Catestatin is useful in detecting patients with stage B heart failure

Screening patients with stage B heart failure(HF) may be one strategy for reducing human morbidity. To describe catestatin levels in different stages of HF and evaluate the diagnostic utility of catestatin for detecting stage B HF, we included 300 patients. Catestatin, BNP testing and echocardiogram were performed. Our studies showed catestatin decreased gradually from stage A to C. There was significant difference between stage A and B. Cutoff value for detecting stage B HF was 19.73?ng/ml for catestatin with 90% sensitivity and 50.9% specificity. These results may have implications in the new method to detect patients with stage B HF.     

Formation of the catecholamine release-inhibitory peptide catestatin from chromogranin A. Determination of proteolytic cleavage sites in hormone storage granules

The catestatin fragment of chromogranin A is an inhibitor of catecholamine release, but its occurrence in vivo has not yet been verified, nor have its precise cleavage sites been established. Here we found extensive processing of catestatin in chromogranin A, as judged by catestatin radioimmunoassay of size-fractionated chromaffin granules. On mass spectrometry, a major catestatin form was bovine chromogranin A(332-364); identity of the peptide was confirmed by diagnostic Met(346) oxidation. Further analysis revealed two additional forms: bovine chromogranin A(333-364) and A(343-362). Synthetic longer (chromogranin A(332-364)) and shorter (chromogranin A(344-364)) versions of catestatin each inhibited catecholamine release from chromaffin cells, with superior potency for the shorter version (IC(50) approximately 2.01 versus approximately 0.35 microm). Radioimmunoassay demonstrated catestatin release from the regulated secretory pathway in chromaffin cells. Human catestatin was cleaved in pheochromocytoma chromaffin granules, with the major form, human chromogranin A(340-372), bounded by dibasic sites. We conclude that catestatin is cleaved extensively in vivo, and the peptide is released by exocytosis. In chromaffin granules, the major form of catestatin is cleaved at dibasic sites, while smaller carboxyl-terminal forms also occur. Knowledge of cleavage sites of catestatin from chromogranin A may provide a useful starting point in analysis of the relationship between structure and function for this peptide.     

Correlation of Plasma Catestatin Level and the Prognosis of Patients with Acute Myocardial Infarction

Catestatin is a peptide which is a potent inhibitor of catecholamine secretion and played essential functions in the cardiovascular system. Previous research found that dramatic changes of catestatin were associated with hemodynamics in acute myocardial infarction (AMI) during the first week after the AMI symptoms onset, but whether catestatin is also involved in the pathophysiological progression after AMI and then a predictor for outcomes is not clear. The aim of this study is to determine the correlation of plasma catestatin levels at different time points and the prognosis of AMI. 100 participants recruited were all patients with AMI, all of who received successful primary percutaneous coronary intervention (PCI) within 12h from the AMI symptom onset in our center; the concentrations of plasma catestatin were evaluated from blood samples of those 100 participants. Subsequent 65 months'' follow-up was performed after discharging to evaluate cardiac adverse events and the association between catestatin levels and prognosis of AMI was examined. We confirmed the dramatic change of catestatin concentrations in the first week of AMI, and the levels of catestatin on D3 were much higher in adverse events group than those in non-adverse events group (p<0.0001), but the ratio of D7/D3 was significantly lower. In addition, the Kaplan-Meier analysis showed that the groups in which the levels on D3 were higher (p<0.0001) and the ratios of D7/D3 were lower (p<0.0001), patients trended to be more susceptive to adverse events after AMI. Furthermore, according to the analysis, we surmised catestatin level on D3 as an appropriate predictor for outcomes in patients with AMI with good specificity as well as sensitivity. All of the evidence confirmed that catestatin plays an important role in the progress of AMI, and may act as a promising target for prognostic prediction.     

Growth differentiation factor 15 in different stages of heart failure: potential screening implications

Identification of individuals in the early stage of heart failure (HF) may allow earlier initiation of disease-modifying treatment. We evaluated concentrations of the growth differentiation factor (GDF)-15at different stages and its potential screening value in 208 subjects. Plasma GDF-15 was measured by using an enzyme-linked immunosorbent assay. GDF-15 was positively correlated with the stages of HF (r=0.804, p<0.001). In distinguishing patients with stage B HF, the area under the curve was 0.873 (p<0.001). These findings indicate that GDF-15 concentration was elevated with the progressing stages of HFand might have potential screening implications for stage B HF.     

