Relationship between plasma level of cardiotrophin-1 and left ventricular mass index in patients with dilated cardiomyopathy

Potential clinical biomarkers and perspectives in diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is a serious cardiovascular complication and the leading cause of death in diabetic patients. Patients typically do not experience any symptoms and have normal systolic and diastolic cardiac functions in the early stages of DCM. Because the majority of cardiac tissue has already been destroyed by the time DCM is detected, research must be conducted on biomarkers for early DCM, early diagnosis of DCM patients, and early symptomatic management to minimize mortality rates among DCM patients. Most of the existing implemented clinical markers are not very specific for DCM, especially in the early stages of DCM. Recent studies have shown that a number of new novel markers, such as galactin-3 (Gal-3), adiponectin (APN), and irisin, have significant changes in the clinical course of the various stages of DCM, suggesting that we may have a positive effect on the identification of DCM. As a summary of the current state of knowledge regarding DCM biomarkers, this review aims to inspire new ideas for identifying clinical markers and related pathophysiologic mechanisms that could be used in the early diagnosis and treatment of DCM.

The role of interleukin-6 in the development of cardiovascular diseases: A review

Currently, the search and study of new biological markers that can provide early diagnosis of cardiovascular diseases, serve as a laboratory tool for assessing the effectiveness of treatment, or be used as prognostic markers and risk stratification criteria is ongoing. Our literature review indicates the potentially important diagnostic and prognostic value of assessing members of the interleukin-6 family. It is expected that further scientific and clinical studies will demonstrate the possibility of using members of the interleukin-6 family as an additional laboratory tool for the diagnosis, risk stratification and prediction of cardiovascular events in cardiac patients. It is necessary to evaluate in detail the possibilities of blockade of these interleukin-6 molecules in patients with cardiovascular diseases in vitro and in vivo.

Coronary artery disease risk factors affected by RNA modification-related genetic variants

Background

Single nucleotide polymorphisms that affect RNA modification (RNAm-SNPs) may have functional roles in coronary artery disease (CAD). The aim of this study was to identify RNAm-SNPs in CAD susceptibility loci and highlight potential risk factors.

Methods

CAD-associated RNAm-SNPs were identified in the CARDIoGRAMplusC4D and UK Biobank genome-wide association studies. Gene expression and circulating protein levels affected by the RNAm-SNPs were identified by QTL analyses. Cell experiments and Mendelian randomization (MR) methods were applied to test whether the gene expression levels were associated with CAD.

Results

We identified 81 RNAm-SNPs that were associated with CAD or acute myocardial infarction (AMI), including m6A-, m1A-, m5C-, A-to-I- and m7G-related SNPs. The m6A-SNPs rs3739998 in JCAD, rs148172130 in RPL14 and rs12190287 in TCF21 and the m7G-SNP rs186643756 in PVT1 were genome-wide significant. The RNAm-SNPs were associated with gene expression (e.g., MRAS, DHX36, TCF21, JCAD and SH2B3), and the expression levels were associated with CAD. Differential m6A methylation and differential expression in FTO-overexpressing human aorta smooth muscle cells and peripheral blood mononuclear cells of CAD patients and controls were detected. The RNAm-SNPs were associated with circulating levels of proteins with specific biological functions, such as blood coagulation, and the proteins (e.g., cardiotrophin-1) were confirmed to be associated with CAD and AMI in MR analyses.

Conclusion

The present study identified RNAm-SNPs in CAD susceptibility genes, gene expression and circulating proteins as risk factors for CAD and suggested that RNA modification may play a role in the pathogenesis of CAD.

The Role of Interleukin-6 Family Members in Cardiovascular Diseases

Cardiovascular disease is one of the main causes of human mortality. Cytokines play crucial roles in the development of cardiovascular disease. Interleukin (IL)-6 family members are a series of cytokines, including IL-6, IL-11, IL-30, IL-31, OSM, LIF, CNTF, CT-1, CT-2, and CLC, that regulate multiple biological effects. Experimental and clinical evidence shows that IL-6 family members are closely related to cardiovascular diseases such as atherosclerosis, hypertension, aortic dissection, cardiac fibrosis, and cardiomyopathy. This review mainly discusses the role of IL-6 family members in cardiovascular disease for the sake of identifying possible intervention targets for cardiovascular disease prevention and treatment.

Increased Expression of Cardiotrophin-1 in Cardiomyopathy Patients

Cardiomyopathy (CM) is a condition of cardiac dysfunction. It is one of the leading causes of mortality in which both genetic and environmental factors are involved. Cardiotrophin-1 (CT-1) level in plasma is associated with CM. It affects the cardiomyocyte differentiation. To evaluate the expression of CT-1 in cardiomyopathy, this study was done on CM subjects attending the Fatima Memorial Hospital, Lahore, Pakistan, between January and June, 2016. A total of 40 subjects were enrolled who were divided into two groups; CM group (n = 20) and a control group (n = 20). A self-designed questionnaire was filled in by each subject to collect data regarding age, body mass index (BMI) and CM history. RNA was isolated from blood after its quantification, cDNA was prepared and reverse-transcriptase-polymerase chain reaction (RT-PCR) was performed for expression of CT-1. The mean age in CM subjects was 40.1±6.03 years, while it was 35.0±3.7 years in the control group. The mean expression of CT-1 in the CM subjects was 5.2±0.66, while it was 1.00±0.001 in the control group. A highly significant difference was observed in CT-1 expression in the CM group, and expression was significantly correlated with age and BMI in CM subjects.

