Galectin-3 is expressed in the myocardium very early post–myocardial infarction

Early Cardiac Ischemia-Reperfusion Injury: Interactions of Autophagy with Galectin-3 and Oxidative Stress

Background: Cardiovascular diseases are the leading cause of death worldwide, including the United Arab Emirates. Ischemia-reperfusion (IR) injury results in the death of cardiac myocytes that were viable immediately before myocardial reperfusion. We aim to investigate the role of galectin-3 (Gal-3) in autophagy during ischemia-reperfusion injuries. Methods: Male C57B6/J and Gal-3 knockout (KO) mice were used for the murine model of IR injury. Heart samples and serum were collected 24 h post-IR and were processed for immunohistochemical and immunofluorescent labeling and an enzyme-linked immunosorbent assay. Results: There was a significant increase in left ventricle (LV) concentrations of Gal-3 in Gal-3 wild-type mice compared to sham mice. There were significantly higher concentrations of LV autophagy proteins and phospho-AMPK in IR Gal-3 KO mice than in IR Gal-3 wild-type mice, compared to lower concentrations of LV phospho-mTOR and p62 in IR Gal-3 KO than in IR wild-type mice. Antioxidant activities were higher in the LVs of IR Gal-3 wild-type mice, while oxidative stress was higher in the LVs of IR Gal-3 KO mice. Conclusions: Our study supports the interaction of Gal-3 with autophagy proteins, oxidative stress, and antioxidant proteins and demonstrates that the absence of Gal-3 can enhance autophagy in the heart after IR injury.

Current Trends in Biohumoral Screening for the Risk of Sudden Cardiac Death: A Systematic Review

Background and Objectives: Sudden cardiac death (SCD) represents a challenge to health systems globally and is met with increased frequency in the population. Over time, multiple screening methods have been proposed, including the analysis of various plasma biomarkers. This article aims to analyze for illustrative purposes the specialized literature in terms of current biomarkers and testing trends, in the case of cardiovascular diseases and implicitly sudden cardiac death. Materials and Methods: In this regard, we searched the PubMed database from 2010 to the present time using the keywords "sudden cardiac death" and "biomarkers". The inclusion criteria were clinical trials that analyzed the effectiveness of screening methods in terms of biomarkers used in stratifying the risk of cardiac distress and/or sudden cardiac death. We excluded reviews, meta-analyses, and studies looking at the effectiveness of treatments. Results: An extended approach was found, through studies that brought to the forefront both classical markers analyzed by new, more performant methods, markers for other pathologies that also determined cardiovascular impact, non-specific molecules with effects on the cardiovascular system, and state-of-the-art markers, such as microRNA. Some molecules were analyzed simultaneously in certain groups of patients. Conclusion: The observed current trend revealed the tendency to define the clinical-biological particularities of the person to be screened.

Recent perspectives on the early expression immunohistochemical markers in post-mortem recognition of myocardial infarction

Acute Myocardial Infarction (AMI) refers to the death of heart tissue in the absence ofperfusion. It is one of the top causes of death globally, particularly in middle andhigher-age groups. However, for the pathologist, the post-mortem macroscopic andmicroscopic diagnosis of early AMI remains challenging. In the early acute stage ofAMI, no microscopic visible signs of tissue alterations like necrosis and neutrophilinfiltration can be seen. In such a scenario, immunohistochemistry (IHC) accounts forthe most suitable and safest alternative to study early diagnostic cases by selectivelydetecting changes in the cell population. This systematic review focuses on themultiple causes/changes that lead to the privation of blood flow as well as tissuechanges induced by the absence of perfusion.We performed a systematic review of the last 10-15 years' publications that focused ondetecting immunohistochemical changes that appear in the cell population in case ofacute myocardial infarction. We found around 160 articles on AMI, which we narroweddown to 50 with the use of specific filters such as: "Acute Myocardial Infarction," "Ischemia," "Hypoxia," "Forensic," "Immunohistochemistry, and "Autopsy." The presentreview comprehensively highlights the current knowledge of specific IHC markers usedas gold standards during post-mortem investigation of acute myocardial infarction. Thepresent review comprehensively highlights the current knowledge of specific IHCmarkers used as gold standards during post-mortem investigation of acute myocardialinfarction, and some new potential immunohistochemical markers that can be used inthe early detection of myocardial infarction.

Galectin-3 Is Associated with Cardiac Fibrosis and an Increased Risk of Sudden Death

BACKGROUND

Myocardial fibrosis is a common postmortem finding among individuals with Sudden Cardiac Death (SCD). Numerous in vivo and in vitro studies have shown that increased galectin-3 (gal3) expression into the myocardium is associated with higher incidence of fibrosis. Although elevated gal3 expression is linked with myocardial fibrosis, its role in predicting the risk of SCD is unknown.

METHODS

We reviewed the clinical datasets and post-mortem examination of 221 subjects who had died suddenly. We examined myocardial pathology including the extent of cardiac hypertrophy, fibrosis, and the degree of coronary atherosclerosis in these subjects. In a select group of SCD subjects, we studied myocardial gal3 and periostin expression using immunohistochemistry. To further examine if a higher level of circulating gal3 can be detected preceding sudden death, we measured serum gal3 in a porcine model of subtotal coronary artery ligation which shows an increased tendency to develop lethal cardiac arrhythmias, including ventricular tachycardia or fibrillation.

RESULTS

Of the total 1314 human subjects screened, 12.7% had SCD. Comparison of age-matched SCD with non-SCD subjects showed that SCD groups had excessive myocardial fibrosis involving both the left ventricular free wall and interventricular septum. In pigs with subtotal coronary artery ligation and SCD, we detected significantly elevated circulating gal3 levels approximately 10 days preceding the SCD event. Immunohistochemistry showed increased myocardial gal3 and periostin expression in pigs that died suddenly, compared to the controls.

