Serum galectin-3 level in systemic sclerosis

Vascular endothelial growth factor as a potential biomarker in systemic sclerosis: a systematic review and meta-analysis

Introduction

Systemic sclerosis (SSc), a chronic autoimmune condition, is characterized by microvascular dysfunction, ineffective angiogenesis, and fibrosis. The identification of robust biomarkers reflecting these processes may assist in clinical management and lead to the discovery of new therapies. We sought to address this issue by conducting a systematic review and meta-analysis of studies investigating one such biomarker, vascular endothelial growth factor (VEGF), in SSc patients and healthy controls and in SSc patients with localized or diffuse disease, different video capillaroscopy patterns (early, active, or late), and presence or absence of complications.

Methods

We searched PubMed, Scopus, and Web of Science from inception to 15 May 2024. We assessed the risk of bias and the certainty of evidence using the JBI checklist for analytical studies and GRADE, respectively.

Results

In 42 eligible studies, compared to controls, patients with SSc had significantly higher plasma or serum VEGF concentrations (standard mean difference, SMD=0.93, 95% CI 0.71 to 1.15, p<0.001; moderate certainty). In further analyses, VEGF concentrations were significantly higher in SSc patients with diffused disease than those with localized disease (SMD=0.30, 95% CI 0.01 to 0.59, p=0.046; very low certainty), in patients with late vs. active video capillaroscopy pattern (SMD=0.35, 95% CI 0.09 to 0.61, p=0.008; very low certainty), and in patients with pulmonary hypertension than those without (SMD=0.93, 95% CI 0.34 to 1.53, p=0.002; very low certainty). By contrast, no significant differences were observed between SSc patients with and without digital ulcers, interstitial lung disease, and telangiectasias, whereas limited evidence was available for alveolitis. Meta-regression and subgroup analysis of studies investigating VEGF in SSc patients and controls showed no significant associations between the effects size and various patient and study characteristics, including SSc duration and use of corticosteroids, immunosuppressors and vasodilators. By contrast, significant associations were observed with the geographical location where the study was conducted.

Discussion

The results of this systematic review and meta-analysis suggest that VEGF can be useful in the assessment and management of SSc and in the identification of novel therapeutic strategies in this patient group.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero, identifier CRD42024552925.

The vascular endothelial growth factor as a candidate biomarker of systemic lupus erythematosus: a GRADE-assessed systematic review and meta-analysis

There is an ongoing search for novel biomarkers of endothelial damage, active disease, and organ dysfunction in systemic lupus erythematosus (SLE). We investigated the role of the vascular endothelial growth factor (VEGF) as a candidate biomarker by conducting a systematic review and meta-analysis of studies examining VEGF concentrations in SLE patients and healthy controls. We searched electronic databases (PubMed, Scopus, and Web of Science) from inception to 31 May 2024 (inclusion criteria: VEGF measurement in SLE patients and healthy controls and SLE patients with and without active disease or specific organ dysfunction in case-control studies, recruitment of adult participants, and availability of the full text in the English language; exclusion criteria: non-case-control studies, participants under 18 years, articles reporting duplicate or irrelevant data, and animal studies). We assessed the risk of bias and the certainty of evidence using the JBI Critical Appraisal Checklist and GRADE, respectively (PROSPERO registration number: CRD42024561636). Circulating VEGF concentrations were significantly higher in SLE patients than in controls (22 studies; standardised mean difference, SMD = 0.71, 95% CI 0.44 to 0.98, p < 0.001; low certainty of evidence). In SLE patients, VEGF concentrations were significantly higher in those with active disease (six studies; SMD = 1.10, 95% CI 0.27 to 1.92, p = 0.009; very low certainty of evidence) and lupus nephritis (four studies; SMD = 0.80, 95% CI 0.03 to 1.57, p = 0.042; very low certainty of evidence). Only one study reported VEGF concentrations in SLE patients with and without pulmonary arterial hypertension. The effect size of the differences in VEGF concentrations between SLE patients and controls was not associated with disease duration, use of glucocorticoids and immunosuppressors, biological matrix assessed, or analytical method used. However, it was significantly associated with the study's geographical location. The evidence was limited by the high but partially explainable heterogeneity and the presence of publication bias which was addressed with the "trim-and-fill" method (SLE presence), the high but partially explainable heterogeneity and lack of assessment of publication bias because of the limited study number (active disease), and the limited study number preventing the identification of sources of heterogeneity, sensitivity analysis, and assessment of publication bias (lupus nephritis). Our results highlight VEGF's potential role as a SLE biomarker and the need for further research, also given the aforementioned limitations, investigating VEGF concentrations in a wide range of SLE patient subgroups.

Endocytic Roles of Glycans on Proteins and Lipids

Most cell surface proteins are decorated by glycans, and the plasma membrane is rich in glycosylated lipids. The mechanisms by which the enormous complexity of these glycan structures on proteins and lipids is exploited to control glycoprotein activity by setting their cell surface residence time and the ways by which they are taken up into cells are still under active investigation. Here, two mechanisms are presented, termed galectin lattices and glycolipid-lectin (GL-Lect)-driven endocytosis, which are among the most prominent to establish a link between glycan information and endocytosis. Types of glycans on glycoproteins and glycolipids are reviewed from the angle of their interaction with glycan-binding proteins that are at the heart of galectin lattices and GL-Lect-driven endocytosis. Examples are given to show how these mechanisms affect cellular functions ranging from cell migration and signaling to vascularization and immune modulation. Finally, outstanding challenges on the link between glycosylation and endocytosis are discussed.

