Galectin-3 interferes with tissue repair and promotes cardiac dysfunction and comorbidities in a genetic heart failure model

Macrophages in Cardiovascular Fibrosis: Novel Subpopulations, Molecular Mechanisms, and Therapeutic Targets

Cardiovascular fibrosis is a common pathological process that contributes to the development and progression of various cardiovascular diseases. Despite being widely believed to be an irreversible and relentless process, preclinical models and clinical trials have shown that cardiovascular fibrosis is an extremely dynamic process. Additionally, as part of the innate immune system, macrophages are heterogeneous cells that are pivotal in tissue regeneration and fibrosis. They participate in fibroblast activation, extracellular matrix remodelling, and the regression of fibrosis. Although we have made some advances in understanding macrophages in cardiovascular fibrosis, a gap still remains between their identification and conversion into effective treatments. Moreover, the traditional M1-M2 paradigm faces many challenges because it does not sufficiently clarify macrophage diversity and their functions. Exploring novel macrophage-based therapies is urgent for cardiovascular fibrosis treatment. Single-cell techniques have shed light on identifying novel subpopulations that differ in function and molecular signature under steady-state and pathological conditions. In this review, we outline the developmental origins of macrophages, which underlie their functions; and recent technology development in the single-cell era. In addition, we describe the markers and mediators of the newly defined macrophage subpopulations and the molecular mechanisms involved to elucidate potential approaches for targeting macrophages in cardiovascular fibrosis.

Identification of fibrosis-associated biomarkers in heart failure and human cancers

BACKGROUND

Heart failure (HF) and cancer share common risk factors and pathophysiological mechanisms, including fibrosis. Identifying biomarkers and therapeutic targets for both conditions is crucial.

MATERIALS AND METHODS

RNA sequencing data from HF patients were analyzed to identify 12 genes associated with myocardial fibrosis. Validation was performed using public datasets, and functional enrichment analyses were conducted. Gene expression patterns and prognostic value in various cancers were assessed.

RESULTS

Fibromodulin (FMOD), Periostin (POSTN), Latent Transforming Growth Factor Beta Binding Protein 2 (LTBP2), Collagen Type I Alpha 1 Chain (COL1A1), Collagen Type VIII Alpha 1 Chain (COL8A1), Asporin (ASPN), and Hemoglobin Subunit Beta (HBB) showed significant dysregulation in heart failure tissues and were implicated in multiple cancer types. Pan-cancer analysis revealed associations between these genes and prognosis. Correlations with cancer-associated fibroblasts were also observed.

CONCLUSION

FMOD, POSTN, LTBP2, COL1A1, COL8A1, ASPN, and HBB are potential biomarkers for HF and cancer with fibrotic microenvironments. Targeting fibrosis may offer novel therapeutic approaches. Further validation and mechanistic studies are needed. This study contributes to understanding HF and cancer at the molecular level and suggests personalized treatment strategies.

The Macrophage-Fibroblast Dipole in the Context of Cardiac Repair and Fibrosis

Stromal and immune cells and their interactions have gained the attention of cardiology researchers and clinicians in recent years as their contribution in cardiac repair is increasingly recognized. The repair process in the heart is a particularly critical constellation of complex molecular and cellular events and interactions that characteristically fail to ensure adequate recovery following injury, insult, or exposure to stress conditions in this regeneration-hostile organ. The tremendous consequence of this pronounced inability to maintain homeostatic states is being translated in numerous ways promoting progress into heart failure, a deadly, irreversible condition requiring organ transplantation. Fibrosis is in fact a repair response eventually promoting cardiac dysfunction and cardiac fibroblasts are the major cellular players in this process, overproducing collagens and other extracellular matrix components when activated. On the other hand, macrophages may differentially affect fibroblasts and cardiac repair depending on their status and subsets. The opposite interaction is also probable. We discuss here the multifaceted aspects and crosstalk of this cell dipole and the opportunities it may offer for beneficial manipulation approaches that will hopefully lead to progress in heart disease interventions.

