Salt intake causes B-type natriuretic peptide elevation independently of blood pressure elevation in the general population without hypertension and heart disease.

ABSTRACT: Excessive salt intake causes hypertension and cardiovascular diseases (CVDs). B-type natriuretic peptide (BNP) is synthesized and released from the ventricle, and is a surrogate marker reflecting various CVDs. Moreover, when a slight BNP elevation is shown, it leads to a poor prognosis in the general population. However, the relationship between salt intake and BNP levels in the general population remains unclear, especially in those without hypertension and heart diseases.In this study, we recruited 1404 participants without hypertension and electrocardiogram abnormalities, who received regular annual health check-ups in Japan. Plasma BNP levels were measured, and daily salt intake levels were evaluated using urinary samples. In addition, some clinical parameters were obtained, and the data were cross-sectionally analyzed.The median of plasma BNP levels was 10.50 pg/mL, and daily salt intake was 8.50 ±â€Š1.85 g. When dividing participants into quartiles according to daily salt intake, those with the highest daily salt intake revealed the highest plasma BNP levels. Plasma BNP levels were significantly and positively associated with daily salt intake. Moreover, multiple linear regression analyses revealed that plasma BNP levels showed a significant positive association with daily salt intake levels after adjustments.Plasma BNP levels were significantly and positively associated with daily salt intake after adjustment in the general population. Plasma BNP levels may be a surrogate marker reflecting salt-induced heart diseases.

Levosimendan Can Improve the Level of B-Type Natriuretic Peptide and the Left Ventricular Ejection Fraction of Patients with Advanced Heart Failure: A Meta-analysis of Randomized Controlled Trials.

BACKGROUND AND AIMS: Levosimendan, a calcium (Ca2+)-sensitizing cardiotonic agent, is mainly used in patients with advanced heart failure. However, no research could explain how levosimendan reduces the mortality in advanced heart failure patients. We aim to illustrate the efficacy of levosimendan through clinical indexes. METHODS: We searched PubMed, Embase, and CENTRAL from 1994 to August 2019 to compare the efficacy of levosimendan infusion for the treatment of advanced heart failure with that of other agents (placebo, dobutamine, furosemide, and prostaglandin E1). Levels of B-type natriuretic peptide (BNP) and N-terminal pro BNP (NT-proBNP), and left ventricular ejection fraction (LVEF) and heart rate (HR) were analyzed. The count data were analyzed by the standardized mean difference (SMD) and its 95% confidence interval (CI) to determine the effect size. We chose the random effect model or the fixed effect model according to the heterogeneity. RESULTS: Nine randomized controlled trials with 413 patients were ultimately enrolled. Compared with other agents (placebo, dobutamine, furosemide, and prostaglandin E1), levosimendan significantly reduced the BNP level (SMD - 0.91; 95% CI - 1.44 to - 0.39; p = 0.001; I2 = 74.3%) and improved the LVEF (SMD 0.74; 95% CI 0.22-1.25; p = 0.005; I2 = 79.7%). However, levosimendan did not significantly change the HR (SMD 0.09; 95% CI - 0.24 to 0.42; p = 0.592; I2 = 51.5%). Meanwhile, we found that the main source of heterogeneity was the use of loaded or unloaded levosimendan. CONCLUSION: Our meta-analysis suggests that intravenous levosimendan can reduce BNP level and increase LVEF in patients with advanced heart failure to reduce the mortality at the shortest follow-up available.

Sleeping Difficulty and Subjective Short Sleep Duration are Associated with Serum N-terminal Pro-brain Natriuretic Peptide Levels in the Elderly Population.

Objective It is well known that poor sleep increases the risk of heart failure (HF). However, the underlying mechanisms remain unclear. In this study, we investigated the association of poor sleep with hemodynamic stress on the left ventricle, which was a key factor for the development of HF in elderly individuals. Methods A total of 2,301 participants (≥65 years old) without cardiac disease were enrolled in this cross-sectional analysis. We evaluated the subjective sleep quality, sleeping difficulty, subjective sleep duration, use of sleeping pills, and daytime dysfunction using the Pittsburgh Sleep Quality Index, a 19-item self-reported questionnaire. We assessed serum N-terminal pro-brain natriuretic peptide (NT-proBNP) as a marker of hemodynamic stress on the left ventricle, and we defined high NT-proBNP as a serum NT-proBNP level ≥ 125 pg/mL. Results Sleeping difficulty was significantly associated with high NT-proBNP levels [odds ratio (OR), 1.46; 95% confidence interval (CI), 1.16-1.85; p<0.005]. A subjective short sleep duration was also significantly associated with high NT-proBNP levels (OR, 1.69; 95% CI, 1.03-2.75; p<0.05). A subjective poor sleep quality, the use of sleeping pills, and daytime dysfunction were not associated with serum NT-proBNP levels. All data were adjusted for the age, sex, body mass index, serum hemoglobin concentration, serum creatinine level, systolic blood pressure, diastolic blood pressure, and use of antihypertensive medications. Conclusion Poor sleep was associated with high hemodynamic stress to the left ventricle in elderly population.

