Galectin-3 Predicts Long-Term Cardiovascular Death in High-Risk Patients With Coronary Artery Disease

Association of serum galectin-3 with risks of death and vascular events in acute ischaemic stroke patients: the role of hyperglycemia

BACKGROUND AND PURPOSE

Whether the association between galectin-3 and stroke outcome is modified by fasting plasma glucose (FPG) is unknown. The aim was to evaluate the prognostic effect of galectin-3 amongst ischaemic stroke patients stratified by FPG.

METHODS

In all, 3082 ischaemic stroke patients were included in this study and serum galectin-3 was tested at baseline. The primary outcome was a composite outcome of death and vascular events, and secondary outcomes were death, stroke recurrence and vascular events within 1 year after stroke.

RESULTS

Increased galectin-3 was significantly associated with the primary outcome, stroke recurrence and vascular events in the patients with hyperglycemia but not in those with normoglycemia (P for interaction < 0.05 for all). The multivariate-adjusted hazard ratios (95% confidence intervals) were 1.72 (1.05-2.84), 2.64 (1.14-6.12) and 2.68 (1.33-5.38) for the primary outcome, stroke recurrence and vascular events, respectively. A linear association between galectin-3 and the primary outcome was observed in hyperglycemic patients (P for linearity = 0.007).

CONCLUSION

Increased galectin-3 was associated with the primary outcome, stroke recurrence and vascular events within 1 year after stroke in the patients with hyperglycemia, suggesting that galectin-3 may be an important prognostic factor for ischaemic stroke patients with hyperglycemia.

Mineralocorticoid Receptor and Aldosterone-Related Biomarkers of End-Organ Damage in Cardiometabolic Disease

The mineralocorticoid receptor (MR) was first identified as a blood pressure regulator, modulating renal sodium handling in response to its principal ligand aldosterone. The mineralocorticoid receptor is also expressed in many tissues other than the kidney, such as adipose tissue, heart and vasculature. Recent studies have shown that MR plays a relevant role in the control of cardiovascular and metabolic function, as well as in adipogenesis. Dysregulation of aldosterone/MR signaling represents an important cause of disease as high plasma levels of aldosterone are associated with hypertension, obesity and increased cardiovascular risk. Aldosterone displays powerful vascular effects and acts as a potent pro-fibrotic agent in cardiovascular remodeling. Mineralocorticoid receptor activation regulates genes involved in vascular and cardiac fibrosis, calcification and inflammation. This review focuses on the role of novel potential biomarkers related to aldosterone/MR system that could help identify cardiovascular and metabolic detrimental conditions, as a result of altered MR activation. Specifically, we discuss: (1) how MR signaling regulates the number and function of different subpopulations of circulating and intra-tissue immune cells; (2) the role of aldosterone/MR system in mediating cardiometabolic diseases induced by obesity; and (3) the role of several MR downstream molecules as novel potential biomarkers of cardiometabolic diseases, end-organ damage and rehabilitation outcome.

Multi-biomarker analysis in patients after transcatheter aortic valve implantation (TAVI)

BACKGROUND

In this study we sought to examine whether transcatheter aortic valve implantation (TAVI) is followed by a change in the plasma levels of novel cardiovascular biomarkers.

METHODS

We collected blood samples of 79 patients with severe aortic valve stenosis undergoing TAVI before and at 7 days, 1 month, 3 months and 6 months post TAVI and analyzed the plasma concentrations of GDF-15, H-FABP, fetuin-A, galectin 3, sST2 and suPAR by means of ELISA.

RESULTS

There was a significant increase in the concentration of fetuin-A (median: 52.44 mg/ml to 113.2 mg/ml, p < 0.001) and a significant decrease of H-FABP after TAVI (median: 4.835 ng/ml to 2.534 ng/ml, p < 0.001). The concentrations of suPAR and sST2 showed an initial increase (suPAR median: 2755 pg/ml 3489 pg/ml, p < 0.001; sST2 median: 5832 pg/ml to 7137 pq/ml, p < 0.001) and subsequently decreased significantly.

CONCLUSION

We hypothesize that the decrease of H-FABP and the increase of fetuin-A could be due to a hemodynamic improvement after valve replacement. The initial increase of suPAR could indicate an inflammatory stimulus and the significant increase in sST2 could be due to the mechanical strain caused by implantation of the valve.

GDF-15, Galectin 3, Soluble ST2, and Risk of Mortality and Cardiovascular Events in CKD

RATIONALE & OBJECTIVE

Inflammation, cardiac remodeling, and fibrosis may explain in part the excess risk for cardiovascular disease (CVD) in patients with chronic kidney disease (CKD). Growth differentiation factor 15 (GDF-15), galectin 3 (Gal-3), and soluble ST2 (sST2) are possible biomarkers of these pathways in patients with CKD.

STUDY DESIGN

Observational cohort study.

SETTING & PARTICIPANTS

Individuals with CKD enrolled in either of 2 multicenter CKD cohort studies: the Seattle Kidney Study or C-PROBE (Clinical Phenotyping and Resource Biobank Study).

EXPOSURES

Circulating GDF-15, Gal-3, and sST2 measured at baseline.

OUTCOMES

Primary outcome was all-cause mortality. Secondary outcomes included hospitalization for physician-adjudicated heart failure and the atherosclerotic CVD events of myocardial infarction and cerebrovascular accident.