Matricellular proteins: From cardiac homeostasis to immune regulation

Tissue repair after myocardial injury is a complex process involving changes in all aspects of the myocardial tissue, including the extracellular matrix (ECM). The ECM is composed of large structural proteins such as collagen and elastin and smaller proteins with major regulatory properties called matricellular proteins. Matricellular cell proteins exert their functions and elicit cellular responses by binding to structural proteins not limited to interactions with cell surface receptors, cytokines, or proteases. At the same time, matricellular proteins act as the "bridge" of information exchange between cells and ECM, maintaining the integrity of the cardiac structure and regulating the immune environment, which is a key factor in determining cardiac homeostasis. In this review, we present an overview of the identified matricellular proteins and summarize the current knowledge regarding their roles in maintaining cardiac homeostasis and regulating the immune system.

C-C Motif Chemokine Ligand 2 and Chemokine Receptor 2 in Cardiovascular and Neural Aging and Aging-Related Diseases

Aging is a prominent risk factor for numerous chronic diseases. Understanding the shared mechanisms of aging can aid in pinpointing therapeutic targets for age-related disorders. Chronic inflammation has emerged as a pivotal mediator of aging and a determinant in various age-related chronic conditions. Recent findings indicate that C-C motif chemokine ligand 2 and receptor 2 (CCL2-CCR2) signaling, an important physiological modulator in innate immune response and inflammatory defense, plays a crucial role in aging-related disorders and is increasingly recognized as a promising therapeutic target, highlighting its significance. This review summarizes recent advances in the investigation of CCL2-CCR2 signaling in cardiovascular and neural aging, as well as in various aging-related disorders. It also explores the underlying mechanisms and therapeutic potentials in these contexts. These insights aim to deepen our understanding of aging pathophysiology and the development of aging-related diseases.

Understanding Galectin-3's Role in Diastolic Dysfunction: A Contemporary Perspective

Diastolic dysfunction, a prevalent condition characterized by impaired relaxation and filling of the left ventricle, significantly contributes to heart failure with preserved ejection fraction (HFpEF). Galectin-3, a β-galactoside-binding lectin, has garnered attention as a potential biomarker and mediator of fibrosis and inflammation in cardiovascular diseases. This comprehensive review investigates the impact of galectin-3 on diastolic dysfunction. We explore its molecular mechanisms, including its involvement in cellular signaling pathways and interaction with components of the extracellular matrix. Evidence from both animal models and clinical studies elucidates galectin-3's role in cardiac remodeling, inflammation, and fibrosis, shedding light on the underlying pathophysiology of diastolic dysfunction. Additionally, we examine the diagnostic and therapeutic implications of galectin-3 in diastolic dysfunction, emphasizing its potential as both a biomarker and a therapeutic target. This review underscores the significance of comprehending galectin-3's role in diastolic dysfunction and its promise in enhancing diagnosis and treatment approaches for HFpEF patients.

Proteomics couples electrical remodelling to inflammation in a murine model of heart failure with sinus node dysfunction

AIMS

In patients with heart failure (HF), concomitant sinus node dysfunction (SND) is an important predictor of mortality, yet its molecular underpinnings are poorly understood. Using proteomics, this study aimed to dissect the protein and phosphorylation remodelling within the sinus node in an animal model of HF with concurrent SND.

METHODS AND RESULTS

We acquired deep sinus node proteomes and phosphoproteomes in mice with heart failure and SND and report extensive remodelling. Intersecting the measured (phospho)proteome changes with human genomics pharmacovigilance data, highlighted downregulated proteins involved in electrical activity such as the pacemaker ion channel, Hcn4. We confirmed the importance of ion channel downregulation for sinus node physiology using computer modelling. Guided by the proteomics data, we hypothesized that an inflammatory response may drive the electrophysiological remodeling underlying SND in heart failure. In support of this, experimentally induced inflammation downregulated Hcn4 and slowed pacemaking in the isolated sinus node. From the proteomics data we identified proinflammatory cytokine-like protein galectin-3 as a potential target to mitigate the effect. Indeed, in vivo suppression of galectin-3 in the animal model of heart failure prevented SND.

