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

Comprehensive Quality Analysis of Conventional and Novel Biomarkers in Diagnosing and Predicting Prognosis of Coronary Artery Disease, Acute Coronary Syndrome, and Heart Failure, a Comprehensive Literature Review

Coronary artery disease (CAD), acute coronary syndrome (ACS), and heart failure (HF) are major global health issues with high morbidity and mortality rates. Biomarkers like cardiac troponins (cTn) and natriuretic peptides (NPs) are crucial tools in cardiology, but numerous new biomarkers have emerged, proving increasingly valuable in CAD/ACS. These biomarkers are classified based on their mechanisms, such as fibrosis, metabolism, inflammation, and congestion. The integration of established and emerging biomarkers into clinical practice is an ongoing process, and recognizing their strengths and limitations is crucial for their accurate interpretation, incorporation into clinical settings, and improved management of CVD patients. We explored established biomarkers like cTn, NPs, and CRP, alongside newer biomarkers such as Apo-A1, IL-17E, IgA, Gal-3, sST2, GDF-15, MPO, H-FABP, Lp-PLA2, and ncRNAs; provided evidence of their utility in CAD/ACS diagnosis and prognosis; and empowered clinicians to confidently integrate these biomarkers into clinical practice based on solid evidence.

Anti-Ferroptotic Effect of Cannabidiol in Human Skin Keratinocytes Characterized by Data-Independent Acquisition-Based Proteomics

Skin cells are susceptible to oxidative stress and various types of cell death, including an iron-dependent form known as ferroptosis. Cannabidiol (CBD) can protect skin cells against oxidative stress, but whether this is attributed to the inhibition of ferroptosis is unknown. Herein, we evaluated the anti-ferroptotic effect of CBD in human keratinocytes using biochemical assays (radical scavenging and iron chelating) and cell-based models (for lipid peroxidation and intracellular iron). CBD's anti-ferroptotic effect was further characterized by proteomic analysis. This study identifies anti-ferroptosis as a mechanism of CBD's skin protective effects.

Association between sleep patterns and galectin-3 in a Chinese community population

BACKGROUND

Irregular sleep patterns have been associated with inflammation. Galectin-3, a novel biomarker, plays an important role in inflammation. We investigated the relationship between sleep patterns and galectin-3 in a Chinese population.

METHODS

A total of 1,058 participants from the Shenzhen-Hong Kong United Network on Cardiovascular Disease study were included in the analysis. Age and sex-adjusted linear regression models were employed to investigate the relationship between galectin-3 level and traditional metabolic biomarkers. Logistic regression models were used to estimate the association among sleep disturbance, nighttime sleep duration, and daytime napping duration and elevated galectin-3, with elevated galectin-3 defined as galectin-3 level > 65.1 ng/ml.

RESULTS

Of study participants, the mean age was 45.3 years and 54.3% were women. Waist circumference, natural logarithm (ln)-transformed triglyceride, and ln-transformed high sensitivity C-reactive protein were positively associated with galectin-3 level (age and sex-adjusted standardized β [95% confidence interval (CI)], 0.12 [0.04, 0.21], 0.11 [0.05, 0.17], and 0.08 [0.02, 0.14], respectively). Sleep disturbance was associated with elevated galectin-3 (odds ratio [95% CI], 1.68 [1.05, 2.68], compared to those without sleep disturbance) after adjusting for traditional metabolic biomarkers. No interaction was observed between galectin-3 and age, sex, obesity, hypertension, and diabetes on sleep disturbance. No association was found between nighttime sleep duration or daytime napping duration and elevated galectin-3.

CONCLUSIONS

Our study provides evidence of a significant association between sleep disturbance and elevated galectin-3 level, independent of traditional metabolic biomarkers. Screening and interventions on galectin-3 could assist in preventing sleep disturbance-induced inflammatory disease.

Cigarette smoke-induced galectin-3 as a diagnostic biomarker and therapeutic target in lung tissue remodeling

Galectin-3 (Gal-3), a multifunctional carbohydrate-binding lectin, has emerged as a key player in various biological processes including inflammation, cancer, cardiovascular diseases and fibrotic disorders, however it remains unclear if Gal-3 is a bystander or drives lung tissue remodeling (LTR). Persistent exposure to cigarette smoke (CS) is the leading cause of oxidative and inflammatory damage to the lung tissues. CS-induced pathological increase in Gal-3 expression has been implicated in the pathogenesis of various respiratory conditions, such as chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF), and lung cancer. We and others have reported that CS induces Gal-3 synthesis and secretion, which modulates the pathological signaling pathways in lung epithelial cells implicating Gal-3 as a novel diagnostic marker and a factor driving LTR in CS-exposed lungs. Therefore, pharmacological interventions targeting Gal-3 and its upstream and downstream signaling pathways can help combat CS-induced LTR. Excitingly, preclinical models have demonstrated the efficacy of interventions such as Gal-3 expression inhibition, Gal-3 receptor blockade, and signaling pathways modulation open up promising avenues for future therapeutic interventions. Furthermore, targeting extracellular vesicles-mediated Gal-3 release and the potential of microRNA-based therapy are emerging as novel therapeutic approaches in CS-induced LTR and have been discussed in this article.