miR-1929-3p Overexpression Alleviates Murine Cytomegalovirus-Induced Hypertensive Myocardial Remodeling by Suppressing Ednra/NLRP3 Inflammasome Activation.

MicroRNAs (miRNAs) play crucial roles in the development of essential hypertension (EH). Previously, we found that the expression of miR-1929-3p was decreased in C57BL/6 mice with hypertension induced by murine cytomegalovirus (MCMV). In this study, we explored the role of miR-1929-3p in hypertension myocardial remodeling in MCMV-infected mice. First, we measured MCMV DNA and host IgG and IgM after infection and determined the expression of miR-1929-3p and its target gene endothelin A receptor (Ednra) mRNA in the myocardium of mice. Then, we performed invasive blood pressure (BP) monitoring. Heart-to-body weight ratio (HW/BW%), along with mRNA levels of B-type natriuretic peptide (BNP) and beta myosin heavy chain (ß-MHC), revealed myocardial remodeling. Hematoxylin/eosin and Masson's trichrome staining indicated morphological changes in the myocardium. Cardiac function was assessed via echocardiography. Moreover, MCMV-infected mice were injected with recombinant adeno-associated virus- (rAAV-) miR-1929-3p overexpression vector. Immunohistochemistry and western blotting showed the expression of Ednra and the activation of NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome. And enzyme-linked immunosorbent assay (ELISA) revealed the concentrations of endothelin-1 (ET-1), interleukin-1ß (IL-1ß), and interleukin-18 (IL-18). In this study, we found that decreased expression of miR-1929-3p in MCMV-infected mice induced high BP and further development of myocardial remodeling cardiac function injury through increased expression of Ednra. Strikingly, overexpression of miR-1929-3p ameliorated these pathological changes of the heart. The positive effect was shown to be associated with inhibition of NLRP3 inflammasome activation and decreased expression of key proinflammatory cytokine IL-1ß. Collectively, these results indicate that miR-1929-3p overexpression may effectively alleviate EH myocardial remodeling by suppressing Ednra/NLRP3 inflammasome activation in MCMV-infected mice.

Natriuretic peptide system expression in murine and human submandibular salivary glands: a study of the spatial localisation of ANB, BNP, CNP and their receptors.

The natriuretic peptide (NP) system comprises of three ligands, the Atrial Natriuretic Peptide (ANP), Brain Natriuretic peptide (BNP) and C-type Natriuretic peptide (CNP), and three natriuretic peptide receptors, NPRA, NPRB and NPRC. Here we present a comprehensive study of the natriuretic peptide system in healthy murine and human submandibular salivary glands (SMGs). We show CNP is the dominant NP in mouse and human SMG and is expressed together with NP receptors in ducts, autonomic nerves and the microvasculature of the gland, suggesting CNP autocrine signalling may take place in some of these glandular structures. These data suggest the NP system may control salivary gland function during homeostasis through the regulation of electrolyte re-absorption, neural stimulation and/or blood vessel wall contraction/relaxation. We also show abnormal expression of NPRA in the stroma of a subset of human SMGs resected from patients diagnosed with oral squamous cell carcinoma (OSCC) of non-salivary gland origin. This finding warrants further research to investigate a possible correlation between early OSCC invasion and NPRA overexpression.

High-level production of N-terminal pro-brain natriuretic peptide, as a calibrant of heart failure diagnosis, in Escherichia coli.