Therapeutic Delivery of miR-148a Suppresses Ventricular Dilation in Heart Failure

Heart failure is preceded by ventricular remodeling, changes in left ventricular mass, and myocardial volume after alterations in loading conditions. Concentric hypertrophy arises after pressure overload, involves wall thickening, and forms a substrate for diastolic dysfunction. Eccentric hypertrophy develops in volume overload conditions and leads wall thinning, chamber dilation, and reduced ejection fraction. The molecular events underlying these distinct forms of cardiac remodeling are poorly understood. Here, we demonstrate that miR-148a expression changes dynamically in distinct subtypes of heart failure: while it is elevated in concentric hypertrophy, it decreased in dilated cardiomyopathy. In line, antagomir-mediated silencing of miR-148a caused wall thinning, chamber dilation, increased left ventricle volume, and reduced ejection fraction. Additionally, adeno-associated viral delivery of miR-148a protected the mouse heart from pressure-overload-induced systolic dysfunction by preventing the transition of concentric hypertrophic remodeling toward dilation. Mechanistically, miR-148a targets the cytokine co-receptor glycoprotein 130 (gp130) and connects cardiomyocyte responsiveness to extracellular cytokines by modulating the Stat3 signaling. These findings show the ability of miR-148a to prevent the transition of pressure-overload induced concentric hypertrophic remodeling toward eccentric hypertrophy and dilated cardiomyopathy and provide evidence for the existence of separate molecular programs inducing distinct forms of myocardial remodeling.

Differences in biochemical and genetic biomarkers in patients with heart failure of various etiologies

BACKGROUND/OBJECTIVES

To evaluate whether biomarkers reflecting pathophysiological pathways and selected single nucleotide polymorphisms differ between patients (pts) with heart failure (HF).

METHODS

110 pts with were involved, including HF pts with preserved ejection fraction (HFpEF, n=51) with hypertensive origin, HF pts with reduced ejection fraction (HFrEF) with ischemic aetiology (ICM) (n=32) and HFrEF with dilated cardiomyopathy (DCM) (n=27). We assessed selected HF biomarkers, echocardiographic examinations and functional polymorphisms selected from six candidate genes: CYP27B1, NOS3, IL-6, TGF beta, TNF alpha, and PPAR gamma.

RESULTS

Higher concentrations of TNF alpha were observed in pts with hypertensive HFpEF compared to pts with DCM (p=0.008). Pts with HFpEF had higher concentrations of TGF beta 1 compared to DCM and ICM (p=0.0001 and p=0.0003, respectively). For the NOS3 -786 C/T rs2070744 polymorphism in DCM there were significantly more CT heterozygotes than in ICM and HFpEF. In multivariate analysis TGF beta 1 (p=0.001) and syndecan 4 (p=0.001) were the only factors distinguishing HFrEF pts with DCM vs HFpEF and also TGF beta 1 (p=0.001) and syndecan 4 (p=0.023) were the only factors distinguishing HFrEF pts with ICM vs HFpEF pts.

CONCLUSIONS

Inflammation mediated through TNF alpha and TGF beta 1 may represent an important component of an inflammatory response that partially drives the pathophysiology of HFpEF. NOS3 -786 C/T rs2070744 polymorphism in DCM may serve as a marker for more rapid progression of heart failure. The only biomarkers independently distinguishing HFpEF and HFrEF are syndecan 4 and TGF beta 1.

Prognostication in Different Heart Failure Phenotypes: The Role of Circulating Biomarkers

Heart failure (HF) is multifactorial syndrome with high cardiovascular (CV) morbidity and mortality rates associated with an increasing prevalence worldwide. Measuring plasma levels of circulating biomarkers, i.e., natriuretic peptides, cardiac-specific troponins, metabolomic intermediates, Galectin-3, ST2, cardiotrophin-1, soluble endoglin and growth differentiation factor 15, may assist in the prognostication of HF development. However, the role of biomarker models in the prediction of an early stage of HF with a preserved ejection fraction (HFpEF) and HF with a reduced ejection fraction (HFrEF) is not still understood. This review explores the knowledge regarding the utility of cardiac biomarkers, aiming to reclassify patients with different phenotypes of HF. The review reports that several biomarkers reflected on subsequently alter collagen turnover, cardiac fibrosis and inflammation, which might have diagnostic and predictive value in HFpEF and HFrEF. The best candidates for determining the early stage of HF development were sST2, Galectin-3, CT-1 and GDF-15. However, increased plasma concentrations of these biomarkers were not specific to a distinct disease group of HFpEF and HFrEF. Finally, more investigations are required to determine the role of novel biomarkers in the prediction of HF and the determination of the early stages of HFpEF and HFrEF development.

microRNA-340-5p Functions Downstream of Cardiotrophin-1 to Regulate Cardiac Eccentric Hypertrophy and Heart Failure via Target Gene Dystrophin

Pathological cardiac hypertrophy inevitably leads to the unfavorable outcomes of heart failure (HF) or even sudden death. microRNAs are key regulation factors participating in many pathophysiological processes. Recently, we observed upregulation of microRNA-340-5p (miR-340) in failing human hearts because of dilated cardiomyopathy, but the functional consequence of miR-340 remains to be clarified.We transfected neonatal cardiomyocytes with miR-340 and found fetal gene expression including Nppa, Nppb and Myh7. We also observed eccentric hypertrophy development upon treatment which was analogous to the phenotype after cardiotrophin-1 (CT-1) stimulation. As a potent inducer of cardiac eccentric hypertrophy, treatment by IL-6 family members CT-1 and leukemia inhibitory factor (LIF) led to the elevation of miR-340. Knockdown of miR-340 using antagomir attenuated fetal gene expression and hypertrophy formation, which means miR-340 could convey the hypertrophic signal of CT-1. To demonstrate the initial factor of miR-340 activation, we constructed a volume overloaded abdominal aorta-inferior vena cava fistula rat HF model. miR-340 and CT-1 were found to be up-regulated in the left ventricle. Dystrophin (DMD), a putative target gene of miR-340 which is eccentric hypertrophy-susceptible, was decreased in this HF model upon Western blotting and immunohistochemistry tests. Luciferase assay constructed in two seed sequence of DMD gene 3'UTR showed decreased luciferase activities, and miR-340 transfected cells resulted in the degradation of DMD.miR-340 is a pro-eccentric hypertrophy miRNA, and its expression is dependent on volume overload and cytokine CT-1 activation. Cardiomyocyte structure protein DMD is a target of miR-340.