Novel Biomarkers and Advanced Cardiac Imaging in Aortic Stenosis: Old and New

Currently, the symptomatic status and left ventricular ejection fraction (LVEF) play a crucial role in aortic stenosis (AS) assessment. However, the symptoms are often subjective, and LVEF is not a sensitive marker of left ventricle (LV) decompensation. Over the past years, the cardiac structure and function research on AS has increased due to advanced imaging modalities and potential therapies. New imaging parameters emerged as predictors of disease progression in AS. LV global longitudinal strain has proved useful for risk stratification in asymptomatic severe AS patients with preserved LVEF. The assessment of myocardial fibrosis by cardiac magnetic resonance is the most studied application and offers prognostic information on AS. Moreover, the usage of biomarkers in AS as objective measures of LV decompensation has recently gained more interest. The present review focuses on the transition from compensatory LV hypertrophy (H) to LV dysfunction and the biomarkers associated with myocardial wall stress, fibrosis, and myocyte death. Moreover, we discuss the potential impact of non-invasive imaging parameters for optimizing the timing of aortic valve replacement and provide insight into novel biomarkers for possible prognostic use in AS. However, data from randomized clinical trials are necessary to define their utility in daily practice.

Serum Galectin-3 Predicts Mortality in Venoarterial Extracorporeal Membrane Oxygenation Patients

Objective

We investigated the potential use of galectin-3 (Gal-3) as a prognostic indicator for patients with cardiogenic shock and developed a predictive mortality model for venoarterial extracorporeal membrane oxygenation (VA-ECMO).

Methods

We prospectively studied patients (survivors and nonsurvivors) who received VA-ECMO for cardiogenic shock from 2019 to 2021. We recorded baseline data, Gal-3, and B-type natriuretic peptide (BNP) before ECMO and 24-72 h after ECMO. We used multivariable logistic regression to analyze significant risk factors and construct a VA-ECMO death prediction model. Receiver operating characteristic (ROC) curves were plotted to assess the predictive efficacy of the model.

Results

We enrolled 73 patients with cardiogenic shock who received VA-ECMO support; 38 (52.05%) died in hospital. The median age was 57 years (interquartile range (IQR): 48-67 years); the median duration of ECMO therapy was 5.8 days (IQR: 4.62-7.57 days); and the median intensive care unit stay was 19.04 days (IQR: 13.92-26.15 days). Compared with the nonsurvivors, survivors had lower acute physiology and chronic health evaluation (APACHE) II scores (p < 0.001), increased left ventricular ejection fraction (p < 0.05), lower Gal-3 levels at 24 and 72 h (both p = 0.001), lower BNP levels at 24 and 72 h (both p = 0.001), and higher platelet counts (p = 0.009). Further multivariable analysis showed that APACHE II score, BNP-T72, and Gal-3-T72 were independent risk factors for death in VA-ECMO patients. Gal-3 and BNP were positively correlated (p < 0.05) and decreased significantly during ECMO treatment. The areas under the ROC curve (AUC) for APACHE II score, Gal-3-T72, and BNP-T72 were 0.687, 0.799, and 0.723, respectively. We constructed a combined prediction model with an AUC of 0.884 (p < 0.01).

Conclusion

Gal-3 may serve as a prognostic indicator for patients receiving VA-ECMO for cardiogenic shock. The combined early warning score is a simple and effective tool for predicting mortality in VA-ECMO patients.

Enhancement of Bottle Gourd Oil Activity via Optimized Self-Dispersing Lipid Formulations (SDLFs) to Mitigate Isoproterenol-Evoked Cardiac Toxicity in Rats via Modulating BMP, MMP2, and miRNA-21 and miRNA-23a Genes' Expression

Bottle gourd (BG) oil (family Cucurbitaceae) has several pharmacological activities including a reduction of the hazard of cardiovascular and atherosclerosis conditions. This work aimed to develop and optimize self-dispersing lipid formulations (SDLFs) of BG oil by applying a full 32 factorial design. The formulation variables (oil concentration and surfactant mixture ratio) showed an obvious impact on the characters of the prepared BG-SDLFs including droplet size (DS), polydispersity index (PDI), emulsification time (ET), and transmission percentage (Tr%). The optimum BG-SDLF composed of 30% oil and Tween 80/Cremophor® RH40 (1:1) showed good emulsification characteristics and a better drug release profile compared with BG oil. In vivo study in isoproterenol-injected rats showed that BG oil and the optimized BG-SDLF improved cardiac function, by elevating the miRNA-23a gene expression level and decreasing miRNA-21 gene expression. They also caused the inhibition of the plasma B-type natriuretic peptide (BNP), N-terminal proatrial natriuretic peptide (NT-pro-BNP), cystatin c, galectin-3, lipoprotein-associated phospholipase A2 (Lp-PLA2), matrix metallopeptidase 2 (MMP2), cardiac troponin I (cTnI), and cardiac troponin T (cTnT). Our study demonstrated that BG oil and the optimized BG-SDLF provided a cardioprotection against isoproterenol-induced cardiac toxicity with better results in groups treated with the optimized BG-SDLF.

Involvement of Galectin-3 in neurocognitive impairment in obstructive sleep apnea via regulating inflammation and oxidative stress through NLRP3

OBJECTIVE

Accumulated studies have revealed that oxidative stress and inflammation play important roles in the development of OSA related cognitive dysfunction. Galectin-3, a member of the galectin family, has been reported to be involved in the neuroinflammatory diseases. However, the relationship between Galectin-3 and cognitive impairment in OSA remains ambiguous.

MATERIALS AND METHODS

47 new diagnosed OSA patients and 18 age-, gender-, education- and body mass index-matched healthy control subjects were enrolled in the present study. All subjects underwent whole-night in-laboratory polysomnography (PSG). Montreal Cognitive Assessment (MoCA) was used to evaluated the cognitive function of OSA patients. Serum Galectin-3, interleukin (IL)-1β and IL-8 were examined by enzyme-linked immunosorbent assay (ELISA). The levels of malonaldehyde (MDA), superoxide dismutase (SOD) and catalase (CAT) were measured to evaluate oxidative stress. Protein level of Galectin-3 and NLRP3 in peripheral blood mononuclear cells (PBMCs) and human microglial clone 3 (HMC3) cells were measured by Western Blot.

