Genetic and pharmacological inhibition of galectin-3 prevents cardiac remodeling by interfering with myocardial fibrogenesis

Disconnect between Fibrotic Response and Right Ventricular Dysfunction

Rationale: Remodeling and fibrosis of the right ventricle (RV) may cause RV dysfunction and poor survival in patients with pulmonary hypertension. Objectives: To investigate the consequences of RV fibrosis modulation and the accompanying cellular changes on RV function. Methods: Expression of fibrotic markers was assessed in the RV of patients with pulmonary hypertension, the murine pulmonary artery banding, and rat monocrotaline and Sugen5416/hypoxia models. Invasive hemodynamic and echocardiographic assessment was performed on galectin-3 knockout or inhibitor-treated mice. Measurements and Main Results: Established fibrosis was characterized by marked expression of galectin-3 and an enhanced number of proliferating RV fibroblasts. Galectin-3 genetic and pharmacologic inhibition or antifibrotic treatment with pirfenidone significantly diminished RV fibrosis progression in the pulmonary artery banding model, without improving RV functional parameters. RV fibrotic regions were populated with mesenchymal cells coexpressing vimentin and PDGFRα (platelet-derived growth factor receptor-α), but generally lacked αSMA (α-smooth muscle actin) positivity. Serum levels of galectin-3 were increased in patients with idiopathic pulmonary arterial hypertension but did not correlate with cardiac function. No changes of galectin-3 expression were observed in the lungs. Conclusions: We identified extrapulmonary galectin-3 as an important mediator that drives RV fibrosis in pulmonary hypertension through the expansion of PDGFRα/vimentin-expressing cardiac fibroblasts. However, interventions effectively targeting fibrosis lack significant beneficial effects on RV function.

The relationship between galectin-3 levels and fragmented QRS (fQRS) in patients with heart failure with reduced left ventricular ejection fraction

BACKGROUND

Fragmented QRS (fQRS) complex is an electrocardiographic pattern which reflects myocardial scarring. We aimed to investigate the relationship between the presence of fragmented QRS (fQRS) on electrocardiogram (ECG) and plasma galectin-3 levels in patients with heart failure (HF) and severely decreased left ventricular ejection fraction (LVEF ≤ 35%).

METHODS

We prospectively enrolled 125 symptomatic HF patients (NYHA class II-III) with severely reduced LVEF (≤35%). fQRS was identified in ECG. Galectin-3 and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels were measured. Patients were divided into two groups based on the presence (n = 40) or absence (n = 85) of a fQRS on ECG.

RESULTS

Majority of patients were male (87.70%), and mean age was 65.1 ± 11.6. Galectin-3 and NT-proBNP levels were found to be significantly higher in the fQRS (+) group compared with the fQRS (-) group (NT-proBNP 5,362 ± 701 pg/ml vs. 4,452 ± 698 pg/ml; p < 0.001, galectin-3 607 ± 89.8 pg/ml vs. 509.4 ± 63.5 pg/ml; p < 0.001). Multivariate analyses revealed galectin-3 and NT-proBNP levels are the presence of fQRS on ECG (p < 0.001 and p < 0.001, respectively). The area under the curve using the galectin-3 level for fQRS was 0.819.

CONCLUSIONS

fQRS and serum galectin-3 levels are associated with myocardial fibrosis and are associated with poor prognosis in heart failure. In our study, a positive correlation was found between serum galectin-3 levels and fQRS on ECG.

Stimulation of β-adrenoceptors up-regulates cardiac expression of galectin-3 and BIM through the Hippo signalling pathway

Background and Purpose

Expression of the pro‐fibrotic galectin‐3 and the pro‐apoptotic BIM is elevated in diseased heart or after β‐adrenoceptor stimulation, but the underlying mechanisms are unclear. This question was addressed in the present study.

Experimental Approach

Wild‐type mice and mice with cardiac transgenic expression of β₂‐adrenoceptors, mammalian sterile‐20 like kinase 1 (Mst1) or dominant‐negative Mst1, and non‐specific galectin‐3 knockout mice were used. Effects of the β‐adrenoceptor agonist isoprenaline or β‐adrenoceptor antagonists were studied. Rat cardiomyoblasts (H9c2) were used for mechanistic exploration. Biochemical assays were performed.

Key Results

Isoprenaline treatment up‐regulated expression of galectin‐3 and BIM, and this was inhibited by non‐selective or selective β‐adrenoceptor antagonists (by 60–70%). Cardiac expression of galectin‐3 and BIM was increased in β₂‐adrenoceptor transgenic mice. Isoprenaline‐induced up‐regulation of galectin‐3 and BIM was attenuated by Mst1 inactivation, but isoprenaline‐induced galectin‐3 expression was exaggerated by transgenic Mst1 activation. Pharmacological or genetic activation of β‐adrenoceptors induced Mst1 expression and yes‐associated protein (YAP) phosphorylation. YAP hyper‐phosphorylation was also evident in Mst1 transgenic hearts with up‐regulated expression of galectin‐3 (40‐fold) and BIM as well as up‐regulation of many YAP‐target genes by RNA sequencing. In H9c2 cells, isoprenaline induced YAP phosphorylation and expression of galectin‐3 and BIM, effects simulated by forskolin but abolished by PKA inhibitors, and YAP knockdown induced expression of galectin‐3 and BIM.

Conclusions and Implications

Stimulation of cardiac β‐adrenoceptors activated the Mst1/Hippo pathway leading to YAP hyper‐phosphorylation with enhanced expression of galectin‐3 and BIM. This signalling pathway would have therapeutic potential.

Linked Articles

This article is part of a themed section on Adrenoceptors—New Roles for Old Players. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.14/issuetoc

Biomarkers Associated with Atrial Fibrosis and Remodeling

Atrial fibrillation is the most common rhythm disturbance encountered in clinical practice. Although often considered as solely arrhythmic in nature, current evidence has established that atrial myopathy constitutes both the substrate and the outcome of atrial fibrillation, thus initiating a vicious, self-perpetuating cycle. This myopathy is triggered by stress-induced (including pressure/volume overload, inflammation, oxidative stress) responses of atrial tissue, which in the long term become maladaptive, and combine elements of both structural, especially fibrosis, and electrical remodeling, with contemporary approaches yielding potentially useful biomarkers of these processes. Biomarker value becomes greater given the fact that they can both predict atrial fibrillation occurrence and treatment outcome. This mini-review will focus on the biomarkers of atrial remodeling (both electrical and structural) and fibrosis that have been validated in human studies, including biochemical, histological and imaging approaches.

Sleep apnea and galectin-3: possible sex-specific relationship

PURPOSE

Sleep apnea is associated with increased risk of cardiovascular disease. Elevated plasma galectin-3 levels, a biomarker associated with myocardial fibrosis, are also associated with adverse cardiovascular events, including heart failure. Our objective was to determine the relationship between severity of sleep apnea and plasma levels of galectin-3 and to determine whether this relationship was modified by sex.

METHODS

We performed a cross-sectional study of 471 Mexican Americans from Starr County, TX who underwent an overnight, in-home sleep evaluation, and plasma measurement of galectin-3. Severity of sleep apnea was based on apnea hypopnea index (AHI). Multivariable linear regression modeling was used to determine the association between categories of sleep apnea and galectin-3. We also tested for interactions by sex.

RESULTS

The mean age was 53 years, and 74% of the cohort was female. The prevalence of moderate to severe sleep apnea (AHI > 15 apnea-hypopnea events per hour) was 36.7%. Moderate to severe sleep apnea was associated with increased levels of galectin-3 in the entire population, but we identified a statistically significant interaction between galectin-3 levels and category of sleep apnea by sex (p for interaction = 0.02). Plasma galectin levels were significantly higher in women with moderate or severe sleep apnea than women with no/mild sleep apnea (multivariable adjusted p < 0.001), but not in men (p = 0.5).

CONCLUSIONS

Sleep apnea is associated elevated galectin-3 levels in women but not men. Our findings highlight a possible sex-specific relationship between sleep apnea and galectin-3, a biomarker of potential myocardial fibrosis that has been associated with increased cardiovascular risk.