ANALYTIC APPROACH

Cox proportional hazards models used to test the association of each biomarker with each outcome, adjusting for demographics, CVD risk factors, and kidney function.

RESULTS

Among 883 participants, mean estimated glomerular filtration rate was 49±19mL/min/1.73m². Higher GDF-15 (adjusted HR [aHR] per 1-SD higher, 1.87; 95% CI, 1.53-2.29), Gal-3 (aHR per 1-SD higher, 1.51; 95% CI, 1.36-1.78), and sST2 (aHR per 1-SD higher, 1.36; 95% CI, 1.17-1.58) concentrations were significantly associated with mortality. Only GDF-15 level was also associated with heart failure events (HR per 1-SD higher, 1.56; 95% CI, 1.12-2.16). There were no detectable associations between GDF-15, Gal-3, or sST2 concentrations and atherosclerotic CVD events.

LIMITATIONS

Event rates for heart failure and atherosclerotic CVD were low.

CONCLUSIONS

Adults with CKD and higher circulating GDF-15, Gal-3, and sST2 concentrations experienced greater mortality. Elevated GDF-15 concentration was also associated with an increased rate of heart failure. Further work is needed to elucidate the mechanisms linking these circulating biomarkers with CVD in patients with CKD.

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.

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.

The Therapeutic Potential of Blocking Galectin-3 Expression in Acute Myocardial Infarction and Mitigating Inflammation of Infarct Region: A Clinical Outcome-Based Translational Study

Introduction

Increased galectin-3 is associated with ischemic cardiomyopathy, although its role in early remodeling post-myocardial infarction (MI) has not been fully elucidated. There are no data demonstrating that blocking galectin-3 expression would have an impact on the heart and that its relationship to remodeling is not simply an epiphenomenon. The direct association between galectin-3 and myocardial inflammation, dysfunction, and adverse cardiovascular outcomes post-MI was examined using clinical and translational studies.

Methods

We performed expression analysis of 9753 genes in murine model of acute MI. For galectin-3 loss of function studies, homozygous galectin-3 knock-out (KO) mice were subjected to coronary artery ligation procedure to induce acute MI (MI, N = 6; Sham, N = 6). For clinical validation, serum galectin-3 levels were measured in 96 patients with ST-elevation MI. Echocardiographic and angiographic parameters of myocardial dysfunction and 3-month composite outcome including mortality, recurrent MI, stroke, and heart failure hospitalization were measured.

Results

In the infarct regions of murine models, galectin-3 was a robustly expressed gene. Elevated galectin-3 expression strongly correlated with macrophage-mediated genes. Galectin-3 KO mice showed reduced myocardial macrophage infiltration after acute MI. Galectin-3 levels were higher in patients with early systolic dysfunction, and predicted 3-month major adverse cardiovascular events (area under the curve [AUC]: 0.917 ± 0.063; P = .001).

Conclusions

Galectin-3 is directly associated with early myocardial inflammation post-MI and may represent a potential target for therapeutic inhibition.

Analysis of novel cardiovascular biomarkers in patients with peripheral artery disease

BACKGROUND

Peripheral artery disease (PAD) is a common form of manifestation of atherosclerosis. PAD has a considerable impact on morbidity, hospitalization rates and health-care costs. Biomarkers have been introduced in many cardiovascular disease entities over the last years. However, an analysis on the correlation of biomarker levels and PAD is still lacking.

METHODS

A total of 106 patients were enrolled in this current study, 51 that were diagnosed with PAD and 55 with excluded coronary and peripheral artery disease as controls. During outpatient visits, plasma samples of all patients were obtained and analyzed for sST2 (hemodynamics and inflammation), galectin-3 (fibrosis and remodeling), GDF-15 (remodeling and inflammation), suPAR (inflammation), and fetuin-A (vascular calcification) by use of ELISA after informed consent.

RESULTS

Compared with controls, patients with PAD showed significantly higher levels of sST2 (5248 vs. 7503 pg/mL, P<0.001), suPAR (2267 vs. 2414 pg/mL, P=0.02), galectin-3 (2795 vs. 4494 pg/mL, P<0.001), and GDF-15 (549 vs. 767 pg/mL, P<0.001). Fetuin-A showed a trend towards lower levels in patients with PAD (117 vs. 100 ng/mL, P=0.119).

CONCLUSIONS

Circulating levels of sST2, suPAR, galectin-3, and GDF-15 were significantly elevated in PAD patients. In contrast, fetuin-A levels showed a decrease in PAD patients indicating increased vascular calcification. Thus, by incorporating different pathophysiological processes present in PAD, tested novel biomarkers facilitate a more precise diagnosis as well as a more accurate evaluation of disease severity and progression.

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.

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.

Serum Galectin-3 and Poor Outcomes Among Patients With Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Elevated galectin-3 has been associated with atherosclerosis and poor outcomes in patients with heart failure. However, it remains unclear whether galectin-3 has any effect on the poor outcomes of ischemic stroke. The aim of the present study was to examine the association between galectin-3 with poor outcomes among patients with acute ischemic stroke.

METHODS

Serum galectin-3 was measured in 3082 patients with acute ischemic stroke. The primary outcome was a combination of death or major disability (modified Rankin Scale score, ≥3) at 3 months after stroke.