RESULTS

Serum Galectin-3 level in severe OSA patients (2.31 ± 0.43 ng/m) was higher than those in mild-moderate OSA patients (1.87 ± 0.32 ng/m, p < 0.001) and those in the healthy controls (1.56 ± 0.22 ng/ml, p < 0.001). Similarly, Galectin-3 level in PBMCs was increased with disease severity (p < 0.01). In addition, OSA patients also showed higher levels of inflammation and oxidative stress (p < 0.01). Patients with OSA scored significantly lower than healthy controls on the MoCA test after controlling for age, gender, education, and BMI. CPAP treatment for 12 weeks effectively reduced the levels of Galectin-3, inflammation and oxidative stress, as well as improved cognitive function of severe OSA patients. Closed correlations were observed between Galectin-3 with sleep respiratory parameters and cognitive dysfunction. In addition, we explored the underlying mechanism of Galectin-3 in neuroinflammation and oxidative stress. We treated HMC3 cells with LPS to mimic neuroinflammatory response in vitro. The results showed that LPS treatment led to a dose-dependent increase in Galectin-3 expression, meanwhile induced inflammation and oxidative stress. Inhibiting Galectin-3 with a specific Galectin-3 inhibitor, TD139, significantly ameliorated LPS-induced neuroinflammation and oxidative stress via suppressing NLRP3.

CONCLUSION

Current findings suggest that increased Galectin-3 might be involved in the cognitive impairment of OSA patients by promoting neuroinflammation and oxidative stress via regulating NLRP3. These results suggested that Galectin-3 inhibition may exert a protective role against the neurocognitive dysfunction associated with OSA.

ER stress and calcium-dependent arrhythmias

The sarcoplasmic reticulum (SR) plays the key role in cardiac function as the major source of Ca²⁺ that activates cardiomyocyte contractile machinery. Disturbances in finely-tuned SR Ca²⁺ release by SR Ca²⁺ channel ryanodine receptor (RyR2) and SR Ca²⁺ reuptake by SR Ca²⁺-ATPase (SERCa2a) not only impair contraction, but also contribute to cardiac arrhythmia trigger and reentry. Besides being the main Ca²⁺ storage organelle, SR in cardiomyocytes performs all the functions of endoplasmic reticulum (ER) in other cell types including protein synthesis, folding and degradation. In recent years ER stress has become recognized as an important contributing factor in many cardiac pathologies, including deadly ventricular arrhythmias. This brief review will therefore focus on ER stress mechanisms in the heart and how these changes can lead to pro-arrhythmic defects in SR Ca²⁺ handling machinery.

Essential Roles of Peroxiredoxin IV in Inflammation and Cancer

Peroxiredoxin IV (Prx4) is a 2-Cysteine peroxidase with ubiquitous expression in human tissues. Prx4 scavenges hydrogen peroxide and participates in oxidative protein folding in the endoplasmic reticulum. In addition, Prx4 is secreted outside the cell. Prx4 is upregulated in several cancers and is a potential therapeutic target. We have summarized historical and recent advances in the structure, function and biological roles of Prx4, focusing on inflammatory diseases and cancer. Oxidative stress is known to activate pro-inflammatory pathways. Chronic inflammation is a risk factor for cancer development. Hence, redox enzymes such as Prx4 are important players in the crosstalk between inflammation and cancer. Understanding molecular mechanisms of regulation of Prx4 expression and associated signaling pathways in normal physiological and disease conditions should reveal new therapeutic strategies. Thus, although Prx4 is a promising therapeutic target for inflammatory diseases and cancer, further research needs to be conducted to bridge the gap to clinical application.

Using the Plasma Proteome for Risk Stratifying Patients with Pulmonary Arterial Hypertension

Rationale: NT-proBNP (N-terminal pro-brain natriuretic peptide), a biomarker of cardiac origin, is used to risk stratify patients with pulmonary arterial hypertension (PAH). Its limitations include poor sensitivity to early vascular pathology. Other biomarkers of vascular or systemic origin may also be useful in the management of PAH. Objectives: Identify prognostic proteins in PAH that complement NT-proBNP and clinical risk scores. Methods: An aptamer-based assay (SomaScan version 4) targeting 4,152 proteins was used to measure plasma proteins in patients with idiopathic, heritable, or drug-induced PAH from the UK National Cohort of PAH (n = 357) and the French EFORT (Evaluation of Prognostic Factors and Therapeutic Targets in PAH) study (n = 79). Prognostic proteins were identified in discovery-replication analyses of UK samples. Proteins independent of 6-minute-walk distance and NT-proBNP entered least absolute shrinkage and selection operator modeling, and the best combination in a single score was evaluated against clinical targets in EFORT. Measurements and Main Results: Thirty-one proteins robustly informed prognosis independent of NT-proBNP and 6-minute-walk distance in the UK cohort. A weighted combination score of six proteins was validated at baseline (5-yr mortality; area under the curve [AUC], 0.73; 95% confidence interval [CI], 0.63-0.85) and follow-up in EFORT (AUC, 0.84; 95% CI, 0.75-0.94; P = 9.96 × 10^-6). The protein score risk stratified patients independent of established clinical targets and risk equations. The addition of the six-protein model score to NT-proBNP improved prediction of 5-year outcomes from AUC 0.762 (0.702-0.821) to 0.818 (0.767-0.869) by receiver operating characteristic analysis (P = 0.00426 for difference in AUC) in the UK replication and French samples combined. Conclusions: The plasma proteome informs prognosis beyond established factors in PAH and may provide a more sensitive measure of therapeutic response.