CONCLUSION

Collectively, we outline the protein and phosphorylation remodeling of SND in heart failure, we highlight a role for inflammation in electrophysiological remodelling of the sinus node, and we present galectin-3 signalling as a target to ameliorate SND in heart failure.

Involvement of Matricellular Proteins in Cellular Senescence: Potential Therapeutic Targets for Age-Related Diseases

Senescence is a physiological and pathological cellular program triggered by various types of cellular stress. Senescent cells exhibit multiple characteristic changes. Among them, the characteristic flattened and enlarged morphology exhibited in senescent cells is observed regardless of the stimuli causing the senescence. Several studies have provided important insights into pro-adhesive properties of cellular senescence, suggesting that cell adhesion to the extracellular matrix (ECM), which is involved in characteristic morphological changes, may play pivotal roles in cellular senescence. Matricellular proteins, a group of structurally unrelated ECM molecules that are secreted into the extracellular environment, have the unique ability to control cell adhesion to the ECM by binding to cell adhesion receptors, including integrins. Recent reports have certified that matricellular proteins are closely involved in cellular senescence. Through this biological function, matricellular proteins are thought to play important roles in the pathogenesis of age-related diseases, including fibrosis, osteoarthritis, intervertebral disc degeneration, atherosclerosis, and cancer. This review outlines recent studies on the role of matricellular proteins in inducing cellular senescence. We highlight the role of integrin-mediated signaling in inducing cellular senescence and provide new therapeutic options for age-related diseases targeting matricellular proteins and integrins.

Understanding aconite's anti-fibrotic effects in cardiac fibrosis

BACKGROUND

The prevalence of cardiac fibrosis, intricately linked to various cardiovascular diseases, continues to rise. Aconite, a traditional Chinese herb renowned for its cardiovascular benefits, holds promise in treating heart ailments. However, the mechanisms underlying its anti-fibrotic effects, particularly in cardiac fibrosis, remain elusive.

HYPOTHESIS/PURPOSE

This study aims to shed light on aconite's potential as an anti-fibrotic agent and elucidate its mechanisms in a rat model of isoproterenol (ISO)-induced cardiac fibrosis.

METHODS

By inducing cardiac fibrosis through ISO injection, the study investigates the role of decoction of white aconite (DWA) in mitigating fibrotic processes. Techniques including metabolomics, RT-qPCR, western blot, and immunofluorescence were employed to unveil the molecular changes induced by DWA.

RESULTS

DWA exhibited a remarkable reduction in echocardiographic parameters, cardiac weight increase, myocardial infarction extent, inflammatory cell infiltration, collagen deposition in heart tissue, and serum CK-MB, cTnT, cTnI levels post ISO injection. Metabolomic analysis unveiled DWA's modulation of 27 metabolites, especially in galactose metabolism, addressing metabolic disturbances in cardiac fibrosis. Additionally, DWA suppressed mRNA expression of fibrosis markers (Collagen I, CTGF, TGF-β), inhibited protein levels of MMP-9, α-SMA, and Galectin-3, while elevating TIMP1 expression.

CONCLUSION

DWA demonstrated potent anti-fibrotic effects by curbing collagen deposition and alleviating metabolic disruptions in cardiac fibrosis via the galactose metabolism pathway, possibly mediated by the Gal-3/TGF-β/Smad signaling pathway.

