Novel insights into the role of cardiotrophin-1 in cardiovascular diseases

Interaction of S100A6 Protein with the Four-Helical Cytokines

S100 is a family of over 20 structurally homologous, but functionally diverse regulatory (calcium/zinc)-binding proteins of vertebrates. The involvement of S100 proteins in numerous vital (patho)physiological processes is mediated by their interaction with various (intra/extra)cellular protein partners, including cell surface receptors. Furthermore, recent studies have revealed the ability of specific S100 proteins to modulate cell signaling via direct interaction with cytokines. Previously, we revealed the binding of ca. 71% of the four-helical cytokines via the S100P protein, due to the presence in its molecule of a cytokine-binding site overlapping with the binding site for the S100P receptor. Here, we show that another S100 protein, S100A6 (that has a pairwise sequence identity with S100P of 35%), specifically binds numerous four-helical cytokines. We have studied the affinity of the recombinant forms of 35 human four-helical cytokines from all structural families of this fold to Ca2+-loaded recombinant human S100A6, using surface plasmon resonance spectroscopy. S100A6 recognizes 26 of the cytokines from all families of this fold, with equilibrium dissociation constants from 0.3 nM to 12 µM. Overall, S100A6 interacts with ca. 73% of the four-helical cytokines studied to date, with a selectivity equivalent to that for the S100P protein, with the differences limited to the binding of interleukin-2 and oncostatin M. The molecular docking study evidences the presence in the S100A6 molecule of a cytokine-binding site, analogous to that found in S100P. The findings argue the presence in some of the promiscuous members of the S100 family of a site specific to a wide range of four-helical cytokines. This unique feature of the S100 proteins potentially allows them to modulate the activity of the numerous four-helical cytokines in the disorders accompanied by an excessive release of the cytokines.

Serum Cardiotrophin-1 Concentration Is Negatively Associated with Controlled Attenuation Parameters in Subjects with Non-Alcoholic Fatty Liver Disease

Background: Since non-alcoholic fatty liver disease (NAFLD) is highly associated with obesity, cardiovascular disease, and diabetes, biomarkers for the diagnosis of NAFLD have become an important issue. Although cardiotrophin-1 (CT-1) has a protective effect on the liver in NAFLD animal models, the serum levels of CT-1 in human subjects with NAFLD were still unknown. Objective: The present study aimed to investigate the relationship between the circulating concentration of CT-1 and the severity of hepatic steatosis graded by the value of the controlled attenuation parameter (CAP) in humans. Design and Methods: The study was designed as a cross-sectional study, and a total of 182 subjects were enrolled. Hepatic steatosis measurement was carried out with a Firoscan® device and recorded by CAP. The enrolled study subjects were categorized into CAP < 238 dB/m, 238 ≤ CAP ≤ 259 dB/m, 260 ≤ CAP ≤ 290 dB/m, and CAP > 290 dB/m. Serum CT-1 concentrations were determined by enzyme-linked immunosorbent assay. The association between the serum CT-1 concentration and NAFLD was examined by multivariate linear regression analysis. Results: Body mass index, percentage of body fat, systolic and diastolic blood pressure, alanine aminotransferase (ALT), cholesterol, triglyceride, hemoglobin A1c and homeostatic model assessment for insulin resistance (HOMA-IR) were significantly increased in groups with higher CAP value, whereas high-density lipoprotein cholesterol was significantly decreased. In addition, serum CT-1 concentrations were significantly decreased in subjects with higher CAP values. In multivariate linear regression models, including age, sex, body fat percentage, CAP, high sensitivity- C reactive protein, uric acid, creatinine, ALT, total cholesterol, and HOMA-IR, only age, CAP and uric acid independently associated with CT-1 levels. Moreover, having NAFLD was independently associated with CT-1 after adjustment for sex, obesity and type 2 diabetes. Conclusions: Serum CT-1 concentrations are decreased in subjects with NAFLD and negatively associated with CAP.

Left Ventricular Hypertrophy and Ventricular Tachyarrhythmia: The Role of Biomarkers

Left ventricular hypertrophy (LVH) refers to a complex rebuilding of the left ventricle that can gradually lead to serious complications-heart failure and life-threatening ventricular arrhythmias. LVH is defined as an increase in the size of the left ventricle (i.e., anatomically), therefore the basic diagnosis detecting the increase in the LV size is the domain of imaging methods such as echocardiography and cardiac magnetic resonance. However, to evaluate the functional status indicating the gradual deterioration of the left ventricular myocardium, additional methods are available approaching the complex process of hypertrophic remodeling. The novel molecular and genetic biomarkers provide insights on the underlying processes, representing a potential basis for targeted therapy. This review summarizes the spectrum of the main biomarkers employed in the LVH valuation.

microRNAs involved in psoriasis and cardiovascular diseases

Psoriasis is a chronic inflammatory disease involving the skin. Both genetic and environmental factors play a pathogenic role in psoriasis and contribute to the severity of the disease. Psoriasis, in fact, has been associated with different comorbidities such as diabetes, metabolic syndrome, gastrointestinal or kidney diseases, cardiovascular disease (CVD), and cerebrovascular diseases (CeVD). Indeed, life expectancy in severe psoriasis is reduced by up to 5 years due to CVD and CeVD. Moreover, patients with severe psoriasis have a higher prevalence of traditional cardiovascular (CV) risk factors, including dyslipidemia, diabetes, smoking, and hypertension. Further, systemic inflammation is associated with oxidative stress increase and induces endothelial damage and atherosclerosis progression. Different miRNA have been already described in psoriasis, both in the skin tissues and in the blood flow, to play a role in the progression of disease. In this review, we will summarize and discuss the most important miRNAs that play a role in psoriasis and are also linked to CVD.