Severe Aortic Valve Stenosis and Pulmonary Hypertension: A Systematic Review of Non-Invasive Ways of Risk Stratification, Especially in Patients Undergoing Transcatheter Aortic Valve Replacement

Patients with severe aortic valve stenosis and concomitant pulmonary hypertension show a significantly reduced survival prognosis. Right heart catheterization as a preoperative diagnostic tool to determine pulmonary hypertension has been largely abandoned in recent years in favor of echocardiographic criteria. Clinically, determination of echocardiographically estimated systolic pulmonary artery pressure falls far short of invasive right heart catheterization data in terms of accuracy. The aim of the present systematic review was to highlight noninvasive possibilities for the detection of pulmonary hypertension in patients with severe aortic valve stenosis, with a special focus on cardiovascular biomarkers. A total of 525 publications regarding echocardiography, cardiovascular imaging and biomarkers related to severe aortic valve stenosis and pulmonary hypertension were analyzed in a systematic database analysis using PubMed Central®. Finally, 39 publications were included in the following review. It was shown that the current scientific data situation, especially regarding cardiovascular biomarkers as non-invasive diagnostic tools for the determination of pulmonary hypertension in severe aortic valve stenosis patients, is poor. Thus, there is a great scientific potential to combine different biomarkers (biomarker scores) in a non-invasive way to determine the presence or absence of PH.

Thiol-based redox-active proteins as cardioprotective therapeutic agents in cardiovascular diseases

Thiol-based redox compounds, namely thioredoxins (Trxs), glutaredoxins (Grxs) and peroxiredoxins (Prxs), stand as a pivotal group of proteins involved in antioxidant processes and redox signaling. Glutaredoxins (Grxs) are considered as one of the major families of proteins involved in redox regulation by removal of S-glutathionylation and thereby reactivation of other enzymes with thiol-dependent activity. Grxs are also coupled to Trxs and Prxs recycling and thereby indirectly contribute to reactive oxygen species (ROS) detoxification. Peroxiredoxins (Prxs) are a ubiquitous family of peroxidases, which play an essential role in the detoxification of hydrogen peroxide, aliphatic and aromatic hydroperoxides, and peroxynitrite. The Trxs, Grxs and Prxs systems, which reversibly induce thiol modifications, regulate redox signaling involved in various biological events in the cardiovascular system. This review focuses on the current knowledge of the role of Trxs, Grxs and Prxs on cardiovascular pathologies and especially in cardiac hypertrophy, ischemia/reperfusion (I/R) injury and heart failure as well as in the presence of cardiovascular risk factors, such as hypertension, hyperlipidemia, hyperglycemia and metabolic syndrome. Further studies on the roles of thiol-dependent redox systems in the cardiovascular system will support the development of novel protective and therapeutic strategies against cardiovascular diseases.

Role of novel biomarkers in diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is commonly defined as cardiomyopathy in patients with diabetes mellitus in the absence of coronary artery disease and hypertension. As DCM is now recognized as a cause of substantial morbidity and mortality among patients with diabetes mellitus and clinical diagnosis is still inappropriate, various expert groups struggled to identify a suitable biomarker that will help in the recognition and management of DCM, with little success so far. Hence, we thought it important to address the role of biomarkers that have shown potential in either human or animal studies and which could eventually result in mitigating the poor outcomes of DCM. Among the array of biomarkers we thoroughly analyzed, long noncoding ribonucleic acids, soluble form of suppression of tumorigenicity 2 and galectin-3 seem to be most beneficial for DCM detection, as their plasma/serum levels accurately correlate with the early stages of DCM. The combination of relatively inexpensive and accurate speckle tracking echocardiography with some of the highlighted biomarkers may be a promising screening method for newly diagnosed diabetes mellitus type 2 patients. The purpose of the screening test would be to direct affected patients to more specific confirmation tests. This perspective is in concordance with current guidelines that accentuate the importance of an interdisciplinary team-based approach.

Lgals9 deficiency ameliorates obesity by modulating redox state of PRDX2

The adipose tissue is regarded as an endocrine organ and secretes bioactive adipokines modulating chronic inflammation and oxidative stress in obesity. Gal-9 is secreted out upon cell injuries, interacts with T-cell immunoglobulin-3 (Tim-3) and induces apoptosis in activated Th1 cells. Gal-9 also binds to protein disulfide isomerase (PDI), maintains PDI on surface of T cells, and increases free thiols in the disulfide/thiol cycles. To explore the molecular mechanism of obesity, we investigated Gal-9^−/− and Gal-9^wt/wt C57BL/6J mice fed with high fat-high sucrose (HFHS) chow. Gal-9^−/− mice were resistant to diet-induced obesity associated with reduction of epididymal and mesenteric fat tissues and improved glucose tolerance compared with Gal-9^wt/wt mice. However, the number of M1, M2 macrophages, and M1/M2 ratio in epididymal fat were unaltered. Under HFHS chow, Gal-9^−/− mice receiving Gal-9^−/− or Gal-9^wt/wt bone marrow-derived cells (BMCs) demonstrated significantly lower body weight compared with Gal-9^wt/wt mice receiving Gal-9^−/− BMCs. We identified the binding between Gal-9 and peroxiredoxin-2 (PRDX2) in sugar chain-independent manner by nanoLC-MS/MS, immunoprecipitation, and pull-down assay. In 3T3L1 adipocytes, Gal-9 knockdown shifts PRDX2 monomer (reduced form) dominant from PRDX2 dimer (oxidized form) under oxidative stress with H₂O₂. The inhibition of Gal-9 in adipocytes may be a new therapeutic approach targeting the oxidative stress and subsequent glucose intolerance in obesity.

