypertensive and cardiac effects of the parental drug.

Jiedu Quyu Decoction mitigates monocrotaline-induced right-sided heart failure associated with pulmonary artery hypertension by inhibiting NLRP3 inflammasome in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Right-side heart failure could accelerate mortality in patients of pulmonary hypertension, Jiedu Quyu Decoction (JDQYF) was used to manage pulmonary hypertension, but its right-sided heart protective effect associated with pulmonary artery hypertension is still unclear.

AIM OF THE STUDY

Here, we evaluated the therapeutic effect of JDQYF on monocrotaline-induced right-sided heart failure associated with pulmonary arterial hypertension in Sprague-Dawley (SD) rats and investigated the potential mechanism of action.

MATERIALS AND METHODS

The main chemical components of JDQYF were detected and analyzed using ultra-high-performance liquid chromatography quadrupole time-of-flight mass spectrometry. The effects of JDQYF were investigated using a rat model of monocrotaline-induced right-sided heart failure associated with pulmonary arterial hypertension. We assessed the morphology of cardiac tissue using histopathology and the structure and function of the right heart using echocardiography. The biomarkers of heart failure, atrial natriuretic peptide and B-type natriuretic peptide, as well as serum pro-inflammatory markers, interleukin (IL)-1β, and IL-18, were measured by enzyme-linked immunosorbent assay (ELISA). Furthermore, the mRNA and protein expression levels of NLRP3 (NOD-, LRR-, and pyrin domain-containing 3), capase-1, IL-1β, and IL-18 in the right heart tissue were examined by real-time quantitative reverse transcription PCR and western blotting.

RESULTS

JDQYF improved ventricular function, alleviated pathological lesions in the right cardiac tissue, reduced the expression levels of biomarkers of heart failure and serum pro-inflammatory factors (IL-1β and IL-18), and downregulated the mRNA and protein expression levels of NLRP3, caspase-1, IL-1β, and IL-18 in the right cardiac tissue.

CONCLUSIONS

JDQYF possesses cardioprotective effect against right heart failure induced by pulmonary arterial hypertension, possibly owing to reduction of cardiac inflammation through the inhibition of NLRP3 inflammasome activation.

Dual function of protein phosphatase 5 (PPP5C): An emerging therapeutic target for drug discovery

Phosphorylation of proteins is reversibly controlled by the kinases and phosphatases in many posttranslational regulation patterns. Protein phosphatase 5 (PPP5C) is a serine/threonine protein phosphatase showing dual function by simultaneously exerting dephosphorylation and co-chaperone functions. Due to this special role, PPP5C was found to participate in many signal transductions related to various diseases. Abnormal expression of PPP5C results in cancers, obesity, and Alzheimer's disease, making it a potential drug target. However, the design of small molecules targeting PPP5C is struggling due to its special monomeric enzyme form and low basal activity by a self-inhibition mechanism. Through realizing the PPP5C's dual function as phosphatase and co-chaperone, more and more small molecules were found to regulate PPP5C with a different mechanism. This review aims to provide insights into PPP5C's dual function from structure to function, which could provide efficient design strategies for small molecules targeting PPP5C as therapeutic candidates.

Central role of laboratory medicine in public health and patient care

Clinical laboratories play a vital role in the healthcare system. Objective medical data provided by clinical laboratories supports approximately 60-70% of clinical decisions, however, evidence supporting this claim is poorly documented and laboratories still lack visibility, despite their indisputable impact on patient care and public health. The International Federation for Clinical Chemistry and Laboratory Medicine (IFCC) Task Force on Outcome Studies in Laboratory Medicine (TF-OSLM) was recently developed to support directed research evaluating the role of laboratory medicine on clinical outcomes. Establishing and documenting this evidence is key to enhance visibility of the field in the eye of the public and other healthcare professionals together with optimizing patient outcomes and health care system operations. In this review, we discuss four areas that exemplify the contribution of laboratory medicine directly to patient care. This includes high-sensitivity cardiac troponin (hs-cTn) and N-terminal pro-B-type natriuretic peptide/B-type natriuretic peptides (NT-proBNP/BNP) for the diagnosis and prognosis of myocardial infarction and heart failure, respectively, and procalcitonin for the management of sepsis and antibiotic stewardship. Emerging markers of traumatic brain injury and the role of laboratory medicine in the fight against the COVID-19 pandemic are discussed along with an introduction to plans of IFCC TF-OSLM.