CONCLUSION

Our study shows that increased gal3 is associated with a higher risk of myocardial fibrosis and the risk of SCD. This supports the importance of larger translational studies to target gal3 to prevent cardiac fibrosis and attenuate the risk of SCD.

Single-cell genomics illustrates heterogeneous phenotypes of myocardial fibroblasts under ischemic insults

Myocardial regenerative strategies are promising where the choice of ideal cell population is crucial for successful translational applications. Herein, we explored the regenerative/repair responses of infarct zone cardiac fibroblast(s) (CF) by unveiling their phenotype heterogeneity at single-cell resolution. CF were isolated from the infarct zone of Yucatan miniswine that suffered myocardial infarction, cultured under simulated ischemic and reperfusion, and grouped into control, ischemia, and ischemia/reperfusion. The single-cell RNA sequencing analysis revealed 19 unique cell clusters suggesting distinct subpopulations. The status of gene expression (log2 fold change (log2 FC) > 2 and log2 FC < -2) was used to define the characteristics of each cluster unveiling with diverse features, including the pro-survival/cardioprotective (Clusters 1, 3, 5, 9, and 18), vasculoprotective (Clusters 2 and 5), anti-inflammatory (Clusters 4 and 17), proliferative (Clusters 4 and 5), nonproliferative (Clusters 6, 8, 11, 16, 17, and 18), proinflammatory (Cluster 6), profibrotic/pathologic (Clusters 8 and 19), antihypertrophic (Clusters 8 and 10), extracellular matrix restorative (Clusters 9 and 12), angiogenic (Cluster 16), and normal (Clusters 7 and 15) phenotypes. Further understanding of these unique phenotypes of CF will provide significant translational opportunities for myocardial regeneration and cardiac management.

Circulating Galectin-3 in Patients with Cardiogenic Shock Complicating Acute Myocardial Infarction Treated with Mild Hypothermia: A Biomarker Sub-Study of the SHOCK-COOL Trial

Background: Galectin-3 (Gal-3) is considered a potential cardiovascular inflammatory marker that may provide additional risk stratification for patients with acute heart failure. It is unknown whether mild therapeutic hypothermia (MTH) impacts Gal-3 levels. Therefore, this biomarker study aimed to investigate the effect of MTH on Gal-3. Methods: In the randomized SHOCK-COOL trial, 40 patients with cardiogenic shock (CS) complicating acute myocardial infraction (AMI) were randomly assigned to the MTH (33 °C) or control group in a 1:1 ratio. Blood samples were collected on the day of admission/day 1, day 2, and day 3. Gal-3 level kinetics throughout these time points were compared between the MTH and control groups. Additionally, potential correlations between Gal-3 and clinical patient characteristics were assessed. Multiple imputations were performed to account for missing data. Results: In the control group, Gal-3 levels were significantly lower on day 3 than on day 1 (day 1 vs. day 3: 3.84 [IQR 2.04−13.3] vs. 1.79 [IQR 1.23−3.50] ng/mL; p = 0.049). Gal-3 levels were not significantly different on any day between the MTH and control groups (p for interaction = 0.242). Spearman’s rank correlation test showed no significant correlation between Gal-3 levels and sex, age, smoking, body mass index (BMI), and levels of creatine kinase-MB, creatine kinase, C-reactive protein, creatinine, and white blood cell counts (all p > 0.05). Patients with lower Gal-3 levels on the first day after admission demonstrated a higher risk of all-cause mortality at 30 days (hazard ratio, 2.67; 95% CI, 1.11−6.42; p = 0.029). In addition, Gal-3 levels on day 1 had a good predictive value for 30-day all-cause mortality with an area under the receiver operating characteristic curve of 0.696 (95% CI: 0.513−0.879), with an optimal cut-off point of less than 3651 pg/mL. Conclusions: MTH has no effect on Gal-3 levels in patients with CS complicating AMI compared to the control group. In addition, Gal-3 is a relatively stable biomarker, independent of age, sex, and BMI, and Gal-3 levels at admission might predict the risk of 30-day all-cause mortality.

The interplay of galectins-1, -3, and -9 in the immune-inflammatory response underlying cardiovascular and metabolic disease

Galectins are β-galactoside-binding proteins that bind and crosslink molecules via their sugar moieties, forming signaling and adhesion networks involved in cellular communication, differentiation, migration, and survival. Galectins are expressed ubiquitously across immune cells, and their function varies with their tissue-specific and subcellular location. Particularly galectin-1, -3, and -9 are highly expressed by inflammatory cells and are involved in the modulation of several innate and adaptive immune responses. Modulation in the expression of these proteins accompany major processes in cardiovascular diseases and metabolic disorders, such as atherosclerosis, thrombosis, obesity, and diabetes, making them attractive therapeutic targets. In this review we consider the broad cellular activities ascribed to galectin-1, -3, and -9, highlighting those linked to the progression of different inflammatory driven pathologies in the context of cardiovascular and metabolic disease, to better understand their mechanism of action and provide new insights into the design of novel therapeutic strategies.