Current Trends in Vascular Biomarkers for Systemic Sclerosis: A Narrative Review

Systemic sclerosis (SSc, scleroderma) is a multifaceted rare connective tissue disease whose pathogenesis is dominated by immune dysregulation, small vessel vasculopathy, impaired angiogenesis, and both cutaneous and visceral fibrosis. Microvascular impairment represents the initial event of the disease, preceding fibrosis by months or years and accounting for the main disabling and/or life-threatening clinical manifestations, including telangiectasias, pitting scars, periungual microvascular abnormalities (e.g., giant capillaries, hemorrhages, avascular areas, ramified/bushy capillaries) clinically detectable by nailfold videocapillaroscopy, ischemic digital ulcers, pulmonary arterial hypertension, and scleroderma renal crisis. Despite a variety of available treatment options, treatment of SSc-related vascular disease remains problematic, even considering SSc etherogenity and the quite narrow therapeutic window. In this context, plenty of studies have highlighted the great usefulness in clinical practice of vascular biomarkers allowing clinicians to assess the evolution of the pathological process affecting the vessels, as well as to predict the prognosis and the response to therapy. The current narrative review provides an up-to-date overview of the main candidate vascular biomarkers that have been proposed for SSc, focusing on their main reported associations with characteristic clinical vascular features of the disease.

Aptamer proteomics of serum exosomes from patients with Primary Raynaud's and patients with Raynaud's at risk of evolving into Systemic Sclerosis

BACKGROUND

A major unmet need for Systemic Sclerosis (SSc) clinical management is the lack of biomarkers for the early diagnosis of patients with Raynaud's Phenomenon at high risk of evolving into SSc.

OBJECTIVE

To identify proteins contained within serum exosomes employing an aptamer proteomic analysis that may serve to reveal patients with Raynaud's Phenomenon at risk of developing SSc.

METHODS

Exosomes were isolated from serum samples from patients with Primary Raynaud's Phenomenon and from patients with Raynaud's Phenomenon harbouring serum antinuclear antibodies (ANA) who may be at high risk of evolving into SSc. The expression of 1,305 proteins was quantified using SOMAscan aptamer proteomics, and associations of the differentially elevated or reduced proteins with the clinical subsets of Raynaud's Phenomenon were assessed.

RESULTS

Twenty one differentially elevated and one differentially reduced (absolute fold change >|1.3|) proteins were identified. Principal component analysis using these 22 most differentially expressed proteins resulted in excellent separation of the two Raynaud's Phenomenon clinical subsets. Remarkably, the most differentially elevated proteins are involved in enhanced inflammatory responses, immune cell activation and cell migration, and abnormal vascular functions.

CONCLUSION

Aptamer proteomic analysis of circulating exosomes identified differentially elevated or reduced proteins between Raynaud's Phenomenon at high risk of evolving into SSc and Primary Raynaud's Phenomenon patients. Some of these proteins are involved in relevant biological pathways that may play a role in SSc pathogenesis including enhanced inflammatory responses, immune cell activation, and endothelial cell and vascular abnormalities.

Increased Expression of Galectin-3 in Skin Fibrosis: Evidence from In Vitro and In Vivo Studies

Skin fibrosis is a hallmark of a wide array of dermatological diseases which can greatly impact the patients' quality of life. Galectin-3 (GAL-3) has emerged as a central regulator of tissue fibrosis, playing an important pro-fibrotic role in numerous organs. Various studies are highlighting its importance as a skin fibrotic diseases biomarker; however, there is a need for further studies that clarify its role. This paper aims to ascertain whether the expression of GAL-3 is increased in relevant in vitro and in vivo models of skin fibrosis. We studied the role of GAL-3 in vitro using normal human dermal fibroblasts (NHDF) and fibrocytes. In addition, we used a skin fibrosis murine model (BALB/c mice) and human biopsies of healthy or keloid tissue. GAL-3 expression was analyzed using real time PCR, Western blot and immunostaining techniques. We report a significantly increased expression of GAL-3 in NHDF and fibrocytes cell cultures following stimulation with transforming growth factor β1 (TGFβ1). In vivo, GAL-3 expression was increased in a murine model of systemic sclerosis and in human keloid biopsies. In sum, this study underlines the involvement of GAL-3 in skin fibrosis using several models of the disease and highlights its role as a relevant target.

Galectin-1 and Galectin-3 Expression in Lesional Skin of Patients With Systemic Sclerosis-Association With Disease Severity

Galectin-1 (Gal-1) and galectin-3 (Gal-3) are carbohydrate-binding proteins involved in normal processes, autoimmunity, and cancer. Increased serum Gal-3 levels in scleroderma were associated with active disease, vasculopathy, and mortality.

OBJECTIVES

The aim of this study was to evaluate Gal-1 and Gal-3 expression in the lesional skin of patients with scleroderma regarding disease severity and organ involvement.

METHODS

A cross-sectional study was conducted on patients diagnosed as systemic sclerosis (SSc), after informed consent. Clinical and serological profiles were reviewed from medical records. Lesional skin biopsies were taken by losange incision from patients. Samples were analyzed by immunohistochemistry and compared with normal skin of a healthy patient. Parametric statistical analysis was done with Student t test and Pearson coefficient. Significance was established as p ≤ 0.05 with a 95% confidence interval.