RESULTS

Compared with the lowest quartile of galectin-3, multivariate adjusted odds ratios (95% confidence intervals) for the highest quartile of galectin-3 were 1.55 (1.15-2.09) for composite outcome, 2.10 (0.89-4.95) for death, and 1.43 (1.05-1.93) for major disability. The addition of galectin-3 to the conventional risk factors significantly improved prediction of the combined outcome of death or major disability in patients with ischemic stroke (net reclassification index, 18.9%; P<0.001; integrated discrimination improvement, 0.4%; P=0.001).

CONCLUSIONS

Higher levels of serum galectin-3 were independently associated with increased risk of death or major disability after stroke onset, suggesting that galectin-3 may have prognostic value in poor outcomes of ischemic stroke.

Galectin-3 as a novel biomarker for disease diagnosis and a target for therapy (Review)

Galectin-3 is a member of the galectin family, which are β‑galactoside‑binding lectins with ≥1 evolutionary conserved carbohydrate‑recognition domain. It binds proteins in a carbohydrate‑dependent and ‑independent manner. Galectin‑3 is predominantly located in the cytoplasm; however, it shuttles into the nucleus and is secreted onto the cell surface and into biological fluids including serum and urine. It serves important functions in numerous biological activities including cell growth, apoptosis, pre‑mRNA splicing, differentiation, transformation, angiogenesis, inflammation, fibrosis and host defense. Numerous previous studies have indicated that galectin‑3 may be used as a diagnostic or prognostic biomarker for certain types of heart disease, kidney disease and cancer. With emerging evidence to support the function and application of galectin‑3, the current review aims to summarize the latest literature regarding the biomarker characteristics and potential therapeutic application of galectin‑3 in associated diseases.

Galectin-3: an emerging biomarker in stroke and cerebrovascular diseases

The carbohydrate-binding molecule galectin-3 has garnered significant attention recently as a biomarker for various conditions ranging from cardiac disease to obesity. Although there have been several recent studies investigating its role in stroke and other cerebrovascular diseases, awareness of this emerging biomarker in the wider neurology community is limited. We performed a systematic search in PubMed, Embase, Scopus, CINAHL, Clinicaltrials.gov and the Cochrane library in November and December 2016 for articles related to galectin-3 and cerebrovascular disease. We included both human and pre-clinical studies in order to provide a comprehensive view of the state of the literature on this topic. The majority of the relevant literature focuses on stroke, cerebral ischemia and atherosclerosis, but some recent attention has also been devoted to intracranial and subarachnoid hemorrhage. Higher blood levels of galectin-3 correlate with worse outcomes in atherosclerotic disease as well as in intracranial and subarachnoid hemorrhage in human studies. However, experimental evidence supporting the role of galectin-3 in these phenotypes is not as robust. It is likely that the role of galectin-3 in the inflammatory cascade within the central nervous system following injury is responsible for many of its effects, but its varied physiological functions and multiple sites of expression mean that it may have different effects depending on the nature of the disease condition and the time since injury. In summary, experimental and human research raises the possibility that galectin-3, which is closely linked to the inflammatory cascade, could be of value as a prognostic marker and therapeutic target in cerebrovascular disease.

The Association between Galectin-3 and hs-CRP and the Clinical Outcome after Non-ST-Elevation Myocardial Infarction with Preexisting Atrial Fibrillation

Increased galectin-3 plasma concentration has been linked to an unfavorable outcome in patients with heart failure or atrial fibrillation (AF). There are no published data about the prognostic utility of galectin-3 and high-sensitivity C-reactive protein (hs-CRP) for long-term clinical outcome in the Non-ST elevation acute myocardial infarction (NSTEMI) patients with preexisting AF. Thirty-two patients with the first acute NSTEMI and preexisting AF and 22 patients without preexisting AF, were prospectively followed for fifteen months. Patients with AF had significantly higher galectin-3 plasma levels (p < 0.05) and hs-CRP concentration (p < 0.01), compared with patients without AF. Galectin-3 plasma concentration was not a significant covariate of the composite outcomes (p = 0.913). Patients with high hs-CRP (above 4.55 mg/L) showed 2.5 times increased risk (p < 0.05) of the composite outcome occurrence (p < 0.05). Besides, three-vessel coronary artery disease, creatinine serum level, and creatinine clearance were significant covariates (p < 0.05; p < 0.05; p < 0.01) of the composite outcome, respectively. Creatinine clearance, solely, has been shown to be an independent predictor of unfavorable prognosis after a 15-month follow-up. Galectin-3 and hs-CRP plasma levels were elevated in NSTEMI patients with AF, but with differential predictive value for an unfavorable clinical outcome. Only hs-CRP was associated with increased risk of composite outcome occurrence.