Primary structure and function of the catecholamine release inhibitory peptide catestatin (chromogranin A(344-364)): identification of amino acid residues crucial for activity

The novel chromogranin A fragment catestatin (bovine chromogranin A(344-364); RSMRLSFRARGYGFRGPGLQL) is a potent inhibitor of catecholamine release (IC50, approximately 0.2-0.3 microM) by acting as a nicotinic cholinergic antagonist. To define the minimal active region within catestatin, we tested the potencies of synthetic serial three-residue deletion (amino-terminal, carboxyl-terminal, or bidirectional) fragments to inhibit nicotine-stimulated catecholamine secretion from PC12 pheochromocytoma cells. The results revealed that a completely active core sequence of catestatin was constituted by chromogranin A(344-364). Nicotinic cationic signal transduction was affected by catestatin fragments in a manner similar to that for secretion (confirming the functional importance of the amino-terminus). To identify crucial residues within the active core, we tested serial single amino acid truncations or single residue substitutions by alanine on nicotine-induced catecholamine secretion and desensitization. Nicotinic inhibition by the active catestatin core was diminished by even single amino acid deletions. Selective alanine substitution mutagenesis of the active core revealed important roles for Met346, Leu348, Phe350, Arg351, Arg353, Gly354, Tyr355, Phe357, and Arg358 on catecholamine secretion, whereas crucial roles to inhibit desensitization of catecholamine release were noted for Arg344, Met346, Leu348, Ser349, Phe350, Arg353, Gly354, Tyr355, Gly356, and Arg358. We conclude that a small, 15-amino acid core of catestatin (chromogranin A(344-364)) is sufficient to exert the peptide's typical inhibitory effects on nicotinic cholinergic-stimulated catecholamine secretion, signal transduction, and desensitization. These studies refine the biologically active domains of catestatin and suggest that the pharmacophores for inhibition of nicotinic secretion and desensitization may not be identical.     

Metabolic disorder in the progression of heart failure

Heart failure(HF) is a major clinical concern owing to its high prevalence and high mortality. Metabolomics, an effective approach to predict diagnostic biomarkers and to explore the altered metabolic pathways in pathogenesis, has been extensively applied in evaluating the course of diseases. In this study, we used this approach to analyse the abundance of metabolites, with liquid chromatograph-mass spectrometer, in plasma samples from rats with transverse aortic constriction(TAC) and patients at different stages of HF. We compared the metabolic parameters within and between TAC rats and patients. An apparent metabolic shift was observed in rats, from compensated hypertrophy stage to decompensated hypertrophy stage, and in patients with HF,from stage A to stage B and subsequently stage C. Diagnostic biomarkers were predicted by comparing the variable importance in the projection scores and fold change analysis within and between rats and patients. Enrichment pathway analysis and network analysis provided an overview of the largely disturbed metabolic pathways, and those interfered at different stages and across species were confirmed. The significantly changed metabolites and pathways revealed the underlying mechanisms of HF pathogenesis, hinted at novel potential biomarkers, and provided potential therapeutic intervention targets for HF.     

Increased circulating IgG levels,myocardial immune cells and IgG deposits support a role for an immune response in pre‐ and end‐stage heart failure