Interleukin-6 signaling, soluble glycoprotein 130, and inflammation in heart failure

Both experimental and clinical evidence accumulated over the last couple of decades has linked inflammatory activation to the initiation and progression of chronic heart failure (HF). Circulating levels of inflammatory mediators are associated with cardiac function and inform risk prediction in patients, but the effect of anti-inflammatory therapy in HF remains uncertain. Interleukin (IL)-6 type cytokines are central to the inflammatory response, and convey their signals through the ubiquitously expressed glycoprotein (gp) 130 receptor subunit. IL-6-type/gp130 signaling therefore represents an inflammatory nexus, with inherent potential for disease modification. This review focuses on the current knowledge of IL-6/gp130 signaling in relation to HF, with a particular emphasis on the role of soluble gp130 (sgp130), a signaling pathway modulator. Biological aspects of sgp130 and IL-6 signaling are discussed, as are potential novel therapeutic approaches to modulate this central inflammatory signaling pathway.

Plasma cardiotrophin-1 levels are associated with hypertensive heart disease: a meta-analysis

Cardiotrophin-1 (CT-1) is a member of the interleukin 6 cytokine superfamily. Plasma CT-1 levels have been associated with heart failure and hypertension in small independent studies. Whether plasma CT-1 levels are associated with progression of hypertensive heart disease is poorly understood. The authors carried out a meta-analysis using published studies and electronic databases. Relevant data were extracted using standardized algorithms. Additional data were obtained directly from investigators when indicated. A total of 18 studies were included that reported on association between CT-1 level and hypertension (n=8), cardiac hypertrophy (n=9), and heart failure (HF) (n=10). The serum levels of CT-1 were significantly higher in patients with hypertension (standard mean difference [SMD], 0.85; 95% confidence interval [CI], 0.64-1.06 fmol/mL), left ventricular hypertrophy (SMD, 0.88; 95% CI 0.60-1.17 fmol/mL), or HF (SMD, 0.66; 95% CI, 0.51-0.80 fmol/mL) compared with controls. Subgroup analysis revealed CT-1 levels to be highest in patients with hypertension-induced hypertrophy with HF, followed by patients with hypertension-induced left ventricular hypertrophy without HF (SMD, 0.52; 95% CI, 0.30-0.75 fmol/mL), patients with hypertension without left ventricular hypertrophy (SMD, 0.67; 95% CI, 0.46-0.88 fmol/mL) as compared with normotensive patients (SMD, 0.74; 95% CI, 10.45-1.04 fmol/mL). Increased plasma CT-1 levels are associated with risk for HF in hypertensive patients. CT-1 may serve as a novel biomarker in determining prognosis in hypertensive patients.

Effect of cardiac resynchronization therapy on cardiotrophin-1 circulating levels in patients with heart failure

Cardiotrophin-1 (CT-1) is a member of the interleukin (IL-6) family of cytokines. Plasma CT-1 levels correlate with the left ventricle mass index in patients with dilatated cardiomyopathy and congestive heart failure (CHF). The aim of this paper was to evaluate CT-1 plasma levels, before and after cardiac resynchronization therapy CRT, and to characterizeits prognostic role in patients with CHF. Fifty-two consecutive patients (M/F = 39/13; 56 ± 11 years old) underwent clinical and echocardiographic evaluation, and blood sample collection at baseline. The same evaluation was repeated 6.4 ± 0.79 months after CRT. Patients with a decreased LV end-systolic volume by at least 15% (reverse remodeling) were considered echo responders to CRT. Twenty-nine patients (56%) were responders to CRT. After CRT, only 15 patients (29%) showed increased CT-1 after CRT. They were all non responders to CRT. A multivariate, logistic model showed CT-1 as an independent predictor of CRT echo response (p = 0.005; OR 0.97). During follow-up (18 ± 7 months), 21 cardiac events in 18 patients occurred. A Cox multivariable model showed plasma BNP pre-CRT (p = 0.02; CI 1.2-5.6; OR 3.1) and CT1 post-CRT (p = 0.01; CI 1.4-4.3; OR 2.7) as independent predictors of cardiac events. Analysis of CT-1 plasma levels deserves future consideration for larger, longitudinal studies in patients with CHF.

Association of cardiotrophin-1 with left ventricular systolic properties in asymptomatic hypertensive patients

OBJECTIVES

Cardiotrophin-1 (CT-1) induces hypertrophic growth and contractile dysfunction in cardiomyocytes. This cross-sectional study was aimed to analyze CT-1 associations with echocardiographically assessed left ventricular systolic properties taking into account the influence of left ventricular growth [i.e. left ventricular hypertrophy (LVH) and inappropriate left ventricular mass (iLVM)] in asymptomatic hypertensive patients.

METHODS

Serum CT-1 was measured by ELISA in 278 asymptomatic hypertensive patients with a left ventricular ejection fraction more than 50% and in 25 age and sex-matched normotensive patients.

RESULTS

Serum CT-1 was increased in hypertensive patients as compared to normotensive patients. CT-1 was directly correlated with parameters of left ventricular mass (LVM) and inversely correlated with parameters assessing myocardial systolic function and left ventricular chamber contractility in hypertensive patients, these associations being independent of a number of potential confounding factors. Interestingly, the associations of CT-1 with myocardial systolic function were independent of LVM even in patients with LVH or iLVM. In addition, there was a significant increment of serum CT-1 in hypertensive patients with LVH or iLVM, especially in those in whom LVH or iLVM were accompanied by impaired myocardial systolic function, as compared to the remaining hypertensive patients and normotensive patients. Plasma amino-terminal pro-brain natriuretic peptide was not correlated with any of the assessed left ventricular systolic parameters in either group of patients.

CONCLUSION

These findings suggest that serum CT-1 is associated with myocardial systolic dysfunction in asymptomatic hypertensive patients, independently of LVM, even in those patients with pathologic left ventricular growth.