Association between Endothelial Cell-Specific Molecule 1 and Galectin-3 in Patients with ST-Segment Elevation Myocardial Infarction: A Pilot Study

The biomarkers galectin-3 (Gal-3) and endothelial cell-specific molecule 1 (ESM-1) reflect endothelial function and inflammation. As a consequence, they play an important role in both the diagnosis and characterization of ST-segment elevation myocardial infarction (STEMI). However, no prior study has explored the association between ESM-1 and Gal-3 in STEMI patients. This study is aimed at determining the ESM-1 and Gal-3 levels in the serum of STEMI patients and then exploring the correlation between the levels of these two biomarkers and their clinical significance in STEMI patients. The participants were divided into two groups: the ST group comprised 35 hospitalized STEMI patients while the control group comprised 24 people with normal coronary arteries. In all the patients, venous blood was taken from the middle of the antecubital fossa. The serum ESM-1 and Gal-3 concentrations were determined using an enzyme-linked immunosorbent assay. The results revealed that the ESM-1 and Gal-3 levels in the STEMI patients were 1.6 and 2.8 times higher, respectively, when compared with the controls (P < 0.001). Moreover, the ESM-1 and Gal-3 levels exhibited a positive linear correlation (r = 0.758, P < 0.001) in the acute STEMI patients. In conclusion, the ESM-1 and Gal-3 levels were found to be significantly elevated and correlated in the STEMI patients. Thus, combining these two biomarkers of endothelial dysfunction and inflammation might be useful for the diagnosis and assessment of STEMI.

Early Doxorubicin Myocardial Injury: Inflammatory, Oxidative Stress, and Apoptotic Role of Galectin-3

Doxorubicin (DOXO) is an effective drug that is used in the treatment of a large number of cancers. Regardless of its important chemotherapeutic characteristics, its usage is restricted because of its serious side effects; the most obvious is cardiotoxicity, which can manifest acutely or years after completion of treatment, leading to left ventricular dysfunction, dilated cardiomyopathy, and heart failure. Galectin 3 (Gal-3) is a beta galactoside binding lectin that has different roles in normal and pathophysiological conditions. Gal-3 was found to be upregulated in animal models, correlating with heart failure, atherosclerosis, and myocardial infarction. Male C57B6/J and B6.Cg-Lgals3 <tm 1 Poi>/J Gal-3 knockout (KO) mice were used for a mouse model of acute DOXO-induced cardiotoxicity. Mice were given DOXO or vehicle (normal saline), after which the mice again had free access to food and water. Heart and plasma samples were collected 5 days after DOXO administration and were used for tissue processing, staining, electron microscopy, and enzyme-linked immunosorbent assay (ELISA). There was a significant increase in the heart concentration of Gal-3 in Gal-3 wild type DOXO-treated mice when compared with the sham control. There were significantly higher concentrations of heart cleaved caspase-3, plasma troponin I, plasma lactate dehydrogenase, and plasma creatine kinase in Gal-3 KO DOXO-treated mice than in Gal-3 wild type DOXO-treated mice. Moreover, there were significantly higher heart antioxidant proteins and lower oxidative stress in Gal-3 wild type DOXO-treated mice than in Gal-3 KO DOXO-treated mice. In conclusion, Gal-3 can affect the redox pathways and regulate cell survival and death of the myocardium following acute DOXO injury.

Circulating Galectin-3 Evaluation in Dogs With Cardiac and Non-cardiac Diseases

Galectin-3 is involved in important biological functions such as fibrogenesis and inflammation. Notably, it is associated with various diseases and plays a major role in cardiac inflammation and fibrosis. Although heart diseases are relatively common in dogs, a few studies have analyzed the circulating galectin-3 concentration in dogs with various heart diseases, including myxomatous mitral valve disease, patent ductus arteriosus, and pulmonic stenosis. The aims of the present study were to evaluate the effect of heart disease on circulating galectin-3 levels in dogs, and also to evaluate the correlation between galectin-3 concentration and conventional echocardiographic indices along with N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentration in dogs with heart diseases. The medical records and archived serum samples of 107 dogs were evaluated retrospectively. In total, 107 dogs were classified into healthy dogs (n = 8), cardiac disease (n = 26), and non-cardiac disease groups (n = 73). The circulatory galectin-3 levels were analyzed using a commercially available canine-specific galectin-3 enzyme-linked immunosorbent assay kit. This study demonstrated that dogs with heart, endocrine, and dermatologic diseases had significantly higher galectin-3 levels than healthy dogs (p = 0.009, p = 0.007, and p = 0.026, respectively). Among dogs with heart diseases, dogs with concentric cardiomyopathy had significantly increased circulatory galectin-3 levels compared with healthy dogs (p = 0.028). E'/A' had a positive association with galectin-3 levels among conventional echocardiographic indices. Moreover, the galectin-3 concentration could predict diastolic dysfunction. In dogs with myxomatous mitral valve disease, a significantly positive correlation was revealed between galectin-3 levels and NT-proBNP levels (p = 0.007). Overall, this study demonstrates that circulatory galectin-3 levels increase in dogs with heart, endocrine, and dermatologic diseases. Moreover, this study demonstrates that galectin-3 concentration could be helpful to evaluate cardiac remodeling and diastolic function. Further large-scale research is required to evaluate the role of circulating galectin-3 in dogs with heart diseases.

Small Endogeneous Peptide Mitigates Myocardial Remodeling in a Mouse Model of Cardioselective Galectin-3 Overexpression

BACKGROUND

Myocardial Gal3 (galectin-3) expression is associated with cardiac inflammation and fibrosis. Increased Gal3 portends susceptibility to heart failure and death. There are no data reporting the causative role of Gal3 to mediate cardiac fibro-inflammatory response and heart failure.