The chronic inflammatory response plays an important role in adverse cardiac remodelling and the development of heart failure (HF). There is also evidence that in the pathogenesis of several cardiovascular diseases, chronic inflammation is accompanied by antibody and complement deposits in the heart, suggestive of a true autoimmune response. However, the role of antibody‐mediated immune responses in HF progression is less clear. We assessed whether immune cell infiltration and immunoglobulin levels are associated with HF type and disease stage, taking sex differences into account. We found IgG deposits and increased infiltration of immune cells in the affected myocardium of patients with end‐stage HF with reduced ejection fraction (HFrEF, n = 20). Circulating levels of IgG1 and IgG3 were elevated in these patients. Furthermore, the percentage of transitional/regulatory B cells was decreased (from 6.9% to 2.4%) compared with healthy controls (n = 5). Similarly, increased levels of circulating IgG1 and IgG3 were observed in men with left ventricular diastolic dysfunction (LVDD, n = 5), possibly an early stage of HF with preserved EF (HFpEF). In conclusion, IgG deposits and infiltrates of immune cells are present in end‐stage HFrEF. In addition, both LVDD patients and end‐stage HFrEF patients show elevated levels of circulating IgG1 and IgG3, suggesting an antibody‐mediated immune response upon cardiac remodelling, which in the early phase of remodelling appear to differ between men and women. These immunoglobulin subclasses might be used as marker for pre‐stage HF and its progression. Future identification of auto‐antigens might open possibilities for new therapeutic interventions.     

Intracellular magnesium in elderly patients with heart failure: Effects of diabetes and renal dysfunction

Hypomagnesemia is frequent in diabetes mellitus (DM), while renal dysfunction (RD) may be associated with hypermagnesemia. Severe cardiac arrhythmias and other adverse clinical manifestations are frequent in heart failure (HF), in DM and in RD. Depletion of intracellular magnesium (icMg), which may coexist with normal serum Mg, might contribute to these deleterious effects. However, icMg content in normomagnesemic HF patients with RD or DM has not been studied. We assessed total icMg in peripheral blood mononuclear cells (PBMC) from 80 normomagnesemic furosemide-treated HF patients who were divided as follows: subgroups A (DM), B (RD), C (DM and RD), and D (free of DM or RD). PBMC from 18 healthy volunteers served as controls. IcMg content (μg/mg cell protein) in HF was lower compared to controls (1.68±0.2 vs. 2.4±0.39, p<0.001). In the entire HF group, a significant inverse correlation was evident between icMg and serum creatinine (r=−0.37) and daily furosemide dosages (r=−0.121). IcMg in the HF subgroups A, B, C, and D was 1.79±0.23, 1.57±0.23, 1.61±0.25, and 1.79±0.39, respectively (p=0.04 between A and B, p=0.08 between B and D, and non-significant in the remaining comparisons). Serum Mg, potassium, calcium, furosemide dosages and left ventricular ejection fraction were comparable in all subgroups. In conclusion, icMg depletion was demonstrable in PBMC, which may be responsible for some of the adverse clinical manifestations in HF patients. In particular, icMg depletion in RD might contribute to cardiac arrhythmias in this patient group. Mg supplementation to normomagnesemic HF patients might therefore prove beneficial.     

Heat Shock Protein 70 Acts as a Potential Biomarker for Early Diagnosis of Heart Failure

Early identification for heart failure (HF) may be useful for disease modifying treatment in order to reduce heart disease progression or even to reverse it. In our previous studies, we have revealed a group of heat shock proteins (HSPs) which might be related to neonatal rat cardiomyocyte hypertrophy by proteomic approach. Here, we confirm that HSPs, including HSP27 and HSP70, altered in the early stage of cardiac remodeling in vivo animal model. Furthermore, plasma concentrations of those HSPs and their potential screening value were evaluated at different stages in 222 patient subjects. Plasma HSP27, HSP70 and HSP90 were measured using enzyme-linked immunosorbent assay. Results indicate that HSP70 was positively correlated to the severity (progression) of HF (r = 0.456, p<0.001). The area under the rate of change (ROC) curve was 0.601 (p = 0.017) in patients with stage B HF and 0.835 (p<0.001) in those with stage C HF. However, HSP27 and HSP90 did not display significant changes in any stage of HF in this study. Taken together, plasma concentrations of HSP70 elevated with the progression of HF and might act as a potential screening biomarker for early diagnosis of HF.     