Increased galectin-3 levels are associated with abdominal aortic aneurysm progression and inhibition of galectin-3 decreases elastase-induced AAA development

Abdominal aortic aneurysm (AAA) evolution is unpredictable and no specific treatment exists for AAA, except surgery to prevent aortic rupture. Galectin-3 has been previously associated with CVD, but its potential role in AAA has not been addressed. Galectin-3 levels were increased in the plasma of AAA patients (n=225) compared with the control group (n=100). In addition, galectin-3 concentrations were associated with the need for surgical repair, independently of potential confounding factors. Galectin-3 mRNA and protein expression were increased in human AAA samples compared with healthy aortas. Experimental AAA in mice was induced via aortic elastase perfusion. Mice were treated intravenously with the galectin-3 inhibitor modified citrus pectin (MCP, 10 mg/kg, every other day) or saline. Similar to humans, galectin-3 serum and aortic mRNA levels were also increased in elastase-induced AAA mice compared with control mice. Mice treated with MCP showed decreased aortic dilation, as well as elastin degradation, vascular smooth muscle cell (VSMC) loss, and macrophage content at day 14 postelastase perfusion compared with control mice. The underlying mechanism(s) of the protective effect of MCP was associated with a decrease in galectin-3 and cytokine (mainly CCL5) mRNA and protein expression. Interestingly, galectin-3 induced CCL5 expression by a mechanism involving STAT3 activation in VSMC. Accordingly, MCP treatment decreased STAT3 phosphorylation in elastase-induced AAA. In conclusion, increased galectin-3 levels are associated with AAA progression, while galectin-3 inhibition decreased experimental AAA development. Our data suggest the potential role of galectin-3 as a therapeutic target in AAA.

Do ANGPTL-4 and galectin-3 reflect the severity of coronary artery disease?

BACKGROUND

Coronary artery disease (CAD) is one of the leading causes of mortality and morbidity worldwide. We thereby sought to investigate whether the biomarkers, angiopoietin-like 4 (ANGPTL-4) and galectin-3, reflect the severity of CAD.

METHODS

Patients were screened based on inclusion/exclusion criteria and written informed consent was obtained from the patients. Serum ANGPTL-4 and galectin-3 was quantified using enzyme-linked immunosorbent assay (ELISA) and correlated with the Global Registry of Acute Coronary Events (GRACE) and GENSINI score using Spearman's rank correlation coefficient and multivariate analysis.

RESULTS

A total of 226 patients consisting of ST-segment elevation myocardial infarction (STEMI), non-STEMI/unstable angina (USA), chronic stable angina (CSA) and normal controls (NCs) participated in the study. ANGPTL-4 and galectin-3 were significantly higher in CAD than the NC group. ANGPTL-4 showed significant negative correlation with GRACE score in acute coronary syndrome (ACS) ( r = -0.211, p = 0.03) patients. ANGPTL-4 showed significant positive correlation with serum creatinine ( r = 0.304, p = 0.056) and body mass index (BMI) ( r = 0.424, p = 0.009) in CSA patients. A modest positive correlation was observed between the serum galectin-3 levels and GRACE score ( r = 0.187, p = 0.055) in ACS patients. However, on multivariate analysis the positive correlation relationship between ANGPTL-4 and galectin-3 with the severity of CAD was not sustained.

CONCLUSION

In conclusion, ANGPTL-4 and galectin-3 do not appear to have a promising role for assessing the severity of CAD. Nevertheless these biomarkers do warrant further exploration in improving the management of CAD.

Cardiac Fibrosis and Arrhythmogenesis

Myocardial injury, mechanical stress, neurohormonal activation, inflammation, and/or aging all lead to cardiac remodeling, which is responsible for cardiac dysfunction and arrhythmogenesis. Of the key histological components of cardiac remodeling, fibrosis either in the form of interstitial, patchy, or dense scars, constitutes a key histological substrate of arrhythmias. Here we discuss current research findings focusing on the role of fibrosis, in arrhythmogenesis. Numerous studies have convincingly shown that patchy or interstitial fibrosis interferes with myocardial electrophysiology by slowing down action potential propagation, initiating reentry, promoting after-depolarizations, and increasing ectopic automaticity. Meanwhile, there has been increasing appreciation of direct involvement of myofibroblasts, the activated form of fibroblasts, in arrhythmogenesis. Myofibroblasts undergo phenotypic changes with expression of gap-junctions and ion channels thereby forming direct electrical coupling with cardiomyocytes, which potentially results in profound disturbances of electrophysiology. There is strong evidence that systemic and regional inflammatory processes contribute to fibrogenesis (i.e., structural remodeling) and dysfunction of ion channels and Ca2+ homeostasis (i.e., electrical remodeling). Recognizing the pivotal role of fibrosis in the arrhythmogenesis has promoted clinical research on characterizing fibrosis by means of cardiac imaging or fibrosis biomarkers for clinical stratification of patients at higher risk of lethal arrhythmia, as well as preclinical research on the development of antifibrotic therapies. At the end of this review, we discuss remaining key questions in this area and propose new research approaches. © 2017 American Physiological Society. Compr Physiol 7:1009-1049, 2017.

Alterations to adipose tissue morphology during inflammatory arthritis is indicative of vasculopathology in DBA/1 mice

The physiologic function of adipose tissue is altered by the host's inflammatory response; the implications for maintaining human health and regulating inflammation-associated disease progression are ill defined. However, this cannot be investigated in humans, therefore the use of animal models is required. With the aim to determine morphological and molecular alterations to perivascular and organ-associated adipose tissues during inflammatory arthritis, collagen-induced arthritis (CIA) was established in male DBA/1 mice. Emerging evidence from this study signposts CIA in the DBA/1 mouse as a model that is relevant to study the development and treatment of early cardiovascular pathology associated with inflammatory arthritis. Here, we show global morphological changes in adipose tissue and the thoracic aorta in animals induced with CIA compared with the non-immunized controls. In CIA, we concluded that the increased cell count in PVAT was, at least in part, caused by an ingress and/or expansion of macrophages that had a mixed phenotype. A substantial increase of galectin-3 was expressed in PVAT from mice with CIA. Galectin-3 is elevated in the blood of patients with CVDs, however, it has never before been measured in PVAT in rodents or humans. Here, PVAT-associated galectin-3 is identified as a potential biomarker for detecting early vascular pathology in CIA and a promising candidate for translation to RA.