New and emerging biomarkers in left ventricular systolic dysfunction--insight into dilated cardiomyopathy

Dilated cardiomyopathy (DCM) is characterized by deteriorating cardiac performance, impaired contraction and dilation of the left ventricle (or both ventricles). Blood markers--known as "biomarkers"--allow insight into underlying pathophysiologic mechanisms and biologic pathways while predicting outcomes and guiding heart failure management and/or therapies. In this review, we provide an alternative approach to conceptualize heart failure biomarkers: the cardiomyocyte, its surrounding microenvironment, and the macroenvironment, integrating these entities which may impact cellular processes involved in the pathogenesis and/or propagation of DCM. Newer biomarkers of left ventricular systolic dysfunction can be categorized under: (a) myocyte stress and stretch, (b) myocyte apoptosis, (c) cardiac interstitium, (d) inflammation, (e) oxidative stress, (f) cardiac energetics, (g) neurohormones, and (h) renal biomarkers. Biomarkers provide insight into the pathogenesis of DCM while predicting and potentially providing prognostic information in these patients with heart failure.

Soluble Glycoprotein 130 Predicts Fatal Outcomes in Chronic Heart Failure

Background—

Glycoprotein 130 (gp130) is the common signal-transducing receptor subunit of the interleukin-6 (IL-6) family, which may be involved in the progression of heart failure (HF). We hypothesized that soluble gp130 would provide prognostic information beyond that of IL-6 in a population with HF from the Controlled Rosuvastatin Multinational Trial in Heart Failure (CORONA).

Methods and Results—

The associations of soluble gp130 and IL-6 with morbidity, mortality, and mode of death were assessed by immunoassays in a subset of 1452 patients enrolled in the CORONA trial, which included patients with HF, aged ≥60 years, in New York Heart Association classes II to IV, who had ischemic heart disease and a reduced left ventricular ejection fraction. In multivariable analyses, including C-reactive protein, IL-6, troponin T, and N-terminal pro-B-type natriuretic peptide, elevated soluble gp130 (fifth quintile versus all lower quintiles) was associated with all-cause mortality (hazard ratio, 1.47 [1.11–1.93]; P =0.006), cardiovascular mortality (hazard ratio, 1.38 [1.01–1.87]; P =0.042), and death from worsening HF (hazard ratio, 1.85 [1.09–3.14]; P =0.002), but not with the primary end point (composite of death from cardiovascular causes, nonfatal myocardial infarction, and nonfatal stroke; hazard ratio, 1.12 [0.84–1.50]; P =0.44). Plasma IL-6 was not associated with outcomes in multivariable analyses.

Conclusions—

Marked elevations in soluble gp130 are associated with total and cardiovascular mortality, as well as deaths from worsening HF, in elderly patients with HF of ischemic cause

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00206310.

Cardiotrophin-1 plasma levels are increased in patients with diastolic heart failure

Background

Cardiotrophin-1 (CT-1) is a member of the interleukin (IL-6) family of cytokines and is increased in various cardiovascular diseases, including chronic heart failure. The aim of the study was to determine if plasma CT-1 is associated with diastolic heart failure (DHF) and to investigate the relationship between CT-1 and echocardiographic parameters.

Material/Methods

Fifty-seven consecutive patients (mean age 57±8 years, 24 males) diagnosed with DHF in our clinic and 33 controls (mean age 55±7 years, 12 males) were included in the study. All study participants underwent echocardiographic evaluation and blood samples were obtained.

Results

CT-1 and NT-proBNP values were significantly higher in DHF subjects than in controls (11.30 [8.09–16.51] vs. 17.5 [8.95–28.74] fmol/mL, P=0.017 and 64 [27.5–95] vs. 82 [55.5–241] pg/mL, P=0.009, respectively). The mitral peak velocity of early diastolic filling (E), mean ratio of E to early diastolic mitral annular velocity (E/Em), and the pulmonary capillary wedge pressure (PCWP) estimated from E/Em measurements were all significantly higher in the patient group (62.27±14.69 vs. 75.67±18.85 cm/sec, 6.40±1.48 vs. 10.30±3.48, and 10 [9–11]vs. 14[12–16] mmHg, P≤0.001 for all). Lateral and septal Em were significantly lower in the patient group (10.69±1.87 vs. 8.69±2.00 cm/sec and 8.91±1.22 vs. 6.65±1.58 cm/sec, P<0.001 for both). CT-1 positively correlated with NT-proBNP (P=0.001, r=0.349), mean E/Em (P=0.003, r=0.307), and estimated mean PCWP (P=0.001, r=0.308).

Conclusions

CT-1 is elevated in patients with DHF and is associated with NT-proBNP and estimated left ventricular filling pressures.

The gp130 receptor cytokine family: regulators of adipocyte development and function

Gp130 cytokines are involved in the regulation of numerous biological processes, including hematopoiesis, immune response, inflammation, cardiovascular action, and neuronal survival. These cytokines share glycoprotein 130 as a common signal transducer in their receptor complex and typically activate STAT3. Most gp130 cytokines have paracrine or endocrine actions, and their levels can be measured in circulation in rodents and humans. In recent years, various laboratories have conducted studies to demonstrate that gp130 cytokines can modulate adipocyte development and function. Therefore, these studies suggest that some gp130 cytokines may be viable anti-obesity therapeutics. In this review, we will summarize the reported effects of gp130 cytokines on adipocyte differentiation and adipocyte function. In addition, the modulation of gp130 cytokines in conditions of obesity, insulin resistance, and Type 2 diabetes will be presented.