Primary sequence characterization of catestatin intermediates and peptides defines proteolytic cleavage sites utilized for converting chromogranin a into active catestatin secreted from neuroendocrine chromaffin cells

Catestatin is an active 21-residue peptide derived from the chromogranin A (CgA) precursor, and catestatin is secreted from neuroendocrine chromaffin cells as an autocrine regulator of nicotine-stimulated catecholamine release. The goal of this study was to characterize the primary sequences of high molecular mass catestatin intermediates and peptides to define the proteolytic cleavage sites within CgA that are utilized in the biosynthesis of catestatin. Catestatin-containing polypeptides, demonstrated by anti-catestatin western blots, of 54-56, 50, 32, and 17 kDa contained NH(2)-terminal peptide sequences that indicated proteolytic cleavages of the CgA precursor at KK downward arrow, KR downward arrow, R downward arrow, and KR downward arrow basic residue sites, respectively. The COOH termini of these catestatin intermediates were defined by the presence of the COOH-terminal tryptic peptide of the CgA precursor, corresponding to residues 421-430, which was identified by MALDI-TOF mass spectrometry. Results also demonstrated the presence of 54-56 and 50 kDa catestatin intermediates that contain the NH(2) terminus of CgA. Secretion of catestatin intermediates from chromaffin cells was accompanied by the cosecretion of catestatin (CgA(344)(-)(364)) and variant peptide forms (CgA(343)(-)(368) and CgA(332)(-)(361)). These determined cleavage sites predicted that production of high molecular mass catestatin intermediates requires cleavage at the COOH-terminal sides of paired basic residues, which is compatible with the cleavage specificities of PC1 and PC2 prohormone convertases. However, it is notable that production of catestatin itself (CgA(344)(-)(364)) utilizes more unusual cleavage sites at the NH(2)-terminal sides of downward arrow R and downward arrow RR basic residue sites, consistent with the cleavage specificities of the chromaffin granule cysteine protease "PTP" that participates in proenkephalin processing. These findings demonstrate that production of catestatin involves cleavage of CgA at paired basic and monobasic residues, necessary steps for catestatin peptide regulation of nicotinic cholinergic-induced catecholamine release.     

Catestatin, a chromogranin A-derived peptide, is sympathoinhibitory and attenuates sympathetic barosensitivity and the chemoreflex in rat CVLM

Hypertension is a major cause of morbidity. The neuropeptide catestatin [human chromogranin A-(352-372)] is a peptide product of the vesicular protein chromogranin A. Studies in the periphery and in vitro studies show that catestatin blocks nicotine-stimulated catecholamine release and interacts with β-adrenoceptors and histamine receptors. Catestatin immunoreactivity is present in the rostral ventrolateral medulla (RVLM), a key site for blood pressure control in the brain stem. Recently, we reported that microinjection of catestatin into the RVLM is sympathoexcitatory and increases barosensitivity. Here, we report the effects of microinjection of catestatin (1 mM, 50 nl) into the caudal ventrolateral medulla (CVLM) in urethane-anesthetized, bilaterally vagotomized, artificially ventilated Sprague-Dawley rats (n = 8). We recorded resting arterial pressure, splanchnic sympathetic nerve activity, phrenic nerve activity, heart rate, and measured cardiovascular homeostatic reflexes. Homeostatic reflexes were evaluated by measuring cardiovascular responses to carotid baroreceptor and peripheral chemoreceptor activation. Catestatin decreased basal levels of arterial pressure (-23 ± 4 mmHg), sympathetic nerve activity (-26.6 ± 5.7%), heart rate (-19 ± 5 bpm), and phrenic nerve amplitude (-16.8 ± 3.3%). Catestatin caused a 15% decrease in phrenic inspiratory period (T(i)) and a 16% increase in phrenic expiratory period (T(e)) but had no net effect on the phrenic interburst interval (T(tot)). Catestatin decreased sympathetic barosensitivity by 63.6% and attenuated the peripheral chemoreflex (sympathetic nerve response to brief hypoxia; range decreased 39.9%; slope decreased 30.1%). The results suggest that catestatin plays an important role in central cardiorespiratory control.     

The influence of heart failure co-morbidity on high-sensitivity troponin T levels in COPD exacerbation in a prospective cohort study: data from the Akershus cardiac examination (ACE) 2 study

Context: Troponin (hs-TnT) levels predict mortality after acute exacerbation of COPD (AECOPD). Whether this is independent of heart failure (HF) is not established.