METHODS

We developed a cardioselective Gal3 gain-of-function mouse (Gal3+/+) using α-myosin heavy chain promotor. We confirmed Gal3-transgene expression with real-time polymerase chain reaction and quantified cardiac/circulating Gal3 with Western blot and immunoassays. We used echocardiogram and cardiac magnetic resonance imaging to measure cardiac volumes, function, and myocardial velocities. Ex vivo, we studied myocardial inflammation/fibrosis and downstream TGF (transforming growth factor) β1-mRNA expression. We examined the effects of acute myocardial ischemia in presence of excess Gal3 by inducing acute myocardial infarction in mice. Two subsets of mice including mice treated with N-acetyl-seryl-aspartyl-lysyl-proline (a Gal3-inhibitor) and mice with genetic Gal3 loss-of-function (Gal3-/-) were studied for comparative analysis of Gal3 function.

RESULTS

Gal3+/+ mice had increased cardiac/circulating Gal3. Gal3+/+ mice showed excess pericardial fat pad, dilated ventricles and cardiac dysfunction, which was partly normalized by N-acetyl-seryl-aspartyl-lysyl-proline. Cardiac magnetic resonance imaging showed reduced myocardial contractile velocities in Gal3+/+. The majority of Gal3+/+ mice did not survive acute myocardial infarction, and the survivors had profound cardiac dysfunction. Myocardial histology of Gal3+/+ mice showed macrophage/mast-cell infiltration, fibrosis and higher TGFβ1-mRNA expression, which were mitigated by both Gal3 gene deletion and N-acetyl-seryl-aspartyl-lysyl-proline administration.

CONCLUSIONS

Our study shows that cardioselective Gal3 overexpression leads to multiple cardiac phenotypic defects including ventricular dilation and cardiac dysfunction. Pharmacological Gal3 inhibition conferred protective effects with reduction of inflammation and fibrosis. Our study highlights the importance of translational studies to counteract Gal3 function and prevent cardiac dysfunction.

Research progress on the role of gal-3 in cardio/cerebrovascular diseases

Galectin-3 (gal-3), a member of the galectin family, is a glycoprotein with high affinity for β-galactoside. Gal-3 is a cytoplasmically synthesized protein that can shuttle between the cytoplasm and nucleus and can even be transported to the membrane and secreted into the extracellular environment. Cardio/cerebrovascular diseases generally refer to ischemic or hemorrhagic diseases occurring in the heart, brain and systemic tissues, which are characterized by high morbidity, high disability rates and high mortality rates. To date, considerable research has demonstrated that gal-3 expression is aberrantly increased and plays important roles in cardio/cerebrovascular diseases, such as acute ischemic stroke (AIS), myocardial fibrosis, acute coronary syndrome (ACS), and heart failure (HF). Hence, understanding the biological roles of gal-3 in these diseases may be essential for cardio/cerebrovascular disease treatment and diagnosis to improve patient quality of life. In this review, we summarize current research on the roles of gal-3 in human cardiovascular diseases and potential inhibitors of gal-3, which may provide new strategies for disease therapies.

Prognostic role of plasma galectin-3 levels in acute coronary syndrome

Aim:

Cystatin C, neutrophil gelatinase-associated lipocalin and galectin-3 have emerged as biomarker candidates to predict cardiovascular outcomes and mortality in the general population as well as in patients with coronary artery or renal disease. However, their predictive role and clinical utility in patients with acute coronary syndromes alone or in combination beyond currently used risk scores remains to be determined.

Methods and results:

Cystatin C, neutrophil gelatinase-associated lipocalin, and galectin-3 were measured in plasmas of 1832 patients at the time of presentation with acute coronary syndromes requiring percutaneous coronary intervention or coronary artery bypass grafting. The primary outcomes were major adverse cardiac and cerebrovascular events (defined as the composite of all-cause mortality, cerebrovascular events, any repeat revascularization or myocardial infarction) and all-cause mortality after 1 year and occurred in 192 (10.5%) and 78 (4.3%) of patients, respectively. All three biomarkers were increased in those with major adverse cardiac and cerebrovascular events compared with those without (p&lt;0.001). However, only galectin-3 (all-cause mortality: hazard ratio=1.027 (95% confidence interval (1.011–1.043); p=0.001), major adverse cardiac and cerebrovascular events: hazard ratio=1.025 (95% confidence interval (1.012–1.037); p&lt;0.001)) but not cystatin C nor neutrophil gelatinase-associated lipocalin emerged as independent predictors of both major adverse cardiac and cerebrovascular events and death. The risks were particularly high in the highest quartile of galectin-3. The integration of galectin-3 into the global registry of acute coronary events (GRACE) score improved the prediction of major adverse cardiac and cerebrovascular events and all-cause mortality significantly. The areas under the receiver operator characteristics curves increased from 0.6701 to 0.6932 for major adverse cardiac and cerebrovascular events (p=0.0474) and from 0.804 to 0.8199 for all-cause mortality (p=0.0197). Finally, we applied net reclassification improvement index using different cut-offs for major adverse cardiac and cerebrovascular events which showed negative results (for the cut-offs of 5% and 15%, net reclassification improvement index 0.028, p=0.586, for the cut-offs of 10% and 20%, net reclassification improvement index 0.072, p=0.1132 and for the cut-offs of 10% and 30% the net reclassification improvement index is 0.0843, p=0.077).

Conclusion:

In acute coronary syndromes patients, galectin-3 has moderate prognostic accuracy, provides statistically significant incremental value in some, but not all models, and that the magnitude of any improvement would seem of questionable clinical value.

Immunohistochemistry in the Detection of Early Myocardial Infarction: Systematic Review and Analysis of Limitations Because of Autolysis and Putrefaction

The postmortem diagnosis of acute myocardial infarction is one of the main problems in forensic practice, especially in cases in which death occurs soon after (from minutes to a few hours) the onset of the ischemic damage. Several authors have highlighted the possibility to overcome the limits of conventional histology in this diagnosis by utilizing immunohistochemistry. In the present research, we examined over 30 scientific studies and picked out over 20 main immunohistochemical antigens analyzed with a view to enabling the rapid diagnosis of early myocardial infarction. The aim of our review was to examine and summarize all the principal markers studied to date and also to consider their limitations, including protein alteration because of cadaveric autolysis and putrefaction.