Heart failure (HF) is a coronary disease that affects people worldwide and has a high mortality rate. N-terminal pro-brain natriuretic peptide (NT-proBNP) has been proven to be a useful and accurate biomarker for diagnosing systolic HF. Here, we report a strategy for the high-level production of recombinant (r)NT-proBNP in Escherichia coli. An Fh8 tag with six histidines was fused to the N terminus of NT-proBNP along with the recognition site of tobacco etch virus (TEV) protease; the 6HFh8-NT-proBNP fusion peptide was expressed in flask cultures of E. coli in almost completely soluble form. The peptide was purified by HisTrap affinity chromatography, and the N-terminal tag was cleaved by TEV protease. After a second round of HisTrap affinity chromatography to remove the TEV protease and N-terminal tag, rNT-proBNP was isolated with high purity (≥ 98%) by carboxymethyl cation exchange chromatography. The final yield of purified rNT-proBNP (97.5 mg/l of bacterial culture; 3.25 mg/g of wet cell) was 55-fold higher than that reported in previous studies (0.5-1.75 mg/l of bacterial culture). Furthermore, the high cell density E. coli fed-batch culture enabled high-level production of rNT-proBNP in the order of grams per liter. The purified rNT-proBNP was detected by enzyme-linked immunosorbent assay and chemiluminescence enzyme immunoassay using commercial monoclonal antibodies recognizing different epitopes, showing a linear dose-response relationship in the range of tested concentrations (slope = 3.58 and r2 = 0.995). These results demonstrate the efficiency of our process for mass producing (gram-to-liter level) rNT-proBNP with acceptable analytical performance.

AIN-93 Diet as an Alternative Model to Lieber-DeCarli Diet for Alcoholic Cardiomyopathy.

BACKGROUND: The Lieber-DeCarli alcoholic liquid diet is a classical method for establishing animal models of alcoholic cardiomyopathy (ACM). No study has reported whether the AIN-93 diet, which is widely used as a standard diet for both long-term and short-term studies with laboratory animals, could be used to construct the ACM animal model. The present study intended to investigate whether the AIN-93 diet could be used to establish a mouse ACM model. METHODS: Twenty-four C57BL/6 male mice were randomly divided into 4 equally sized groups. In ethanol (EtOH)-fed groups, mice were fed a 4%-EtOH (w/v, 28% of total calories) alcoholic liquid diet of Lieber-DeCarli or the AIN-93 diet for chronic alcohol exposure for 180 days. In control-fed groups, mice were fed with non-EtOH liquid diets with the same calories as EtOH-fed groups. Morphological observations of the hearts and molecular investigation of the brain natriuretic peptide (BNP) were carried out by echocardiography, hematoxylin and eosin (H&E) and immunohistochemistry (IHC) staining, real-time quantitative polymerase chain reaction (qPCR), and enzyme-linked immunosorbent assay. RESULTS: Echocardiography showed that mice fed with either the 4%-EtOH Lieber-DeCarli diet or the 4%-EtOH AIN-93 diet had dilated ventricles and poor cardiac function. IHC staining of BNP, qPCR of BNP mRNA, and plasma concentration of BNP showed an up-regulated expression in mice fed with both the 4%-EtOH Lieber-DeCarli and 4%-EtOH AIN-93 diets. Less fatty liver was also observed in mice fed the AIN-93 alcoholic diet than those fed the Lieber-DeCarli alcoholic diet. CONCLUSIONS: The AIN-93 alcoholic liquid diet can be used to establish ACM animal models, as with the conventional Lieber-DeCarli alcoholic liquid diet.

Efficacy and safety of spironolactone in the heart failure with mid-range ejection fraction and heart failure with preserved ejection fraction: A meta-analysis of randomized clinical trials.

BACKGROUND: Recent studies have shown the efficacy for using spironolactone to treat heart failure with reduced ejection fraction (HFrEF), but the efficacy of spironolactone for heart failure with mid-range ejection fraction (HFmrEF) and heart failure with preserved ejection fraction (HFpEF) is unclear. This meta-analysis investigated the efficacy and safety of spironolactone in patients with HFmrEF and HFpEF. METHODS AND RESULTS: We searched several databases including PubMed and the Cochrane Collaboration, for randomized controlled trials (RCTs) that assessed spironolactone treatment in HFmrEF and HFpEF. Eleven RCTs including 4539 patients were included. Spironolactone reduced hospitalizations (odds ratio [OR], 0.84; 95% confidence interval [CI], 0.73-0.95; P = .006), improved New York Heart Association functional classifications (NYHA-FC) (OR, 0.35; 95% CI, 0.19-0.66; P = .001), decreased the levels of brain natriuretic peptide (BNP) (mean difference [MD], - 44.80 pg/mL; 95% CI, -73.44--16.17; P = .002), procollagen type I C-terminal propeptide (PICP) (MD, -27.04 ng/mL; 95% CI, -40.77--13.32, P < .001) in HFmrEF and HFpEF. Besides, it improved 6-minute walking distances (6-MWD) (standard weighted mean difference [SMD], 0.45 m; 95% CI, 0.27-0.64; P < .001), decreased amino-terminal peptide of procollagen type-III (PIIINP) (SMD, -0.37 µg/L; 95% CI, -0.59--0.15; P = .001) in HFpEF only. The risks of hyperkalemia (P<.001) and gynecomastia (P<.001) were increased. CONCLUSION: Patients with HFmrEF and HFpEF could benefit from spironolactone treatment, with reduced hospitalizations, BNP levels, improved NYHA-FC, alleviated myocardial fibrosis by decreasing serum PICP in HFmrEF and HFpEF, decreased PIIINP levels and increased 6-MWD only in HFpEF. The risks of hyperkalemia and gynecomastia were significantly increased with the spironolactone treatment.