Oxidative Stress and Vascular Damage in the Context of Obesity: The Hidden Guest

The vascular system plays a central role in the transport of cells, oxygen and nutrients between different regions of the body, depending on the needs, as well as of metabolic waste products for their elimination. While the structure of different components of the vascular system varies, these structures, especially those of main arteries and arterioles, can be affected by the presence of different cardiovascular risk factors, including obesity. This vascular remodeling is mainly characterized by a thickening of the media layer as a consequence of changes in smooth muscle cells or excessive fibrosis accumulation. These vascular changes associated with obesity can trigger functional alterations, with endothelial dysfunction and vascular stiffness being especially common features of obese vessels. These changes can also lead to impaired tissue perfusion that may affect multiple tissues and organs. In this review, we focus on the role played by perivascular adipose tissue, the activation of the renin-angiotensin-aldosterone system and endoplasmic reticulum stress in the vascular dysfunction associated with obesity. In addition, the participation of oxidative stress in this vascular damage, which can be produced in the perivascular adipose tissue as well as in other components of the vascular wall, is updated.

Review of galectin-3 inhibitors in the treatment of nonalcoholic steatohepatitis

INTRODUCTION

Galectin-3 (Gal-3) is a β-galactoside binding protein associated with many disease pathologies, including chronic inflammation and fibrogenesis. It has been implicated in the disease severity of NASH, although its precise role is unknown. Inhibition of Gal-3 has shown to improve and prevent fibrosis progression and has now reached phase III clinical trial in NASH patients.

AREAS COVERED

This discusses the role of Gal-3 in NASH. It brings together the current findings of Gal-3 in NASH and hepatic fibrosis by analyzing recent data from animal model studies and clinical trials.

EXPERT OPINION

Gal-3 inhibitors, in particular, Belapectin (GR-MD-02), have shown promising results for NASH with advanced fibrosis. In a phase 2 trial, Belapectin did not meet the primary endpoint. However, a sub-analysis of Belapectin among a separate group of patients without esophageal varices showed 2 mg/kg of GR-MD-02 reduced HVPG and the development of new varices. A subsequent study is under way, aiming to replicate the positive findings in phase 2 and demonstrate greater efficacy. If Belapectin is shown to be effective, it will be coupled with other drugs that target steatohepatitis to maximize efficacy and disease reversal.

Adding insult to injury - Inflammation at the heart of cardiac fibrosis

The fibrotic response has evolutionary worked in tandem with the inflammatory response to facilitate healing following injury or tissue destruction as a result of pathogen clearance. However, excessive inflammation and fibrosis are key pathological drivers of organ tissue damage. Moreover, fibrosis can occur in several conditions associated with chronic inflammation that are not directly caused by overt tissue injury or infection. In the heart, in particular, fibrotic adverse cardiac remodeling is a key pathological driver of cardiac dysfunction in heart failure. Cardiac fibroblast activation and immune cell activation are two mechanistic domains necessary for fibrotic remodeling in the heart, and, independently, their contributions to cardiac fibrosis and cardiac inflammation have been studied and reviewed thoroughly. The interdependence of these two processes, and how their cellular components modulate each other's actions in response to different cardiac insults, is only recently emerging. Here, we review recent literature in cardiac fibrosis and inflammation and discuss the mechanisms involved in the fibrosis-inflammation axis in the context of specific cardiac stresses, such as myocardial ischemia, and in nonischemic heart conditions. We discuss how the search for anti-inflammatory and anti-fibrotic therapies, so far unsuccessful to date, needs to be based on our understanding of the interdependence of immune cell and fibroblast activities. We highlight that in addition to the extensively reviewed role of immune cells modulating fibroblast function, cardiac fibroblasts are central participants in inflammation that may acquire immune like cell functions. Lastly, we review the gut-heart axis as an example of a novel perspective that may contribute to our understanding of how immune and fibrotic modulation may be indirectly modulated as a potential area for therapeutic research.

Targeting cardiac fibrosis in heart failure with preserved ejection fraction: mirage or miracle?

Cardiac fibrosis is central to the pathology of heart failure, particularly heart failure with preserved ejection fraction (HFpEF). Irrespective of the underlying profibrotic condition (e.g. ageing, diabetes, hypertension), maladaptive cardiac fibrosis is defined by the transformation of resident fibroblasts to matrix-secreting myofibroblasts. Numerous profibrotic factors have been identified at the molecular level (e.g. TGFβ, IL11, AngII), which activate gene expression programs for myofibroblast activation. A number of existing HF therapies indirectly target fibrotic pathways; however, despite multiple clinical trials in HFpEF, a specific clinically effective antifibrotic therapy remains elusive. Therapeutic inhibition of TGFβ, the master-regulator of fibrosis, has unfortunately proven toxic and ineffective in clinical trials to date, and new approaches are needed. In this review, we discuss the pathophysiology and clinical implications of interstitial fibrosis in HFpEF. We provide an overview of trials targeting fibrosis in HFpEF to date and discuss the promise of potential new therapeutic approaches and targets in the context of underlying molecular mechanisms.

Pharmacological Inhibition of Galectin-3 Ameliorates Diabetes-Associated Cognitive Impairment, Oxidative Stress and Neuroinflammation in vivo and in vitro

Background

In diabetes, cognitive impairment is linked with oxidative stress and neuroinflammation. As the only chimeric member of the galectin family, galectin-3 (Gal3) induces neuroinflammation and cognitive impairment in models of Alzheimer’s disease (AD); however, its role in diabetes-associated cognitive impairment is not established.

Methodology

Here, we investigated the effects of Gal3 inhibition on cognitive impairment and the possible underlying molecular events in diabetes. We investigated the effects of the Gal3 inhibitor modified citrus pectin (MCP; 100 mg/kg/day oral for 6 weeks) in vivo in high-fat diet (HFD)/streptozotocin (STZ)-induced diabetic rats. Additionally, the effects of MCP on high glucose (HG)-stimulated BV-2 microglial cells were investigated in vitro.