Galectin-3: A Potential Prognostic and Diagnostic Marker for Heart Disease and Detection of Early Stage Pathology

The use of molecular biomarkers for the early detection of heart disease, before their onset of symptoms, is an attractive novel approach. Ideal molecular biomarkers, those that are both sensitive and specific to heart disease, are likely to provide a much earlier diagnosis, thereby providing better treatment outcomes. Galectin-3 is expressed by various immune cells, including mast cells, histiocytes and macrophages, and plays an important role in diverse physiological functions. Since galectin-3 is readily expressed on the cell surface, and is readily secreted by injured and inflammatory cells, it has been suggested that cardiac galectin-3 could be a marker for cardiac disorders such as cardiac inflammation and fibrosis, depending on the specific pathogenesis. Thus, galectin-3 may be a novel candidate biomarker for the diagnosis, analysis and prognosis of various cardiac diseases, including heart failure. The goals of heart disease treatment are to prevent acute onset and to predict their occurrence by using the ideal molecular biomarkers. In this review, we discuss and summarize recent developments of galectin-3 as a next-generation molecular biomarker of heart disease. Furthermore, we describe how galectin-3 may be useful as a diagnostic marker for detecting the early stages of various heart diseases, which may contribute to improved early therapeutic interventions.

Association between new circulating proinflammatory and anti-inflammatory adipocytokines with coronary artery disease

Supplemental Digital Content is available in the text.

The aim of this study was to evaluate the diagnostic and risk predictive value of emerging proinflammatory and anti-inflammatory adipocytokines on coronary artery disease (CAD).

Value of Galectin-3 in Acute Myocardial Infarction

Galectins are an ancient family of lectins characterized by evolutionarily conserved amino acid sequences and β-galactoside recognition and binding sites. Galectin-3 (Gal-3) is one of 15 known galectins. This protein has important functions in numerous biological activities, including cardiac fibrosis and heart failure. In recent years, many studies have shown that Gal-3 is closely associated with acute myocardial infarction (AMI) and may be a promising biomarker for the assessment of severity as well as prognosis prediction in AMI patients, but controversy still exists. In this review, we summarize the latest literature on the relationship between Gal-3 and unstable plaques, the secretion kinetics of Gal-3 during the acute phase of AMI, and the value of Gal-3 in the prediction of post-AMI remodeling. Finally, the possible value of Gal-3 as a biological target for AMI therapy is examined.

The utility of growth differentiation factor-15, galectin-3, and sST2 as biomarkers for the diagnosis of heart failure with preserved ejection fraction and compared to heart failure with reduced ejection fraction: a systematic review

The objective was to evaluate the diagnosis of heart failure with preserved ejection fraction (HFpEF) using the biomarkers, growth differentiation factor-15 (GDF-15), galectin-3 (Gal-3), and soluble ST2 (sST2), and to determine whether they can differentiate HFpEF from heart failure with reduced ejection fraction (HFrEF). Medline and Embase databases were searched with the terms diastolic heart failure or HFpEF, biomarkers, and diagnosis, limited to years 2000 to 2019. There were significantly and consistently higher levels of GDF-15, Gal-3, and sST2 in HFpEF compared to no heart failure. Importantly, the magnitude of the increase in GDF-15 or Gal-3 and possibly sST2,correlated with a greater degree of diastolic dysfunction. There were no significant differences between GDF-15, Gal-3, and sST2 in patients with HFpEF vs HFrEF. In the studies assessing these three biomarkers, BNP was significantly greater in heart failure than controls. Furthermore, BNP was significantly higher in HFrEF compared to HFpEF. The diagnostic utility of GDF-15, Gal-3, and sST2 compared to BNP was evaluated by comparing ROC curves. The data supports the contention that to distinguish HFpEF from HFrEF, an index is needed that incorporates GDF-15, Gal-3, or sST2 as well as BNP. The three biomarkers GDF-15, Gal-3, or sST2 can identify patients with HFpEF compared to individuals without heart failure but cannot differentiate HFpEF from HFrEF. BNP is higher in and is better at differentiating HFrEF from HFpEF. Indices that incorporate GDF-15, Gal-3, or sST2 as well as BNP show promise in differentiating HFpEF from HFrEF.

Galectin-3 as a Next-Generation Biomarker for Detecting Early Stage of Various Diseases

Galectin-3 is a β-galactoside-binding lectin which is important in numerous biological activities in various organs, including cell proliferation, apoptotic regulation, inflammation, fibrosis, and host defense. Galectin-3 is predominantly located in the cytoplasm and expressed on the cell surface, and then often secreted into biological fluids, like serum and urine. It is also released from injured cells and inflammatory cells under various pathological conditions. Many studies have revealed that galectin-3 plays an important role as a diagnostic or prognostic biomarker for certain types of heart disease, kidney disease, viral infection, autoimmune disease, neurodegenerative disorders, and tumor formation. In particular, it has been recognized that galectin-3 is extremely useful for detecting many of these diseases in their early stages. The purpose of this article is to review and summarize the recent literature focusing on the biomarker characteristics and long-term outcome predictions of galectin-3, in not only patients with various types of diseases, but associated animal models.