Cardiotrophin-1 in cardiovascular regulation

Cardiotrophin (CT)-1 was discovered by coupling expression cloning with an embryonic stem cell-based model of cardiogenesis. Comparison of similarity in amino acid sequence and conformational structure indicates that CT-1 is a member of the interleukin (IL)-6 type cytokine family that shares the transmembrane signaling protein, glycoprotein (gp) 130 as a receptor. These cytokines mediate overlapping pleiotropic actions on a variety of cell types including cardiac myocytes, hepatocytes, megakaryocytes, osteoclasts, and neuronal cells. CT-lmediates its hypertrophic and cytoprotective properties through the Janus kinase/signal transducers and activators of transcription (JAK/STAT), mitogen-activated protein (MAP) kinase, phosphatidylinositol (PI) 3 kinase, and nuclear factor kappa B (NFkappaB) pathways. CT-1 gene and protein are distributed not only in the heart, but also in the pulmonary, renal, gastrointestinal, cerebral, and muscular tissues. CT-1 could also be synthesized and secreted from vascular endothelial cells and adipocytes. CT-1 has hypertrophic actions on the cardiac myocytes, skeletal muscle cells, and smooth muscle cells as well as cytoprotective actions on the cardiac myocytes, neuronal cells, and hepatocytes. CT-1 is circulating in the body, and its plasma concentration is increased in various cardiovascular and renal diseases such as hypertension, congestive heart failure, myocardial infarction, valvular heart disease, metabolic syndrome, and chronic kidney disease. Treatment with CT-1 is beneficial in experimental animal models of cardiovascular diseases. CT-1 specifically protects the cardiac myocytes from ischemic damage when CT-1 is given not only prior to the ischemia, but also given at the time of reoxygenation. Current evidence suggests that CT-1 plays an important role in the regulation of the cardiovascular system.

Cardiotrophin-1 plasma levels are associated with the severity of hypertrophy in hypertrophic cardiomyopathy

AIMS

Cardiotrophin-1 (CT-1) is a cytokine that induces hypertrophy in cardiomyocytes and is associated with left ventricular hypertrophy (LVH) in hypertensive patients. The objective of this study was to evaluate whether plasma CT-1 is associated with hypertrophic cardiomyopathy (HCM).

METHODS AND RESULTS

The study was performed in 124 patients with HCM. All patients underwent a full clinical evaluation and an echocardiogram. Left ventricular hypertrophy was evaluated by the measurement of the maximal LV wall thickness and the Spirito's LVH score. Plasma CT-1 was measured by an enzyme-linked immunosorbent assay. Compared with controls, patients with HCM exhibited higher (P < 0.001) plasma CT-1 levels. Significant correlations were found between CT-1 and maximal LV wall thickness (r = 0.284, P = 0.001) and the Spirito's LVH score (r = 0.287, P = 0.006) in HCM patients. In addition, the levels of CT-1 were higher (P = 0.02) in patients with severe LVH (maximal LV wall thickness ≥30 mm) than in patients with mild or moderate LVH (maximal LV wall thickness <30 mm).

CONCLUSIONS

These findings show that plasma CT-1 is associated with the severity of LVH in patients with HCM. Further studies are required to ascertain whether CT-1 is a diagnostic biomarker of this cardiomyopathy.

Novel biomarkers in heart failure: an overview

Heart failure is a complex systemic syndrome resulting from significant impairment of cardiac function. A vast array of biological pathways is now known to be involved in heart failure, including deleterious pathways promoting its development and progression, as well as compensatory cardioprotective pathways. Some of the components of these pathways are now recognized as biomarkers of this condition, and can aid diagnosis, prognostication and guide management. As the understanding of the pathophysiology of heart failure progresses, further candidate biomarkers are being identified. This article reviews the literature regarding the more recently identified biomarkers and outlines areas requiring further study.

gp130-mediated pathway and heart failure

Binding of ligands to gp130 activates at least three different downstream signaling pathways: the signal transducer and activator of transcription (STAT), the Src-homology tyrosine phosphatase 2-ras-MAPK and the PI3K/Akt pathways. Cardiac-specific disruption of gp130 was shown to result in heart failure in response to mechano-stress accompanied by an increase in apoptosis of cardiac myocytes. Inactivation of STAT3 resulting from the loss of gp130 may be a key event in the transition from cardiac hypertrophy to heart failure. Proper vascular growth would be essential for normal cardiac development and the remodeling process. In addition to various factors, such as bcl-xL, inducible nitric oxide synthase and reactive oxygen species-scavenging proteins, VEGF has also been identified as a target gene of STAT3 and together can promote cardiac myocyte survival by preventing apoptosis and restoration of energy deprivation. In this regard, the gp130-receptor system and its main downstream mediator, STAT3, play a key role in the prevention of heart failure. In this review, current knowledge of the IL-6 family of cytokines relating to human cardiac disease is summarized, in addition to the potential role of gp130-mediated signaling systems in various models of experimental heart failure.

Cardiotrophin-1. Review

BACKGROUND

Cardiotrophin-1 is newly discovered chemokin with a lot of functions. Aim of our work was to describe most important of them.

METHODS

systematically scan of available scientific resources.

RESULTS

Cardiotrophin-1 stimulates the proliferation of cardiomyocytes. Cardiotrophin-1 expression and plasma values are elevated in individuals with heart failure and have high diagnostic efficacy for the heart failure. Plasma values are also an independent prognostic factor. Preliminary findings suggest that the determination of plasma cardiotrophin-1 may be useful for the follow-up of hypertensive heart disease in routine clinical practice. Cardiotrophin-1 also plays an important cardioprotective effect on myocardial damage, is a potent regulator of signaling in adipocytes in vitro and in vivo and potentiates the elevation the acute-phase proteins. Cardiotrophin-1 may play also an important protective role in other organ systems (such as hematopoietic, neuronal, developmental).

CONCLUSION

Cardiotrophin is a newly discovered chemokin with a lot of system effects and is stable in system circulation hence permitting its development in the routine clinical investigation.

Molecular regulation of cardiac hypertrophy

Heart failure is one of the leading causes of mortality in the western world and encompasses a wide spectrum of cardiac pathologies. When the heart experiences extended periods of elevated workload, it undergoes hypertrophic enlargement in response to the increased demand. Cardiovascular disease, such as that caused by myocardial infarction, obesity or drug abuse promotes cardiac myocyte hypertrophy and subsequent heart failure. A number of signalling modulators in the vasculature milieu are known to regulate heart mass including those that influence gene expression, apoptosis, cytokine release and growth factor signalling. Recent evidence using genetic and cellular models of cardiac hypertrophy suggests that pathological hypertrophy can be prevented or reversed and has promoted an enormous drive in drug discovery research aiming to identify novel and specific regulators of hypertrophy. In this review we describe the molecular characteristics of cardiac hypertrophy such as the aberrant re-expression of the fetal gene program. We discuss the various molecular pathways responsible for the co-ordinated control of the hypertrophic program including: natriuretic peptides, the adrenergic system, adhesion and cytoskeletal proteins, IL-6 cytokine family, MEK-ERK1/2 signalling, histone acetylation, calcium-mediated modulation and the exciting recent discovery of the role of microRNAs in controlling cardiac hypertrophy. Characterisation of the signalling pathways leading to cardiac hypertrophy has led to a wealth of knowledge about this condition both physiological and pathological. The challenge will be translating this knowledge into potential pharmacological therapies for the treatment of cardiac pathologies.