High glucose induced calcium overload via impairment of SERCA/PLN pathway and mitochondrial dysfunction leads to oxidative stress in H9c2 cells and amelioration with ferulic acid.

Oxidative stress and associated complications are the major pathological concerns of diabetic cardiomyopathy (DC). We aim to elucidate the mechanisms by which high glucose (HG) induced alteration in calcium homeostasis and evaluation of the beneficial effect of two concentrations (10 and 25 µm) of ferulic acid (FA). HG was induced in H9c2 cardiomyoblast by treating with glucose (33 mm) for 48 h, and FA was co-treated. Intracellular calcium ([Ca2+ ]i) overload was found increased significantly with HG. For elucidation of mechanism, the SERCA pathway and mitochondrial integrity (transmembrane potential and permeability transition pore) were explored. Then, we assessed oxidative stress, and cell injury with brain natriuretic peptide (BNP), atrial natriuretic peptide (ANP), and lactate dehydrogenase (LDH) release. HG caused significant [Ca2+ ]i overload through downregulation of SERCA2/1, pPLN, and pPKA C-α; and upregulation of PLN and PKA C-α and alteration in the integrity of mitochondria with HG. The [Ca2+ ]i overload in turn caused oxidative stress via generation of reactive oxygen species, lipid peroxidation, and protein carbonylation. This resulted in cell injury which was evident with significant release of BNP, ANP, and LDH. FA co-treatment was effective to mitigate all pathological changes caused by HG. From the overall results, we conclude that [Ca2+ ]i overload via SERCA pathway and altered mitochondrial integrity is the main cause for oxidative stress during HG. Based on our result, we report that FA could be an attractive nutraceutical for DC.

The efficacy and safety of soluble guanylate cyclase stimulators in patients with heart failure: A systematic review and meta-analysis.

BACKGROUND: Several randomized controlled trials (RCTs) have been investigated the benefits of soluble guanylate cyclase (sGC) stimulators in the treatment of heart failure, but a comprehensive evaluation is lacking. We performed a meta-analysis to evaluate the efficacy and safety of oral sGC stimulators (vericiguat and riociguat) in patients with heart failure. METHODS: Studies were searched and screened in PubMed, Embase, and Cochrane Library. Eligible RCTs were included that reported mortality, the change of EuroQol Group 5-Dmensional Self-report Questionnaire (EQ-5D) US index, N-terminal pro-B-type natriuretic peptide (NT-proBNP), or serious adverse events (SAEs). Relative risk or weight mean difference (WMD) was estimated using fixed effect model or random effect model. Analysis of sensitivity and publication bias was conducted. RESULTS: Five trials with a total of 1200 patients were included. sGC stimulators had no impact on the mortality (1.25; 95% confidence interval 0.50-3.11) and significantly improved EQ-5D US index (0.04; 95% confidence interval 0.020-0.05). Furthermore, in comparison with control group, NT-proBNP was statistically decreased in riociguat group (-0.78; 95% confidence interval -1.01 to -0.47), but not in vericiguat group (0.04, 95% confidence interval -0.18 to 0.25). There were not obverse differences in SAEs between sGC stimulators and control groups (0.90; 95% confidence interval 0.72-1.12). CONCLUSION: Our meta-analysis suggests that sGC stimulators could improve the quality of life in patients with heart failure with good tolerance and safety, but their long-term benefits need to be observed in the future. sGC stimulators are likely to be promising add-on strategies for the treatment of heart failure.

Renal papillary tip extract stimulates BNP production and excretion from cardiomyocytes.