Gal-3 (Galectin-3) and KCa3.1 Mediate Heterogeneous Cell Coupling and Myocardial Fibrogenesis Driven by βAR (β-Adrenoceptor) Activation

Heart failure is associated with sympatho-βAR (β-adrenoceptor) activation and cardiac fibrosis. Gal-3 (galectin-3) and K_Ca3.1 channels that are upregulated in diverse cells of diseased heart are implicated in mediating myocardial inflammation and fibrosis. It remains unclear whether Gal-3 interacts with K_Ca3.1 leading to cardiac fibrosis in the setting of βAR activation. We tested the effect of K_Ca3.1 blocker TRAM-34 on cardiac fibrosis and inflammation in cardiac-restricted β₂-TG (β₂AR overexpressed transgenic) mice and determined K_Ca3.1 expression in β₂-TG×Gal-3^-/- mouse hearts. Mechanisms of K_Ca3.1 in mediating Gal-3 induced fibroblast activation were studied ex vivo. Expression of Gal-3 and K_Ca3.1 was elevated in β₂-TG hearts. Gal-3 gene deletion in β₂-TG mice decreased K_Ca3.1 expression in inflammatory cells but not in fibroblasts. Treatment of β₂-TG mice with TRAM-34 for 1 or 2 months significantly ameliorated cardiac inflammation and fibrosis and reduced Gal-3 level. In cultured fibroblasts, Gal-3 upregulated K_Ca3.1 expression and channel currents with enhanced membrane potential and Ca²⁺ entry through TRPV4 (transient receptor potential V4) and TRPC6 (transient receptor potential C6) channels leading to fibroblast activation. In conclusion, βAR stimulation promotes Gal-3 production that upregulates K_Ca3.1 channels in noncardiomyocyte cells and activates K_Ca3.1 channels in fibroblasts leading to hyperpolarization of membrane potential and Ca²⁺ entry via TRP channels. Gal-3-K_Ca3.1 signaling mobilizes diverse cells facilitating regional inflammation and fibroblast activation and hence myocardial fibrosis.

Myocardial Injury After Ischemia/Reperfusion Is Attenuated By Pharmacological Galectin-3 Inhibition

Although optimal therapy for myocardial infarction includes reperfusion to restore blood flow to the ischemic region, ischemia/reperfusion (IR) also initiates an inflammatory response likely contributing to adverse left ventricular (LV) extracellular matrix (ECM) remodeling. Galectin-3 (Gal-3), a β-galactoside-binding-lectin, promotes cardiac remodeling and dysfunction. Our aim is to investigate whether Gal-3 pharmacological inhibition using modified citrus pectin (MCP) improves cardiac remodeling and functional changes associated with IR. Wistar rats were treated with MCP from 1 day before until 8 days after IR (coronary artery ligation) injury. Invasive hemodynamics revealed that both LV contractility and LV compliance were impaired in IR rats. LV compliance was improved by MCP treatment 8 days after IR. Cardiac magnetic resonance imaging showed decreased LV perfusion in IR rats, which was improved with MCP. There was no difference in LV hypertrophy in MCP-treated compared to untreated IR rats. However, MCP treatment decreased the ischemic area as well as Gal-3 expression. Gal-3 blockade paralleled lower myocardial inflammation and reduced fibrosis. These novel data showing the benefits of MCP in compliance and ECM remodeling in IR reinforces previously published data showing the therapeutic potential of Gal-3 inhibition.

Galectin 3 and Galectin 3 Binding Protein Improve the Risk Stratification after Myocardial Infarction

Background: Acute myocardial infarction (AMI) survivors are at risk of major adverse cardiac events and their risk stratification is a prerequisite to tailored therapeutic approaches. Biomarkers could be of great utility in this setting. Methods: We sought to evaluate the utility of the combined assessment of Galectin 3 (Gal-3) and Galectin 3 binding protein (Gal-3bp) for post-AMI risk stratification in a large, consecutive population of AMI patients. The primary outcomes were: Recurrent angina/AMI and all-cause mortality at 12 months after the index event. Results: In total, 469 patients were included. The median Gal-3bp was 9.1 μg/mL (IQR 5.8–13.5 μg/mL), while median Gal-3 was 9.8 ng/mL (IQR 7.8–12.8 ng/mL). During the 12 month follow-up, 34 patients died and 41 had angina pectoris/reinfarction. Gal-3 was associated with all-cause mortality, while Gal-3bp correlated with the risk of angina/myocardial infarction even when corrected for other significant covariates. The final multivariable model for mortality prediction included patients’ age, left ventricular ejection fraction (LVEF), Gal-3, and renal function. The ROC curve estimated for this model has an area under the curve (AUC) of 0.84 (95%CI 0.78–0.9), which was similar to the area under the ROC curve obtained using the GRACE score 1-year mortality. Conclusions: The integrated assessment of Gal-3 and Gal-3bp could be helpful in risk stratification after AMI.

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.

Left ventricular remodeling after the first myocardial infarction in association with LGALS-3 neighbouring variants rs2274273 and rs17128183 and its relative mRNA expression: a prospective study

Post-infarct left ventricular remodeling (LVR) process increases the risk of heart failure (HF). Circulating galectin-3 has been associated with fibrosis, inflammation and cardiac dysfunction during the remodeling process after myocardial infarction (MI). The aims of this prospective case study were to investigate the association of potentially functional variants in the vicinity of LGALS-3 locus, rs2274273 and rs17128183 with maladaptive LVR and whether these variants could affect LGALS-3 mRNA expression in peripheral blood mononuclear cells of patients 6 months after the first MI. This study encompassed 167 patients with acute MI that were followed up for 6 months. Evidence of LVR was obtained by repeated 2D Doppler echocardiography. Rs2274273, rs17128183 and LGALS-3 mRNA expression were detected by TaqMan^® technology. Rs2274273 and rs17128183 rare allele bearing genotypes, according to the dominant model (CT+TT vs. CC and AG+GG vs. AA, respectively), were significantly and independently associated with maladaptive LVR (adjusted OR = 3.02, P = 0.016; adjusted OR = 3.14, P = 0.019, respectively) and higher LGALS-3 mRNA expression (fold induction 1.203, P = 0.03 and 1.214, P = 0.03, respectively). Our exploratory results suggest that rs2274273 and rs17128183 variants affect LGALS-3 mRNA and bear the risk for maladaptive LVR post-MI remodeling. Further replication and validation in a larger group of patients is inevitable.