Material and methods: Prospectively included AECOPD patients adjudicated for acute HF categorized into three groups: (A) AECOPD, but acute HF the primary cause for hospitalization; (B) AECOPD the primary cause, but co-existing myocardial dysfunction and (C) AECOPD without myocardial dysfunction.

Results: About 103 AECOPD patients; 18% A, 27% B and 54% C. Hs-TnT level differed between the groups: (ng/l, median) A: 41, B: 25 and C: 15, p?=?0.03 for A versus B and p?=?0.005 for B versus C. During a median 826 days, 47% died. In Cox analysis, hs-TnT levels remained associated with mortality (hazard ratio per 10?ng/l 1.3, p?<?0.0001).

Conclusion: hs-TnT levels are influenced by myocardial dysfunction/HF in AECOPD, but provide independent prognostic information. The prognostic merit of hs-TnT cannot be attributed to HF alone.     

Dramatic changes in catestatin are associated with hemodynamics in acute myocardial infarction

Acute myocardial infarction (AMI) is characterized by complex neuroendocrine activation. To investigate catestatin profiles, serial catestatin levels were determined by enzyme-linked immunosorbent assay in the first week after AMI in 50 patients. Catestatin levels reduced at admission and negatively correlated with heart rates; it increased significantly on the third day but remained decreased at 1 week and positively with blood pressure. In a subgroup of 20 patients admitted within 4?h after onset, circulating catestatin correlated inversely with norepinephrine. Catestatin might be involved in the course of AMI and act as a tool in monitoring the progression of AMI.     

Interaction of the catecholamine release-inhibitory peptide catestatin (human chromogranin A(352-372)) with the chromaffin cell surface and Torpedo electroplax: implications for nicotinic cholinergic antagonism

The catecholamine release-inhibitory chromogranin A fragment catestatin (chromogranin A(344-364)) exhibits non-competitive antagonism of nicotinic cholinergic signaling in chromaffin cells. A previous homology model of catestatin's likely structure suggested a mode of interaction of the peptide with the nicotinic receptor, but direct evidence has been lacking. Here we found that [125I]-catestatin binds to the surface of intact PC12 and bovine chromaffin cells with high affinity (K(D)=15.2+/-1.53 nM) and specificity (lack of displacement by another [N-terminal] fragment of chromogranin A). Nicotinic agonist (carbamylcholine) did not displace [125I]-catestatin from chromaffin cells, nor did catestatin displace the nicotinic agonist [3H]-epibatidine; these observations indicate a catestatin binding site separate from the agonist binding pocket on the nicotinic receptor, a finding consistent with catestatin's non-competitive nicotinic mechanism. [125I]-catestatin could be displaced from chromaffin cells by substance P (IC(50) approximately 5 microM), though at far lower potency than displacement by catestatin itself (IC(50) approximately 350-380 nM), suggesting that catestatin and substance P occupy an identical or overlapping non-competitive site on the nicotinic receptor, at different affinities (catestatin > substance P). Small, non-peptide non-competitive nicotinic antagonists (hexamethonium or clonidine) did not diminish [125I]-catestatin binding, suggesting distinct non-competitive binding sites on the nicotinic receptor for peptide and non-peptide antagonists. Similar binding and inhibitory profiles for [125I]-catestatin were observed on chromaffin cells as well as nicotinic receptor-enriched Torpedo membranes. Covalent cross-linking of [125I]-catestatin to Torpedo membranes suggested specific contacts of [125I]-catestatin with the delta, gamma, and beta subunits of the nicotinic receptor, a finding consistent with prior homology modeling of the interaction of catestatin with the extracellular face of the nicotinic heteropentamer. We conclude that catestatin occludes the nicotinic cation pore by interacting with multiple nicotinic subunits at the pore vestibule. Such binding provides a physical explanation for non-competitive antagonism of the peptide at the nicotinic receptor.     