BACKGROUND: Brain natriuretic peptide (BNP) is an important biomarker for patients with cardiovascular diseases, including heart failure, hypertension and cardiac hypertrophy. It is also known that BNP levels are relatively higher in patients with chronic kidney disease and no heart disease; however, the mechanism remains unclear. METHODS AND RESULTS: We developed a BNP reporter mouse and occasionally found that this promoter was activated specifically in the papillary tip of the kidneys, and its activation was not accompanied by BNP mRNA expression. No evidence was found to support the existence of BNP isoforms or other nucleotide expression apart from BNP and tdTomato. The pBNP-tdTomato-positive cells were interstitial cells and were not proliferative. Unexpectedly, both the expression and secretion of BNP increased in primary cultured neonatal cardiomyocytes after their treatment with an extract of the renal papillary tip. Intraperitoneal injection of the extract of the papillary tips reduced blood pressure from 210 mmHg to 165 mmHg, the decrease being accompanied by an increase in serum BNP and urinary cGMP production in stroke-prone spontaneously hypertensive (SHR-SP) rats. Furthermore the induction of BNP by the papillary extract from rats with heart failure due to myocardial infarction was increased in cardiomyocytes. CONCLUSIONS: These results suggested that the papillary tip express a substance that can stimulate BNP production and secretion from cardiomyocytes.

Type 1 diabetes mellitus induces structural changes and molecular remodelling in the rat kidney.

There is much evidence that diabetes mellitus (DM)-induced hyperglycemia (HG) is responsible for kidney failure or nephropathy leading to cardiovascular complications. Cellular and molecular mechanism(s) whereby DM can damage the kidney is still not fully understood. This study investigated the effect of streptozotocin (STZ)-induced diabetes (T1DM) on the structure and associated molecular alterations of the isolated rat left kidney following 2 and 4 months of the disorder compared to the respective age-matched controls. The results revealed hypertrophy and general disorganized architecture of the kidney characterized by expansion in glomerular borders, tubular atrophy and increased vacuolization of renal tubular epithelial cells in the diabetic groups compared to controls. Electron microscopic analysis revealed ultrastructural alterations in the left kidney highlighted by an increase in glomerular basement membrane width. In addition, increased caspase-3 immunoreactivity was observed in the kidney of T1DM animals compared to age-matched controls. These structural changes were associated with elevated extracellular matrix (ECM) deposition and consequently, altered gene expression profile of ECM key components, together with elevated levels of key mediators (MMP9, integrin 5α, TIMP4, CTGF, vimentin) and reduced expressions of Cx43 and MMP2 of the ECM. Marked hypertrophy of the kidney was highlighted by increased atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) gene expression. These changes also correlated with increased TGFß1 activity, gene expression in the left kidney and elevated active TGFß1 in the plasma of T1DM rats compared to control. The results clearly demonstrated that TIDM could elicit severe structural changes and alteration in biochemical markers (remodelling) in the kidney leading to diabetic nephropathy (DN).

QTc prolongation, increased NT-proBNP and pre-clinical myocardial wall remodeling in excessive alcohol consumers: The SABPA study.

Alcohol contributes greatly to vascular and structural modifications. Due to differences in the metabolism and tolerance of alcohol between ethnic groups, the manner of these modifications may differ. We investigated the association between alcohol consumption - measured via ethnic-specific gamma glutamyl transferase (γ-GT) cut-points - and markers of cardiac perfusion, electrical activity, and pre-clinical structural alterations. A South African target population study was performed in a bi-ethnic cohort (n = 405). Alcohol consumption was determined according to previously defined ethnic-specific γ-GT cut-points, where γ-GT ≥ 19.5 U/L and γ-GT ≥ 55 U/L indicated excessive alcohol consumption in Caucasians and Africans, respectively. Ambulatory 24-h blood pressure and electrocardiograms (ECG), 10-lead ECG left ventricular hypertrophy (LVH), ischemic events, N-terminal pro-brain natriuretic peptide (NT-proBNP), and QTc prolongation were assessed. Fasting blood samples were obtained. A poorer cardio-metabolic profile and mean 24-h hypertensive and ECG-LVH values were evident in high γ-GT groups of both ethnicities, when compared to their low counterparts. The African high γ-GT group reported a higher intake of alcohol and presented significant increases in NT-proBNP (p < 0.001), QTc prolongation (p = 0.008), and ischemic events (p = 0.013). Regression analyses revealed associations between ECG-LVH and NT-proBNP, QTc prolongation, ischemic events, and SBP, in the African high γ-GT group exclusively. High alcohol consumers presented delayed electrical conduction in the heart accompanied by ECG-LVH, ischemic events, and increased vaso-responsiveness, predominantly in Africans. Ultimately, increased left ventricular distension on a pre-clinical level may elevate the risk for future cardiovascular events in this population.