Towards better definition, quantification and treatment of fibrosis in heart failure. A scientific roadmap by the Committee of Translational Research of the Heart Failure Association (HFA) of the European Society of Cardiology

Fibrosis is a pivotal player in heart failure development and progression. Measurements of (markers of) fibrosis in tissue and blood may help to diagnose and risk stratify patients with heart failure, and its treatment may be effective in preventing heart failure and its progression. A lack of pathophysiological insights and uniform definitions has hampered the research in fibrosis and heart failure. The Translational Research Committee of the Heart Failure Association discussed several aspects of fibrosis in their workshop. Early insidious perturbations such as subclinical hypertension or inflammation may trigger first fibrotic events, while more dramatic triggers such as myocardial infarction

and myocarditis give rise to full blown scar formation and ongoing fibrosis in diseased hearts. Aging itself is also associated with a cardiac phenotype that includes fibrosis. Fibrosis is an extremely heterogeneous phenomenon, as several stages of the fibrotic process exist, each with different fibrosis subtypes and a different composition of various cells and proteins — resulting in a very complex pathophysiology. As a result, detection of fibrosis, e.g. using current cardiac imaging modalities or plasma biomarkers, will detect only specific subforms of fibrosis, but cannot capture all aspects of the complex fibrotic process. Furthermore, several anti‐fibrotic therapies are under investigation, but such therapies generally target aspecific aspects of the fibrotic process and suffer from a lack of precision. This review discusses the mechanisms and the caveats and proposes a roadmap for future research.

Galectin-3 and risk of cardiovascular events and all-cause mortality in type 2 diabetes

AIMS

Recent clinical studies have shown that galectin-3 is a prognostic indicator in patients with coronary heart disease and in patients with heart failure. Experimental data suggest that galectin-3 may play a role in atherogenesis. We have evaluated whether serum galectin-3 level is associated with cardiovascular outcome in type 2 diabetes.

MATERIALS AND METHODS

Galectin-3 was measured in baseline samples in 1495 persons with type 2 diabetes. The primary cardiovascular outcome, incident cardiovascular events, was defined as first non-fatal myocardial infarction, non-fatal stroke, coronary revascularization, or death from cardiovascular cause. The secondary outcome was all-cause mortality.

RESULTS

At baseline, 12% of the subjects had prevalent cardiovascular disease. Serum galectin-3 was increased in the group with incident cardiovascular events compared with those who remained free of events during follow up (9.03 ± 2.98 ng/mL vs 8.15 ± 2.76, P < 0.01). Serum galectin-3 was also significantly increased in those subjects with a fatal outcome. The hazard ratios (HR) for cardiovascular events and all-cause mortality for individuals in the top quartile were 2.50 (95% CI 1.87, 3.36, P < 0.001) and 3.92 (95%CI 2.55, 6.01, P < 0.001), respectively. In a multivariate Cox regression analysis including traditional risk factors, log (eGFR), baseline albuminuria, and cardiovascular disease status, the HR per standard deviation change in galectin-3 was 1.13 (95% CI 1.02, 1.26, P = 0.02) for cardiovascular events and 1.17 (95% CI 1.01, 1.35, P = 0.04) for all-cause mortality.

CONCLUSIONS

Serum galectin-3 is associated with adverse cardiovascular outcomes in persons with type 2 diabetes independent of traditional risk factors.

Drug Targets for Heart Failure with Preserved Ejection Fraction: A Mechanistic Approach and Review of Contemporary Clinical Trials

Heart failure with preserved ejection fraction (HFpEF) accounts for over half of prevalent heart failure (HF) worldwide, and prognosis after hospitalization for HFpEF remains poor. Due, at least in part, to the heterogeneous nature of HFpEF, drug development has proved immensely challenging. Currently, there are no universally accepted therapies that alter the clinical course of HFpEF. Despite these challenges, important mechanistic understandings of the disease have revealed that the pathophysiology of HFpEF is distinct from that of HF with reduced ejection fraction and have also highlighted potential new therapeutic targets for HFpEF. Of note, HFpEF is a systemic syndrome affecting multiple organ systems. Depending on the organ systems involved, certain novel therapies offer promise in reducing the morbidity of the HFpEF syndrome. In this review, we aim to discuss novel pharmacotherapies for HFpEF based on its unique pathophysiology and identify key research strategies to further elucidate mechanistic pathways to develop novel therapeutics in the future.

Galectin-3 in Acute Myocardial Infarction Patients with Atrial Fibrillation

OBJECTIVE

Atrial fibrillation (AF) is common in acute myocardial infarction (AMI), and galectin-3 is possibly involved in its occurrence. Galectin-3 has been shown to play a central role in fibrosis and tissue remodeling and has a role in inflammatory and proliferative responses. The aim of our study was to measure galectin-3 levels in patients with myocardial infarction and to compare its levels in patients with or without AF, in order to investigate the potential predictive role of galectin-3 in this setting.

SUBJECTS AND METHODS

The study included 51 consecutive AMI patients with AF; 27 AMI patients (52.9%) had permanent/persistent AF, and 24 patients (47.1%) had paroxysmal AF. Thirty-eight consecutive AMI patients without AF were used as a control group. Blood samples were obtained from venous blood on the third day after reperfusion.

RESULTS

Patients with AF had higher levels of C-reactive protein (p < 0.01) and galectin-3 (p < 0.05) than those without AF. Patients with high galectin-3 had 4.4 times greater odds of having AF. Galectin-3 levels were lower in patients without AF (p < 0.01) than in those with permanent/persistent AF.

CONCLUSION

AMI patients with AF had higher levels of galectin-3 than those without this arrhythmia. This biomarker of inflammation and fibrosis could be a potential target for treating AMI patients at high risk.

Procollagen C-Proteinase Enhancer 1 (PCPE-1) in Liver Fibrosis

Fibrosis is characterized by excessive deposition of collagen and additional extracellular matrix (ECM) components in response to chronic injuries. Liver fibrosis often results from chronic hepatitis C virus infection and alcohol abuse that can deteriorate to cirrhosis and liver failure. Current noninvasive diagnostic methods of liver fibrosis are limited in their ability to detect and differentiate between early and intermediate stages of fibrosis. New biomarkers of fibrosis that reflect ECM turnover are therefore badly needed. Procollagen C-proteinase enhancer 1 (PCPE-1), a connective tissue glycoprotein that functions as a positive regulator of C-terminal procollagen processing and subsequent collagen fibril assembly, is a promising candidate. Its tissue distribution and expression profile overlap those of collagen, and its expression in fibrosis is upregulated in parallel to the increase in collagen expression. The potential of PCPE-1 as a biomarker of liver fibrosis was recently established using a CCl₄ mouse model of liver fibrosis by showing that the increase in collagen and PCPE-1 content in the fibrotic mouse liver was reflected by elevated plasma levels of PCPE-1. This was achieved using a newly developed highly sensitive, specific, accurate, and reproducible ELISA for mouse PCPE-1, which is based on commercially available antibodies and is offered as a new research tool in the field. A similar ELISA test was developed for human PCPE-1, and preliminary results with plasma from liver fibrosis patients revealed increased plasma concentrations of PCPE-1 in some patients. The protocols of both ELISA tests are outlined herein in great detail to permit their application by any laboratory with similar interests.

Longitudinal Change in Galectin-3 and Incident Cardiovascular Outcomes

BACKGROUND

Galectin-3 (Gal-3) has been associated with heart failure (HF) and poor cardiovascular outcomes. However, the effect of longitudinal changes in Gal-3 on clinical outcomes remains unclear.

OBJECTIVES

The authors sought to study clinical determinants of change in Gal-3 among community-dwelling individuals. Further, they sought to examine the role of serial Gal-3 measurements in predicting risk of future HF, cardiovascular disease (CVD), and mortality.

METHODS

A total of 2,477 participants in the Framingham Heart Study Offspring cohort underwent measurement of plasma Gal-3 levels at 2 examinations (1995 to 1998 and 2005 to 2008). Linear regression models were used to examine clinical correlates of change in Gal-3. Proportional hazards models were used to relate future clinical outcomes with change in Gal-3.