Multiplex quantitative imaging of human myocardial infarction by mass spectrometry-immunohistochemistry

Simultaneous assessment of a panel of protein markers is becoming essential in order to enhance biomarker research and improve diagnostics. Specifically, postmortem diagnostics of early myocardial ischemia in sudden cardiac death cases could benefit from a multiplex marker assessment in the same tissue section. Current analytical antibody-based techniques (immunohistochemistry and immunofluorescence) limit multiplex analysis usually to not more than three antibodies. In this study, mass spectrometry-immunohistochemistry (MS-IHC) was performed by combining laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) with rare-metal-isotope-tagged antibodies as a technique for multiplex analysis of human postmortem myocardial tissue samples. Tissue sections with myocardial infarction were simultaneously analyzed for seven primary, rare-metal-isotope-tagged antibodies (troponin T, myoglobin, fibronectin, C5b-9, unphosphorylated connexin 43, VEGF-B, and JunB). Comparison between the MS-IHC approach and chromogenic IHC showed similar patterns in ionic and optical images. In addition, absolute quantification was performed by MS-IHC, providing a proportional relationship between the signal intensity and the local marker concentration in tissue sections. These data demonstrated that LA-ICP-MS combined with rare-metal-isotope-tagged antibodies is an efficient strategy for simultaneous testing of multiple markers and allows not only visualization of molecules within the tissue but also quantification of the signal. Such imaging approach has a great potential in both diagnostics and pathology-related research.

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.

Understanding cardiac extracellular matrix remodeling to develop biomarkers of myocardial infarction outcomes

Cardiovascular Disease (CVD) is the most common cause of death in industrialized countries, and myocardial infarction (MI) is a major CVD with significant morbidity and mortality. Following MI, the left ventricle (LV) undergoes a wound healing response to ischemia that results in extracellular matrix (ECM) scar formation to replace necrotic myocytes. While ECM accumulation following MI is termed cardiac fibrosis, this is a generic term that does not differentiate between ECM accumulation that occurs in the infarct region to form a scar that is structurally necessary to preserve left ventricle (LV) wall integrity and ECM accumulation that increases LV wall stiffness to exacerbate dilation and stimulate the progression to heart failure. This review focuses on post-MI LV ECM remodeling, targeting the discussion on ECM biomarkers that could be useful for predicting MI outcomes.

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.

Galectin-3 in Peripheral Artery Disease. Relationships with Markers of Oxidative Stress and Inflammation

Galectin-3 is a modulator of oxidative stress, inflammation, and fibrogenesis involved in the pathogenesis of vascular diseases. The present study sought to characterize, in patients with peripheral artery disease (PAD), the localization of galectin-3 in arterial tissue, and to analyze the relationships between the circulating levels of galectin-3 and oxidative stress and inflammation. It also sought to compare the diagnostic accuracy of galectin-3 with that of other biochemical markers of this disease. We analyzed femoral or popliteal arteries from 50 PAD patients, and four control arteries. Plasma from 86 patients was compared with that from 72 control subjects. We observed differences in the expression of galectin-3 in normal arteries, and arteries from patients with PAD, with a displacement of the expression from the adventitia to the media, and the intima. In addition, plasma galectin-3 concentration was increased in PAD patients, and correlated with serologic markers of oxidative stress (F2-isoprostanes), and inflammation [chemokine (C−C motif) ligand 2, C-reactive protein, β-2-microglobulin]. We conclude that the determination of galectin-3 has good diagnostic accuracy in the assessment of PAD and compares well with other analytical parameters currently in use.

Galectin-3 inhibition ameliorates hypoxia-induced pulmonary artery hypertension

Galectin-3 (Gal-3) is a β-galactoside-binding lectin, which is important in inflammation, fibrosis and heart failure. The present study aimed to investigate the role and mechanism of Gal-3 in hypoxia-induced pulmonary arterial hypertension (PAH). Male C57BL/6J and Gal-3^−/− mice were exposed to hypoxia, then the right ventricular systolic pressure (RVSP) and Fulton's index were measured, and Gal-3 mRNA and protein expression in the pulmonary arteries was analyzed by reverse transcription-quantitative polymerase chain reaction and western blotting. Compared with the control, hypoxia increased the mRNA and protein expression levels of Gal-3 in wild type murine pulmonary arteries. Gal-3 deletion reduced the hypoxia-induced upregulation of RVSP and Fulton's index. Furthermore, human pulmonary arterial endothelial cells (HPAECs) and human pulmonary arterial smooth muscle cells (HPASMCs) were stimulated by hypoxia in vitro, and Gal-3 expression was inhibited by small interfering RNA. The inflammatory response of HPAECs, and the proliferation and cell cycle distribution of HPASMCs was also analyzed. Gal-3 inhibition alleviated the hypoxia-induced inflammatory response in HPAECs, including tumor necrosis factor-α and interleukin-1 secretion, expression of intercellular adhesion molecule-1 and adhesion of THP-1 monocytes. Gal-3 inhibition also reduced hypoxia-induced proliferation of HPASMCs, partially by reducing cyclin D1 expression and increasing p27 expression. Furthermore, Gal-3 inhibition suppressed HPASMC switching from a ‘contractile’ to a ‘synthetic’ phenotype. In conclusion, Gal-3 serves a fundamental role in hypoxia-induced PAH, and inhibition of Gal-3 may represent a novel therapeutic target for the treatment of hypoxia-induced PAH.