Serum levels of galectin-1, galectin-3, and galectin-9 are associated with large artery atherosclerotic stroke

The aim of this study was to assess the expression patterns of serum galectin-1 (Gal-1), galectin-3 (Gal-3), galectin-9 (Gal-9), and galectin-3 binding protein (Gal-3BP) and their associations with stroke outcome in large artery atherosclerotic (LAA) stroke. The serum levels of Gal-1, Gal-3, Gal-9, and Gal-3BP were measured by ELISA in 130 patients with LAA stroke and 130 age- and sex-matched controls. Serum samples were collected from the patients on day 1, day 6, and in the 4th week after ischaemic stroke (IS). An unfavourable outcome was defined as a modified Rankin Scale score of >2 on day 90 after IS. Our results indicated that the Gal-3 and Gal-9 levels were higher in patients with LAA stroke than in controls. A higher Gal-3 level was independently associated with an unfavourable outcome both on day 1 and day 6 after IS. In addition, Gal-9 and Gal-1 levels were upregulated on day 6 and in the 4th week after IS, respectively. For Gal-3BP, no difference was detected between patients and controls and no predictive value was found in patients. In conclusion, these findings suggest that the serum levels of Gal-1, Gal-3, and Gal-9 may be associated with LAA stroke.

Meta-Analysis of the Usefulness of Plasma Galectin-3 to Predict the Risk of Mortality in Patients With Heart Failure and in the General Population

Galectin-3 is an emerging biomarker of myocardial fibrosis, inflammation, and immune response. We sought to examine the relation of plasma galectin-3 with cardiovascular (CVD) mortality, all-cause mortality, and incident heart failure (HF). We performed a literature search for all relevant publications using Ovid MEDLINE, Google Scholar, and other databases up to January 2016. Two reviewers independently extracted data and assessed risk of bias. We extracted hazard ratios (HRs) from regression models that adjusted for age, gender, race, body mass index, smoking, hypertension, hyperlipidemia, diabetes, natriuretic peptides, and renal function, when available. A total of 18 studies with 32,350 participants (323,090 person-years of follow-up) met criteria for analysis. The mean age was 57.3 years and 47.2% of participants were women, with a follow-up duration median of 5 years, interquartile range: 2.9 to 10 years. Of the 18 studies, 13 (72%) adjusted for N-terminal probrain natriuretic peptide and renal function in the multivariable adjusted models. Using a random-effects meta-analysis, we found an HR of 1.10 (95% CI 1.05 to 1.14) for all-cause mortality, 1.22 (95% CI 1.05 to 1.39) for CVD mortality, and 1.12 (95% CI 1.04 to 1.21) for HF risk for each 1 SD increase in galectin-3 level. In a subgroup analysis of CVD mortality, the HR was 1.44 (1.09 to 1.79) for patients with HF and 1.09 (0.91 to 1.27) for the general population. In conclusion, our results suggest that elevated plasma galectin-3 is associated with a higher risk of all-cause mortality, CVD mortality, and HF. It may add prognostic value beyond that provided by traditional CVD risk factors.

Cohort profile of BIOMArCS: the BIOMarker study to identify the Acute risk of a Coronary Syndrome-a prospective multicentre biomarker study conducted in the Netherlands

PURPOSE

Progression of stable coronary artery disease (CAD) towards acute coronary syndrome (ACS) is a dynamic and heterogeneous process with many intertwined constituents, in which a plaque destabilising sequence could lead to ACS within short time frames. Current CAD risk assessment models, however, are not designed to identify increased vulnerability for the occurrence of coronary events within a precise, short time frame at the individual patient level. The BIOMarker study to identify the Acute risk of a Coronary Syndrome (BIOMArCS) was designed to evaluate whether repeated measurements of multiple biomarkers can predict such 'vulnerable periods'.

PARTICIPANTS

BIOMArCS is a multicentre, prospective, observational study of 844 patients presenting with ACS, either with or without ST-elevation and at least one additional cardiovascular risk factor.

METHODS AND ANALYSIS

We hypothesised that patterns of circulating biomarkers that reflect the various pathophysiological components of CAD, such as distorted lipid metabolism, vascular inflammation, endothelial dysfunction, increased thrombogenicity and ischaemia, diverge in the days to weeks before a coronary event. Divergent biomarker patterns, identified by serial biomarker measurements during 1-year follow-up might then indicate 'vulnerable periods' during which patients with CAD are at high short-term risk of developing an ACS. Venepuncture was performed every fortnight during the first half-year and monthly thereafter. As prespecified, patient enrolment was terminated after the primary end point of cardiovascular death or hospital admission for non-fatal ACS had occurred in 50 patients. A case-cohort design will explore differences in temporal patterns of circulating biomarkers prior to the repeat ACS.

FUTURE PLANS AND DISSEMINATION

Follow-up and event adjudication have been completed. Prespecified biomarker analyses are currently being performed and dissemination through peer-reviewed publications and conference presentations is expected from the third quarter of 2016. Should identification of a 'vulnerable period' prove to be feasible, then future research could focus on event reduction through pharmacological or mechanical intervention during such periods of high risk for ACS.