RESULTS

Biopsies of 10 patients and a healthy control (9 female, 1 male) were analyzed. The mean age was 54.5 years (18-74 years). Four of 10 patients had diffuse, 4 had limited scleroderma, 1 had overlap syndrome, and 1 had sclerodermiform graft-versus-host disease. The mean fibroblasts count per field was 13.2 in scleroderma versus 7.2 in normal skin. The mean expression of Gal-1 in scleroderma fibroblasts was 13% (0%-56%) and 47.5% for Gal-3 (6.5%-95.5%); in normal skin, the mean expression was 91% (90%-95%) for Gal-1 and 97% (89%-100%) for Gal-3. A higher Gal-3 expression in scleroderma (within its lower expression compared with normal skin) was associated with pulmonary artery hypertension (p = 0.004) and to a higher modified Rodnan's skin score (p = 0.0003). In a similar manner, anti-centromere antibodies were associated with a higher Gal-1 expression in SSc skin fibroblasts (p = 0.04).

CONCLUSIONS

Gal-1 and Gal-3 had a lower expression in scleroderma lesional skin compared with a normal control. We found a significant correlation between a higher Gal-3 expression (within the lower ones compared with normal skin) in fibroblasts from SSc patients and severe disease (pulmonary hypertension and a higher modified Rodnan's skin score) compared with patients with lower expression of this protein. Similarly, the presence of anti-centromere antibodies was associated with a higher expression of Gal-1 within this group of patients.

Serum galectin-3 and TGF-beta levels in patients with sarcoidosis

INTRODUCTION

Sarcoidosis is a chronic granulomatous disease that develops with non-caseified granuloma formation. Galectin-3 is a multifunctional protein operating in biological processes such as fibrosis, angiogenesis, and immune activation.

PURPOSE

This study evaluates the levels of serum galectin-3 and TGF-beta in sarcoidosis patients to determine a possible correlation with clinical findings.

MATERIAL AND METHOD

Forty-four biopsy-proven sarcoidosis patients followed in a single centre and 41 age and sex-matched healthy volunteers were included in the study. The levels of serum galectin-3 and TGF-beta were evaluated by ELISA method.

RESULTS

Among the 44 sarcoidosis patients, 13(29.5%) were male and 31(70.5%) were female. The average patient age was 47.4 and the average disease duration was 3.2 years. The level of serum galectin-3 was found to be the same as in the control group and had no significance statistically (p=.977). No correlation was determined between the level of serum galectin-3 and clinical and laboratory findings of sarcoidosis (p>.05). The level of serum TGF-beta was found to be higher in the sarcoidosis patients when compared to that of the control group (p=.005). While a correlation was found between serum TGF-beta and enthesitis, sacroiliitis, and arthralgia (p=.006, p=.034, p=.02), no correlation was determined on the other clinical and laboratory findings (p>.05).

CONCLUSION

While the level of serum galectin-3 was determined to be normal in sarcoidosis patients, a high level of serum TGF-beta was found. These findings show that TGF-beta may play an important role in sarcoidosis pathogenesis and the formation of granuloma.

Cellular and Molecular Diversity in Scleroderma

With the increasing armamentarium of high-throughput tools available at manageable cost, it is attractive and informative to determine the molecular underpinnings of patient heterogeneity in systemic sclerosis (SSc). Given the highly variable clinical outcomes of patients labelled with the same diagnosis, unravelling the cellular and molecular basis of disease heterogeneity will be crucial to predicting disease risk, stratifying management and ultimately informing a patient-centered precision medicine approach. Herein, we summarise the findings of the past several years in the fields of genomics, transcriptomics, and proteomics that contribute to unraveling the cellular and molecular heterogeneity of SSc. Expansion of these findings and their routine integration with quantitative analysis of histopathology and imaging studies into clinical care promise to inform a scientifically driven patient-centred personalized medicine approach to SSc in the near future.

Therapeutic potential of galectin-1 and galectin-3 in autoimmune diseases

Galectins are a highly conserved protein family that binds to β-galactosides. Different members of this family play a variety of biological functions in physiological and pathological processes such as angiogenesis, regulation of immune cell activity, and cell adhesion. Galectins are widely distributed and play a vital role both inside and outside cells. It can regulate homeostasis and immune function in vivo through mechanisms such as apoptosis. Recent studies indicate that galectins exhibit pleiotropic roles in inflammation. Furthermore, emerging studies have found that galectins are involved in the occurrence and development of autoimmune diseases such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), type 1 diabetes (T1D) and systemic sclerosis (SSc) by regulating cell adhesion, apoptosis, and other mechanisms. This review will briefly discuss the biological characteristics of the two most widely expressed and extensively explored members of the galectin family, galectin-1 and galectin-3, as well as their pathogenetic and therapeutic roles in autoimmune diseases. These information may provide a novel and promising therapeutic target for autoimmune diseases.

Association of Circulating Vascular Endothelial Growth Factor Levels With Autoimmune Diseases: A Systematic Review and Meta-Analysis

Background

Autoimmune diseases (ADs) are characterized by immune-mediated tissue damage, in which angiogenesis is a prominent pathogenic mechanism. Vascular endothelial growth factor (VEGF), an angiogenesis modulator, is significantly elevated in several ADs including rheumatoid arthritis (RA), systemic sclerosis (SSc), and systemic lupus erythematosus (SLE). We determined whether circulating VEGF levels were associated with ADs based on pooled evidence.

Methods

The analyses included 165 studies from the PubMed, EMBASE, Cochrane Library, and Web of Science databases and fulfilled the study criteria. Comparisons of circulating VEGF levels between patients with ADs and healthy controls were performed by determining pooled standard mean differences (SMDs) with 95% confidence intervals (CIs) in a random-effect model using STATA 16.0. Subgroup, sensitivity, and meta-regression analyses were performed to determine heterogeneity and to test robustness.