Regulation of Myocardial Extracellular Matrix Dynamic Changes in Myocardial Infarction and Postinfarct Remodeling

The article represents literature review dedicated to molecular and cellular mechanisms underlying clinical manifestations and outcomes of acute myocardial infarction. Extracellular matrix adaptive changes are described in detail as one of the most important factors contributing to healing of damaged myocardium and post-infarction cardiac remodeling. Extracellular matrix is reviewed as dynamic constantly remodeling structure that plays a pivotal role in myocardial repair. The role of matrix metalloproteinases and their tissue inhibitors in fragmentation and degradation of extracellular matrix as well as in myocardium healing is discussed. This review provides current information about fibroblasts activity, the role of growth factors, particularly transforming growth factor β and cardiotrophin-1, colony-stimulating factors, adipokines and gastrointestinal hormones, various matricellular proteins. In conclusion considering the fact that dynamic transformation of extracellular matrix after myocardial ischemic damage plays a pivotal role in myocardial infarction outcomes and prognosis, we suggest a high importance of further investigation of mechanisms underlying extracellular matrix remodeling and cell-matrix interactions in cardiovascular diseases.

Usefulness of Biomarkers for Predicting Response to Cardiac Resynchronization Therapy

Cardiac Resynchronization Therapy (CRT) is an effective treatment strategy for heart failure. It significantly improves clinical symptoms and decreases mortality and long-term morbidity. However, some patients do not respond properly to this treatment. In this review, the role of different biomarkers in predicting response to CRT is discussed. Some biomarkers, including natriuretic peptides and inflammatory markers have promising results but further trials are needed for more evaluation.

Immunopathogenesis and biomarkers of recurrent atrial fibrillation following ablation therapy in patients with preexisting atrial fibrillation

INTRODUCTION

Recurrent atrial fibrillation (RAF) following ablation therapy occurs in about 50% of patients. The pathogenesis of RAF is unknown, but is believed to be driven by atrial remodeling in the setting of background inflammation. Structural, electrophysiological and mechanical remodeling has been associated with atrial fibrillation (AF). Inflammation and fibrotic remodeling are the major factors perpetuating AF, as mediators released from the atrial tissues and cardiomyocytes due to mechanical and surgical injury could initiate the inflammatory process. In this article, we have critically reviewed the key mediators that may serve as potential biomarkers to predict RAF. Areas covered: Damage associated molecular patterns, heat shock proteins, inflammatory cytokines, non-inflammatory markers, markers of inflammatory cell activity, and markers of collagen deposition and metabolism are evaluated as potential biomarkers with molecular treatment options in RAF. Expert commentary: Establishing biomarkers to predict RAF could be useful in reducing morbidity and mortality. Investigations into the role of DAMPs participating in a sterile immune response may provide greater insight into the pathogenesis of RAF. Markers evaluating immune cell activity, collagen deposition, and levels of heat shock proteins show the greatest promise as potential biomarkers to predict RAF and develop novel therapies.

New therapies for the treatment of heart failure: a summary of recent accomplishments

Despite continuous efforts to prevent cardiovascular diseases (CVDs), heart failure prevails as the number one cause of death in developed countries. To properly treat CVDs, scientists had to take a closer look at the factors that contribute to their pathogenesis and either modernize current pharmaceuticals or develop brand new treatments. Enhancement of current drugs, such as tolvaptan and omecamtiv mecarbil, sheds new light on already-known therapies. Tolvaptan, a vasopressin antagonist, could be adopted in heart failure therapy as it reduces pre- and afterload by decreasing systolic blood pressure and blood volume. Omecamtiv mecarbil, which is a myosin binding peptide, could aid cardiac contractility. The next generation vasodilators, serelaxin and ularitide, are based on naturally occurring peptides and they reduce peripheral vascular resistance and increase the cardiac index. In combination with their anti-inflammatory properties, they could turn out to be extremely potent drugs for heart failure treatment. Cardiotrophin has exceeded many researchers’ expectations, as evidence suggests that it could cause sarcomere hypertrophy without excessive proliferation of connective tissue. Rapid progress in gene therapy has caused it to finally be considered as one of the viable options for the treatment of CVDs. This novel therapeutic approach could restore stable heart function either by restoring depleted membrane proteins or by balancing the intracellular calcium concentration. Although it has been set back by problems concerning its long-term effects, it is still highly likely to succeed.