Catestatin (CgA344-364) stimulates rat mast cell release of histamine in a manner comparable to mastoparan and other cationic charged neuropeptides

Catestatin (bovine CgA(344-364)) is a cationic peptide, which besides reducing catecholamine secretion from chromaffin cells in vitro also acts a potent vasodilator in the rat in vivo. The alleged histamine releasing effect of catestatin was tested in vitro in rat mast cells. The most active domain of catestatin (bovine CgA(344-358): RSMRLSFRARGYGFR) caused concentration-dependent (0.01-5 microM) release of histamine from peritoneal and pleural mast cells. The potency and efficacy of catestatin was higher than for the wasp venom peptide, mastoparan. Only in the pleural cells was neurotensin (NT) more potent than catestatin, mastoparan and substance P (SP), consistent with a receptor-mediated histamine release by neurotensin. Amongst these cationic peptides, substance P was least effective. The acidic CgA peptide (WE-14, bovine CgA (324-337)) neither stimulated nor modulated histamine release by the cationic peptides. The catestatin and neurotensin evoked histamine release were suppressed by pertussis toxin (PTX), suggesting involvement of a G(i) subunit. Electron micrographs of rat pleural mast cells responding to catestatin revealed a concentration-dependent discharge of granular material. We propose that catestatin activates histamine release from rat mast cells by a mechanism analogous to that already established for mastoparan and other amphiphilic cationic neuropeptides (the peptidergic pathway) and distinct from the mechanism of inhibition of catecholamine release from chromaffin cells.     

Type‐specific dysregulation of matrix metalloproteinases and their tissue inhibitors in end‐stage heart failure patients: relationship between MMP‐10 and LV remodelling

Although past studies observed the changes of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in end‐stage heart failure (HF) patients, a consistent and clear pattern of type‐specific MMPs and/or TIMPs has yet to be further defined. In this study, proteomic approach of human protein antibody arrays was used to compare MMP and TIMP expression levels of left ventricular (LV) myocardial samples from end‐stage HF patients due to dilated cardiomyopathy (DCM) with those from age‐ and sex‐ matched non‐failing patients. Western blot analysis, immunohistochemistry and ELISA were used for validation of our results. We observed that MMP‐10 and ‐7 abundance increased, accompanied by decreased TIMP‐4 in DCM failing hearts (n= 8) compared with non‐failing hearts (n= 8). The results were further validated in a cohort of 34 end‐stage HF patients derived from three forms of cardiomyopathies. Cardiac and plasma MMP‐10 levels were positively correlated with the LV end‐diastolic dimension in this HF cohort. In addition, we observed that insulin‐like growth factor‐2 promoted MMP‐10 production in neonatal rat cardiomyocytes. In conclusion, this study demonstrated a selective up‐regulation of MMP‐10 and ‐7 along with a discordant change of TIMP‐4, and a positive correlation between MMP‐10 levels and the degree of LV dilation in end‐stage HF patients. Our findings suggest that type‐specific dysregulation of MMPs and TIMPs is associated with LV remodelling in end‐stage HF patients, and MMP‐10 may act as a novel biomarker for LV remodelling.     

Comprehensive plasma metabolomic and lipidomic analyses reveal potential biomarkers for heart failure

Heart failure is a syndrome with symptoms or signs caused by cardiac dysfunction. In clinic, four stages (A, B, C, and D) were used to describe heart failure progression. This study was aimed to explore plasma metabolomic and lipidomic profiles in different HF stages to identify potential biomarkers. Metabolomics and lipidomics were performed using plasma of heart failure patients at stages A (n?=?49), B (n?=?61), and C+D (n?=?26). Analysis of Variance (ANOVA) was used for screening dysregulated molecules. Bioinformatics was used to retrieve perturbed metabolic pathways. Univariate and multivariate receiver operating characteristic curve (ROC) analyses were used for potential biomarker screening. Stage A showed significant difference to other stages, and 142 dysregulated lipids and 134 dysregulated metabolites were found belonging to several metabolic pathways. Several marker panels were proposed for the diagnosis of heart failure stage A versus stage B-D. Several molecules, including lysophosphatidylcholine 18:2, cholesteryl ester 18:1, alanine, choline, and Fructose, were found correlated with B-type natriuretic peptide or left ventricular ejection fractions. In summary, using untargeted metabolomic and lipidomic profiling, several dysregulated small molecules were successfully identified between HF stages A and B-D. These molecules would provide valuable information for further pathological researches and biomarker development.