TRIAL REGISTRATION NUMBER

NTR1698 and NTR1106.

Myocardial and Serum Galectin-3 Expression Dynamics Marks Post-Myocardial Infarction Cardiac Remodelling

BACKGROUND

Acute myocardial infarction (MI) causes significant changes in cardiac morphology and function. Galectin-3 is a novel and potentially therapeutically important mediator of cardiac remodelling. Myocardial and serum galectin-3 expression dynamics in response to the early cardiovascular outcomes after acute MI are not fully elucidated.

METHODS

We first performed a comprehensive longitudinal microarray analyses in mice after acute MI. We then measured the serum levels of galectin-3 in a translational porcine model of coronary microembolism-induced post-ischaemic cardiac remodelling. We validated our pre-clinical studies in humans by measuring serum galectin-3 levels of 52 patients with acute ST-elevation MI (STEMI) and 11 healthy controls. We analysed galectin-3 data in relation to the development of major adverse cardiovascular outcomes (MACO).

RESULTS

Of the 9,753 genes profiled at infarcted and remote myocardium at eight different time points, dynamic myocardial overexpression of galectin-3 mRNA was detected. In a pig model of diffuse myocardial damage and cardiac remodelling, galectin-3 localised to the areas of tissue damage and myocardial fibrosis, with proportionate increase of their serum galectin-3 expression levels. In humans, increased serum galectin-3 level was associated with in-hospital MACO.

CONCLUSIONS

In this translational study, we demonstrated that galectin-3 is dynamically overexpressed in response to acute MI-induced cardiac remodelling. Elevated galectin-3 levels are associated with the development of in-hospital MACO.

Vascular proteomics in metabolic and cardiovascular diseases

The vasculature is essential for proper organ function. Many pathologies are directly and indirectly related to vascular dysfunction, which causes significant morbidity and mortality. A common pathophysiological feature of diseased vessels is extracellular matrix (ECM) remodelling. Analysing the protein composition of the ECM by conventional antibody-based techniques is challenging; alternative splicing or post-translational modifications, such as glycosylation, can mask epitopes required for antibody recognition. By contrast, proteomic analysis by mass spectrometry enables the study of proteins without the constraints of antibodies. Recent advances in proteomic techniques make it feasible to characterize the composition of the vascular ECM and its remodelling in disease. These developments may lead to the discovery of novel prognostic and diagnostic markers. Thus, proteomics holds potential for identifying ECM signatures to monitor vascular disease processes. Furthermore, a better understanding of the ECM remodelling processes in the vasculature might make ECM-associated proteins more attractive targets for drug discovery efforts. In this review, we will summarize the role of the ECM in the vasculature. Then, we will describe the challenges associated with studying the intricate network of ECM proteins and the current proteomic strategies to analyse the vascular ECM in metabolic and cardiovascular diseases.

Prognostic Utility of Galectin-3 for Recurrent Cardiovascular Events During Long-term Follow-up in Patients with Stable Coronary Heart Disease: Results of the KAROLA Study

BACKGROUND

Galectin-3 has emerged as a potential useful novel biomarker for heart failure and cardiovascular disease (CVD). However, it remains unclear whether galectin-3 is associated with recurrent cardiovascular events during long-term follow-up of patients with stable coronary heart disease (CHD) after adjustment for multiple established and novel risk factors.

METHODS

We measured galectin-3 at baseline in a cohort consisting of 1035 CHD patients and followed them for 13 years to assess a combined CVD end point. Moreover, we adjusted for multiple traditional and novel risk factors.

RESULTS

Galectin-3 concentration was positively associated with the number of affected coronary arteries, history of heart failure, and multiple traditional risk factors. Also, galectin-3 correlated significantly with emerging risk factors [e.g., cystatin C, N-terminal pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity (hs)-troponin]. During follow-up (median 12.0 years), 260 fatal and nonfatal CVD events occurred. The top quartile of galectin-3 concentration was significantly associated with CVD events compared to the bottom quartile after adjustment for age and sex [hazard ratio (HR) 1.88 (95% CI, 1.30-2.73), P = 0.001 for trend] as well as for established CVD risk factors (HR 1.67, 95% CI, 1.14-2.46, P = 0.011 for trend). However, after adjustment for other biomarkers available [including eGFR (estimated glomerular filtration rate), sST2 protein, GDF-15 (growth differentiation factor 15), NT-proBNP, and hs-troponin], the association was no longer statistically significant [HR 1.11 (95% CI 0.72-1.70), P = 0.82 for trend].

CONCLUSIONS

Galectin-3 does not independently predict recurrent cardiovascular events in patients with established CHD after adjustment for markers of hemodynamic stress, myocardial injury, inflammation, and renal dysfunction.

Prognostic biomarkers in acute coronary syndrome

The acute coronary syndrome (ACS) is a leading cause of death around the globe. Beside a still high mortality rate, additional complications of ACS include arrhythmias, left ventricular mural thrombus, cardiac fibrosis, heart failure (HF), cardiogenic shock, mitral valve dysfunction, aneurysms, up to cardiac rupture. Despite many prognostic tools have been developed over the past decades, efforts are still ongoing to identify reliable and predictive biomarkers, which may help predict the prognosis of these patients and especially the risk of HF. Recent evidence suggests that the value of a discrete number of biomarkers of myocardial fibrosis, namely the soluble form of suppression of tumorigenicity 2 (sST2) and galectin-3 (GAL-3), may be predictive of HF and death in patients with ACS. Interestingly, the already promising predictive value of these biomarkers when measured alone was shown to be consistently magnified when combined with other and well-established cardiac biomarkers such natriuretic peptides and cardiac troponins. This article is hence aimed to review the current knowledge about cardiac biomarkers of fibrosis and adverse remodeling.