Cardiotrophin-1 is expressed in adipose tissue and upregulated in the metabolic syndrome

Adipose tissue is a target for cardiotrophin-1 (CT-1), a cytokine member of the IL-6 family of cytokines that is involved in cardiac growth and dysfunction. However, it is unknown whether adipocytes are a source of CT-1 and whether CT-1 is overexpressed in diseases characterized by increased fat depots [i.e., the metabolic syndrome (MS)]. Thus this work aimed 1) to test whether adipose tissue expresses CT-1 and whether CT-1 expression can be modulated and 2) to compare serum CT-1 levels in subjects with and without MS diagnosed by National Cholesterol Education Program Adult Treatment Panel III criteria. Gene and protein expression of CT-1 was determined by real-time RT-PCR, ELISA, and Western blotting. CT-1 expression progressively increased, along with differentiation time from preadipocyte to mature adipocyte in 3T3-L1 cells. CT-1 expression was enhanced by glucose in a dose-dependent manner in these cells. mRNA and protein CT-1 expression was also demonstrated in human adipose biopsies. Immunostaining showed positive staining in adipocytes. Finally, increased CT-1 serum levels were observed in patients with MS compared with control subjects (127 +/- 9 vs. 106 +/- 4 ng/ml, P < 0.05). Circulating levels of CT-1 were associated with glucose levels (r = 0.2, P < 0.05). Taken together, our data suggest that adipose tissue can be recognized as a source of CT-1, which could account for the high circulating levels of CT-1 in patients with MS.

Association of depressed cardiac gp130-mediated antiapoptotic pathways with stimulated cardiomyocyte apoptosis in hypertensive patients with heart failure

OBJECTIVE

To investigate whether the glycoprotein (gp130)-mediated survival pathway, which protects cardiomyocytes from apoptosis, is depressed in left ventricular hypertrophy hypertensive patients with chronic heart failure.

METHODS

Transvenous endomyocardial biopsies were obtained in 52 hypertensive patients with left ventricular hypertrophy: 28 without heart failure and 24 with heart failure. gp130 and gp130-dependent antiapoptotic pathways p42/44 mitogen-activated protein kinase (MAPK) and phosphatidylinositol-3 kinase (PI3K)/protein kinase B (Akt) as well as gp130 agonist cardiotrophin-1 were analyzed by reverse transcriptase-polymerase chain reaction and western blot. Apoptosis was assessed by DNA end-labeling (TUNEL), caspase-3 immunostaining and caspase substrate poly(ADP-ribose) polymerase cleavage.

RESULTS

gp130 protein expression (P < 0.05) and p42/44 MAPK and PI3K/Akt activation (P < 0.01) were decreased in heart-failure hypertensive patients compared with nonheart-failure hypertensive individuals. No changes in gp130 mRNA expression were found between the two groups. Cardiotrophin-1 was increased (P < 0.05) at both the mRNA and protein levels in heart-failure hypertensive individuals compared with nonheart-failure hypertensive individuals. Cardiomyocyte apoptosis was increased (P < 0.01) in heart-failure hypertensive individuals compared with nonheart-failure hypertensive individuals. Inverse correlations (P < 0.01) occurred between cardiomyocyte apoptosis and p42/44 MAPK and PI3K/Akt activation in all hypertensive patients. Cardiotrophin-1 correlated inversely (r = -0.554, P < 0.05) with gp130 in all hypertensive individuals. In cultured HL-1 cardiomyocytes, cardiotrophin-1 decreased (P < 0.05) the gp130:phosphorylated gp130 (at Ser782) ratio and increased (P < 0.05) gp130ubiquitination.

CONCLUSIONS

An association exists between depression of the gp130 cytoprotective pathway and stimulation of cardiomyocyte apoptosis in hypertensive patients that develop heart failure. Whether the excess of cardiotrophin-1 induces ligand-induced receptor down-regulation in these patients requires further study.

Plasma level of cardiotrophin-1 as a prognostic predictor in patients with chronic heart failure

BACKGROUND

Cardiotrophin-1 (CT-1) is a member of the interleukin (IL-6) family of cytokines and is increased in patients with chronic heart failure (CHF).

AIMS

To evaluate the prognostic role of CT-1 in patients with CHF.

METHODS AND RESULTS

We measured the plasma levels of CT-1, brain natriuretic peptide (BNP), and IL-6 in 125 patients with CHF. Patients were monitored for a mean follow-up period of 2.9 years. Plasma levels of CT-1 increased with severity of CHF. There was a significant negative correlation between plasma CT-1 and left ventricular ejection fraction. There was a significant correlation between plasma CT-1 and log IL-6. During the follow-up period, 37 patients died. High plasma levels of CT-1, BNP, and IL-6 were independent predictors of mortality on stepwise multivariate analysis. The hazard ratio for mortality in patients with plasma BNP>170 pg/mL and CT-1>658 fmol/mL was 2.48 (95% confidence interval, 1.217-5.060) compared to those with plasma BNP>170 pg/mL and CT-1<658 fmol/mL (p=0.0124).

CONCLUSION

These findings indicate that plasma CT-1 measurement provides additional prognostic information and that combined levels of CT-1 and BNP are more accurate at predicting mortality in patients with CHF than either marker alone.