Results

We found that MCP attenuated memory impairment in diabetic rats in the Morris water maze test and reduced insulin resistance, oxidative stress, and neuroinflammation. In HG-stimulated BV-2 microglial cells, MCP increased cell viability and decreased oxidative stress and the production of proinflammatory cytokines.

Conclusion

The results of this study indicate that the inhibition of Gal3 by MCP ameliorates diabetes-associated cognitive impairment, oxidative stress, and neuroinflammation, suggesting that Gal3 could be a potential new target for therapeutic intervention to prevent cognitive impairment in diabetes.

Oxidative Stress in Cardiovascular Diseases

Reactive oxygen species (ROS) are subcellular messengers in signal transductions pathways with both beneficial and deleterious roles. ROS are generated as a by-product of mitochondrial respiration or metabolism or by specific enzymes such as superoxide dismutases, glutathione peroxidase, catalase, peroxiredoxins, and myeloperoxidases. Under physiological conditions, the low levels of ROS production are equivalent to their detoxification, playing a major role in cellular signaling and function. In pathological situations, particularly atherosclerosis or hypertension, the release of ROS exceeds endogenous antioxidant capacity, leading to cell death. At cardiovascular levels, oxidative stress is highly implicated in myocardial infarction, ischemia/reperfusion, or heart failure. Here, we will first detail the physiological role of low ROS production in the heart and the vessels. Indeed, ROS are able to regulate multiple cardiovascular functions, such as cell proliferation, migration, and death. Second, we will investigate the implication of oxidative stress in cardiovascular diseases. Then, we will focus on ROS produced by NAPDH oxidase or during endothelial or mitochondrial dysfunction. Given the importance of oxidative stress at the cardiovascular level, antioxidant therapies could be a real benefit. In the last part of this review, we will detail the new therapeutic strategies potentially involved in cardiovascular protection and currently under study.

Soluble St2 Induces Cardiac Fibroblast Activation and Collagen Synthesis via Neuropilin-1

Circulating levels of soluble interleukin 1 receptor-like 1 (sST2) are increased in heart failure and associated with poor outcome, likely because of the activation of inflammation and fibrosis. We investigated the pathogenic role of sST2 as an inductor of cardiac fibroblasts activation and collagen synthesis. The effects of sST2 on human cardiac fibroblasts was assessed using proteomics and immunodetection approaches to evidence the upregulation of neuropilin-1 (NRP-1), a regulator of the profibrotic transforming growth factor (TGF)-β1. In parallel, sST2 increased fibroblast activation, collagen and fibrosis mediators. Pharmacological inhibition of nuclear factor-kappa B (NF-κB) restored NRP-1 levels and blocked profibrotic effects induced by sST2. In NRP-1 knockdown cells, sST2 failed to induce fibroblast activation and collagen synthesis. Exogenous NRP-1 enhanced cardiac fibroblast activation and collagen synthesis via NF-κB. In a pressure overload rat model, sST2 was elevated in association with cardiac fibrosis and was positively correlated with NRP-1 expression. Our study shows that sST2 induces human cardiac fibroblasts activation, as well as the synthesis of collagen and profibrotic molecules. These effects are mediated by NRP-1. The blockade of NF-κB restored NRP-1 expression, improving the profibrotic status induced by sST2. These results show a new pathogenic role for sST2 and its mediator, NRP-1, as cardiac fibroblast activators contributing to cardiac fibrosis.

Galectin-3 inhibition attenuates doxorubicin-induced cardiac dysfunction by upregulating the expression of peroxiredoxin-4

Doxorubicin (DOX) is a highly efficient chemotherapeutic drug limited by its cardiotoxicity. Galectin-3 (Gal-3) overexpression is associated with several cardiovascular diseases. In this study, the in vivo models of DOX-treated rats and the in vitro model of DOX-treated H9C2 cells were used. DOX induced cardiac injury and dysfunction accompanied with the upregulation of Gal-3 at the end of the experiment, while inhibition of Gal-3 with modified citrus pectin (MCP) exhibited a dramatic improvement in cardiac function of the DOX-treated rats, as manifested by increased left ventricular systolic pressure and ±dp/dt_max and decreased left ventricular end-diastolic pressure. The plasma levels of myocardial injury markers such as lactate dehydrogenase, creatine kinase, creatine kinase-MB, and cardiac troponin I were decreased after MCP treatment. In parallel, MCP attenuated myocardial tissue markers of oxidative stress such as hydrogen peroxide and malondialdehyde restored the activities of superoxide dismutase, catalase, and glutathione peroxidase and upregulated antioxidant peroxiredoxin-4 (Prx-4). To further verify the role of Prx-4, it was downregulated by siRNA-mediated knockdown in H9C2 cells. MCP could not reverse DOX-induced oxidative stress in Prx-4-knock-down cells. In conclusion, Gal-3 mediated DOX-induced cardiotoxicity and Gal-3 inhibition attenuated DOX-induced cardiac dysfunction by upregulating the expression of Prx-4 to reduce myocardial oxidative stress.