Cardiotrophin 1 stimulates beneficial myogenic and vascular remodeling of the heart

The post-natal heart adapts to stress and overload through hypertrophic growth, a process that may be pathologic or beneficial (physiologic hypertrophy). Physiologic hypertrophy improves cardiac performance in both healthy and diseased individuals, yet the mechanisms that propagate this favorable adaptation remain poorly defined. We identify the cytokine cardiotrophin 1 (CT1) as a factor capable of recapitulating the key features of physiologic growth of the heart including transient and reversible hypertrophy of the myocardium, and stimulation of cardiomyocyte-derived angiogenic signals leading to increased vascularity. The capacity of CT1 to induce physiologic hypertrophy originates from a CK2-mediated restraining of caspase activation, preventing the transition to unrestrained pathologic growth. Exogenous CT1 protein delivery attenuated pathology and restored contractile function in a severe model of right heart failure, suggesting a novel treatment option for this intractable cardiac disease.

Cardiotrophin-1 stimulates the neural differentiation of human umbilical cord blood-derived mesenchymal stem cells and survival of differentiated cells through PI3K/Akt-dependent signaling pathways

Cardiotrophin-1 (CT1) plays an important role in the differentiation, development, and survival of neural stem cells. In this study, we analyzed its effects on the stimulation of human umbilical cord blood-derived mesenchymal stem cells in terms of their potential to differentiate into neuron-like cells, their survival characteristics, and the molecular mechanisms involved. The treatment of cells with neural induction medium (NIM) and CT1 generated more cells that were neuron-like and produced stronger expression of neural-lineage markers than cells treated with NIM and without CT1. Bcl-2 and Akt phosphorylation (p-Akt) expression levels increased significantly in cells treated with both NIM and CT1. This treatment also effectively blocked cell death following neural induction and decreased Bax, Bak and cleaved-caspase 3 expression compared with cells treated with NIM without CT1. In addition, the inhibition of phosphatidylinositol 3-kinase (PI3K) abrogated p-Akt and Bcl-2 expression. Thus, PI3K/Akt contribute to CT1-stimulated neural differentiation and to the survival of differentiated cells.

Potential novel biomarkers of cardiovascular dysfunction and disease: cardiotrophin-1, adipokines and galectin-3

Cardiovascular disease is one of the main burdens of healthcare systems worldwide. Nevertheless, assessing cardiovascular risk in both apparently healthy individuals and low/high-risk patients remains a difficult issue. Already established biomarkers (e.g. brain natriuretic peptide, troponin) have significantly improved the assessment of major cardiovascular events and diseases but cannot be applied to all patients and in some cases do not provide sufficiently accurate information. In this context, new potential biomarkers that reflect various underlying pathophysiological cardiac and vascular modifications are needed. Also, a multiple biomarker evaluation that shows changes in the cardiovascular state is of interest. This review describes the role of selected markers of vascular inflammation, atherosclerosis, atherothrombosis, endothelial dysfunction and cardiovascular fibrosis in the pathogenesis and prognosis of cardiovascular disease: the potential use of cardiotrophin-1, leptin, adiponectin, resistin and galectin-3 as biomarkers for various cardiovascular conditions is discussed.

Zhibitai and low-dose atorvastatin reduce blood lipids and inflammation in patients with coronary artery disease

BACKGROUND

Atorvastatin decreases blood lipids but is associated with side effects. Zhibitai is a traditional Chinese medicine used to treat blood lipid disorders. The objective of this study is to evaluate the lipid-lowering effect, antiinflammatory effect, and adverse events of zhibitai combined to atorvastatin in patients with coronary heart diseases (CHDs).

METHODS

Patients with CHD (n = 150) were randomized to: zhibitai 480 mg + atorvastatin 10 mg (ZA10 group), atorvastatin 20 mg (A20 group), and atorvastatin 40 mg (A40 group). Lipid profile, cardiotrophin-1 (CT-1), and C-reactive protein (CRP) were measured after 4 and 8 weeks of treatment. Self-reported side effects, liver function, kidney function, and creatine kinase levels were monitored.

RESULTS

After 8 weeks, triglycerides, total cholesterol (TC), LDL-cholesterol (LDL-C), and apolipoprotein B100 (ApoB100) levels were decreased in the ZA10 group (-64%, -37%, -46%, and -54%, respectively, compared with baseline), and these changes were similar to those of the A40 group (P > 0.05). CT-1 and high sensitivity-C reactive protein (hs-CRP) levels were significantly decreased in the ZA10 group after 4 and 8 weeks (4 weeks: -73% and 96%; 8 weeks: -89% and -98%; all P < 0.01), without differences among the 3 groups (P > 0.05). After 8 weeks of treatment, adverse events (abdominal distention, nausea, vomiting, and hunger) were found in 4, 5, and 7 patients in the ZA10, A20, and A40 groups, respectively.

CONCLUSION

ZA10 significantly reduced triglycerides, TC, LDL-C, ApoB, CT-1, and hs-CRP levels in patients with CHD, similar to the effects of A40 and A20, but ZA10 lead to fewer adverse events.

Cardiotrophin-1 decreases intestinal sugar uptake in mice and in Caco-2 cells

AIM

Cardiotrophin-1 (CT-1) is a member of the IL-6 family of cytokines with a key role in glucose and lipid metabolism. In the current investigation, we examined the in vivo and in vitro effects of CT-1 treatment on intestinal sugar absorption in different experimental models.

METHODS

rCT-1 effects on α-Methyl-D-glucoside uptake were assessed in everted intestinal rings from wild-type and CT-1(-/-) mice and in Caco-2 cells. rCT-1 actions on SGLT-1 expression in brush border membrane vesicles and the identification of the potential signalling pathways involved were determined by Western blot.