RESULTS

The following clinical correlates were associated with greater longitudinal increases in Gal-3 levels: age, female sex, hypertension, diabetes, body mass index, interim development of chronic kidney disease, and HF (p < 0.0001 for all in multivariable model). Change in Gal-3 was associated with future HF (hazard ratio [HR]: 1.39 per 1-SD increase; 95% confidence interval [CI]: 1.13 to 1.71), CVD (HR: 1.29; 95% CI: 1.11 to 1.51), and all-cause mortality (HR: 1.30; 95% CI: 1.17 to 1.46). Change in Gal-3 was associated with both HF with preserved as well as reduced ejection fraction (p < 0.05 for both).

CONCLUSIONS

Longitudinal changes in Gal-3 are associated with traditional cardiovascular risk factors and renal disease. In turn, change in Gal-3 predicts future HF, CVD, and mortality in the community. Future studies are needed to determine whether serial Gal-3 measures may be useful in disease prevention.

Galectin-3 exacerbates ox-LDL-mediated endothelial injury by inducing inflammation via integrin β1-RhoA-JNK signaling activation

Oxidized low‐density lipoprotein (Ox‐LDL)‐induced endothelial cell injury plays a crucial role in the pathogenesis of atherosclerosis (AS). Plasma galectin‐3 (Gal‐3) is elevated inside and drives diverse systemic inflammatory disorders, including cardiovascular diseases. However, the exact role of Gal‐3 in ox‐LDL‐mediated endothelial injury remains unclear. This study explores the effects of Gal‐3 on ox‐LDL‐induced endothelial dysfunction and the underlying molecular mechanisms. In this study, Gal‐3, integrin β1, and GTP‐RhoA in the blood and plaques of AS patients were examined by ELISA and western blot respectively. Their levels were found to be obviously upregulated compared with non‐AS control group. CCK8 assay and flow cytometry analysis showed that Gal‐3 significantly decreased cell viability and promoted apoptosis in ox‐LDL‐treated human umbilical vascular endothelial cells (HUVECs). The upregulation of integrinβ1, GTP‐RhoA, p‐JNK, p‐p65, p‐IKKα, and p‐IKKβ induced by ox‐LDL was further enhanced by treatment with Gal‐3. Pretreatment with Gal‐3 increased expression of inflammatory factors (interleukin [IL]‐6, IL‐8, and IL‐1β), chemokines(CXCL‐1 and CCL‐2) and adhesion molecules (VCAM‐1 and ICAM‐1). Furthermore, the promotional effects of Gal‐3 on NF‐κB activation and inflammatory factors in ox‐LDL‐treated HUVECs were reversed by the treatments with integrinβ1‐siRNA or the JNK inhibitor. We also found that integrinβ1‐siRNA decreased the protein expression of GTP‐RhoA and p‐JNK, while RhoA inhibitor partially reduced the upregulated expression of p‐JNK induced by Gal‐3. In conclusion, our finding suggests that Gal‐3 exacerbates ox‐LDL‐mediated endothelial injury by inducing inflammation via integrin β1‐RhoA‐JNK signaling activation.

Differential Prognostic Value of Galectin-3 According to Carbohydrate Antigen 125 Levels in Transcatheter Aortic Valve Implantation

INTRODUCTION AND OBJECTIVES

Galectin-3 (Gal-3) and carbohydrate antigen 125 (CA125) have been associated with adverse outcomes after transcatheter aortic valve implantation (TAVI). Experimental data have suggested a potential molecular interaction. Therefore, we assessed the association of Gal-3 and CA125 with prognosis after TAVI.

METHODS

A total of 439 patients were enrolled. The primary endpoint was a composite of all-cause mortality or readmission for worsening heart failure after TAVI.

RESULTS

The primary endpoint occurred in 16.4%. Gal-3 was dichotomized at ≥ 8.71 ng/mL into elevated and not elevated. Gal-3 was elevated in 31.9% and was associated with a higher risk of the primary endpoint (25% vs 12.4%, HR, 2.26; P<.001). After multivariable adjustment, the association of elevated Gal-3 with the primary endpoint was borderline significant (HR, 1.59; P=.068). CA125 was dichotomized at ≥ 18.4 U/mL, accordingly. CA125 was elevated in 51.9% and was also associated with a higher risk of the primary endpoint (25.4% vs 6.6%, HR, 4.20; P<.001). After multivariable adjustment, elevated CA125 (HR, 2.83; P=.001) remained independently associated with the primary endpoint. A differential prognostic effect of Gal-3 was found across CA125 status (P for interaction=.048). Elevated Gal-3 was associated with a higher risk of the primary endpoint when CA125 was elevated (38.8% vs 18.2%, HR, 2.02; P=.015) but lacked significance when CA125 was not elevated (6.6% vs 6.7%, HR, 1.16; P=.981).

CONCLUSIONS

In patients undergoing TAVI, Gal-3 predicted adverse clinical outcomes only when CA125 was elevated.

Echocardiographic diastolic function evolution in patients with an anterior Q-wave myocardial infarction: insights from the REVE-2 study

Aims

Myocardial fibrosis plays a key role in the development of adverse left ventricular remodelling after myocardial infarction (MI). This study aimed to determine whether the circulating levels of BNP, collagen peptides, and galectin‐3 are associated with diastolic function evolution (both deterioration and improvement) at 1 year after an anterior MI.

Methods and results

The REVE‐2 is a prospective multicentre study including 246 patients with a first anterior Q‐wave MI. Echocardiographic assessment was performed at hospital discharge and ±1 year after MI. BNP, galectin‐3, and collagen peptides were measured ±1 month after MI. Left ventricular diastolic dysfunction (DD) was defined according to the presence of at least two criteria of echocardiographic parameters: septal e′ < 8 cm/s, lateral e′ < 10 cm/s, and left atrial volume ≥ 34 mL/m². At baseline, 87 (35.4%) patients had normal diastolic function and 159 (64.6%) patients had DD. Follow‐up of 61 patients among the 87 patients with normal diastolic function at baseline showed that 22 patients (36%) developed DD at 1 year post‐MI. The circulating levels of amino‐terminal propeptide of type III procollagen > 6 mg/L [odds ratio (OR) = 5.29; 95% confidence interval (CI) = 1.05–26.66; P = 0.044], galectin‐3 > 13 μg/L (OR = 5.99; 95% CI = 1.18–30.45; P = 0.031), and BNP > 82 ng/L (OR = 10.25; 95% CI = 2.36–44.50; P = 0.002) quantified at 1 month post‐MI were independently associated with 1 year DD. Follow‐up of the 137 patients with DD at baseline among the 159 patients showed that 36 patients (26%) had a normalized diastolic function at 1 year post‐MI. Patients with a BNP > 82 ng/L were less likely to improve diastolic function (OR = 0.06; 95% CI = 0.01–0.28; P = 0.0003).

Conclusions

The present study suggests that circulating levels of amino‐terminal propeptide of type III procollagen, galectin‐3, and BNP may be independently associated with new‐onset DD in post‐MI patients.

Galectin-1 as an Emerging Mediator of Cardiovascular Inflammation: Mechanisms and Therapeutic Opportunities

Galectin-1 (Gal-1), an evolutionarily conserved β-galactoside-binding lectin, controls immune cell homeostasis and tempers acute and chronic inflammation by blunting proinflammatory cytokine synthesis, engaging T-cell apoptotic programs, promoting expansion of T regulatory (Treg) cells, and deactivating antigen-presenting cells. In addition, this lectin promotes angiogenesis by co-opting the vascular endothelial growth factor receptor (VEGFR) 2 signaling pathway. Since a coordinated network of immunomodulatory and proangiogenic mediators controls cardiac homeostasis, this lectin has been proposed to play a key hierarchical role in cardiac pathophysiology via glycan-dependent regulation of inflammatory responses. Here, we discuss the emerging roles of Gal-1 in cardiovascular diseases including acute myocardial infarction, heart failure, Chagas cardiomyopathy, pulmonary hypertension, and ischemic stroke, highlighting underlying anti-inflammatory mechanisms and therapeutic opportunities. Whereas Gal-1 administration emerges as a potential novel treatment option in acute myocardial infarction and ischemic stroke, Gal-1 blockade may contribute to attenuate pulmonary arterial hypertension.