Soluble galectin-3 is associated with premature myocardial infarction

BACKGROUND

Inflammatory responses are pivotal in the initiation and development of premature atherosclerotic lesions. Galectin-3 represents a valuable biomarker for both progression and destabilization of atherosclerotic lesions. This study aims to assess the involvement of galectin-3 in premature myocardial infarction.

DESIGN

In this multicentre case-control study, we assessed circulating galectin-3 levels in 144 patients comprising 72 consecutive survivors of acute myocardial infarction (≤ 40 years) and 72 hospital controls frequency matched for age, gender and centre.

RESULTS

Patients with acute myocardial infarction showed significantly higher galectin-3 levels as compared to controls in the acute phase of acute myocardial infarction (2552 ± 1992 vs. 1666 ± 829 pg/mL; P < 0·001) as well as in the stable phase 1 year after the index event (3692 ± 1774 vs. 1666 ± 829 pg/mL; P < 0·001). Circulating galectin-3 was significantly and independently associated with premature myocardial infarction in the logistic regression analysis (acute phase: adj. OR per 1-SD change 2·03, 95% CI 1·30-3·19; P = 0·002; stable phase: adj. OR of 6·54 (95% CI 2·56-16·68; P < 0·001). Moreover, we observed a significant correlation between circulating galectin-3 and leucocyte count (r = 0·35, P < 0·001), non-HDL cholesterol (r = 0·23, P = 0·014) and HDL cholesterol (r = -0·29, P = 0·002).

CONCLUSION

We demonstrated that elevated levels of circulating galectin-3 are strongly associated with premature myocardial infarction. Galectin-3 might serve as link between dyslipidaemia as driving force of plaque formation with inflammation as initiator of plaque rupture in patients with premature acute myocardial infarction.

Circulating Galectin-3 Levels Are Increased in Patients with Ischemic Heart Disease, but Are Not Influenced by Acute Myocardial Infarction

OBJECTIVES

Galectin-3 (Gal-3) is involved in cardiac inflammation and fibrosis, and is in use as a biomarker that indicates increased risk in heart failure. This study examined the relationship between Gal-3 levels and acute and old myocardial infarction (MI) in patients assessed by cardiac magnetic resonance (CMR) imaging.

METHODS

Group 1 consisted of 38 patients with ST-elevation MI and single-vessel disease treated with primary percutaneous coronary intervention (PCI). Group 2 consisted of 52 patients with prior complicated MI. Twenty-two controls were included. CMR was performed in group 1 at 2 days, 1 week, 2 months and 1 year following PCI and in group 2 at >4 years after MI.

RESULTS

Median Gal-3 was elevated in patients compared with controls, group 1: 11.93 ng/ml (IQR 6.34-17.52, p = 0.03), group 2: 12.96 (IQR 6.33-19.29, p = 0.03) and controls: 10.16 (IQR 5.59-14.73). Gal-3 levels did not change during acute MI, and there was no relationship between Gal-3 and infarct size, troponin-T, high-sensitivity C-reactive protein, left-ventricular (LV) volumes or LV ejection fraction (LVEF) in group 1. In group 2, Gal-3 correlated modestly with MI size (r = 0.28, p < 0.05), LV end-diastolic volume index (r = 0.40, p < 0.01), LV end-systolic volume index (r = 0.43, p < 0.01) and LVEF (r = -0.39, p < 0.01).

CONCLUSION

There was no relationship between Gal-3 levels and acute ischemic myocardial injury. A significant, modest relationship between Gal-3 levels, MI size and LV remodeling was only found in patients with old MI.

Association between serum galectin-3 levels and coronary atherosclerosis and plaque burden/structure in patients with type 2 diabetes mellitus

BACKGROUND

Levels of galectin-3, a member of a family of soluble β-galactoside-binding lectins, are reported to be higher in patients with type 2 diabetes mellitus (DM) and metabolic syndrome. Conflicting results exist on the effects of galectin-3 in diabetic patients. The aim of this study was to investigate the relationship between galectin-3 levels and coronary artery disease (CAD), coronary plaque burden, and plaque structures in patients with type 2 DM.

PATIENTS AND METHODS

A total of 158 consecutive patients with type 2 DM undergoing planned coronary computed tomography angiography (CCTA) were included in this study. The study population was divided into CAD and non-CAD groups according to the presence of CCTA-determined coronary atherosclerosis.

RESULTS

Galectin-3 concentrations were significantly higher in the CAD group than in the non-CAD group (1412.0 ± 441.7 vs. 830.2 ± 434.9 pg/ml, P < 0.001). Galectin-3 levels were correlated positively with BMI, high-sensitivity C-reactive protein, the total number of diseased vessels, the number of plaques (all, P < 0.001), and the calcified plaque type (P = 0.001). In addition, galectin-3 levels were found to be a significant independent predictor of coronary atherosclerosis in type 2 diabetic patients (P = 021; odds ratio, 1.002; 95% confidence interval, 1.000-1.003).