RESULTS

In vivo administration (0.2 mg kg(-1) ) of rCT-1 caused a significant decrease on α-Methyl-D-glucoside uptake in everted intestinal rings from wild-type and CT-1(-/-) mice after short-term and long-term treatments. Similarly, in vitro treatment (1-50 ng mL(-1) ) with rCT-1 reduced α-Methyl-D-glucoside uptake in everted intestinal rings. In Caco-2 cells, rCT-1 treatment (20 ng mL(-1) , 1 and 24 h) lowered apical uptake of α-Methyl-D-glucoside in parallel with a decrease on SGLT-1 protein expression. rCT-1 promoted the phosphorylation of STAT-3 after 5 and 15 min treatment, but inhibited the activation by phosphorylation of AMPK after 30 and 60 min. Interestingly, pre-treatment with the JAK/STAT inhibitor (AG490) and with the AMPK activator (AICAR) reversed the inhibitory effects of rCT-1 on α-Methyl-D-glucoside uptake. AICAR also prevented the inhibition of SGLT-1 observed in rCT-1-treated cells.

CONCLUSIONS

CT-1 inhibits intestinal sugar absorption by the reduction of SGLT-1 levels through the AMPK pathway, which could also contribute to explain the hypoglycaemic and anti-obesity properties of CT-1.

Cardiotrophin-1: A new predictor of atrial fibrillation relapses after successful cardioversion

We aimed to investigate whether or not cardiotrophin-1 (CT-1) can be used as a predictor of sinus rhythm constancy in patients with atrial fibrillation (AF) converted to sinus rhythm. Thirty two patients with AF (48-78 years), without any structural heart disease were enrolled for the study. The control group consisted of 32, age and gender matched healthy persons. Measurements of CT-1 were made after transthoracic and transesophageal echocardiography prior to cardioversion (CV). Relapses of AF were investigated by monthly electrocardiograms (ECGs) and ambulatory ECGs at 1st, 3rd, and 6th month. At the end of 6th month, measurements of CT-1 were repeated. At the beginning patients with AF had increased CT-1 levels when compared to controls (0.94 ± 0.32 pg/mL vs. 0.30 ± 0.12 pg/mL, [p < 0.001]). At the end of follow-up of the 32 patients, 17 (53%) had AF relapse. Age, initial duration of AF, left ventricle diameters, ejection fraction, left atrium appendix flow rates were similar among patients with and without AF relapse. However, basal left atrium diameter (4.24 ± 0.14 cm vs. 4.04 ± 0.22 cm, p = 0.005), pulmonary artery pressure (32.82 ± 5 vs. 28.60 ± 6.23 mmHg, p = 0.004) and CT-1 values (1.08 ± 0.37 vs. 0.82 ± 0.16 pg/mL, p = 0.02) were significantly increased in patients with AF relapse. Furthermore, patients with relapsed AF had higher CT-1 levels at 6th month when compared to those in sinus rhythm (1.00 ± 0.40 vs. 0.71 ± 0.23 pg/mL). We conclude that post-CV, AF relapses are more frequent among patients with increased baseline CT-1 levels, and CT-1 may be a potential predictor of AF relapse.

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.

Gene expression of cytokines, growth factors and apoptosis regulators in a neonatal model of pulmonary stenosis

BACKGROUND

Right ventricular remodeling due to pulmonary stenosis increases morbidity in children. Its pathophysiology needs to be clarified.

METHODS

Six newborn lambs underwent pulmonary arterial banding, seven sham operation. mRNA encoding for cytokines, growth factors and regulators of apoptosis was sequentially measured in myocardium and blood before and up to 12 weeks postoperatively.

RESULTS

Experimental animals showed hypertrophy and fibrosis of the right ventricular myocardium, myocardial over-expression of CT-1-mRNA and higher blood concentrations of mRNA encoding for VEGF, TGF-β, Bak and BcL-xL than controls, respectively.

CONCLUSION

Neonatal pulmonary stenosis leads to myocardial hypertrophy that is associated with CT-1 gene expression and with activation of growth- and apoptosis pathways in blood cells.

Stimulation of cardiomyogenesis from mouse embryonic stem cells by nuclear translocation of cardiotrophin-1

BACKGROUND

Cardiotrophin-1 (CT-1) controls cardiomyogenesis of mouse embryonic stem (ES) cells.

OBJECTIVES

To investigate the signaling pathway underlying the action of CT-1 on cardiac cell differentiation.

METHODS

Protein expression was analyzed by western blot technique and cardiac areas by immunohistochemistry. Calcium, reactive oxygen species (ROS) and nitric oxide (NO) were assessed by microfluorometry using fluo-4, H2DCF, and DAF-2DA, respectively. Gene inactivation of CT-1 was achieved by siRNA technology.