Immunohistochemical detection of early myocardial infarction: a systematic review

The postmortem diagnosis of early myocardial infarction is a challenge for forensic pathologists because the routine histology is neither specific. Many authors have suggested the use of the immunohistochemistry to fill the gaps in the histological diagnosis of early myocardial infarction. This review aims to analyse advances of immunohistochemical detection of early cardiac damage due to ischaemia. To this purpose, we reviewed experimental studies that investigated immunohistochemical markers and their estimated timing of expression. The review was performed according to specific inclusion and exclusion criteria, and a total of 23 studies assessing the immunohistochemical markers for the diagnosis and timing of early myocardial infarction were identified. The literature review highlights that the analysed markers are complement components, others being inflammatory mediators, cardiac cell proteins, plasma proteins, stress or hypoxia-induced factors and proteins associated with heart failure. All studies demonstrate the effectiveness of the tested markers in the early detection of myocardial infarction in both animal and human samples.

Utility of galectin-3 in predicting post-infarct remodeling after acute myocardial infarction based on extracellular volume fraction mapping

AIMS

ST-segment elevation myocardial infarction (STEMI) triggers remote extracellular matrix expansion. Myocardial extracellular volume fraction (ECV), determined by cardiovascular magnetic resonance, permits quantification of interstitial space expansion. Our aim was to determine the relationship between early serum fibrosis biomarkers and 180-day post-infarct remote myocardium remodeling using ECV.

METHODS AND RESULTS

In 26 patients with STEMI, functional imaging, T1-mapping, and late-gadolinium-enhancement were performed on a 3-T CMR scanner at baseline (days 3 to 5) and 180days. Biomarkers were measured at days 1, 3, and 7 after STEMI. The mean initial and follow-up left ventricular ejection fraction (LVEF) were 48.3±18.1% and 52.6±12.3%, respectively. Initial infarct size was 11.6±16.8% of LV mass. ECV in the remote myocardium at 180days correlated with indexed end-systolic volume (r=0.4, p=0.045). A significant correlation was observed between galectin-3 at day 7 and ECV at 6months (r=0.428, p=0.037). A trend towards a direct correlation was found for BNP (r=0.380, p=0.059). Multivariate analysis revealed that BNP and galectin-3 were independent predictors of long-term changes in ECV and explained nearly 30% of the variance in this parameter (r²=0.34; p=0.01). A galectin-3 cutoff value of 10.15ng/mL was the most powerful predictor of high ECV values (≥28.5%) at follow-up. Galectin-3 at day 7 was an independent predictor of high ECV values at follow-up (OR=22.51; CI 95%: 2.1-240.72; p=0.01) with 0.76 AUC (CI: 0.574-0.964; p=0.03).

CONCLUSIONS

Galectin-3 measured acutely after STEMI is an independent predictor of increased ECV at 6-month follow-up that might be useful for long-term risk stratification.

TAM receptor tyrosine kinase function and the immunopathology of liver disease

Tyro3, Axl, MERTK (TAM) receptor tyrosine kinases are implicated in the regulation of the innate immune response through clearance of apoptotic cellular debris and control of cytokine signaling cascades. As a result they are pivotal in regulating the inflammatory response to tissue injury. Within the liver, immune regulatory signaling is employed to prevent the overactivation of innate immunity in response to continual antigenic challenge from the gastrointestinal tract. In this review we appraise current understanding of the role of TAM receptor function in the regulation of both innate and adaptive immunity, with a focus on its impact upon hepatic inflammatory pathology.

Galectin-3 Participates in Cardiovascular Remodeling Associated With Obesity

Remodeling, diastolic dysfunction, and arterial stiffness are some of the alterations through which obesity affects the cardiovascular system. Fibrosis and inflammation are important mechanisms underlying cardiovascular remodeling, although the precise promoters involved in these processes are still unclear. Galectin-3 (Gal-3) induces inflammation and fibrosis in the cardiovascular system. We have investigated the potential role of Gal-3 in cardiac damage in morbidly obese patients, and we have evaluated the protective effect of the Gal-3 inhibition in the occurrence of cardiovascular fibrosis and inflammation in an experimental model of obesity. Morbid obesity is associated with alterations in cardiac remodeling, mainly left ventricular hypertrophy and diastolic dysfunction. Obesity and hypertension are the main determinants of left ventricular hypertrophy. Insulin resistance, left ventricular hypertrophy, and circulating levels of C-reactive protein and Gal-3 are associated with a worsening of diastolic function in morbidly obese patients. Obesity upregulates Gal-3 production in the cardiovascular system in a normotensive animal model of diet-induced obesity by feeding for 6 weeks a high-fat diet (33.5% fat). Gal-3 inhibition with modified citrus pectin (100 mg/kg per day) reduced cardiovascular levels of Gal-3, total collagen, collagen I, transforming and connective growth factors, osteopontin, and monocyte chemoattractant protein-1 in the heart and aorta of obese animals without changes in body weight or blood pressure. In morbidly obese patients, Gal-3 levels are associated with diastolic dysfunction. In obese animals, Gal-3 blockade decreases cardiovascular fibrosis and inflammation. These data suggest that Gal-3 could be a novel therapeutic target in cardiac fibrosis and inflammation associated with obesity.