PPAR Alpha Activation by Clofibrate Alleviates Ischemia/Reperfusion Injury in Metabolic Syndrome Rats by Decreasing Cardiac Inflammation and Remodeling and by Regulating the Atrial Natriuretic Peptide Compensatory Response

Metabolic syndrome (MetS) is a cluster of factors that increase the risk of developing diabetes, stroke, and heart failure. The pathophysiology of injury by ischemia/reperfusion (I/R) is highly complex and the inflammatory condition plays an important role by increasing matrix remodeling and cardiac apoptosis. Natriuretic peptides (NPs) are cardiac hormones with numerous beneficial effects mainly mediated by a cell surface receptor named atrial natriuretic peptide receptor (ANPr). Although NPs are powerful clinical markers of cardiac failure, their role in I/R is still controversial. Peroxisome proliferator-activated receptor α agonists exert cardiovascular therapeutic actions; however, their effect on the NPs’ signaling pathway has not been extensively studied. Our study provides important insight into the regulation of both ANP and ANPr in the hearts of MetS rats and their association with the inflammatory conditions caused by damage from I/R. Moreover, we show that pre-treatment with clofibrate was able to decrease the inflammatory response that, in turn, decreases myocardial fibrosis, the expression of metalloprotease 2 and apoptosis. Treatment with clofibrate is also associated with a decrease in ANP and ANPr expression.

Prognostic Value of Soluble AXL in Serum from Heart Failure Patients with Preserved and Reduced Left Ventricular Ejection Fraction

Heart failure (HF) is classified according to the degree of reduction in left ventricular ejection fraction (EF) in HF with reduced, mildly reduced, and preserved EF. Biomarkers could behave differently depending on EF type. Here, we analyze the soluble form of the AXL receptor tyrosine kinase (sAXL) in HF patients with reduced and preserved EF. Two groups of HF patients with reduced (HFrEF; n = 134) and preserved ejection fraction (HFpEF; n = 134) were included in this prospective observational study, with measurements of candidate biomarkers and functional, clinical, and echocardiographic variables. A Cox regression model was used to determine predictors for clinical events: cardiovascular mortality and all-cause mortality. sAXL circulating values predicted outcome in HF: for a 1.0 ng/mL increase in serum sAXL, the mortality hazard ratio (HR) was 1.019 for HFrEF (95% CI 1.000 to 1.038) and 1.032 for HFpEF (95% CI 1.013 to 1.052). In a multivariable Cox regression analysis, sAXL and NT-proBNP were independent markers for all-cause and cardiovascular mortality in HFpEF. In contrast, only NT-proBNP remained significant in the HFrEF group. When analyzing the event-free survival at a mean follow-up of 3.6 years, HFrEF and HFpEF patients in the higher quartile of sAXL had a reduced survival time. Interestingly, sAXL is a reliable predictor for all-cause and cardiovascular mortality only in the HFpEF cohort. The results suggest an important role for AXL in HFpEF, supporting sAXL evaluation in larger clinical studies and pointing to AXL as a potential target for HF therapy.

Diagnostic and prognostic biomarkers reflective of cardiac remodelling in diabetes mellitus: A scoping review

AIMS

The aim of this scoping review is to evaluate the current biomarkers used in the assessment of adverse cardiac remodelling in people with diabetes mellitus (DM) and in the diagnosis and prognosis of subsequent cardiovascular disease. We aim to discuss the biomarkers' pathophysiological roles as a reflection of the cardiac remodelling mechanisms in the presence of DM.

METHODS

We performed the literature search to include studies from 2003 to 2021 using the following databases: MEDLINE, Scopus, Web of Science, PubMed, and Cochrane library. Articles that met our inclusion criteria were screened and appraised before being included in this review. The PRISMA guidelines for Scoping Reviews were followed.

RESULTS

Our literature search identified a total of 43 eligible articles, which were included in this scoping review. We identified 15 different biomarkers, each described by at least two studies, that were used to determine signs of cardiac remodelling in cardiovascular disease (CVD) and people with DM. NT-proBNP was identified as the most frequently employed biomarker in this context; however, we also identified emerging biomarkers including hs-CRP, hs-cTnT, and Galectin-3.

CONCLUSION

There is a complex relationship between DM and cardiovascular health, where more research is needed. Current biomarkers reflective of adverse cardiac remodelling in DM are often used to diagnose other CVDs, such as NT-proBNP for heart failure. Hence there is a need for identification of specific biomarkers that can detect early signs of cardiac remodelling in the presence of DM. Further research into these biomarkers and mechanisms can deepen our understanding of their role in DM-associated CVD and lead to better preventative therapies.

The Neurohormonal Overactivity Syndrome in Heart Failure

Heart failure (HF) is categorized arbitrarily based on the left ventricular ejection fraction (LVEF) in HF with reduced (HFrEF; LVEF < 40%), mildly reduced (HFmrEF; LVEF 40−49%), or preserved ejection fraction (HFpEF; LVEF ≥ 50%). In this opinion paper, based on (patho)physiological considerations, we contend that the neurohormonal overactivity syndrome (NOHS), which is present in all symptomatic HF patients irrespective of their LVEF, not only contributes to the development of signs and symptoms but it is also a major determinant of patients’ outcomes. In this regard, NHOS is the only currently available treatment target in HF and should be combatted in most patients with the combined use of diuretics and neurohormonal inhibitors (β-blockers, angiotensin receptor-neprilysin inhibitor/angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, mineralocorticoid antagonists, and sodium-glucose co-transporter 2 inhibitors). Unfortunately, despite the advances in therapeutics, HF mortality remains high. Probably machine learning approaches could better assess the multiple and higher-dimension interactions leading to the HF syndrome and define clusters of HF treatment efficacy.