CONCLUSION

Galectin-3 is a novel, promising biomarker that may help identify type 2 diabetic patients who may require early CAD intervention because of the potential risk of coronary atherosclerosis.

Short- and Long-term Biologic Variability of Galectin-3 and Other Cardiac Biomarkers in Patients with Stable Heart Failure and Healthy Adults

BACKGROUND

Galectin-3 (Gal-3) has been suggested as a prognostic biomarker in heart failure (HF) patients that may better reflect disease progression than traditional markers, including B-type natriuretic peptide (BNP) and cardiac troponins. To fully establish the utility of any biomarker in HF, its biologic variability must be characterized.

METHODS

To assess biologic variability, 59 patients were prospectively recruited, including 23 male and 16 female patients with stable HF and 10 male and 10 female healthy individuals. Gal-3, BNP, and high-sensitivity cardiac troponin I (hs-cTnI) were assayed at 5 time points within a 3-week period to assess short-term biologic variability. Long-term (3-month) biologic variability was assessed with samples collected at enrollment and after 4, 8, and 12 weeks.

RESULTS

Among healthy individuals, mean short-term biologic variability, expressed as intraindividual CV (CVI), was 4.5% for Gal-3, 29.0% for BNP, and 14.5% for hs-cTnI; long-term biologic variability was 5.5% for Gal-3, 34.7% for BNP, and 14.7% for hs-cTnI. In stable HF patients, mean short-term biologic variability was 7.1% for Gal-3, 22.5% for BNP, and 8.5% for hs-cTnI, and mean long-term biologic variability was 7.7% for Gal-3, 27.6% for BNP, and 9.6% for hs-cTnI.

CONCLUSIONS

The finding that Gal-3 has minimal intraindividual biological variability adds to its potential as a useful biomarker in HF patients.

Circulating Galectin-3 Is Associated With Cardiometabolic Disease in the Community

BACKGROUND

Circulating Galectin-3 (Gal-3) concentrations are associated with an increased incidence of heart failure, atrial fibrillation, chronic kidney disease, and mortality. Recent evidence suggests that Gal-3 may also be an important modulator of cardiometabolic traits such as adiposity, insulin resistance, and hyperglycemia. We examined the associations of blood Gal-3 concentrations and cardiometabolic disease traits in the Framingham Heart Study.

METHODS AND RESULTS

In cross-sectional analyses of 2946 Framingham Heart Study participants (mean age 59 years, 55% women), higher Gal-3 concentrations were associated with higher body mass index, waist circumference, and triglycerides (P<0.0001 for all). Higher Gal-3 was associated with greater odds of obesity (multivariable-adjusted odds ratio 1.16 per 1-SD increase in log-Gal-3, 95% CI 1.06-1.28, P=0.002) and hypertension (odds ratio 1.18, 95% CI 1.07-1.29, P=0.0006). In prospective analyses, Gal-3 was associated with incident metabolic syndrome (hazard ratio 1.22, 95% CI 1.10-1.36, P=0.0002) and diabetes (hazard ratio 1.21, 95% CI 1.04-1.41, P=0.02), in age- and sex-adjusted, but not multivariable-adjusted models.

CONCLUSIONS

In this large, community-based sample, circulating Gal-3 was associated with abdominal adiposity, dyslipidemia, and hypertension in cross-sectional analyses, but Gal-3 did not predict incident cardiometabolic disease after adjusting for cardiometabolic risk factors. Future investigations should focus on further elucidating mechanisms linking Gal-3 with cardiometabolic disease and on assessing whether modulation of the Gal-3 pathway might have positive cardiometabolic effects.

Galectin-3 blockade inhibits cardiac inflammation and fibrosis in experimental hyperaldosteronism and hypertension

Hypertensive cardiac remodeling is accompanied by molecular inflammation and fibrosis, 2 mechanisms that finally affect cardiac function. At cardiac level, aldosterone promotes inflammation and fibrosis, although the precise mechanisms are still unclear. Galectin-3 (Gal-3), a β-galactoside-binding lectin, is associated with inflammation and fibrosis in the cardiovascular system. We herein investigated whether Gal-3 inhibition could block aldosterone-induced cardiac inflammation and fibrosis and its potential role in cardiac damage associated with hypertension. Aldosterone-salt-treated rats presented hypertension, cardiac inflammation, and fibrosis that were prevented by the pharmacological inhibition of Gal-3 with modified citrus pectin. Cardiac inflammation and fibrosis presented in spontaneously hypertensive rats were prevented by modified citrus pectin treatment, whereas Gal-3 blockade did not modify blood pressure levels. In the absence of blood pressure modifications, Gal-3 knockout mice were resistant to aldosterone-induced cardiac inflammation. In human cardiac fibroblasts, aldosterone increased Gal-3 expression via its mineralocorticoid receptor. Gal-3 and aldosterone enhanced proinflammatory and profibrotic markers, as well as metalloproteinase activities in human cardiac fibroblasts, effects that were not observed in Gal-3-silenced cells treated with aldosterone. In experimental hyperaldosteronism, the increase in Gal-3 expression was associated with cardiac inflammation and fibrosis, alterations that were prevented by Gal-3 blockade independently of blood pressure levels. These data suggest that Gal-3 could be a new molecular mechanism linking cardiac inflammation and fibrosis in situations with high-aldosterone levels, such as hypertension.