PPARδ activation improves cardiac mitochondrial homeostasis in desmin deficient mice but does not alleviate systolic dysfunction

Peroxisome proliferator-activated receptor (PPAR) δ is a major transcriptional regulator of cardiac energy metabolism with pleiotropic properties, including anti-inflammatory, anti-oxidative and cardioprotective action. In this study, we sought to investigate whether pharmacological activation of PPARδ via intraperitoneal administration of the selective ligand GW0742 could ameliorate heart failure and mitochondrial dysfunction that have been previously reported in a characterized genetic model of heart failure, the desmin null mice (Des-/-). Our studies demonstrate that treatment of Des-/- mice with the PPARδ agonist attenuated cardiac inflammation, fibrosis and cardiac remodeling. In addition, PPARδ activation alleviated oxidative stress in the failing myocardium as evidenced by decreased ROS levels. Importantly, PPARδ activation stimulated mitochondrial biogenesis, prevented mitochondrial and sarcoplasmic reticulum vacuolar degeneration and improved the mitochondrial intracellular distribution. Finally, PPARδ activation alleviated the mitochondrial respiratory dysfunction, prevented energy depletion and alleviated excessive autophagy and mitophagy in Des-/- hearts. Nevertheless, improvement of all these parameters did not suffice to overcome the significant structural deficiencies that desmin deletion incurs in cardiomyocytes and cardiac function did not improve significantly. In conclusion, pharmacological PPARδ activation in Des-/- hearts exerts protective effects during myocardial degeneration and heart failure by preserving the function and quality of the mitochondrial network. These findings implicate PPARδ agonists as a supplemental constituent of heart failure medications.

High blood galectin-3 level associated with risk of frailty in aging

Background

Frailty is one of the most problematic expressions of population aging, but its underlying mechanism has not been fully elucidated. Circulating galectin-3 (Gal-3) is involved in the pathogenesis of many age-related diseases. This study aims to explore the influence of circulating Gal-3 on the regulation of frailty and aging and to identify the potential mechanism further.

Methods

In this cross-sectional analysis, the Fried frailty phenotype (FP) was assessed among 149 community elderly residents in Shanghai. Peripheral blood mononuclear cells (PBMCs) were isolated by the Ficoll-Paque density gradient method, and differentially expressed genes (DEGs) encoding transcription factors in frailty were detected by Illumina and bioinformatics analyzed with R software. Gene Ontology (GO) enrichment analyses and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to explore the functional roles of these DEGs and the target genes related to frailty phenotypes. The serum Gal-3 concentration was tested by enzyme-linked immunosorbent assay (ELISA). Mouse frailty phenotype was used to construct an in vivo model of frailty, after which the serum levels of circulating Gal-3 and its gene expression levels in mouse tissues were determined.

Results

Participants' mean age was 72.04 ± 7.05 years. In total, 21.48% were frail and 36.91% were pre-frail. The mean serum Gal-3 concentration was 46.34 ± 17.99 ng/mL in frail participants, 32.30 ± 8.14 ng/mL in pre-frail participants, and 26.00 ± 5.87 ng/mL in non-frail individuals (p < 0.001). Significant positive correlations between serum Gal-3 level and FP score, SARC-F score, C-reactive protein (CRP), interleukin-6, etc., were observed. In addition, the KEGG pathway and GO enrichment analyses showed that 265 DEGs in PBMCs of frail participants were mainly related to inflammatory response, translation, RNA binding, protein binding, ribosome, and primary immunodeficiency. LGALS3 was identified as the overlapping gene between frailty-related DEGs and aging-related DEGs. The elevated serum Gal-3 concentration in the in vivo model of frailty was consistent with the results in participants.

Conclusion

In both community-dwelling older adults and aged mice, serum Gal-3 concentration was positively correlated with frailty. This circulating mediator may be a promising indicator of frailty.

Clinical trial registration

Chinese Clinical Trial Registry identifier, ChiCTR2000036399.

Targeting galectin-3 in inflammatory and fibrotic diseases

Galectin (Gal)-3 is a β-galactoside-binding lectin emerging as a key player in cardiac, hepatic, renal, and pulmonary fibrosis and inflammation, respiratory infections caused by COVID-19, and neuroinflammatory disorders. Here, we review recent information highlighting Gal-3 as a relevant therapeutic target in these specific disease conditions. While a causal link was difficult to establish until now, we discuss how recent strategic breakthroughs allowed us to identify new-generation Gal-3 inhibitors with improved potency, selectivity, and bioavailability, and report their usefulness as valuable tools for proof-of-concept studies in various preclinical models of the aforementioned diseases, with emphasis on those actually in clinical stages. We also address critical views and suggestions intended to expand the therapeutic opportunities provided by this complex target.