Survival pathways in hypertrophy and heart failure: the gp130-STAT3 axis

Circulating levels of interleukin (IL)-6 and related cytokines are elevated in patients with congestive heart failure and after myocardial infarction. Serum IL-6 concentrations are related to decreasing functional status of these patients and provide important prognostic information.Moreover, in the failing human heart, multiple components of the IL-6- glycoprotein (gp)130 receptor system are impaired, implicating an important role of this system in cardiac pathophysiology.Experimental studies have shown that the common receptor subunit of IL-6 cytokines is phosphorylated in response to pressure overload and myocardial infarction and that it subsequently activates at least three different downstream signaling pathways, the signal transducers and activators of transcription 1 and 3 (STAT1/3), the Src-homology tyrosine phosphatase 2 (SHP2)-Ras-ERK, and the PI3K-Akt system. Gp130 receptor mediated signaling promotes cardiomyocyte survival, induces hypertrophy, modulates cardiac extracellular matrix and cardiac function. In this regard, the gp130 receptor system and its main downstream mediator STAT3 play a key role in cardioprotection. This review summarizes the current knowledge of IL-6 cytokines, gp130 receptor and STAT3 signaling in the heart exposed to physiological (aging, pregnancy) and pathophysiological stress (ischemia, pressure overload, inflammation and cardiotoxic agents) with a special focus on the potential role of individual IL-6 cytokines.

Novel and potential future biomarkers for assessment of the severity and prognosis of chronic heart failure

Over the last two decades, the pathophysiology and biomolecular basis of heart failure syndrome has reached sound and more comprehensive understanding. This knowledge has allowed expert researchers and clinicians to explore an entirely new spectrum of potential biochemical markers derived from different cellular and signaling pathways that lead to myocardial hypertrophy, chronic damage of the myocyte, apoptosis, and, ultimately, myocardial remodeling. Indeed, the link between myocardial remodeling and adverse outcomes, as well as the recognition of the myocardial interstitium as a multifunctional dynamic entity strongly influenced by systemic neurohormonal and inflammatory activation, has provided a solid ground for research of biomarkers that might correlate with severity and prognostication in chronic heart failure. This paper reviews and summarize recent literature on some of the most interesting circulating biomarkers with potential use for the stratification of patients with chronic heart failure.

Comparison of Soluble Glycoprotein 130 and Cardiac Natriuretic Peptides as Long-term Predictors of Heart Failure Progression

BACKGROUND

In patients with heart failure, B-type natriuretic peptides (BNP, N-BNP) and atrial natriuretic peptide (ANP) are established prognostic markers. However, circulating interleukin (IL)-6-related cytokines and soluble glycoprotein 130 (sgp130), their common subunit for signal transduction, are also increased. We hypothesized that levels of circulating sgp130 and cardiac peptides provide independent prediction of worsening pump failure in the long term.

METHODS

A series of 76 patients (77% male, 54 ischemic and 17 nonischemic, left ventricular ejection fraction 22% +/- 7%) had blood samples drawn for assay of sgp130, oncostatin-M, N-ANP, N-BNP, and BNP. A composite end point of worsening pump failure (requiring hospitalization, intravenous therapy, or urgent heart transplantation) and pump failure death was used for follow-up.

RESULTS

During follow-up (up to 7 years), rate of worsening pump failure was 22.3%, including death. N-ANP (5666 +/- 3100 vs 7850 +/- 12164 fmol/ml), N-BNP (278 +/- 284 vs 250 +/- 297 pmol/ml), and oncostatin-M (15 +/- 28 vs 16 +/- 63 pg/ml) were similar in those who incurred worsening pump failure and in others. Mean sgp130 levels were 389 +/- 123 ng/ml in patients who developed worsening heart failure (Group A) and 289 +/- 123 ng/ml in stable patients (Group B; p < 0.0001). Mean BNP was 567 +/- 774 pg/ml in Group A and 307 +/- 324 pg/ml in Group B (p < 0.05). By using a cutoff value of 286 ng/ml for gp130 in Kaplan-Meier analysis, we found that the rate of freedom from worsening heart failure was significantly higher in patients below compared with patients above this cutoff point (p = 0.03). In univariate and multivariate Cox regression analysis, only sgp130 emerged as statistically significant (p < 0.001).

CONCLUSIONS

In addition to BNP, sgp130 could be useful in identifying patients at high risk for heart failure progression.

Usefulness of plasma cardiotrophin-1 in assessment of left ventricular hypertrophy regression in hypertensive patients

OBJECTIVE

We investigated whether regression of left ventricular hypertrophy (LVH) in response to antihypertensive treatment is associated with plasma cardiotrophin-1 (CT-1) in hypertensive patients.

METHODS

The study was performed in 47 patients with mild to moderate essential hypertension, and LVH was assessed echocardiographically. The family doctor gave antihypertensive treatment and followed all patients. LVH regression was diagnosed if the baseline left ventricular mass index (LVMI) decreased to normal values after 1 year of treatment. Plasma CT-1 was determined by an enzyme-linked immunosorbent assay.

RESULTS

The LVMI was normalized in 23 patients (49%) and persisted at an abnormally increased level in 24 patients (51%) after 1 year of treatment, whereas the reduction in clinic and home blood pressure was similar in the two groups: CT-1 decreased (-48%, P < 0.005) and increased (+35%, P < 0.05) in patients in whom LVH regressed and LVH persisted, respectively. Final values of CT-1 were inversely correlated (r = 0.534, P < 0.001) with the decrease in LVMI after treatment in all patients. A significant association (chi2 = 16.87, P < 0.001) was found between normalization of CT-1 and regression of LVH with treatment. A cut-off value of 41 fmol/ml for CT-1 provided a relative risk of 43.13 (95% confidence interval, 4.88-380.48) for detecting LVH regression.

CONCLUSION

These results show an association between treatment-induced decrease of plasma CT-1 and LVH regression in essential hypertension. Although preliminary, these findings suggest that the determination of plasma CT-1 may be useful for the follow-up of hypertensive heart disease in routine clinical practice.

Is plasma cardiotrophin-1 a marker of hypertensive heart disease?

OBJECTIVE

This study was designed to investigate whether plasma concentration of cardiotrophin-1 (CT-1), a cytokine that induces cardiomyocyte hypertrophy and stimulates cardiac fibroblasts, is related to hypertensive heart disease, as defined by the presence of echocardiographically assessed left ventricular hypertrophy (LVH).