Results

Compared with healthy subjects, circulating VEGF levels were significantly higher in patients with SLE (SMD 0.84, 95% CI 0.25-1.44, P = 0.0056), RA (SMD 1.48, 95% CI 0.82-2.15, P <0.0001), SSc (SMD 0.56, 95% CI 0.36-0.75, P <0.0001), Behcet's disease (SMD 1.65, 95% CI 0.88-2.41, P <0.0001), Kawasaki disease (SMD 2.41, 95% CI 0.10-4.72, P = 0.0406), ankylosing spondylitis (SMD 0.78, 95% CI 0.23-1.33, P = 0.0052), inflammatory bowel disease (SMD 0.57, 95% CI 0.43-0.71, P <0.0001), psoriasis (SMD 0.98, 95% CI 0.62-1.34, P <0.0001), and Graves' disease (SMD 0.69, 95% CI 0.20-1.19, P = 0.0056). Circulating VEGF levels correlated with disease activity and hematological parameters in ADs.

Conclusion

Circulating VEGF levels were associated with ADs and could predict disease manifestations, severity and activity in patients with ADs.

Systematic Review Registration

PROSPERO, identifier CRD42021227843.

Genetic variants in LGALS3 are related to lower galectin-3 serum levels and clinical outcomes in systemic sclerosis patients: A case-control study

INTRODUCTION

Systemic sclerosis (SSc) is a rare complex disease characterized by vascular damage, autoimmunity, and extensive skin and internal organs fibrosis. Galectin-3 (Gal-3) is encoded by gene LGALS3 (Lectin, Galactoside-Binding, Soluble, 3; 14q22.3) and it has been reported to play a central role in self-tolerance, inflammation, and fibrosis.

OBJECTIVE

To investigate associations among LGALS3 single nucleotide polymorphisms (SNPs) and serum levels Gal-3 and SSc susceptibility and their clinical features.

METHODS

A case-control study with 88 patients and 151 matched controls was performed. LGALS3 variants were analyzed by the TaqMan real-time polymerase chain reaction (PCR) system whereas Gal-3 serum levels were measured by sandwich enzyme linked immunosorbent assay (ELISA). Associations among genotypes, clinical features, and Gal-3 levels were performed by univariable and multivariable analysis through statistical packages.

RESULTS

The LGALS3 rs4652 A/C genotype was more frequent in SSc patients than controls according to overdominant model [OR 1.89 (CI 95% 1.01 - 3.52); p = .046]. Also, LGALS3 rs4652 C/C polymorphic genotype was associated with lower patient Gal-3 levels (p = .03) and control group (p = 0.005), as noted by generalized linear model (GLM). The LGALS3 rs1009977 G/T controls showed higher Gal-3 levels than wild-type and polymorphic genotypes (p = .03); however, in SSc patients, no difference was found. None of the LGALS3 SNPs or Gal-3 levels was associated with clinical manifestations in SSc patients. Considering only the SSc group, GLM analysis pointed LGALS3 rs4652 and rs2075601, pulmonary arterial hypertension (PAH), myopathy, and health assessment questionnaire (HAQ) and scleroderma health assessment questionnaire (SHAQ) as important predictors for Gal-3 levels.

CONCLUSION

The LGALS3 rs4652 A/C was more frequent in SSc patients and related to lower Gal-3 levels. These findings were corroborated through a GLM to estimate Gal-3 values. Also, by model equations, Gal-3 levels may be predicted by HAQ, SHAQ, PAH, myopathy, and LGALS3 rs4652 and rs2075601 factors. In these ways, we suggest that galectins may be promising biomarkers to identify susceptibility to SSc as well as to identify HAQ, SHAQ, PAH, and myopathy outcomes.

Emerging role of galectin family in inflammatory autoimmune diseases

Galectin family is a group of glycan-binding proteins. Members in this family are expressed in different tissues, immune or non-immune cells. These molecules are important regulators in innate and adaptive immune response, performing significantly in a broad range of cellular and pathophysiological functions, such as cell proliferation, adhesion, migration, and invasion. Findings have shown that expression of galectins is abnormal in many inflammatory autoimmune diseases, such as systemic lupus erythematosus, rheumatoid arthritis, osteoarthritis, sjögren's syndrome, systemic sclerosis. Galectins also function as intracellular and extracellular disease regulators mainly through the binding of their carbohydrate recognition domain to glycoconjugates. Here, we review the state-of-the-art of the role that different galectin family members play in immune cells, contributing to the complex inflammatory diseases. Hopefully collection of the information will provide a preliminary theoretical basis for the exploration of new targets for treatment of the disorders.

Circulating Galectin-1 and Galectin-3 in Sera From Patients With Systemic Sclerosis: Associations With Clinical Features and Treatment

Systemic Sclerosis (SSc) is a rheumatic disease characterized by fibrosis, microvascular damage and immune dysregulation. Two major subsets, limited cutaneous systemic sclerosis (lcSSc) and diffuse cutaneous systemic sclerosis (dcSSc) can be defined, according to the extent of skin involvement. Increasing evidence indicates a role for galectins in immune and vascular programs, extracellular matrix remodeling and fibrosis, suggesting their possible involvement in SSc. Here, we determined serum levels of galectin (Gal)-1 and Gal-3 in 83 SSc patients (dcSSc n = 17; lcSSc n = 64; ssSSc n = 2), and evaluated their association with clinical manifestations of the disease. Patients with dcSSc showed lower Gal-3 levels, compared to lcSSc (p = 0.003), whereas no considerable difference in Gal-1 levels was detected between groups. Remarkably, higher concentrations of Gal-1 were associated with the presence of telangiectasias (p = 0.015), and higher concentrations Gal-3 were associated with telangiectasias (p = 0.021), diarrhea (p = 0.039) and constipation (p = 0.038). Moreover, lower Gal-3 levels were associated with the presence of tendinous retractions (p = 0.005). Patients receiving calcium blockers (p = 0.048), methotrexate (p = 0.046) or any immunosuppressive treatment (p = 0.044) presented lower concentrations of Gal-3 compared to those not receiving such treatments. The presence of telangiectasia and the type of SSc maintained their statistical association with Gal-3 (β 0.25; p = 0.022 and β 0.26; p = 0.017, respectively) in multiple linear regression models. In conclusion, serum levels of Gal-3 are associated with clinical manifestations of SSc. Among them, the presence of telangiectasias could be explained by the central role of this lectin in the vascularization programs.