Galectin-3 deficiency ameliorates fibrosis and remodeling in dilated cardiomyopathy mice with enhanced Mst1 signaling

Dilated cardiomyopathy (DCM) is a major cause of heart failure without effective therapy. Fibrogenesis plays a key role in the development of DCM, but little is known of the expression of the profibrotic factor galectin-3 (Gal-3) and its role in DCM pathophysiology. In a mouse DCM model with transgenic (TG) overexpression of mammalian sterile 20-like kinase 1 (Mst1), we studied Gal-3 expression and effects of the Gal-3 inhibitor modified citrus pectin (MCP) or Gal-3 gene knockout (KO). Gal-3 deletion in TG mice (TG/KO) was achieved by crossbreeding Mst1-TG mice with Gal-3 KO mice. The DCM phenotype was assessed by echocardiography and micromanometry. Cardiac expression of Gal-3 and fibrosis were determined. The cardiac transcriptome was profiled by RNA sequencing. Mst1-TG mice at 3-8 mo of age exhibited upregulated expression of Gal-3 by ~40-fold. TG mice had dilatation of cardiac chambers, suppressed left ventricular (LV) ejection fraction, poor LV contractility and relaxation, a threefold increase in LV collagen content, and upregulated fibrotic genes. Four-month treatment with MCP showed no beneficial effects. Gal-3 deletion in Mst1-TG mice attenuated chamber dilatation, organ congestion, and fibrogenesis. RNA sequencing identified profound disturbances by Mst1 overexpression in the cardiac transcriptome, which largely remained in TG/KO hearts. Gal-3 deletion in Mst1-TG mice, however, partially reversed the dysregulated transcriptional signaling involving extracellular matrix remodeling and collagen formation. We conclude that cardiac Mst1 activation leads to marked Gal-3 upregulation and transcriptome disturbances in the heart. Gal-3 deficiency attenuated cardiac remodeling and fibrotic signaling. NEW & NOTEWORTHY We found in a transgenic mouse dilated cardiomyopathy (DCM) model a pronounced upregulation of galectin-3 in cardiomyocytes. Galectin-3 gene deletion reduced cardiac fibrosis and fibrotic gene profiles and ameliorated cardiac remodeling and dysfunction. These benefits of galectin-3 deletion were in contrast to the lack of effect of treatment with the galectin-3 inhibitor modified citrus pectin. Our study suggests that suppression of galectin-3 mRNA expression could be used to treat DCM with high cardiac galectin-3 content.

Cardiac fibrosis: Cell biological mechanisms, molecular pathways and therapeutic opportunities

Cardiac fibrosis is a common pathophysiologic companion of most myocardial diseases, and is associated with systolic and diastolic dysfunction, arrhythmogenesis, and adverse outcome. Because the adult mammalian heart has negligible regenerative capacity, death of a large number of cardiomyocytes results in reparative fibrosis, a process that is critical for preservation of the structural integrity of the infarcted ventricle. On the other hand, pathophysiologic stimuli, such as pressure overload, volume overload, metabolic dysfunction, and aging may cause interstitial and perivascular fibrosis in the absence of infarction. Activated myofibroblasts are the main effector cells in cardiac fibrosis; their expansion following myocardial injury is primarily driven through activation of resident interstitial cell populations. Several other cell types, including cardiomyocytes, endothelial cells, pericytes, macrophages, lymphocytes and mast cells may contribute to the fibrotic process, by producing proteases that participate in matrix metabolism, by secreting fibrogenic mediators and matricellular proteins, or by exerting contact-dependent actions on fibroblast phenotype. The mechanisms of induction of fibrogenic signals are dependent on the type of primary myocardial injury. Activation of neurohumoral pathways stimulates fibroblasts both directly, and through effects on immune cell populations. Cytokines and growth factors, such as Tumor Necrosis Factor-α, Interleukin (IL)-1, IL-10, chemokines, members of the Transforming Growth Factor-β family, IL-11, and Platelet-Derived Growth Factors are secreted in the cardiac interstitium and play distinct roles in activating specific aspects of the fibrotic response. Secreted fibrogenic mediators and matricellular proteins bind to cell surface receptors in fibroblasts, such as cytokine receptors, integrins, syndecans and CD44, and transduce intracellular signaling cascades that regulate genes involved in synthesis, processing and metabolism of the extracellular matrix. Endogenous pathways involved in negative regulation of fibrosis are critical for cardiac repair and may protect the myocardium from excessive fibrogenic responses. Due to the reparative nature of many forms of cardiac fibrosis, targeting fibrotic remodeling following myocardial injury poses major challenges. Development of effective therapies will require careful dissection of the cell biological mechanisms, study of the functional consequences of fibrotic changes on the myocardium, and identification of heart failure patient subsets with overactive fibrotic responses.

Evaluation of serum procollagen C-proteinase enhancer 1 level as a fibrosis marker in patients with chronic hepatitis B

AIM

Although liver biopsy has long been considered the gold standard for staging fibrosis, because of the disadvantages and risks of biopsy, several noninvasive processes such as serum biomarkers have been introduced for the assessment of liver fibrosis. The aim of this study was to assess the diagnostic value of serum procollagen C-proteinase enhancer 1 (PCPE-1) as a noninvasive fibrosis marker in treatment-naive chronic hepatitis B patients.

PATIENTS AND METHODS

This study included 126 patients with biopsy-proven hepatitis B and 50 healthy controls. Fibrosis stage was determined using the Ishak scoring system. The PCPE-1 level was measured using the enzyme-linked immunosorbent assay assay, and the aspartate aminotransferase to platelet ratio index and the FIB-4 index were calculated using the formulas described in Appendix 1 (Supplemental digital content 1, http://links.lww.com/EJGH/A277).

RESULTS

Serum PCPE-1 levels of chronic hepatitis B patients were found to be significantly lower than those of the healthy control group (4.49±2.74 vs. 42.9±59.6 pg/ml, respectively, P<0.001). There was a statistically significant negative correlation between serum PCPE-1 level and fibrosis stage (P=0.011; r=-0.226). A statistically significant negative correlation was found between serum PCPE-1 level and necroinflammatory activity (P=0.030; r=-0.194). PCPE-1 levels of patients with liver fibrosis scores of F1-2 were statistically significantly lower than those of the healthy control group (P<0.001) (area under the receiver operating characteristic: 0.955). The area under the receiver operating characteristic of the PCPE-1 level was 0.615 for the prediction of fibrosis (F0 vs. F1-6) (P=0.039).

CONCLUSION

Serum PCPE-1 might be used as a noninvasive marker of liver fibrosis. Further animal and human studies are needed to assess the utility of this marker.

Plasma levels of heart failure biomarkers are primarily a reflection of extracardiac production

Plasma heart failure (HF) biomarkers, like natriuretic peptides, are important in diagnosis, prognosis and HF treatment. Several novel HF biomarkers have been identified, including Gal-3, GDF-15 and TIMP-1, but their clinical potential remains vague. Here we investigated plasma biomarker levels in relation to tissue expression and structural and functional cardiac changes. Methods: Cardiac remodeling, cardiac function, and plasma and tissue biomarker levels were investigated in mice after myocardial infarction induced by temporal and permanent LAD ligation (tLAD and pLAD). In addition, a pressure overload model induced by transverse aortic constriction (TAC) and an obese/hypertensive HFpEF-like mouse model were investigated. Results: Plasma levels of ANP and its cardiac expression were strictly associated with cardiac remodeling and function. Gal-3, GDF-15 and TIMP-1 cardiac expressions were also related to cardiac remodeling and function, but not their plasma levels. Only directly after myocardial infarction could elevated plasma levels of Gal-3 and TIMP-1 be detected. Eight weeks after infarction, plasma levels were not elevated despite enhanced cardiac expression and low EF (18.3±3.3%, pLAD). Plasma levels of TIMP-1 and GDF-15 were elevated after TAC, but this also correlated with increased lung expression and congestion. In obese-hypertensive mice, elevated plasma levels of Gal-3, GDF-15 and TIMP1 were associated with increased adipose tissue expression and not with cardiac function. Conclusions: The Gal-3, GDF-15 and TIMP-1 plasma pool levels are hardly influenced by dynamic changes in cardiac expression. These biomarkers are not specific for indices of cardiac remodeling, but predominantly reflect stress in other affected tissues and hence provide health information beyond the heart.