METHODS

The study was performed in 31 normotensive subjects and 111 patients with never-treated essential hypertension (54 without LVH and 57 with LVH). Causes of LVH other than hypertension were excluded after a complete medical workup. A novel enzyme-linked immunosorbent assay was developed to measure plasma CT-1.

RESULTS

Plasma CT-1 was increased (P < 0.001) in hypertensives compared with normotensives. The value of CT-1 was higher (P < 0.001) in hypertensives with LVH than in hypertensives without LVH. Some 31% of patients without LVH exhibited values of CT-1 above the upper normal limit in normotensives. A direct correlation was found between CT-1 and left ventricular mass index (r = 0.319, P < 0.001) in all subjects. Receiver operating characteristic curves showed that a cutoff of 39 fmol/ml for CT-1 provided 75% specificity and 70% sensitivity for predicting LVH with a relative risk of 6.21 (95% confidence interval, 2.95 to 13.09).

CONCLUSIONS

These results show an association between LVH and the plasma concentration of CT-1 in essential hypertension. Although preliminary, these findings suggest that the determination of CT-1 may be an easy and reliable method for the initial screening and diagnosis of hypertensive heart disease.

Transplantation of cardiotrophin-1–expressing myoblasts to the left ventricular wall alleviates the transition from compensatory hypertrophy to congestive heart failure in Dahl salt-sensitive hypertensive rats

OBJECTIVES

We investigated whether autologous transplantation of skeletal myoblasts (MB) transferred with cardiotrophin-1 (CT-1) gene could retard the transition to heart failure (HF) in Dahl salt-sensitive (DS) hypertensive rats.

BACKGROUND

Although MB is a therapeutic candidate for chronic HF, little is known about the efficiency of this strategy when applied in nonischemic HF. Cardiotrophin-1 has potent hypertrophic and survival effects on cardiac myocytes. We hypothesized that transplantation of CT-1-expressing myoblasts could provide cardioprotective effects against ventricular remodeling in DS hypertensive rats.

METHODS

The DS rats were fed a high salt diet for 6 weeks and developed left ventricular (LV) hypertrophy at 11 weeks. At this stage, animals underwent MB to the myocardium with skeletal myoblasts transferred with CT-1 gene using retrovirus (transplantation of CT-1-expressing myoblasts [MB + CT], n = 31) or myoblasts alone (MB, n = 31). The sham group rats were injected with phosphate-buffered saline (n = 24).

RESULTS

At 17 weeks, MB and MB + CT groups showed a significant alleviation of LV dilation and contractile dysfunction compared with the sham group. The degree of alleviation was significantly greater in the MB + CT group than the MB group (LV end-diastolic dimension: sham 7.06 +/- 0.14 mm, MB 6.51 +/- 0.16 mm, MB + CT 6.24 +/- 0.07 mm; fractional shortening: sham 32.1 +/- 1.4%, MB 38.5 +/- 1.5%, MB + CT 43.2 +/- 0.8%). Histological examination revealed that the myocyte size was 20% larger in the MB + CT group at 17 weeks than in the age-matched sham group. Upregulation of renin-angiotensin and endothelin systems during the transition to HF was attenuated by myoblast transplantation, and this effect was enhanced in the MB + CT group.

CONCLUSIONS

Transplantation of skeletal myoblasts combined with CT-1-gene transfer could be a useful therapeutic strategy for HF.

The role of transsignalling via the agonistic soluble IL-6 receptor in human diseases

The activation of cells that do not express the membrane bound interleukin-6 6 receptor (IL-6R) by IL-6 and the soluble IL-6 receptor (sIL-6R) is termed transsignalling. Transsignalling may be an pathogenetic factor in human diseases as diverse as multiple myeloma (MM), Castleman's disease, prostate carcinoma, Crohn's disease, systemic sclerosis, Still's disease, osteoporosis and cardiovascular diseases. IL-6 and sIL-6R may directly or indirectly enhance their own production on endothelial or bone marrow stromal cells. Positive feedback autocrine loops thus created in affected organs may either cause or maintain disease progression. In autoimmune or vasculitic disease, the ability of the IL-6/sIL-6R complex to inhibit apoptosis of autoreactive T-cells may be central to the development of tissue specific autoimmunity. The anti-apoptotic effect of the IL-6/sIL-6R complex may be involved in tumour genesis and resistance to chemotherapy. Only in rare cases, where counterregulation has failed, there is a notable systemic effect of IL-6/sIL-6R. Appropriate animal models are necessary to establish the pathogenetic role of the IL-6/sIL-6R complex. A specific treatment option for diseases influenced by the sIL-6R could be based on gp130-Fc, a soluble gp130 (sgp130) linked to the Fc-fragment of IgG1. gp130-Fc has shown efficacy in vivo in animal models of Crohn's disease.

Inhibitory molecules in signal transduction pathways of cardiac hypertrophy

Cardiac hypertrophy is induced by a variety of diseases, such as hypertension, valvular diseases, myocardial infarction, and endocrine disorders. Although cardiac hypertrophy may initially be a beneficial response that normalizes wall stress and maintains normal cardiac function, prolonged hypertrophy is a leading cause of heart failure and sudden death. A number of studies have elucidated molecules responsible for the development of cardiac hypertrophy, including the mitogen-activated protein (MAP) kinases pathway, Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway, and calcium/calmodulin-dependent protein phosphatase calcineurin pathway. These molecules may be targets for therapies designed to prevent the progression of cardiac hypertrophy. Numerous studies have focused on characterization of the intracellular signal transduction molecules that promote cardiac hypertrophy in order to clarify the molecular mechanisms, but there have been only a few reports on the inhibitory regulators of hypertrophic response. Recently, several molecules have attracted much attention as endogenous inhibitory regulators of cardiac hypertrophy. Enhancement of these inhibitory regulators would also seem to be a potential approach for the pharmacological treatment of hypertrophy. In this review, we summarize the inhibitory molecules of cardiac hypertrophy.