RESULTS

CT-1 as well as its receptor gp 130 were transiently upregulated during differentiation of ES cells. Exogenous CT-1 enhanced cardiomyogenesis, increased the cardiac transcription factors MEF2c, Nkx-2.5, TEAD3 and GATA4, the cardiac proteins α-actinin, MLC2a, MYH7, MLC1a, MLC2v and HCN4 as well as vascular endothelial growth factor (VEGF), platelet-derived growth factor-BB (PDGF-BB), fibroblast growth factor-2 (FGF-2) and atrial natriuretic peptide (ANP). CT-1 downregulation by small interfering RNA (siRNA) inhibited cardiomyogenesis and decreased VEGF, PDGF-BB, FGF-2 and ANP expression. CT-1 raised intracellular calcium which was abolished by the intracellular calcium chelator BAPTA, AM and thapsigargin. Moreover, CT-1 treatment increased ROS, followed by NO generation and NOS3 activation. During ES cell differentiation CT-1 was translocated to the cell nucleus. Exogenous CT-1 induced nuclear translocation of endogenous CT-1, which was inhibited by BAPTA, the NOS inhibitor L-N(G)-Nitroarginine methyl ester (l-NAME), the radical scavenger N-(2-mercaptopropionyl)-glycine (NMPG) as well as the janus kinase 2 (JAK2) inhibitor AG490 and the PI3 kinase (PI3K) inhibitor LY294002.

CONCLUSIONS

Nuclear translocation of CT-1 regulates cardiomyogenesis of ES cells and involves calcium, NO, ROS as well as CT-1 regulated signaling pathways.

Anthracyclines/trastuzumab: new aspects of cardiotoxicity and molecular mechanisms

Anticancer drugs continue to cause significant reductions in left ventricular ejection fraction resulting in congestive heart failure. The best-known cardiotoxic agents are anthracyclines (ANTHs) such as doxorubicin (DOX). For several decades cardiotoxicity was almost exclusively associated with ANTHs, for which cumulative dose-related cardiac damage was the use-limiting step. Human epidermal growth factor (EGF) receptor 2 (HER2; ErbB2) has been identified as an important target for breast cancer. Trastuzumab (TRZ), a humanized anti-HER2 monoclonal antibody, is currently recommended as first-line treatment for patients with metastatic HER2(+) tumors. The use of TRZ may be limited by the development of drug intolerance, such as cardiac dysfunction. Cardiotoxicity has been attributed to free-iron-based, radical-induced oxidative stress. Many approaches have been promoted to minimize these serious side effects, but they are still clinically problematic. A new approach to personalized medicine for cancer that involves molecular screening for clinically relevant genomic alterations and genotype-targeted treatments is emerging.

The impact of age-related dysregulation of the angiotensin system on mitochondrial redox balance

Aging is associated with the accumulation of various deleterious changes in cells. According to the free radical and mitochondrial theory of aging, mitochondria initiate most of the deleterious changes in aging and govern life span. The failure of mitochondrial reduction-oxidation (redox) homeostasis and the formation of excessive free radicals are tightly linked to dysregulation in the Renin Angiotensin System (RAS). A main rate-controlling step in RAS is renin, an enzyme that hydrolyzes angiotensinogen to generate angiotensin I. Angiotensin I is further converted to Angiotensin II (Ang II) by angiotensin-converting enzyme (ACE). Ang II binds with equal affinity to two main angiotensin receptors—type 1 (AT₁R) and type 2 (AT₂R). The binding of Ang II to AT₁R activates NADPH oxidase, which leads to increased generation of cytoplasmic reactive oxygen species (ROS). This Ang II-AT₁R–NADPH-ROS signal triggers the opening of mitochondrial K_ATP channels and mitochondrial ROS production in a positive feedback loop. Furthermore, RAS has been implicated in the decrease of many of ROS scavenging enzymes, thereby leading to detrimental levels of free radicals in the cell. AT₂R is less understood, but evidence supports an anti-oxidative and mitochondria-protective function for AT₂R. The overlap between age related changes in RAS and mitochondria, and the consequences of this overlap on age-related diseases are quite complex. RAS dysregulation has been implicated in many pathological conditions due to its contribution to mitochondrial dysfunction. Decreased age-related, renal and cardiac mitochondrial dysfunction was seen in patients treated with angiotensin receptor blockers. The aim of this review is to: (a) report the most recent information elucidating the role of RAS in mitochondrial redox hemostasis and (b) discuss the effect of age-related activation of RAS on generation of free radicals.

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.

Myocardial cardiotrophin-1 is differentially induced in congenital cardiac defects depending on hypoxemia

ABSTRACT: Aim: Cardiotrophin-1 (CT-1) is upregulated by hypoxemia and hemodynamic overload and is characterized by potent hypertrophic and protective properties on cardiac cells. This study aimed to investigate whether CT-1 is differentially induced in the myocardium of infants with congenital cardiac defects depending on hypoxemia. Methods & results: Infants with Tetralogy of Fallot (n = 8) or with large nonrestrictive ventricular septal defect (n = 8) undergoing corrective surgery were investigated. Expression of CT-1 was assessed at mRNA and protein levels in the right atrial and ventricular myocardium. The activation of the STAT-3 and VEGF were measured. Degradation of cardiac troponin-I served as a marker of myocardial damage. CT-1 was detected in all patients with levels negatively correlating to the arterial oxygen saturation. Higher CT-1 expression in Tetralogy of Fallot patients was associated with activation of the JAK/STAT pathway and higher cardiac troponin-I degradation. Conclusion: CT-1 may mediate myocardial hypertrophy and dysfunction in infants with congenital cardiac defects, particularly in those with hypoxemia.