Galectin-3 down-regulates antioxidant peroxiredoxin-4 in human cardiac fibroblasts: a new pathway to induce cardiac damage

Galectin-3 (Gal-3) is increased in heart failure (HF) and promotes cardiac fibrosis and inflammation. We investigated whether Gal-3 modulates oxidative stress in human cardiac fibroblasts, in experimental animal models and in human aortic stenosis (AS). Using proteomics and immunodetection approaches, we have identified that Gal-3 down-regulated the antioxidant peroxiredoxin-4 (Prx-4) in cardiac fibroblasts. In parallel, Gal-3 increased peroxide, nitrotyrosine, malondialdehyde, and N-carboxymethyl-lysine levels and decreased total antioxidant capacity. Gal-3 decreased prohibitin-2 expression without modifying other mitochondrial proteins. Prx-4 silencing increased oxidative stress markers. In Gal-3-silenced cells and in heart from Gal-3 knockout mice, Prx-4 was increased and oxidative stress markers were decreased. Pharmacological inhibition of Gal-3 with modified citrus pectin restored cardiac Prx-4 as well as prohibitin-2 levels and improved oxidative status in spontaneously hypertensive rats. In serum from 87 patients with AS, Gal-3 negatively correlated with total antioxidant capacity and positively correlated with peroxide. In myocardial biopsies from 26 AS patients, Gal-3 up-regulation paralleled a decrease in Prx-4 and in prohibitin-2. Cardiac Gal-3 inversely correlated with Prx-4 levels in myocardial biopsies. These data suggest that Gal-3 decreased Prx-4 antioxidant system in cardiac fibroblasts, increasing oxidative stress. In pathological models presenting enhanced cardiac Gal-3, the decrease in Prx-4 expression paralleled increased oxidative stress. Gal-3 blockade restored Prx-4 expression and improved oxidative stress status. In AS, circulating levels of Gal-3 could reflect oxidative stress. The alteration of the balance between antioxidant systems and reactive oxygen species production could be a new pathogenic mechanism by which Gal-3 induces cardiac damage in HF.

Galectin-3 as a Predictor of Left Ventricular Reverse Remodeling in Recent-Onset Dilated Cardiomyopathy

Objectives

Studies have evaluated the association of galectin-3 and outcome in patients with heart failure. However, there is still scarce evidence concerning the clinical usefulness and predictive value of galectin-3 for left ventricular reverse remodeling (LVRR) in patients with recent-onset dilated cardiomyopathy (RODCM).

Patients and Methods

Baseline galectin-3 was measured in 57 patients with RODCM. All patients were followed for at least 12 months. The study end point was LVRR at 12 months, defined as an absolute improvement of the left ventricular ejection fraction of ≥10% to a final value of ≥35%, accompanied by a decrease in the left ventricular end diastolic diameter of at least 10%, as assessed by echocardiography. In receiver operating characteristic curve analysis, the optimum cut-off value for baseline galectin-3 with the highest Youden index was 59 ng/ml.

Results

Overall, LVRR at 12 months was observed in 38 patients (66%). In a univariate analysis, NYHA functional class and baseline galectin-3 levels were associated with LVRR. After adjustment for covariates, galectin-3 remained an independent predictor for LVRR.

Conclusions

Our study suggests that baseline galectin-3 is an independent predictor of LVRR. Low levels of galectin-3 may be regarded a useful biomarker of favorable ventricular remodeling in patients with RODCM.

Biomarkers, myocardial fibrosis and co-morbidities in heart failure with preserved ejection fraction: an overview

The prevalence of heart failure with preserved ejection fraction (HFpEF) is steadily increasing. Its diagnosis remains difficult and controversial and relies mostly on non-invasive echocardiographic detection of left ventricular diastolic dysfunction and elevated filling pressures. The large phenotypic heterogeneity of HFpEF from pathophysiologic al underpinnings to clinical manifestations presents a major obstacle to the development of new therapies targeted towards specific HF phenotypes. Recent studies suggest that natriuretic peptides have the potential to improve the diagnosis of early HFpEF, but they still have significant limitations, and the cut-off points for diagnosis and prognosis in HFpEF remain open to debate. The purpose of this review is to present potential targets of intervention in patients with HFpEF, starting with myocardial fibrosis and methods of its detection. In addition, co-morbidities are discussed as a means to treat HFpEF according to cut-points of biomarkers that are different from usual. Biomarkers and approaches to co-morbidities may be able to tailor therapies according to patients' pathophysiological needs. Recently, soluble source of tumorigenicity 2 (sST2), growth differentiation factor 15 (GDF-15), galectin-3, and other cardiac markers have emerged, but evidence from large cohorts is still lacking. Furthermore, the field of miRNA is a very promising area of research, and further exploration of miRNA may offer diagnostic and prognostic applications and insight into the pathology, pointing to new phenotype-specific therapeutic targets.

Upregulated galectin-3 is not a critical disease mediator of cardiomyopathy induced by β2-adrenoceptor overexpression

Preclinical studies have demonstrated that anti-galectin-3 (Gal-3) interventions are effective in attenuating cardiac remodeling, fibrosis, and dysfunction. We determined, in a transgenic (TG) mouse model of fibrotic cardiomyopathy, whether Gal-3 expression was elevated and whether Gal-3 played a critical role in disease development. We studied mice with fibrotic cardiomyopathy attributable to cardiac overexpression of human β2-adrenoceptors (β2-TG). Cardiac expression levels of Gal-3 and fibrotic or inflammatory genes were determined. The effect of Gal-3 inhibition in β2-TG mice was studied by treatment with Gal-3 inhibitors ( N-acetyllactosamine and modified citrus pectin) or by deletion of Gal-3 through crossing β2-TG and Gal-3 knockout mice. Changes in cardiomyopathy phenotypes were assessed by echocardiography and biochemical assays. In β2-TG mice at 3, 6, and 9 mo of age, upregulation of Gal-3 expression was observed at mRNA (~6- to 15-fold) and protein (~4- to 8-fold) levels. Treatment of β2-TG mice with N-acetyllactosamine (3 wk) or modified citrus pectin (3 mo) did not reverse cardiac fibrosis, inflammation, and cardiomyopathy. Similarly, Gal-3 gene deletion in β2-TG mice aged 3 and 9 mo did not rescue the cardiomyopathy phenotype. In conclusion, the β2-TG model of cardiomyopathy showed a robust upregulation of Gal-3 that correlated with disease severity, but Gal-3 inhibitors or Gal-3 gene deletion had no effect in halting myocardial fibrosis, remodeling, and dysfunction. Gal-3 may not be critical for cardiac fibrogenesis and remodeling in this cardiomyopathy model.

NEW & NOTEWORTHY We showed a robust upregulation of cardiac galectin-3 (Gal-3) expression in a mouse model of cardiomyopathy attributable to cardiomyocyte-restricted transgenic activation of β2-adrenoceptors. However, pharmacological and genetic inhibition of Gal-3 did not confer benefit in this model, implying that Gal-3 may not be a critical disease mediator of cardiac remodeling in this model.

Biomarkers for heart failure: small molecules with high clinical relevance

Heart failure (HF) is a rising epidemic due to the ageing population and progress in all areas of medicine. Thus, research efforts are made to ensure a timely diagnosis, to improve prognosis and treatment of the disease and to facilitate risk prediction at the population level. Because of their noninvasive determination with mostly high sensitivity and accuracy, circulating blood biomarkers are becoming increasingly important for daily clinical practice. Natriuretic peptides, especially B-type natriuretic peptide (BNP), N-terminal pro-B-type natriuretic peptide (Nt-proBNP) and midregional pro-atrial natriuretic peptide (MR-proANP) and cardiac troponins are established blood biomarkers in HF diagnosis and prognosis of HF-related outcomes. Inflammatory molecules as C-reactive protein (CRP) may have added value in anti-inflammatory therapy guidance. Next-generation biomarkers including soluble source of tumorigenicity 2 (sST2), growth differentiation factor-15 (GDF-15), galectin-3 (Gal-3) and diverse microribonucleic acids (miRNAs) may have additional benefit in assessment of cardiac remodeling or differentiation of HF subtypes. Multimarker approaches containing different combinations of established and novel biomarkers might improve HF risk prediction at the population level once they are used on top of clinical variables.