Serum galectin-3 and galectin-3 binding protein levels in systemic lupus erythematosus and cutaneous lupus erythematosus

INTRODUCTION

The roles of galectin-3 (Gal-3) and galectin-3 binding protein (G3BP) in systemic lupus erythematosus (SLE) are of ongoing interest, but the data are insufficient due to highly limited available studies. There are no data on cutaneous lupus erythematosus (CLE).

AIM

To assess serum Gal-3 and G3BP concentrations in SLE patients with and without LE-specific skin lesions, CLE patients and to correlate levels of proteins with clinical and laboratory parameters.

MATERIAL AND METHODS

The study included 71 SLE patients with and without LE-specific skin lesions, 23 CLE patients and 40 controls. Gal-3 and G3BP were measured by specific enzyme-linked immunosorbent assays (ELISA).

RESULTS

Serum Gal-3 and G3BP concentrations were significantly higher in SLE with and without LE-specific lesions compared to controls, but without differences between SLE groups. Gal-3 and G3BP levels were also elevated in CLE compared to controls (p = 0.001, p = 0.005; respectively). There was a positive correlation between G3BP level and CLASI activity score both in CLE (r = 0.55, p = 0.006) and in SLE patients with LE-specific lesions (r = 0.36, p = 0.02). G3BP and Gal-3 levels did not differ in SLE with LE-specific lesions and CLE. There was a positive correlation between serum G3BP level and the SLEDAI score in SLE patients (r = 0.26, p = 0.03).

CONCLUSIONS

Our findings indicate that serum G3BP and Gal-3 are elevated in CLE. Additionally, G3BP might be associated with the extent of skin lesions. There are no differences between G3BP and Gal-3 concentrations in SLE with and without LE-specific skin lesions.

Metabolic mediators determine the association of antinuclear antibody subtypes with specific clinical symptoms in systemic sclerosis

PURPOSE

The aim of this study was to investigate the possible link between different types of systemic sclerosis-specific antinuclear antibodies, adipokines and endothelial molecules which were recently found to have a pathogenic significance in systemic sclerosis.

MATERIALS/METHODS

Serum concentration of adiponectin, resistin, leptin, endothelin-1, fractalkine and galectin-3 were determined in the sera of patients with systemic sclerosis (n ​= ​100) and healthy controls (n ​= ​20) using ELISA.

RESULTS

The following associations between antinuclear antibodies and increased serum concentrations were identified: anticentromere antibodies with endothelin-1 (p ​< ​0.0001; mean level in patients 2.21 vs control group 1.31 ​pg/ml), anti-topoisomerase I antibodies with fractalkine (p ​< ​0.0001; 3.68 vs 1.68 ​ng/ml) and galectin-3 (p ​= ​0.0010, 6.39 vs 3.26 ​ng/ml). Anti-RNA polymerase III antibodies were associated with increased resistin (p ​< ​0.0001; 15.13 vs 8.54 ​ng/ml) and decreased adiponectin (p ​< ​0.0001; 2894 vs 8847 ​ng/ml).

CONCLUSION

In systemic sclerosis metabolic and vascular factors may serve as mediators between immunological abnormalities and non-immune driven clinical symptoms.

Galectin-3 Plasma Levels Are Associated with Risk Profiles in Pulmonary Arterial Hypertension

Galectin-3 is a circulating biomarker of fibrosis whose prognostic role in pulmonary arterial hypertension (PAH) has not been fully explored. We undertook a pilot study to evaluate the relationship between galectin-3 plasma levels and validated risk scores in PAH. The study included 70 PAH patients admitted to a single referral center from June 2016 to June 2018. Patients were stratified according to the REVEAL 2.0 risk score, according to the parameters suggested by the European Society of Cardiology and European Respiratory Society (ESC/ERS) Guidelines, and according to a focused echocardiographic assessment of right heart performance. The association between galectin-3 levels and risk profiles was evaluated by generalized linear regression model with adjustment for etiology. Galectin-3 plasma levels increased linearly in the three risk strata based on the REVEAL 2.0 score (from 16.0 ± 5.7 in low-risk to 22.4 ± 6.3 in intermediate-risk and in 26.9 ± 7.7 ng/mL in high-risk patients (p for trend < 0.001). Galectin-3 levels were significantly lower in low-risk patients defined according to the prognostic parameters of ESC/ERS Guidelines (delta between low-risk and intermediate/high-risk = -9.3, 95% CI -12.8 to -5.8, p < 0.001, p < 0.001). Additionally, galectin-3 levels were lower in the low-risk profile defined on the basis of the echocardiographic evaluation of right heart performance (delta between low-risk and intermediate-/high-risk = -6.3, 95% CI -9.9 to -2.7, p = 0.001). Galectin-3 plasma levels are directly associated with several risk profiles in PAH patients. The prognostic role of this biomarker in PAH is worthwhile to be explored in larger prospective studies.