Diagnostic value of atrial natriuretic peptide (ANP), B-type natriuretic peptide (BNP) and their correlation with lipoproteins in dogs with myxomatous mitral valve disease

BACKGROUND

Myxomatous mitral valve disease (MMVD) is the most common diagnosed cardiovascular disease in dogs. Atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) tests are used to diagnose congestive heart failure, but there are conflicting reports about their value in diagnosing the subclinical stages of MMVD in dogs. Moreover, the diagnostic value of blood lipoproteins in dogs with MMVD is still unclear. The purpose of this study was to assess the serum concentrations of ANP, BNP and lipoproteins of dogs with MMVD and to evaluate the correlation of the levels of ANP and BNP with lipoproteins.

RESULTS

This study was performed on 24 dogs with MMVD and 10 healthy dogs. Dogs with MMVD were classified in to stages B1 (n = 11), B2 (n = 6), C (n = 4) and D (n = 3) groups according to the classification suggested by American College of Veterinary Internal Medicine guidelines. Our results showed that the mean serum BNP levels were significantly increased for all MMVD groups compared to control dogs. The mean serum ANP levels for the stage B2, C and D groups were significantly higher than the control group, while the mean serum ANP concentrations did not differ significantly between the stage B1 and control groups. An increase in BNP level was observed in 87.5% of patients. Although BNP concentrations were elevated in 100% of dogs with stages C, D and B2, high BNP was observed in 72.72% of dogs with stage B1. Regarding ANP, 58.33% of patients had an increase in ANP. However, elevated ANP levels were found in only 27.27% of patients in stage B1, while increased ANP levels were observed in 66.66 and 100% of patients in stage B2 and C/D groups respectively. Also, in all patients with MMVD, the mean serum concentrations of high-density lipoprotein cholesterol (HDL-C) were approximately 1.7 to 2 times significantly lower than the control group. Additionally, the mean serum low-density lipoprotein cholesterol (LDL-C) increased significantly (1.9-2.7 times) compared to the control group. There was a significant inverse correlation between HDL-C and BNP, and HDL-C and ANP. LDL-C showed a significant positive correlation with BNP, and ANP. Also, LDL-C, but not HDL-C, had a significant positive correlation with LA/AO ratio, LVIDd, LVIDdN and VHS. BNP and ANP showed a significant positive correlation with LA/AO, LVIDd, LVIDdN and VHS.

CONCLUSIONS

Serum BNP has a greater diagnostic value than serum ANP in dogs with MMVD. In addition, serum BNP can be used to determine the subclinical stages of B1 and B2 MMVD. This study also suggests that dogs with subclinical MMVD, showed an increase in BNP along with a decrease in HDL-C and an increase in LDL-C, which are known to be risk factors for cardiovascular diseases in human. However, it seems that high LDL-C is more involved in the pathogenesis of MMVD than low HDL-C. Therefore, periodic testing of serum lipoproteins is recommended in high-risk patients, even if total cholesterol levels are normal.

Exercise training after myocardial infarction increases survival but does not prevent adverse left ventricle remodeling and dysfunction in high-fat diet fed mice

AIMS

Aerobic exercise is an important component of rehabilitation after cardiovascular injuries including myocardial infarction (MI). In human studies, the beneficial effects of exercise after an MI are blunted in patients who are obese or glucose intolerant. Here, we investigated the effects of exercise on MI-induced cardiac dysfunction and remodeling in mice chronically fed a high-fat diet (HFD).

MAIN METHODS

C57Bl/6 male mice were fed either a standard (Chow; 21% kcal/fat) or HFD (60% kcal/fat) for 36 weeks. After 24 weeks of diet, the HFD mice were randomly subjected to an MI (MI) or a sham surgery (Sham). Following the MI or sham surgery, a subset of mice were subjected to treadmill exercise.

KEY FINDINGS

HFD resulted in obesity and glucose intolerance, and this was not altered by exercise or MI. MI resulted in decreased ejection fraction, increased left ventricle mass, increased end systolic and diastolic diameters, increased cardiac fibrosis, and increased expression of genes involved in cardiac hypertrophy and heart failure in the MI-Sed and MI-Exe mice. Exercise prevented HFD-induced cardiac fibrosis in Sham mice (Sham-Exe) but not in MI-Exe mice. Exercise did, however, reduce post-MI mortality.

SIGNIFICANCE

These data indicate that exercise significantly increased survival after MI in a model of diet-induced obesity independent of effects on cardiac function. These data have important translational ramifications because they demonstrate that environmental interventions, including diet, need to be carefully evaluated and taken into consideration to support the effects of exercise in the cardiac rehabilitation of patients who are obese.

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.