Mechanisms responsible for increased circulating levels of galectin-3 in cardiomyopathy and heart failure

Galectin-3 is a biomarker of heart disease. However, it remains unknown whether increase in galectin-3 levels is dependent on aetiology or disease-associated conditions and whether diseased heart releases galectin-3 into the circulation. We explored these questions in mouse models of heart disease and in patients with cardiomyopathy. All mouse models (dilated cardiomyopathy, DCM; fibrotic cardiomyopathy, ischemia-reperfusion, I/R; treatment with β-adrenergic agonist isoproterenol) showed multi-fold increases in cardiac galectin-3 expression and preserved renal function. In mice with fibrotic cardiomyopathy, I/R or isoproterenol treatment, plasma galectin-3 levels and density of cardiac inflammatory cells were elevated. These models also exhibited parallel changes in cardiac and plasma galectin-3 levels and presence of trans-cardiac galectin-3 gradient, indicating cardiac release of galectin-3. DCM mice showed no change in circulating galectin-3 levels nor trans-cardiac galectin-3 gradient or myocardial inflammatory infiltration despite a 50-fold increase in cardiac galectin-3 content. In patients with hypertrophic cardiomyopathy or DCM, plasma galectin-3 increased only in those with renal dysfunction and a trans-cardiac galectin-3 gradient was not present. Collectively, this study documents the aetiology-dependency and diverse mechanisms of increment in circulating galectin-3 levels. Our findings highlight cardiac inflammation and enhanced β-adrenoceptor activation in mediating elevated galectin-3 levels via cardiac release in the mechanism.

Identification of galectin-3 as an autoantigen in patients with IgG4-related disease

BACKGROUND

The antigenic trigger that drives expansion of circulating plasmablasts and CD4⁺ cytotoxic T cells in patients with IgG₄-related disease (IgG₄-RD) is presently unknown.

OBJECTIVE

We sought to sequence immunoglobulin genes from single-cell clones of dominantly expanded plasmablasts and generate recombinant human mAbs to identify relevant antigens in patients with IgG₄-RD by using mass spectrometry.

METHODS

Paired heavy and light chain cDNAs from dominant plasmablast clones were expressed as mAbs and used to purify antigens by using immunoaffinity chromatography. Affinity-purified antigens were identified by using mass spectrometry and validated by means of ELISA. Plasma levels of the antigen of interest were also determined by using ELISA.

RESULTS

mAbs expressed from the 2 dominant plasmablast clones of a patient with multiorgan IgG₄-RD stained human pancreatic tissue sections. Galectin-3 was identified as the antigen specifically recognized by both mAbs. Anti-galectin-3 autoantibody responses were predominantly of the IgG₄ isotype (28% of the IgG₄-RD cohort, P = .0001) and IgE isotype (11% of the IgG₄-RD cohort, P = .009). No significant responses were seen from the IgG₁, IgG₂, or IgG₃ isotypes. IgG₄ anti-galectin-3 autoantibodies correlated with increased plasma galectin-3 levels (P = .001), lymphadenopathy (P = .04), total IgG level increase (P = .05), and IgG₄ level increase (P = .03).

CONCLUSION

Affinity chromatography using patient-derived mAbs identifies relevant autoantigens in patients with IgG₄-RD. IgG₄ galectin-3 autoantibodies are present in a subset of patients with IgG₄-RD and correlate with galectin-3 plasma levels. The marked increases in levels of circulating IgG₄ and IgE observed clinically are, at least in part, caused by the development of IgG₄- and IgE-specific autoantibody responses.

Galectin-3 in Heart Failure: An Update of the Last 3 Years

Galectin-3 plays a role in tissue inflammation, repair, and fibrosis. This article specifically focuses on heart failure (HF), in which galectin-3 has been shown to be a useful biomarker in prognosis and risk stratification, especially in HF with preserved ejection fraction. Experimental research has shown that galectin-3 directly induces pathologic remodeling of the heart, and is therefore considered a culprit protein in the development of cardiac fibrosis in HF, with potentially relevant clinical implications. In summary, galectin-3 is a biomarker and biotarget in cardiac remodeling and fibrosis and future research will target galectin-3-centered diseases.

Galectin-3 is independently associated with progression of nephropathy in type 2 diabetes mellitus

AIMS/HYPOTHESIS

Galectin-3 has been implicated in cardiac and renal fibrosis and serves as a prognostic clinical indicator in heart failure. The aim of the present study was to evaluate whether serum galectin-3 level is associated with progressive kidney disease in type 2 diabetes.

METHODS

Galectin-3 was measured in baseline samples by ELISA in 1320 participants with type 2 diabetes with eGFR ≥30 ml min^-1 1.73 m^-2. The primary outcome was defined as doubling of serum creatinine and/or initiation of renal replacement therapy during follow-up. The secondary outcome was progression to macroalbuminuria in individuals with normo- or microalbuminuria at baseline.

RESULTS

Serum galectin-3 levels were significantly increased in a random subgroup of 270 type 2 diabetic individuals with eGFR >60 ml min^-1 1.73 m^-2 compared with an age- and sex-matched non-diabetic control group (7.58 ± 2.29 ng/ml vs 6.10 ± 1.91 ng/ml, respectively, p < 0.01). In the whole diabetic cohort, after a mean follow-up of 9 years, galectin-3 was independently associated with doubling of serum creatinine (HR 1.19; 95% CI 1.14, 1.24, p < 0.001) and incident macroalbuminuria (HR 1.20; 95% CI 1.12, 1.30, p < 0.001), even after adjusting for traditional risk factors, baseline eGFR and albuminuria status. Individuals with galectin-3 levels in the highest quartile had a fourfold risk of renal function loss and threefold risk of incident macroalbuminuria.

CONCLUSIONS/INTERPRETATION

Serum galectin-3 was independently associated with progressive renal disease in type 2 diabetes. Further mechanistic studies are warranted to determine whether galectin-3 is simply a disease biomarker or is also a mediator of the development and progression of diabetic nephropathy.

Novel heart failure biomarkers: why do we fail to exploit their potential?

Plasma biomarkers are useful tools in the diagnosis and prognosis of heart failure (HF). In the last decade, numerous studies have aimed to identify novel HF biomarkers that would provide superior and/or additional diagnostic, prognostic, or stratification utility. Although numerous biomarkers have been identified, their implementation in clinical practice has so far remained largely unsuccessful. Whereas cardiac-specific biomarkers, including natriuretic peptides (ANP and BNP) and high sensitivity troponins (hsTn), are widely used in clinical practice, other biomarkers have not yet proven their utility. Galectin-3 (Gal-3) and soluble suppression of tumorigenicity 2 (sST2) are the only novel HF biomarkers that are included in the ACC/AHA HF guidelines, but their clinical utility still needs to be demonstrated. In this review, we will describe natriuretic peptides, hsTn, and novel HF biomarkers, including Gal-3, sST2, human epididymis protein 4 (HE4), insulin-like growth factor-binding protein 7 (IGFBP-7), heart fatty acid-binding protein (H-FABP), soluble CD146 (sCD146), interleukin-6 (IL-6), growth differentiation factor 15 (GDF-15), procalcitonin (PCT), adrenomedullin (ADM), microRNAs (miRNAs), and metabolites like 5-oxoproline. We will discuss the biology of these HF biomarkers and conclude that most of them are markers of general pathological processes like fibrosis, cell death, and inflammation, and are not cardiac- or HF-specific. These characteristics explain to a large degree why it has been difficult to relate these biomarkers to a single disease. We propose that, in addition to clinical investigations, it will be pivotal to perform comprehensive preclinical biomarker investigations in animal models of HF in order to fully reveal the potential of these novel HF biomarkers.