GDF11 Attenuated ANG II-Induced Hypertrophic Cardiomyopathy and Expression of ANP, BNP and Beta-MHC Through Down- Regulating CCL11 in Mice.

BACKGROUND: Growth differentiation factor 11 (GDF11) decreases with age, and increased C-C motif chemokine 11 (CCL11) is involved in aging. However, the effects of GDF11 on Angiotensin II (ANG II)-induced hypertrophic cardiomyopathy and expression of markers for volume overload and hypertrophy such as ANP, BNP and beta-MHC, as well as the relationship between GDF11 and CCL11 in hypertrophic cardiomyopathy are unclear. Therefore, the current study aimed to examine the effects of GDF11 on ANG II-induced hypertrophic cardiomyopathy and expression of ANP, BNP and beta-MHC in mice, and explore possible molecular mechanisms. METHODS: Vectors were constructed and viruses were packaged. Mouse cardiomyocytes were treated with ANG II for 24 h. Meanwhile, mouse cardiomyocytes were divided into 4 groups: (1) control; (2) ANG II; (3) ANG II+GDF11; and (4) ANG II+CCL11. Furthermore, mouse cardiomyocytes were treated with GDF11 and CCL11 proteins for 48 h, respectively. The thickness of IVS and LVPS during systole and diastole were measured by cardiac ultrasound in the mouse model of hypertrophic cardiomyopathy. The relative expression of ANP, BNP, beta-MHC, CCL11 and GDF11 in cardiomyocytes or heart tissue of mice was detected by qPCR or Western blot. 3'- UTR luciferase reporter assay was utilized to examine the relationship between GDF11 and the expression of CCL11. RESULTS: The expression of ANP, BNP, and beta-MHC in mouse cardiomyocytes was significantly increased after the cells were treated with 800 nM ANG II, which was utilized in the following cell experiments. After ANG II treatment, 0.2 ng/ml GDF11 group displayed the highest inhibition of expression of ANP, BNP and beta-MHC in mouse cardiomyocytes, whereas 50 ng/ml CCL11 group displayed the highest stimulation of the expression. GDF11 at 10 ng/ml significantly decreased the expression of CCL11 in mouse cardiomyocytes as compared to the control group. Mice treated with ANG II had increased thickness of IVS and LVPS during both systole and diastole, which was significantly attenuated by GDF11 overexpression. GDF11 overexpression attenuated the increase in expression of ANP, BNP and beta-MHC in the mice model of hypertrophic cardiomyopathy. The relative serum concentration of GDF11 was markedly decreased, and CCL11 was dramatically increased in mice with hypertrophic cardiomyopathy. GDF11 overexpression restored the serum concentration of GDF11 and CCL11 in the mice model of hypertrophic cardiomyopathy. In addition, GDF11 interference group had markedly increased expression of CCL11, whereas GDF11 overexpression group had significantly decreased expression of CCL11 in luciferase reporter assay. CONCLUSIONS: GDF11 attenuated ANG II-induced hypertrophic cardiomyopathy and expression of ANP, BNP and beta-MHC through down-regulating CCL11 in mice.

IL-18 stimulates B-type natriuretic peptide synthesis by cardiomyocytes in vitro and its plasma levels correlate with B-type natriuretic peptide in non-overloaded acute heart failure patients.

BACKGROUND: An altered IL-18 pathway in heart failure (HF) has recently been described and this cytokine was shown to be of clinical and prognostic utility. Cardiomyocytes are a target of this cytokine which exerts inflammatory, hypertrophic, and profibrotic activities. B-type natriuretic peptide is a cardiac hormone produced in response to cardiac filling to regulate cardiovascular homeostasis. The aim of the study was to verify the ability of IL-18 to induce B-type natriuretic peptide synthesis in vitro and to analyse the relationship between these two molecules in plasma in vivo from acute HF patients. METHODS AND RESULTS: We demonstrated the ability of IL-18 to directly stimulate a murine cardiomyocyte cell line to express the B-type natriuretic peptide gene, synthesize the relative protein through a PI3K-AKT-dependent transduction, and induce a cell secretory phenotype with B-type natriuretic peptide release. A correlation between IL-18 and B-type natriuretic peptide plasma levels was found in non-overloaded acute HF patients, and in subgroups of acute HF patients with diabetes and coronary artery disease. Acute HF patients with renal failure had significantly higher IL-18 plasma levels than patients without. IL-18 plasma levels were correlated with C-reactive protein plasma levels. CONCLUSIONS: This study provides the first evidence of the ability of IL-18 to induce B-type natriuretic peptide synthesis in vitro and outlines the relationship between the two molecules in acute HF patients with an ongoing inflammatory status.