Stimulatory Effects of Cardiotrophin 1 on Atherosclerosis

Cardiotrophin 1 (CT-1), an interleukin-6 family cytokine, was recently shown to be expressed in the intima of early atherosclerotic lesions in the human carotid artery. CT-1 stimulates proatherogenic molecule expression in human vascular endothelial cells and monocyte migration. However, it has not been reported whether CT-1 accelerates atherosclerosis. This study was performed to examine the stimulatory effects of CT-1 on human macrophage foam cell formation and vascular smooth muscle cell migration and proliferation in vitro, and on the development of atherosclerotic lesions in apolipoprotein E–deficient (ApoE −/− ) mice in vivo. CT-1 was expressed at high levels in endothelial cells and macrophages in both humans and ApoE −/− mice. CT-1 significantly enhanced oxidized low-density lipoprotein–induced foam cell formation associated with increased levels of CD36 and acyl-CoA:cholesterol acyltransferase-1 expression in human monocyte–derived macrophages. CT-1 significantly stimulated the migration, proliferation, and collagen-1 expression in human aortic vascular smooth muscle cells. Four-week infusion of CT-1 into ApoE −/− mice significantly accelerated the development of aortic atherosclerotic lesions with increased monocyte/macrophage infiltration, vascular smooth muscle cell proliferation, and collagen-1 content in the aortic wall. Activation of inflammasome, such as apoptosis-associated speck-like protein containing a caspase recruitment domain, nuclear factor κB, and cyclooxygenase-2, was observed in exudate peritoneal macrophages from ApoE −/− mice infused with CT-1. Infusion of anti–CT-1–neutralizing antibody alone into ApoE −/− mice significantly suppressed monocyte/macrophage infiltration in atherosclerotic lesions. These results indicate that CT-1 accelerates the development of atherosclerotic lesions by stimulating the inflammasome, foam cell formation associated with CD36 and acyl-CoA:cholesterol acyltransferase-1 upregulation in macrophages, and migration, proliferation, and collagen-1 production in vascular smooth muscle cells.

Cardiotrophin-1 is not associated with carotid or coronary disease and is inversely associated with obesity in patients undergoing coronary angiography

INTRODUCTION

Cardiotrophin-1 (CT-1) is a member of the interleukin-6 superfamily with known hypertrophic and protective actions upon cardiac myocytes. Although its effects on myocardial tissue and its role in hypertensive heart disease are well documented, there are no studies on CT-1 blood levels in patients with coronary artery disease. In this study we aimed to verify the relationships of serum CT-1 with vascular disease and metabolic parameters in a population of patients undergoing coronary angiography due to clinical indications.

MATERIAL AND METHODS

Serum levels of CT-1 were investigated in a cohort of 81 consecutive patients (median age 68 years (95% CI: 64-71), 59 males) undergoing coronary angiography and carotid Doppler ultrasound. Exclusion criteria were: acute coronary syndrome, already-established ischemic cardiopathy, chronic inflammatory diseases and presence or past history of cancer.

RESULTS

Levels of CT-1 were inversely correlated with body mass index (BMI) and waist circumference (WC) (ρ = -0.261, p = 0.02; ρ = -0.224, p = 0.05, respectively). Moreover, obese patients showed significantly lower CT-1 concentrations than non-obese ones (1.18 (0.64-1.64) ng/ml vs. 1.56 (1.37-2.04) ng/ml, p = 0.013), and serum CT-1 was significantly reduced in patients with elevated compared to those with normal WC (1.43 (0.94-1.60) ng/ml vs. 1.64 (1.39-2.49) ng/ml, p = 0.047). Concentrations of CT-1 did not correlate either with the other parameters of metabolic syndrome or with markers of cardiovascular disease (carotid intima-media thickness, presence of carotid or coronary artery plaques).

CONCLUSIONS

Our results failed to demonstrate any association between CT-1 and carotid or coronary disease. The inverse association with BMI and WC fits with the latest experimental data on the role of CT-1 in dysmetabolic conditions and could help to further clarify the role of CT-1 in obesity and diabetes.

Serum cardiotrophin-1 and IL-6 levels in patients with obstructive sleep apnea syndrome

Obstructive sleep apnea syndrome (OSAS) is associated with increased rates of cardiovascular diseases (CVD). Basic mechanisms involved in the increased cardiovascular risk of OSAS remain unclear. Inflammation has been shown to potentially play a critical role in this association. The aim of the present study was to investigate the level of cardiotrophin-1 (CT-1) in patients with OSAS. Forty-eight newly diagnosed OSAS patients and 37 nonapneic controls were enrolled in this study. Demographic data, cigarette smoking status, previous history of chronic diseases including CVD and metabolic diseases and drugs, and habits were obtained by a standardized questionnaire. All patients underwent polysomnographic evaluation. The mean age was 48.3 ± 12.3 (24-74) years in OSAS group. Median apnea-hypopnea index was 23.6 (6-91.8) and median body mass index was 30.4 (24.2-49.4) in the OSAS group. Plasma CT-1 levels in OSAS and control groups, respectively, were 12.03 ± 1.08 and 11.85 ± 1.18 pg/ml. There was no significant difference in the plasma levels of CT-1 and IL-6 between the OSAS group and the controls.