Diagnostic Power of Galectin-3 in Rheumatic Diseases

Background: The purpose of our study was to assess the diagnostic power of galectin-3 and compare its between rheumatic diseases and with routinely used tests such as CRP and ESR. Methods: Eighty-two patients with rheumatoid arthritis (RA), 49 patients with systemic sclerosis (SSc), and 18 patients with systemic lupus erythematosus (SLE) were enrolled in this study. The control group comprised 30 healthy controls. Serum galectin-3 concentration was measured using immunochemical method. Results: The galectin-3 concentration were significantly elevated in the RA, SSc, and SLE in comparison to the controls (p = 0.000, p = 0.000, p < 0.001; respectively). However, there were no significant differences in the serum galectin-3 levels between rheumatic diseases (H = 0.395, p = 0.821). In RA and SSc patients, galectin-3 positively correlated with erythrocyte sedimentation rate (R = 0.332, p = 0.004; R = 0.384, p = 0.009; respectively). ROC analysis revealed that galectin-3 had an excellent diagnostic power in RA (AUC = 0.911) and SSc (AUC = 0.903) and very good for SLE (AUC = 0.859). Conclusion: We concluded that diagnostic power of serum galectin-3 is as great as CRP and ESR in rheumatic diseases and it can be a very good laboratory marker in RA and SSc patients and a useful tool in the diagnosis of SLE.

Serum Galectin-3 and TGF-Beta Levels in Patients With Sarcoidosis

INTRODUCTION

Sarcoidosis is a chronic granulomatous disease that develops with non-caseified granuloma formation. Galectin-3 is a multifunctional protein operating in biological processes such as fibrosis, angiogenesis, and immune activation.

PURPOSE

This study evaluates the levels of serum galectin-3 and TGF-beta in sarcoidosis patients to determine a possible correlation with clinical findings.

MATERIAL AND METHOD

Forty-four biopsy-proven sarcoidosis patients followed in a single centre and 41 age and sex-matched healthy volunteers were included in the study. The levels of serum galectin-3 and TGF-beta were evaluated by ELISA method.

RESULTS

Among the 44 sarcoidosis patients, 13(29.5%) were male and 31(70.5%) were female. The average patient age was 47.4 and the average disease duration was 3.2 years. The level of serum galectin-3 was found to be the same as in the control group and had no significance statistically (p=.977). No correlation was determined between the level of serum galectin-3 and clinical and laboratory findings of sarcoidosis (p>.05). The level of serum TGF-beta was found to be higher in the sarcoidosis patients when compared to that of the control group (p=.005). While a correlation was found between serum TGF-beta and enthesitis, sacroiliitis, and arthralgia (p=.006, p=.034, p=.02), no correlation was determined on the other clinical and laboratory findings (p>.05).

CONCLUSION

While the level of serum galectin-3 was determined to be normal in sarcoidosis patients, a high level of serum TGF-beta was found. These findings show that TGF-beta may play an important role in sarcoidosis pathogenesis and the formation of granuloma.

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.

Galectin-3 orchestrates the histology of mesentery and protects liver during lupus-like syndrome induced by pristane

Galectin-3 (Gal-3) controls intercellular and cell-extracellular matrix interactions during immunological responses. In chronic inflammation, Gal-3 is associated with fibrotic events, regulates B cell differentiation and delays lupus progression. Gal-3 deficient mice (Lgals3^−/−) have intense germinal center formation and atypical plasma cell generation correlated to high levels IgG, IgE, and IgA. Here, we used pristane (2,6,10,14-tetramethylpentadecane) to induce lupus-like syndrome in Lgals3^−/− and Lgals3^+/+ BALB/c mice. Mesentery and peritoneal cells were monitored because promptly react to pristane injected in the peritoneal cavity. For the first time, mesenteric tissues have been associated to the pathogenesis of experimental lupus-like syndrome. In Lgals3^+/+ pristane-induced mice, mesentery was hallmarked by intense fibrogranulomatous reaction restricted to submesothelial regions and organized niches containing macrophages and B lymphocytes and plasma cells. In contrast, Lgals3^−/− pristane-treated mice had diffuse mesenteric fibrosis affecting submesothelium and peripheral tissues, atypical M1/M2 macrophage polarization and significant DLL1⁺ cells expansion, suggesting possible involvement of Notch/Delta pathways in the disease. Early inflammatory reaction to pristane was characterized by significant disturbances on monocyte recruitment, macrophage differentiation and dendritic cell (DC) responses in the peritoneal cavity of pristane-induced Lgals3^−/− mice. A correlative analysis showed that mesenteric damages in the absence of Gal-3 were directly associated with severe portal inflammation and hepatitis. In conclusion, it has suggested that Gal-3 orchestrates histological organization in the mesentery and prevents lupoid hepatitis in experimental lupus-like syndrome by controlling macrophage polarization, Notch signaling pathways and DC differentiation in mesenteric structures.

Galectin 3: an extraordinary multifunctional protein in dermatology. Current knowledge and perspectives

Galectin 3 is a unique ~31 kDa protein that recognizes the N-acetyl-lactosamine structure of several glycoconjugates. It mainly occurs in epithelial and myeloid cells, but is also found in a variety of human cell types. In view of the crucial role played by galectin 3 in the regulation of cellular processes of essential importance and in the pathogenetic mechanisms of diverse disorders, it is not surprising that, particularly in the last three decades, the attention of the scientific community has been increasingly drawn to this extraordinary and multifunctional galectin. In this paper the authors summarize current knowledge on the expression of galectin 3 in normal and diseased human skin, its implications in the pathogenesis, diagnosis and prognosis of cutaneous disorders, and the perspectives of a novel approach to the treatment of the latter using galectin 3 or its inhibitors/antagonists.