Role of Galectin in Cardiovascular Conditions including Cirrhotic Cardiomyopathy

Abnormal cardiac function in the setting of cirrhosis and in the absence of a primary cardiac disease is known as cirrhotic cardiomyopathy. The pathogenesis of cirrhotic cardiomyopathy is multifactorial but broadly is comprised of two pathways. The first is due to cirrhosis and synthetic liver failure with abnormal structure and function of many substances, including proteins, lipids, hormones, and carbohydrates such as lectins. The second is due to portal hypertension which invariably accompanies cirrhosis. Portal hypertension leads to a leaky, congested gut with resultant endotoxemia and systemic inflammation. This inflammatory phenotype comprises oxidative stress, cellular apoptosis, and inflammatory cell infiltration. Galectins exert all these pro-inflammatory mechanisms across many different tissues and organs, including the heart. Effective therapies for improving cardiac function in patients with cirrhosis are not available. Conventional strategies for other noncirrhotic heart diseases, including vasodilators, are not feasible because of the significant baseline vasodilation in cirrhotic patients. Therefore, exploring new treatment modalities for cirrhotic cardiomyopathy is of great importance. Galectin-3 inhibitors such as modified citrus pectin, N-acetyllactosamine, TD139 and GB0139 exert anti-apoptotic, anti-oxidative and anti-inflammatory effects and thus have potential therapeutic interest. This review briefly summarizes the physiological and pathophysiological role of galectin and specifically examines its role in cardiac disease processes. We present a more detailed discussion of galectin in cardiovascular complications of cirrhosis, particularly cirrhotic cardiomyopathy. Finally, therapeutic studies of galectin-3 inhibitors in cirrhotic cardiomyopathy are reviewed.

Ultrasonic Microbubble Cavitation Deliver Gal-3 shRNA to Inhibit Myocardial Fibrosis after Myocardial Infarction

Galectin-3 (Gal-3) participates in myocardial fibrosis (MF) in a variety of ways. Inhibiting the expression of Gal-3 can effectively interfere with MF. This study aimed to explore the value of Gal-3 short hairpin RNA (shRNA) transfection mediated by ultrasound-targeted microbubble destruction (UTMD) in anti-myocardial fibrosis and its mechanism. A rat model of myocardial infarction (MI) was established and randomly divided into control and Gal-3 shRNA/cationic microbubbles + ultrasound (Gal-3 shRNA/CMBs + US) groups. Echocardiography measured the left ventricular ejection fraction (LVEF) weekly, and the heart was harvested to analyze fibrosis, Gal-3, and collagen expression. LVEF in the Gal-3 shRNA/CMB + US group was improved compared with the control group. On day 21, the myocardial Gal-3 expression decreased in the Gal-3 shRNA/CMBs + US group. Furthermore, the proportion of the myocardial fibrosis area in the Gal-3 shRNA/CMBs + US group was 6.9 ± 0.41% lower than in the control group. After inhibition of Gal-3, there was a downregulation in collagen production (collagen I and III), and the ratio of Col I/Col III decreased. In conclusion, UTMD-mediated Gal-3 shRNA transfection can effectively silence the expression of Gal-3 in myocardial tissue, reduce myocardial fibrosis, and protect the cardiac ejection function.