Emerging Actors in Diabetic Cardiomyopathy: Heartbreaker Biomarkers or Therapeutic Targets?

The diabetic heart is characterized by metabolic disturbances that are often accompanied by local inflammation, oxidative stress, myocardial fibrosis, and cardiomyocyte apoptosis. Overall changes result in contractile dysfunction, concentric left ventricular (LV) hypertrophy, and dilated cardiomyopathy, that together affect cardiac output and eventually lead to heart failure, the foremost cause of death in diabetic patients. There are currently several validated biomarkers for the diagnosis and risk assessment of cardiac diseases, but none is capable of discriminating patients with diabetic cardiomyopathy (DCM). In this review we point to several novel candidate biomarkers from new activated molecular pathways (including microRNAs) with the potential to detect or prevent DCM in its early stages, or even to treat it once established. The prospective use of selected biomarkers that integrate inflammation, oxidative stress, fibrosis, and metabolic dysregulation is widely discussed.

Galectin-3 in Atrial Fibrillation: Mechanisms and Therapeutic Implications

Maintenance of atrial fibrillation is a complex mechanism, including extensive electrical and structural remodeling of the atria which involves progressive fibrogenesis. Galectin-3 is a biomarker of fibrosis, and, thus, may be involved in atrial remodeling in atrial fibrillation patients. We review the role of galectin-3 in AF mechanisms and its potential therapeutic implications.

The effects of galectin-3 depletion apheresis on induced skin inflammation in a porcine model

Galectin-3 (Gal-3), a β-galactoside-binding lectin that is expressed in mammalian cells, is known to modulate several biological functions such as cell-cell adhesion, macrophage activation, angiogenesis, metastasis, and fibrosis. The goal of this study was to evaluate the ability of Gal-3 depletion apheresis using an adsorption column with immobilized anti-Gal-3-antibody to reduce inflammation induced by Complete Freund's Adjuvant injection in a skin inflammation porcine model. Here, we report that plasma perfusion by apheresis through a Gal-3 binding immuno-affinity column reduces plasma Gal-3 levels to below limits of quantitative detection, and results in significant decrease in skin inflammation, including degree and duration of inflammatory lesions. Human plasma was tested ex vivo and found to be efficiently depleted using the anti-Gal-3 affinity column. This study demonstrates the potential of Gal-3 depletion apheresis as a therapeutic method for inflammation-mediated disease, supporting continued research in this area for clinical application.

Ticagrelor attenuates myocardial ischaemia-reperfusion injury possibly through downregulating galectin-3 expression in the infarct area of rats

AIMS

The full benefits of myocardial revascularization strategies applied to acute myocardial infarction patients might be reduced by myocardial ischaemia and reperfusion (I/R) injury. It is known that inflammation plays an important role in the pathogenesis of I/R injury and galectin-3, a known inflammatory factor, is actively involved in ischaemia-induced inflammation and fibrosis of various organs. Previous studies demonstrated that anti-platelets therapy with ticagrelor, a new P2Y12 receptor antagonist, could effectively attenuate myocardial I/R injury and I/R injury-related inflammatory responses. It remains unknown whether the cardioprotective effects of ticagrelor are also mediated by modulating myocardial galectin-3 expression.

METHODS

We determined the ratio of infarct area (IA)/area at risk (AAR), expression of galectin-3, TNF-α and IL-6 in infarct area of rats treated with placebo (equal volume saline per gastric gavage immediately after LAD ligation, then once daily till study end) or ticagrelor (150 mg kg^-1 dissolved in saline per gastric gavage immediately after LAD ligation, then once daily till study end) at 24 h, 3 and 7 days post I (45 min)/R injury. Sham-operated rats served as control.

RESULTS

Our results showed that ticagrelor treatment significantly reduced IA/AAR ratio at 3 and 7 days post I/R, downregulated mRNA and protein expression of galectin-3, as well as mRNA expression of TNF-α and IL-6 in infarct area at 24 h, 3 and 7 days post I/R.

CONCLUSIONS

Our results suggest that the cardioprotective effects of ticagrelor might partly be mediated by downregulating galectin-3 expression in infarct area in this rat model of myocardial I/R injury.

The Predictive Value of Plasma Galectin-3 for Ards Severity and Clinical Outcome

BACKGROUND

Galectin-3 is a β-galactoside-binding lectin implicated as a mediator in a variety of inflammatory and fibrotic diseases. However, information about galectin-3 release in patients with acute respiratory distress syndrome (ARDS) is very limited. We sought to determine whether plasma galectin-3 levels were increased in ARDS patients and were associated with disease severity.

METHODS

Patients admitted to intensive care unit (ICU) within 48 h and diagnosed with ARDS were identified. In addition, healthy subjects were assigned to a control group. Plasma samples were collected from patients within 48 h after ICU admission as well as healthy subjects. Plasma galectin-3 levels were measured by enzyme-linked immunosorbent assay. The primary outcome was mortality at 28 days.

RESULTS

Sixty-three ARDS patients were identified. Among these, 27 patients died within 28 days of admission. The plasma galectin-3 levels of the patients were significantly higher than those of control subjects (median [IQR]: 12.37 [7.94-18.79] vs. 5.01 [4.15-5.69] ng/mL, respectively, P <0.0001). Furthermore, galectin-3 levels were significantly higher in non-surviving patients than in those who survived (15.38 [11.59-22.98] vs. 10.07 [7.39-15.54] ng/mL, respectively, P = 0.0136). Plasma galectin-3 levels were significantly correlated with acute physiology and chronic health evaluation II scores and arterial oxygen tension/inspiratory oxygen fraction ratios (Spearman rho = 0.44, P <0.0001 and -0.616, P <0.0001, respectively). At an optimal cutoff of 10.59 ng/mL, the sensitivity and specificity of galectin-3 for prediction of 28-day mortality were 81.48% (95% CI 0.62-0.94) and 55.56% (95% CI 0.38-0.72), respectively.

CONCLUSIONS

Higher levels of galectin-3 were significantly associated with disease severity and worse outcomes in ARDS patients.

Is galectin-3 a promoter of ventricular dysfunction?

Heart failure is nowadays a common condition associated with high mortality and increased healthcare-related costs. Over the years, the research on heart failure management has been extensive in order to better diagnose and treat the condition. Since the progression of left ventricular dysfunction is a consequence of myocardial inflammation, apopotosis, and fibrosis leading to myocardium remodelling, several molecules that are involved in the inflammation pathways have been explored as possible biomarkers for the condition. The study of biomarkers and their key roles in inflammation could allow early identification of patients with heart failure, improve prognostic assessment, and provide a target for future therapies. Among currently studied biomarkers, extensive research has been conducted on galectin-3, a galactoside-binding lectin, which is synthetised and secreted when cardiomyocytes and fibroblasts are submitted to mechanical stress. Accordingly, it has been hypothesised that galectin-3 could be a promoter of left ventricular dysfunction. Galectin-3 has been shown to mediate inflammation by several different pathways which are further detailed in the current review. Also, we aimed to provide a comprehensive overview of existing evidence on the utility of galectin-3 in clinical settings associated with heart failure.

Galectin-3 Activation and Inhibition in Heart Failure and Cardiovascular Disease: An Update

Galectin-3 is a versatile protein orchestrating several physiological and pathophysiological processes in the human body. In the last decade, considerable interest in galectin-3 has emerged because of its potential role as a biotarget. Galectin-3 is differentially expressed depending on the tissue type, however its expression can be induced under conditions of tissue injury or stress. Galectin-3 overexpression and secretion is associated with several diseases and is extensively studied in the context of fibrosis, heart failure, atherosclerosis and diabetes mellitus. Monomeric (extracellular) galectin-3 usually undergoes further "activation" which significantly broadens the spectrum of biological activity mainly by modifying its carbohydrate-binding properties. Self-interactions of this protein appear to play a crucial role in regulating the extracellular activities of this protein, however there is limited and controversial data on the mechanisms involved. We therefore summarize (recent) literature in this area and describe galectin-3 from a binding perspective providing novel insights into mechanisms by which galectin-3 is known to be "activated" and how such activation may be regulated in pathophysiological scenarios.