Update on the pathophysiological activities of the cardiac molecule cardiotrophin-1 in obesity

Cardiotrophin-1 (CT-1) is a heart-targeting cytokine that has been reported to exert a variety of activities also in other organs such as the liver, adipose tissue, and atherosclerotic arteries. CT-1 has been shown to induce these effects via binding to a transmembrane receptor, comprising the leukaemia inhibitory factor receptor (LIFRβ) subunit and the glycoprotein 130 (gp130, a common signal transducer). Both local and systemic concentrations of CT-1 have been shown to potentially play a critical role in obesity. For instance, CT-1 plasma concentrations have been shown to be increased in metabolic syndrome (a cluster disease including obesity) probably due to adipose tissue overexpression. Interestingly, treatment with exogenous CT-1 has been shown to improve lipid and glucose metabolism in animal models of obesity. These benefits might suggest a potential therapeutic role for CT-1. However, beyond its beneficial properties, CT-1 has been also shown to induce some adverse effects, such as cardiac hypertrophy and adipose tissue inflammation. Although scientific evidence is still needed, CT-1 might be considered as a potential example of damage/danger-associated molecular pattern (DAMP) in obesity-related cardiovascular diseases. In this narrative review, we aimed at discussing and updating evidence from basic research on the pathophysiological and potential therapeutic roles of CT-1 in obesity.

Exercise rescued chronic kidney disease by attenuating cardiac hypertrophy through the cardiotrophin-1 -> LIFR/gp 130 -> JAK/STAT3 pathway

BACKGROUND

Chronic kidney disease (CKD) is usually associated with cardiac apoptosis and/or cardiac hypertrophy. We hypothesized that exercise can reduce the CKD-induced cardiac damage.

METHODS AND RESULTS

The doxorubicin-induced CKD (DRCKD) model was used in rats to compare two exercise models: 60-min running and 60-min swimming. Results indicated that in healthy normal groups, the signals cardiotrophin-1 (CT-1), interleukin 6 (IL-6), leukaemia inhibitory factor receptor (LIFR), and gp130 were upregulated and janus kinase (JAK) and signal transducer and activation of transcription (STAT) were downregulated by both exercises. In contrast, all signals were highly upregulated in CKD. After exercise training, all signals (CT-1, IL-6, LIFR, gp130, and STAT) were downregulated, with JAK being only slightly upregulated in the running group but not in the swimming group. The myocyte death pathway (CT-1/IL-6 → LIFR/gp130 → PI3K → Akt → Bad) was excluded due to no change found for Bad. Nitric oxide (NO; normal, 15.63 ± 0.86 µmol/l) was significantly suppressed in CKD rats (2.95 ± 0.32 µmol/l), and both running and swimming training highly upregulated the NO level to 30.33 ± 1.03 µmol/l and 27.82 ± 2.47 µmol/l in normal subjects and 24.0 ± 3.2 µmol/l and 22.69 ± 3.79 µmol/l in the DRCKD rats, respectively. The endothelial progenic cells CD34 were significantly suppressed in DRCKD rats, which were not rescued significantly by exercise. In contrast, the CD 34 cells were only slightly suppressed in the healthy subjects by exercise.

CONCLUSION

Both exercise regimens were beneficial by rescuing cardiac function in CKD victims. Its action mechanism was by way of inhibiting myocyte death and rescuing cardiac hypertrophy.

Cardiotrophin-1 induces sarcoplasmic reticulum Ca(2+) leak and arrhythmogenesis in adult rat ventricular myocytes

AIMS

Plasma levels of cardiotrophin-1 (CT-1) are elevated in several cardiovascular diseases and are correlated with the severity of the pathology. However, the mechanisms by which this inflammatory cytokine participates in the pathology of the heart are not completely understood. It is well established that alterations in intracellular calcium ([Ca(2+)](i)) handling are involved in cardiac dysfunction during heart failure, but it is unknown whether CT-1 modulates [Ca(2+)](i) handling in adult cardiomyocytes. Here we have analyzed for the first time the effects of CT-1 on [Ca(2+)](i) homeostasis in adult rat cardiomyocytes.

METHODS AND RESULTS

L-type calcium current (I(CaL)) was recorded using patch-clamp techniques, and [Ca(2+)](i) transients and Ca(2+) sparks were viewed by confocal microscopy. Treatment of cardiomyocytes with 1 nM CT-1 for 20-60 min induced a significant increase in I(CaL) density, [Ca(2+)](i) transients, and cell shortening compared with control cells. Our study reveals that CT-1 increases I(CaL) by a protein kinase A-dependent mechanism, and Ca(2+) sparks by a Ca(2+)/calmodulin kinase II-dependent and protein kinase A-independent mechanism. Cardiomyocytes treated with CT-1 exhibited a higher occurrence of arrhythmogenic behaviour, manifested as spontaneous Ca(2+) waves and aftercontractions.

CONCLUSION

Our findings provide evidence that cardiomyocytes treated with CT-1 present high spontaneous Ca(2+) release during diastole, a mechanism linked to arrhythmogenicity in the pathologic heart.