The emerging role of leptin in obesity-associated cardiac fibrosis: evidence and mechanism

Cardiac fibrosis is a hallmark of various cardiovascular diseases, which is quite commonly found in obesity, and may contribute to the increased incidence of heart failure arrhythmias, and sudden cardiac death in obese populations. As an endogenous regulator of adiposity metabolism, body mass, and energy balance, obesity, characterized by increased circulating levels of the adipocyte-derived hormone leptin, is a critical contributor to the pathogenesis of cardiac fibrosis. Although there are some gaps in our knowledge linking leptin and cardiac fibrosis, this review will focus on the interplay between leptin and major effectors involved in the pathogenesis underlying cardiac fibrosis at both cellular and molecular levels based on the current reports. The profibrotic effect of leptin is predominantly mediated by activated cardiac fibroblasts but may also involve cardiomyocytes, endothelial cells, and immune cells. Moreover, a series of molecular signals with a known profibrotic property is closely involved in leptin-induced fibrotic events. A more comprehensive understanding of the underlying mechanisms through which leptin contributes to the pathogenesis of cardiac fibrosis may open up a new avenue for the rapid emergence of a novel therapy for preventing or even reversing obesity-associated cardiac fibrosis.

Galectin-3 critically mediates the hepatoprotection conferred by M2-like macrophages in ACLF by inhibiting pyroptosis but not necroptosis signalling

We previously documented that M2-like macrophages exert a hepatoprotective effect in acute-on-chronic liver failure (ACLF) by inhibiting necroptosis signalling. Nevertheless, the molecular mechanism behind this hepatoprotection still needs to be further dissected. Galectin-3 (GAL3) has been reported to be critically involved in the pathogenesis of multiple liver diseases, whereas the potential role of GAL3 in ACLF remains to be explored. Herein, we hypothesised that GAL3 plays a pivotal role in the hepatoprotection conferred by M2-like macrophages in ACLF by inhibiting necroptosis. To test this hypothesis, we first assessed the expression of GAL3 in control and fibrotic mice with or without acute insult. Second, loss- and gain-of-function experiments of GAL3 were performed. Third, the correlation between GAL3 and M2-like macrophage activation was analysed, and the potential role of GAL3 in M2-like macrophage-conferred hepatoprotection was confirmed. Finally, the molecular mechanism underlying GAL3-mediated hepatoprotection was dissected. GAL3 was found to be obviously upregulated in fibrotic mice with or without acute insult but not in acutely injured mice. Depletion of GAL3 aggravated hepatic damage in fibrotic mice upon insult. Conversely, adoptive transfer of GAL3 provided normal mice enhanced resistance against acute insult. The expression of GAL3 is closely correlated with M2-like macrophage activation. Through adoptive transfer and depletion experiments, M2-like macrophages were verified to act as a major source of GAL3. Importantly, GAL3 was confirmed to hold a pivotal place in the hepatoprotection conferred by M2-like macrophages through loss- and gain-of-function experiments. Unexpectedly, the depletion and adoptive transfer of GAL3 resulted in significant differences in the expression levels of pyroptosis but not necroptosis signalling molecules. Taken together, GAL3 plays a pivotal role in the hepatoprotection conferred by M2-like macrophages in ACLF by inhibiting pyroptosis but not necroptosis signalling. Our findings provide novel insights into the pathogenesis and therapy of ACLF.

Role of the CCL2-CCR2 axis in cardiovascular disease: Pathogenesis and clinical implications

The CCL2-CCR2 axis is one of the major chemokine signaling pathways that has received special attention because of its function in the development and progression of cardiovascular disease. Numerous investigations have been performed over the past decades to explore the function of the CCL2-CCR2 signaling axis in cardiovascular disease. Laboratory data on the CCL2-CCR2 axis for cardiovascular disease have shown satisfactory outcomes, yet its clinical translation remains challenging. In this article, we describe the mechanisms of action of the CCL2-CCR2 axis in the development and evolution of cardiovascular diseases including heart failure, atherosclerosis and coronary atherosclerotic heart disease, hypertension and myocardial disease. Laboratory and clinical data on the use of the CCL2-CCR2 pathway as a targeted therapy for cardiovascular diseases are summarized. The potential of the CCL2-CCR2 axis in the treatment of cardiovascular diseases is explored.