Deep analyses of the associations of a series of biomarkers with insulin resistance, metabolic syndrome, and diabetes risk in nondiabetic middle-aged and elderly individuals: results from a Chinese community-based study.

OBJECTIVE: The current study was designed to perform deep analyses of the associations of biomarkers, including high-sensitivity C-reactive protein (hs-CRP), N-terminal prohormone of brain natriuretic peptide (NT-proBNP), and homocysteine (Hcy), with insulin resistance (IR), metabolic syndrome (MetS), and diabetes risk and evaluate the abilities of biomarkers to identify IR, MetS, and diabetes risk in Chinese community-dwelling middle-aged and elderly residents. PARTICIPANTS AND METHODS: A total of 396 participants older than 45 years underwent physical examinations and laboratory analyses following standardized protocol. RESULTS: Serum hs-CRP concentrations were able to identify MetS, Chinese diabetes risk score (CDRS) ≥4, high-density lipoprotein-cholesterol (HDL-c) <0.9/1.0 mmol/L, and HDL-c <1.0/1.3 mmol/L (P<0.05 for all). Serum NT-proBNP concentrations were able to identify homeostasis model assessment of IR >1.5, CDRS ≥4, overweight, and blood pressure (BP) ≥140/90 mmHg (P<0.05 for all). Serum Hcy concentrations were able to identify CDRS ≥4, general obesity, overweight, and BP ≥140/90 mmHg (P<0.05 for all). Serum hs-CRP concentrations were independently associated with MetS as well as HDL-c <1.0/1.3 mmol/L and HDL-c <0.9/1.0 mmol/L (P<0.05 for all). Serum NT-proBNP concentrations were independently associated with BP ≥140/90 mmHg (P<0.05). Serum Hcy concentrations were independently associated with CDRS ≥4 (P<0.05). CONCLUSION: Serum HDL-c levels were the major determinant of the associations between serum hs-CRP levels and MetS and the key link between inflammation and MetS. There was no other association of these biomarkers with IR, MetS, and diabetes risk after full adjustment.

Cucurbitacin-I induces hypertrophy in H9c2 cardiomyoblasts through activation of autophagy via MEK/ERK1/2 signaling pathway.

Cucurbitacin-I, a natural triterpenoids initially identified in medicinal plants, shows a potent anticancer effect on a variety of cancer cell types. Nevertheless, the cardiotoxicity of cucurbitacin-I has not heretofore been reported. In this study, the mechanisms of cucurbitacin-I-induced cardiotoxicity were examined by investigating the role of MAPK-autophagy-dependent pathways. After being treated with 0.1-0.3µM cucurbitacin-I for 48h, H9c2 cells showed a gradual decrease in the cell viabilities, a gradual increase in cell size, and mRNA expression of ANP and BNP (cardiac hypertrophic markers). Cucurbitacin-I concentration-dependent apoptosis of H9c2 cells was also observed. The increased apoptosis of H9c2 cells was paralleling with the gradually strong autophagy levels. Furthermore, an autophagy inhibitor, 3-MA, was used to block the cucurbitacin-I-stirred autophagy, and then the hypertrophy and apoptosis induced by 0.3µM cucurbitacin-I were significantly attenuated. In addition, cucurbitacin-I exposure also activated the MAPK signaling pathways, including ERK1/2, JNK, and p38 kinases. Interestingly, only the ERK inhibitor U0126, but not the JNK inhibitor SP600125 and p38 MAPK inhibitor SB203580, weakened the induction of 0.3µM cucurbitacin-I in hypertrophy, autophagy and apoptosis. Our findings suggest that cucurbitacin-I can increase the autophagy levels of H9c2 cells, most likely, through the activation of an ERK-autophagy dependent pathway, which results in the hypertrophy and apoptosis of cardiomyocytes.

Genetic Dissection of Cardiac Remodeling in an Isoproterenol-Induced Heart Failure Mouse Model.