Evaluation of left and right ventricle by two-dimensional speckle tracking echocardiography in systemic sclerosis patients without overt cardiac disease

BACKGROUND/OBJECTIVE

The aim was to evaluate the left and right ventricular functions concurrently by two-dimensional speckle tracking echocardiography (STE) in systemic sclerosis (SSc) patients without overt cardiac disease.

METHODS

A total of 47 patients with SSc and 36 age- and sex-matched controls were evaluated cross-sectionally. Two-dimensional STE was used to assess the longitudinal peak systolic strains (PSS) of both ventricles including apical long-axis (APLAX), apical four-chamber (4-CH), apical two-chamber (2-CH), and global longitudinal measurements. Any association of metabolic, cardiac, and inflammatory biomarkers with PSS was investigated.

RESULTS

The longitudinal PSS of the left ventricle [APLAX, 4-CH, 2-CH and global] were significantly lower in SSc patients than controls (- 18.2 ± 3.2 vs - 19.8 ± 2.7% p = 0.02; - 17.8 ± 3.5 vs. - 20.3 ± 3.3% p = 0.001; - 18.6 ± 3.1 vs. - 21.8 ± 3% p < 0.001; - 17.5 ± 5.7 vs. - 20.6 ± 2.7% p = 0.003, respectively). No difference was found between the groups for right ventricular strains. The longitudinal PSS-4CH correlated positively with CRP and ESR (r = 0.349, p = 0.016; r = 0.356, p = 0.014, respectively) and negatively with serum Galectin-3 (r = - 0.362, p = 0.012). Global longitudinal PSS-left ventricle (LV) correlated positively with CRP and homocysteine (r = 0.297, p = 0.043; r = 0.313, p = 0.041, respectively) and negatively with serum Galectin-3 (r = -0.314, p = 0.041). After multivariable adjustment, CRP remained the only predictor of longitudinal PSS-4CH (95% CI 0.35, 0.70, p = 0.028) and global longitudinal PSS of left ventricle (95% CI 0.004, 0.22, p = 0.043).

CONCLUSIONS

Biventricular evaluation of patients with SSc by two dimensional STE revealed reduced left ventricular longitudinal strains, despite preserved right ventricular strain, and no diastolic dysfunction. In SSc without overt cardiac disease, global cardiac assessment with 2DSTE is a promising method which seems to contribute to the detection of patients without clinical findings.

KEY POINTS

• Two dimensional STE revealed reduced left ventricular longitudinal strains, despite preserved right ventricular strain in SSc patients without overt cardiac disease. • CRP was the predictor of decreased longitudinal strains. • Cardiac assessment in SSc should be made globally.

The expression and function of galectins in skin physiology and pathology

The galectin family comprises β-galactoside-binding proteins widely expressed in many organisms. There are at least 16 family members, which can be classified into three groups based on their carbohydrate-recognition domains. Pleiotropic functions of different galectins in physiological and pathological processes through extracellular or intracellular actions have been revealed. In the skin, galectins are expressed in a variety of cells, including keratinocytes, melanocytes, fibroblasts, dendritic cells, lymphocytes, macrophages and endothelial cells. Expression of specific galectins is reported to affect cell status, such as activation or death, and regulate the interaction between different cell types or between cells and the extracellular matrix. In vitro cellular studies, in vivo animal studies and studies of human clinical material have revealed the pathophysiologic roles of galectins in the skin. The pathogenesis of diverse non-malignant skin disorders, such as atopic dermatitis, psoriasis, contact dermatitis and wound healing, as well as skin cancers, such as melanoma, squamous cell carcinoma, basal cell carcinoma and cutaneous haematologic malignancy can be regulated by different galectins. Revelation of biological roles of galectins in skin may pave the way to future development of galectin-based therapeutic strategies for skin diseases.

Early Hyperbaric Oxygen Treatment Attenuates Burn-Induced Neuroinflammation by Inhibiting the Galectin-3-Dependent Toll-Like Receptor-4 Pathway in a Rat Model

Hyperbaric oxygen (HBO) treatment has been proven to decrease neuroinflammation in rats. This study aimed to determine the potential mechanism underlying the anti-inflammatory effects of HBO treatment on burn-induced neuroinflammation in rats. Thirty-six adult male Sprague-Dawley (SD) rats were randomly assigned to the following six groups (n = 6 per group): (1) sham burn with sham HBO treatment; (2) sham burn with HBO treatment; (3) burn with one-week sham HBO treatment; (4) burn with two-week sham HBO treatment; (5) burn with one-week HBO treatment; and (6) burn with two-week HBO treatment. SD rats that received third-degree burn injury were used as a full-thickness burn injury model. Subsequently, we analyzed the expression of proteins involved in the galectin-3 (Gal-3)-dependent Toll-like receptor-4 (TLR-4) pathway through enzyme-linked immunosorbent assay (ELISA), immunohistochemistry (IHC) analysis, and Western blotting. A behavior test was also conducted, which revealed that HBO treatment significantly suppressed mechanical hypersensitivity in the burn with HBO treatment group compared to the burn with sham HBO treatment group (p < 0.05). ELISA results showed that tumor necrosis factor α (TNF-α) and interleukin 1 beta (IL-1β) levels in the dorsal horn of the spinal cord and the skin significantly decreased in the burn with HBO treatment group compared with the burn with sham HBO treatment group (p < 0.05). Western blotting results demonstrated that HBO treatment significantly reduced the expression of Gal-3 and TLR-4 in the dorsal horn of the spinal cord in the burn with HBO treatment group compared with the burn with sham HBO treatment group (p < 0.05). IHC analysis showed that the expression of Gal-3, TLR-4, CD68 and CD45 in the dorsal horn of the spinal cord was significantly lower in the burn with HBO treatment group than in the burn with sham HBO treatment group (p < 0.05), and the expression of CD68 and macrophage migration inhibitory factor (MIF) in the right hind paw skin was significantly lower. The expression of vimentin and fibroblast growth factor in the right hind paw skin was significantly higher after HBO treatment (p < 0.05). This study proved that early HBO treatment relieves neuropathic pain, inhibits the Gal-3-dependent TLR-4 pathway, and suppresses microglia and macrophage activation in a rat model.