Ageing-related changes in the levels of β-catenin, CacyBP/SIP, galectin-3 and immunoproteasome subunit LMP7 in the heart of men

Aging is a major risk factor for morbidity and mortality from cardiovascular causes in men. To better understand the cellular processes related to age-related cardiac complications, we undertook research aimed at comparative evaluation of genes expression and distribution of β-catenin, CacyBP/SIP, galectin-3 and LMP7 in the heart of healthy men in different age groups. The study was conducted on the hearts of 12 men (organ donors) without a history of cardiovascular disease, who were divided into two age groups: men under and men over 45 years of age. On paraffin sections, immunohistochemical reactions were performed to detect β-catenin, CacyBP/SIP, galectin-3 and immunoproteasome subunit LMP7. The expression of genes coding β-catenin, CacyBP/SIP, galectin-3 and LMP7 was also evaluated by real-time PCR method. In the heart of men over 45 years old, both gene expression and immunoreactivity of β-catenin, CacyBP/SIP, galectin-3 and LMP7 were stronger compared to younger individuals. The results of the presented studies suggest that β-catenin, CacyBP/SIP, galectin-3 and immunoproteasomes might be involved in the internal regulation of heart homeostasis during ageing.

Circulating galectin-3 on admission and prognosis in acute heart failure patients: a meta-analysis

Changes of serum galectin-3 have been associated with the pathogenesis of many cardiovascular diseases. The aim of the study was to evaluate the prognostic role of serum galectin-3 in patients with acute heart failure (AHF) in a meta-analysis. Follow-up studies evaluating the association between serum galectin-3 on admission and clinical outcomes in AHF patients were identified via search of PubMed and Embase databases. A random effects or a fixed effects model was applied to pool the results depending on the heterogeneity. Subgroup analysis was used to evaluate the influences of study characteristics on the outcomes. Overall, 7057 AHF patients from eighteen follow-up studies were included. Higher serum galectin-3 was associated with higher risks of all-cause mortality (adjusted risk ratio [RR], 1.58; p < 0.001), mortality/HF rehospitalization (RR, 1.68; p < 0.001), and cardiovascular mortality (RR, 1.29; p = 0.04), but not HF rehospitalization (RR, 1.24; p = 0.25) in AHF patients. Subgroup analyses showed that study characteristics including study design, sample size, age, gender, left ventricular ejection fraction, galectin-3 variable type, follow-up duration, and adjustment of type B natriuretic peptide did not significantly impact the results. Significant heterogeneities were detected for the outcomes of all-cause mortality and mortality/HF rehospitalization. However, trim-and-fill analyses by including the imputed studies to generate symmetrical funnel plots showed similar significant meta-analysis results. These results suggested that higher serum galectin-3 may be associated with poor prognosis in AHF patients. Further studies are needed to determine the mechanisms underlying the potential prognostic role of galectin-3 in AHF.

Protective role of peroxiredoxin-4 in heart failure

Recently, we have read with great interest the article published by Ibarrola et al. (Clin. Sci. (Lond.) (2018) 132, 1471-1485), which used proteomics and immunodetection methods to show that Galectin-3 (Gal-3) down-regulated the antioxidant peroxiredoxin-4 (Prx-4) in cardiac fibroblasts. Authors concluded that 'antioxidant activity of Prx-4 had been identified as a protein down-regulated by Gal-3. Moreover, Gal-3 induced a decrease in total antioxidant capacity which resulted in a consequent increase in peroxide levels and oxidative stress markers in cardiac fibroblasts.' We would like to point out some results stated in the article that need further investigation and more detailed discussion to clarify certain factors involved in the protective role of Prx-4 in heart failure.

(Letter to the Editor) Response to: protective role of peroxiredoxin-4 in heart failure

We thank Ahmed et al. for their letter regarding our study 'Galectin-3 down-regulates antioxidant peroxiredoxin-4 in human cardiac fibroblasts' [1]. As emphasized by Ahmed et al., Prx-4 levels decrease [2] whereas MFN-2, OPA-1 and PGC-1α levels increase [3] in dilated cardiomyopathy (DCM). Moreover, Gal-3 expression is also increased in DCM [4]. In our study, we showed in vitro that Gal-3 decreased Prx-4 without modifying MFN-2 or PGC-1α levels in human cardiac fibroblasts. Although cardiac Prx-4 decrease could be a direct consequence of Gal-3 effects on cardiac fibroblasts, we cannot exclude the possibility that other factors increase MFN-2, OPA-1 and PGC-1α levels in both cardiac fibroblasts or cardiomyocytes in the context of DCM. Further studies are needed to clarify the association between Prx-4 decrease and the increase in other mitochondrial proteins in DCM.

Pleiotropic Effects of Modified Citrus Pectin

Modified citrus pectin (MCP) has a low-molecular-weight degree of esterification to allow absorption from the small intestinal epithelium into the circulation. MCP produces pleiotropic effects, including but not limited to its antagonism of galectin-3, which have shown benefit in preclinical and clinical models. Regarding cancer, MCP modulates several rate-limiting steps of the metastatic cascade. MCP can also affect cancer cell resistance to chemotherapy. Regarding fibrotic diseases, MCP modulates many of the steps involved in the pathogenesis of aortic stenosis. MCP also reduces fibrosis to the kidney, liver, and adipose tissue. Other benefits of MCP include detoxification and improved immune function. This review summarizes the pleiotropic effects of MCP.

Rethinking the impact of RG-I mainly from fruits and vegetables on dietary health

Rhamnogalacturonan I (RG-I) pectin is composed of backbone of repeating disaccharide units →2)-α-L-Rhap-(1→4)-α-D-GalpA-(1→ and neutral sugar side-chains mainly consisting of arabinose and galactose having variable types of linkages. However, since traditional pectin extraction methods damages the RG-I structure, the characteristics and health effects of RG-I remains unclear. Recently, many studies have focused on RG-I, which is often more active than the homogalacturonan (HG) portion of pectic polysaccharides. In food products, RG-I is common to fruits and vegetables and possesses many health benefits. This timely and comprehensive review describes the many different facets of RG-I, including its dietary sources, history, metabolism and potential functionalities, all of which have been compiled to establish a platform for taking full advantage of the functional value of RG-I pectin.