We aimed to understand the genetic control of cardiac remodeling using an isoproterenol-induced heart failure model in mice, which allowed control of confounding factors in an experimental setting. We characterized the changes in cardiac structure and function in response to chronic isoproterenol infusion using echocardiography in a panel of 104 inbred mouse strains. We showed that cardiac structure and function, whether under normal or stress conditions, has a strong genetic component, with heritability estimates of left ventricular mass between 61% and 81%. Association analyses of cardiac remodeling traits, corrected for population structure, body size and heart rate, revealed 17 genome-wide significant loci, including several loci containing previously implicated genes. Cardiac tissue gene expression profiling, expression quantitative trait loci, expression-phenotype correlation, and coding sequence variation analyses were performed to prioritize candidate genes and to generate hypotheses for downstream mechanistic studies. Using this approach, we have validated a novel gene, Myh14, as a negative regulator of ISO-induced left ventricular mass hypertrophy in an in vivo mouse model and demonstrated the up-regulation of immediate early gene Myc, fetal gene Nppb, and fibrosis gene Lgals3 in ISO-treated Myh14 deficient hearts compared to controls.

Suppressive Effects of Glucose-Dependent Insulinotropic Polypeptide on Cardiac Hypertrophy and Fibrosis in Angiotensin II-Infused Mouse Models.

BACKGROUND: Activation of glucose-dependent insulinotropic polypeptide receptor (GIPR) has been shown to be protective against atherosclerosis. However, effects of GIP on the heart have remained unclear. To address this question, in vitro and in vivo experiments were conducted. METHODS AND RESULTS: In isolated mouse cardiomyocytes, GIPR mRNA was detected by reverse transcription-polymerase chain reaction, and GIP stimulation increased adenosine 3',5'-cyclic monophosphate production. In apolipoprotein E-knockout mice, infusion of angiotensin II (AngII; 2,000 ng·kg(-1)·min(-1)) significantly increased the heart weights, and co-administration of GIP (25 nmol·kg(-1)·day(-1)) reversed this increase (both P<0.01). In the left ventricular walls, GIP suppressed AngII-induced cardiomyocyte hypertrophy by 34%, apoptosis by 77%, and interstitial fibrosis by 79% (all P<0.01). Furthermore, GIP reduced AngII-induced expression of transforming growth factor-ß1 (TGF-ß1) and hypoxia inducible factor-1α. In wild-type mice, cardiac hypertrophy was induced by AngII to a lesser extent, and prevented by GIP. In contrast, GIP did not show any cardioprotective effect against AngII-induced cardiac hypertrophy in GIPR-knockout mice. In an in vitro experiment using mouse cardiomyocytes, GIP suppressed AngII-induced mRNA expression of B-type natriuretic peptide and TGF-ß1. CONCLUSIONS: It was demonstrated that cardiomyocytes represent a direct target of GIP action in vitro, and that GIP ameliorated AngII-induced cardiac hypertrophy via suppression of cardiomyocyte enlargement, apoptosis, and fibrosis in vivo. (Circ J 2016; 80: 1988-1997).

Inhibition of miR-154 Protects Against Cardiac Dysfunction and Fibrosis in a Mouse Model of Pressure Overload.

Expression of miR-154 is upregulated in the diseased heart and was previously shown to be upregulated in the lungs of patients with pulmonary fibrosis. However, the role of miR-154 in a model of sustained pressure overload-induced cardiac hypertrophy and fibrosis had not been assessed. To examine the role of miR-154 in the diseased heart, adult male mice were subjected to transverse aortic constriction for four weeks, and echocardiography was performed to confirm left ventricular hypertrophy and cardiac dysfunction. Mice were then subcutaneously administered a locked nucleic acid antimiR-154 or control over three consecutive days (25 mg/kg/day) and cardiac function was assessed 8 weeks later. Here, we demonstrate that therapeutic inhibition of miR-154 in mice with pathological hypertrophy was able to protect against cardiac dysfunction and attenuate adverse cardiac remodelling. The improved cardiac phenotype was associated with attenuation of heart and cardiomyocyte size, less cardiac fibrosis, lower expression of atrial and B-type natriuretic peptide genes, attenuation of profibrotic markers, and increased expression of p15 (a miR-154 target and cell cycle inhibitor). In summary, this study suggests that miR-154 may represent a novel target for the treatment of cardiac pathologies associated with cardiac fibrosis, hypertrophy and dysfunction.