Cardiotrophin-1 in hypertensive heart disease

Hypertensive heart disease, here defined by the presence of pathologic left ventricular hypertrophy in the absence of a cause other than arterial hypertension, is characterized by complex changes in myocardial structure including enhanced cardiomyocyte growth and non-cardiomyocyte alterations that induce the remodeling of the myocardium, and ultimately, deteriorate left ventricular function and facilitate the development of heart failure. It is now accepted that a number of pathological processes mediated by mechanical, neurohormonal, and cytokine routes acting on the cardiomyocyte and the non-cardiomyocyte compartments are responsible for myocardial remodeling in the context of arterial hypertension. For instance, cardiotrophin-1 is a cytokine member of the interleukin-6 superfamily, produced by cardiomyocytes and non-cardiomyocytes in situations of biomechanical stress that once secreted interacts with its receptor, the heterodimer formed by gp130 and gp90 (also known as leukemia inhibitory factor receptor beta), activating different signaling pathways leading to cardiomyocyte hypertrophy, as well as myocardial fibrosis. Beyond its potential mechanistic contribution to the development of hypertensive heart disease, cardiotrophin-1 offers the opportunity for a new translational approach to this condition. In fact, recent evidence suggests that cardiotrophin-1 may serve as both a biomarker of left ventricular hypertrophy and dysfunction in hypertensive patients, and a potential target for therapies aimed to prevent and treat hypertensive heart disease beyond blood pressure control.

Silver nanoparticles administered to chicken affect VEGFA and FGF2 gene expression in breast muscle and heart

Nanoparticles of colloidal silver (AgNano) can influence gene expression. Concerning trials of AgNano application in poultry nutrition, it is useful to reveal whether they affect the expression of genes crucial for bird development. AgNano were administered to broiler chickens as a water solution in two concentrations (10 and 20 ppm). After dissection of the birds, breast muscles and hearts were collected. Gene expression of FGF2 and VEGFA on the mRNA and protein levels were evaluated using quantitative polymerase chain reaction and enzyme-linked immunosorbent assay methods. The results for gene expression in the breast muscle revealed changes on the mRNA level (FGF2 was up-regulated, P < 0.05) but not on the protein level. In the heart, 20 ppm of silver nanoparticles in drinking water increased the expression of VEGFA (P < 0.05), at the same time decreasing FGF2 expression both on the transcriptional and translational levels. Changes in the expression of these genes may lead to histological changes, but this needs to be proven using histological and immunohistochemical examination of tissues. In general, we showed that AgNano application in poultry feeding influences the expression of FGF2 and VEGFA genes on the mRNA and protein levels in growing chicken.

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.

Role of cardiotrophin-1 in obesity and insulin resistance

Cardiotrophin-1 (CT-1) is a member of the gp130 family of cytokines. In a recent study we examined the metabolic features of ct-1 null mice and the effects on body composition, glucose and lipid metabolism of acute and chronic administration of recombinant CT-1. Our data revealed that CT-1 is a key regulator of energy metabolism with potential applications in the treatment of obesity and the metabolic syndrome. This commentary discusses the significance of these findings in the context of other key studies in the field of obesity and insulin resistance.

Vascular effects of glycoprotein130 ligands--part II: biomarkers and therapeutic targets

Glycoprotein130 (gp130) ligands are defined by the use of the common receptor subunit gp130 and comprise interleukin (IL)-6, oncostatin M (OSM), IL-11, leukemia inhibitory factor (LIF), cardiotrophin-1 (CT-1), cardiotrophin-like cytokine (CLC), ciliary neurotrophic factor (CNTF), IL-27 and neuropoietin (NP). In part I of this review we addressed the pathophysiological functions of gp130 ligands with respect to the vascular wall. In part II of this review on the vascular effects of gp130 ligands we will discuss data about possible use of these molecules as biomarkers to predict development or progression of cardiovascular diseases. Furthermore, the possibility to modulate circulating levels of gp130 ligands or their tissue expression by specific antibodies, soluble gp130 protein, renin-angiotensin-aldosterone system (RASS) inhibitors, statins, agonists of peroxisome proliferator-activated receptors (PPAR), hormone replacement therapy, nonsteroidal anti-inflammatory drugs (NSAID) or lifestyle modulating strategies are presented. Recent knowledge about the application of recombinant cytokines from the gp130 cytokine family as therapeutic agents in obesity or atherosclerosis is also summarized. Thus the purpose of this review is to cover a possible usefulness of gp130 ligands as biomarkers and targets for therapy in cardiovascular pathologies.

Cardiotrophin-1 is a key regulator of glucose and lipid metabolism

Cardiotrophin-1 (CT-1) is a member of the gp130 family of cytokines. We observed that ct-1(-/-) mice develop mature-onset obesity, insulin resistance, and hypercholesterolemia despite reduced calorie intake. Decreased energy expenditure preceded and accompanied the development of obesity. Acute treatment with rCT-1 decreased blood glucose in an insulin-independent manner and increased insulin-stimulated AKT phosphorylation in muscle. These changes were associated with stimulation of fatty acid oxidation, an effect that was absent in AMPKα2(-/-) mice. Chronic rCT-1 treatment reduced food intake, enhanced energy expenditure, and induced white adipose tissue remodeling characterized by upregulation of genes implicated in the control of lipolysis, fatty acid oxidation, and mitochondrial biogenesis and genes typifying brown fat phenotype. Moreover, rCT-1 reduced body weight and corrected insulin resistance in ob/ob and in high-fat-fed obese mice. We conclude that CT-1 is a master regulator of fat and glucose metabolism with potential applications for treatment of obesity and insulin resistance.

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 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.