Galectin-3 in patients with coronary heart disease and atrial fibrillation

OBJECTIVE

To observe the change of the inflammatory factor Galectin-3 in patients with coronary heart disease, and the correlation between Galectin-3 and the severity of the disease. To observe changes of Galectin-3 in patients with atrial fibrillation (AF) before and after radiofrequency ablation, and the changes of Galectin-3 before and after an interim treatment with a high dose of atorvastatin on patients with acute myocardial infarction(AMI).

METHODS

Patients with coronary heart disease and atrial fibrillation having normal heart function were selected, among them, the patients with AMI were given a short term treatment of 80mg atorvastatin before PCI, and patients with atrial fibrillation underwent radiofrequency catheter ablation. ELISA technique was equipped to observe the Galectin-3 changes in patients with coronary heart disease and that of patients with AF before and after radiofrequency ablation.

RESULTS

Galectin-3 level of the AMI group was higher than that of the unstable angina pectoris (UAP) group, and its levels were higher than that of the stable angina pectoris (SAP) group, the differences were statistically significant among both groups (P<0.05); Galectin-3 level of multivessel coronary disease group was higher than that of single vessel group, in which a statistically significant difference was noted (P<0.05); There was no statistically significant difference associated in the drop of Galectin-3 levels in patients with AMI after PCI (P>0.05); Galectin-3 of patients with AF decreased after RFCA, but no statistical significance noted (P>0.05); Galectin-3 was negatively correlated with the LVEF value(r=-0.405, P<0.05).

CONCLUSION

Galectin-3 belongs to a class of inflammatory mediators that is associated with the degree of myocardial inflammation and fibrosis. It is related to the severity of myocardial ischemia and is negatively correlated with the cardiac ejection fraction.

Clinical Phenotyping of Heart Failure with Biomarkers: Current and Future Perspectives

INTRODUCTION

Heart failure (HF) is a complex clinical syndrome with diverse risk factors and etiologies, differing underlying pathophysiology, and large phenotypic heterogeneity.

RECENT FINDINGS

Advances in imaging techniques coupled with clinical trials that targeted only in those with impaired left ventricular ejection fraction (LVEF) have largely shaped the current management strategy for HF that focuses predominantly in patients with systolic HF. In contrast, there are no effective treatments for HF with preserved ejection fraction (HFpEF). Instead of this "one-size-fits-all" approach to treatment, better precision to define HF phenotypic classifications may lead to more efficient and effective HF disease management.

CONCLUSION

Integrating variables-including clinical variables, HF biomarkers, imaging, genotypes, metabolomics, and proteomics-can identify different pathophysiologies, lead to more precise phenotypic classification, and warrant investigation in future clinical trials.

Fibrosis-Related Gene Expression in Single Ventricle Heart Disease

OBJECTIVE

To evaluate fibrosis and fibrosis-related gene expression in the myocardium of pediatric subjects with single ventricle with right ventricular failure.

STUDY DESIGN

Real-time quantitative polymerase chain reaction was performed on explanted right ventricular myocardium of pediatric subjects with single ventricle disease and controls with nonfailing heart disease. Subjects were divided into 3 groups: single ventricle failing (right ventricular failure before or after stage I palliation), single ventricle nonfailing (infants listed for primary transplantation with normal right ventricular function), and stage III (Fontan or right ventricular failure after stage III). To evaluate subjects of similar age and right ventricular volume loading, single ventricle disease with failure was compared with single ventricle without failure and stage III was compared with nonfailing right ventricular disease. Histologic fibrosis was assessed in all hearts. Mann-Whitney tests were performed to identify differences in gene expression.

RESULTS

Collagen (Col1α, Col3) expression is decreased in single ventricle congenital heart disease with failure compared with nonfailing single ventricle congenital heart disease (P = .019 and P = .035, respectively), and is equivalent in stage III compared with nonfailing right ventricular heart disease. Tissue inhibitors of metalloproteinase (TIMP-1, TIMP-3, and TIMP-4) are downregulated in stage III compared with nonfailing right ventricular heart disease (P = .0047, P = .013 and P = .013, respectively). Matrix metalloproteinases (MMP-2, MMP-9) are similar between nonfailing single ventricular heart disease and failing single ventricular heart disease, and between stage III heart disease and nonfailing right ventricular heart disease. There is no difference in the prevalence of right ventricular fibrosis by histology in subjects with single ventricular failure heart disease with right ventricular failure (18%) compared with those with normal right ventricular function (38%).

CONCLUSIONS

Fibrosis is not a primary contributor to right ventricular failure in infants and young children with single ventricular heart disease. Additional studies are required to understand whether antifibrotic therapies are beneficial in this population.

Neurohormonal Blockade and Circulating Cardiovascular Biomarkers During Anthracycline Therapy in Breast Cancer Patients: Results From the PRADA (Prevention of Cardiac Dysfunction During Adjuvant Breast Cancer Therapy) Study

BACKGROUND

Anthracyclines are associated with cardiotoxic effects. Cardiovascular biomarkers may reflect myocardial injury, dysfunction, inflammation, and fibrosis and may precede and predict the development of left ventricular impairment. The aim of this study was to assess: (1) longitudinal change in circulating cardiovascular biomarkers, (2) the effect of metoprolol succinate and candesartan cilexetil on the biomarker response, and (3) the associations between on-treatment changes in biomarker concentrations and subsequent left ventricular dysfunction in patients with early breast cancer receiving anthracyclines.

METHODS AND RESULTS

This report encompasses 121 women included in the 2×2 factorial, placebo-controlled, double-blind PRADA (Prevention of Cardiac Dysfunction During Adjuvant Breast Cancer Therapy) trial with metoprolol and candesartan given concomitantly with anticancer therapy containing the anthracycline, epirubicin (total cumulative dose, 240-400 mg/m²). Cardiovascular magnetic resonance, echocardiography images, and circulating levels of biomarkers were obtained before and after anthracycline treatment. Cardiac troponins I and T, B-type natriuretic peptide, N-terminal pro-B-type natriuretic peptide, C-reactive protein, and galectin-3 increased during anthracycline therapy (all P<0.05). The troponin response was attenuated by metoprolol (P<0.05), but not candesartan. There was no association between change in biomarker concentrations and change in cardiac function during anthracycline therapy.

CONCLUSIONS

Treatment with contemporary anthracycline doses for early breast cancer is associated with increase in circulating cardiovascular biomarkers. This increase is, however, not associated with early decline in ventricular function. Beta-blockade may attenuate early myocardial injury, but whether this attenuation translates into reduced risk of developing ventricular dysfunction in the long term remains unclear.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrial.gov. Unique identifier: NCT01434134.

Prospective Validation of a Screening Biomarker Approach Combining Amino-Terminal Pro-Brain Natriuretic Peptide With Galectin-3 Predicts Death and Cardiovascular Events in Asymptomatic Hemodialysis Patients

Cardiovascular (CV) disease is a major cause of death in hemodialysis patients. Biomarkers used to identify high-risk asymptomatic patients would allow early evaluation of cardiac dysfunction and appropriate therapeutic intervention. Amino-terminal pro-brain natriuretic peptide (NT-proBNP) and galectin-3 (Gal-3) may serve this purpose. Plasma levels of NT-proBNP and Gal-3 were measured in 173 patients. Patients were prospectively followed for occurrences of major CV events or death. The association of NT-proBNP and Gal-3 with outcome was analyzed. The prognostic abilities for the combined outcome of Gal-3 and/or NT-proBNP were evaluated. During a median follow-up of 36 months, there were 47 incident outcomes (death and CV events). In the univariable Cox analysis, age, hypertension, albumin, phosphorus levels, and combined elevation of NT-proBNP with Gal-3 above the median (hazard ratio [HR] = 3.65, 95% confidence interval [CI] = 1.45-9.21) were associated with outcomes. In multivariable Cox analysis, both NT-proBNP and Gal-3 values above the median remained associated with outcomes (HR = 3.34, 95% CI = 1.30-8.56). In clinically asymptomatic dialysis patients, combined use of NT-proBNP and Gal-3 may improve risk stratification for death and CV events.