Soluble ST2 promotes oxidative stress and inflammation in cardiac fibroblasts: an in vitro and in vivo study in aortic stenosis

Background: Soluble ST2 (interleukin 1 receptor-like 1) (sST2) is involved in inflammatory diseases and increased in heart failure (HF). We herein investigated sST2 effects on oxidative stress and inflammation in human cardiac fibroblasts and its pathological role in human aortic stenosis (AS).

Methods and results: Using proteomics and immunodetection approaches, we have identified that sST2 down-regulated mitofusin-1 (MFN-1), a protein involved in mitochondrial fusion, in human cardiac fibroblasts. In parallel, sST2 increased nitrotyrosine, protein oxidation and peroxide production. Moreover, sST2 enhanced the secretion of pro-inflammatory cytokines interleukin (IL)-6, IL-1β and monocyte chemoattractant protein-1 (CCL-2). Pharmacological inhibition of transcriptional factor nuclear factor κB (NFκB) restored MFN-1 levels and improved oxidative status and inflammation in cardiac fibroblasts. Mito-Tempo, a mitochondria-specific superoxide scavenger, as well as Resveratrol, a general antioxidant, attenuated oxidative stress and inflammation induced by sST2. In myocardial biopsies from 26 AS patients, sST2 up-regulation paralleled a decrease in MFN-1. Cardiac sST2 inversely correlated with MFN-1 levels and positively associated with IL-6 and CCL-2 in myocardial biopsies from AS patients.

Conclusions: sST2 affected mitochondrial fusion in human cardiac fibroblasts, increasing oxidative stress production and inflammatory markers secretion. The blockade of NFκB or mitochondrial reactive oxygen species restored MFN-1 expression, improving oxidative stress status and reducing inflammatory markers secretion. In human AS, cardiac sST2 levels associated with oxidative stress and inflammation. The present study reveals a new pathogenic pathway by which sST2 promotes oxidative stress and inflammation contributing to cardiac damage.

β-Adrenoceptor activation affects galectin-3 as a biomarker and therapeutic target in heart disease

Myocardial fibrosis is a key histopathological component that drives the progression of heart disease leading to heart failure and constitutes a therapeutic target. Recent preclinical and clinical studies have implicated galectin-3 (Gal-3) as a pro-fibrotic molecule and a biomarker of heart disease and fibrosis. However, our knowledge is poor on the mechanism(s) that determine the blood level or regulate cardiac expression of Gal-3. Recent studies have demonstrated that enhanced β-adrenoceptor activity is a determinant of both circulating concentration and cardiac expression of Gal-3. Pharmacological or transgenic activation of β-adrenoceptors leads to increased blood levels of Gal-3 and up-regulated cardiac Gal-3 expression, effect that can be reversed with the use of β-adrenoceptor antagonists. Conversely, Gal-3 gene deletion confers protection against isoprenaline-induced cardiotoxicity and fibrogenesis. At the transcription level, β-adrenoceptor stimulation activates cardiac mammalian sterile-20-like kinase 1, a pivotal kinase of the Hippo signalling pathway, which is associated with Gal-3 up-regulation. Recent studies have suggested a role for the β-adrenoceptor-Hippo signalling pathway in the regulation of cardiac Gal-3 expression thereby contributing to the onset and progression of heart disease. This implies a therapeutic potential of the suppression of Gal-3 expression. In this review, we discuss the effects of β-adrenoceptor activity on Gal-3 as a biomarker and causative mediator in the setting of heart disease and point out pivotal knowledge gaps. LINKED ARTICLES: This article is part of a themed section on Adrenoceptors-New Roles for Old Players. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.14/issuetoc.

Galectin-3 aggravates ox-LDL-induced endothelial dysfunction through LOX-1 mediated signaling pathway

Galectin-3, a biomarker linking oxidative stress and inflammation, participates in different mechanisms related to atherothrombosis, such as inflammation, proliferation, or macrophage chemotaxis. Accumulating evidence indicates that galectin-3 may also promote atherogenesis through inducing endothelial dysfunction. Lectin-like oxidized low-density lipoprotein (oxLDL) receptor-1 (LOX-1), a receptor for oxLDL uptake, contributes to oxLDL-induced endothelial dysfunction. Whether galectin-3 induces endothelial dysfunction through modulation of LOX-1-mediated signaling remains unclear. In the present study, we explored the mechanisms underlying galectin-3 enhanced cytotoxicity of oxLDL in human umbilical vein endothelial cells (HUVECs) and the role of LOX-1. Incubation of HUVECs with galectin-3 increased the expression of LOX-1 in RNA and protein levels. In addition, the expression of LOX-1 induced by oxLDL was promoted by galectin-3. However, pretreatment of LOX-1 antibody reduced LOX-1 mRNA expression level in cells with oxLDL plus galectin-3 incubation. Compared to cells treated with oxLDL alone, reactive oxygen species (ROS) generation via nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation and subsequent activation of p38 mitogen-activated protein kinases followed by nuclear factor kappa B (NF-κB) activation and related inflammatory responses including adhesion molecule expression, adhesiveness of monocytic cells, and IL-8 release were also aggravated in cells treated with galectin-3 combined with oxLDL. Compared to cells treated with galectin-3 plus oxLDL group. We found that LOX-1 antibody mitigated NADPH oxidase activity, p-38 up-regulation, NF-κB activation, and proinflammatory responses in cells treated with galectin-3 combined with oxLDL. We conclude that galectin-3 enhances endothelial LOX-1 expression and propose a new mechanism by which galectin-3 may promote endothelial dysfunction by inducing inflammation via LOX-1/ROS/p38/NF-κB-mediated signaling pathway.