Galectin-3: One Molecule for an Alphabet of Diseases, from A to Z

Galectin-3 (Gal-3) regulates basic cellular functions such as cell-cell and cell-matrix interactions, growth, proliferation, differentiation, and inflammation. It is not surprising, therefore, that this protein is involved in the pathogenesis of many relevant human diseases, including cancer, fibrosis, chronic inflammation and scarring affecting many different tissues. The papers published in the literature have progressively increased in number during the last decades, testifying the great interest given to this protein by numerous researchers involved in many different clinical contexts. Considering the crucial role exerted by Gal-3 in many different clinical conditions, Gal-3 is emerging as a new diagnostic, prognostic biomarker and as a new promising therapeutic target. The current review aims to extensively examine the studies published so far on the role of Gal-3 in all the clinical conditions and diseases, listed in alphabetical order, where it was analyzed.

Association of Serum Galectin-3 with the Acute Exacerbation of Chronic Obstructive Pulmonary Disease

BACKGROUND Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) aggravates the overall severity in COPD patients, resulting in severe morbidity and mortality. However, there are no objective biomarkers currently available to predict the development of AECOPD. Several studies have indicated that galectin-3 (Gal-3) is involved in diseases characterized by excessive inflammatory response and fibrosis. The objective of this study was to examine the dynamic changes of Gal-3 in acute exacerbation and convalescence phases of COPD. MATERIAL AND METHODS Serum levels of Gal-3, high sensitivity C-reactive protein (hsCRP), and prohormone of brain natriuretic peptide (pro-BNP) were determined using multiplex enzyme-linked immunosorbent assay kits. Serum levels of Gal-3 in 44 patients with COPD were further analyzed and correlated with the parameters of lung function and the biomarkers of systemic inflammation. RESULTS The mean level of serum Gal-3 was significantly higher in acute exacerbation of COPD compared with the level in COPD convalescence phase (32.10±9.83 versus 29.02±8.68 ng/mL, p<0.01). Serum levels of Gal-3 positively correlated with hsCRP (r=0.354, p=0.018 for total patients) and pro-BNP (r=0.319, p=0.035 for total patients) in AECOPD. In addition, the level of Gal-3 was the highest in the current smoker group, and the lowest in the never-smoker group in either the acute exacerbation phase (33.91±3.55 versus 29.12±11.73 ng/mL, p=0.036) or the convalescence phase (30.94±3.40 versus 27.76±9.68 ng/mL, p=0.045) of COPD. CONCLUSIONS Our results indicated that serum Gal-3 is increased in AECOPD patients, which is also positively associated with systemic inflammation and smoking in patients with COPD, suggesting that Gal-3 might be a valuable biomarker for AECOPD.

Serum galectin-3 levels and delirium among postpartum intensive care unit women

OBJECTIVE

Inflammation correlates with delirium. Galectin-3 is a proinflammatory protein. This study aimed to determine relation of serum galectin-3 levels to delirium of postpartum intensive care unit (ICU) women.

MATERIALS AND METHODS

In this prospective observational study, serum galectin-3, S100B, and C-reactive protein levels of 412 postpartum ICU women and 412 healthy women were measured. Delirium and Acute Physiology and Chronic Health Care Evaluation II (APCHCE II) scores were recorded.

RESULTS

Serum levels of galectin-3, S100B, and C-reactive protein were significantly elevated in the postpartum women than in the healthy women. Galectin-3 levels were highly associated with APCHCE II scores and S100B and C-reactive protein levels. Galectin-3, C-reactive protein, and S100B levels and APCHCE II scores were identified as independent predictors for delirium. Area under the curve (AUC) of serum galectin-3 levels was similar to that of S100B levels, and significantly exceeded those of C-reactive protein levels and APCHCE II scores. Moreover, galectin-3 significantly improved the AUCs of APCHCE II scores, S100B levels, and C-reactive protein levels.

CONCLUSIONS

Galectin-3, involved in inflammatory process underlying delirium-related brain injury, might be a potential biomarker to predict delirium of postpartum ICU women.

High Expression of Galectin-3 in Patients with IgG4-Related Disease: A Proteomic Approach

Objectives

Immunoglobulin G4-related disease (IgG4-RD) is a multiorgan condition manifesting itself in different forms. This study aimed to investigate protein expression profiles and to find the possible biomarker for IgG4-RD by liquid chromatography mass spectrometry (LC-MS) using tissue sections in IgG4-RD patients.

Methods

Protein expression profiles in five IgG4-related pancreatitis and three normal pancreatic samples were compared using LC-MS and were validated by quantitative real-time PCR (qRT-PCR), immunoblotting, and immunohistochemistry. ELISA was employed in the serum of 20 patients with systemic IgG4-RD before and during steroid treatment.

Results

LC-MS indicated that the levels of 17 proteins were significantly higher and 12 others were significantly lower in IgG4-related pancreatitis patients compared to controls. Among these proteins, galectin-3 levels were 13-fold higher in IgG4-related pancreatitis (P < 0.01). These results were confirmed by immunoblotting and qRT-PCR. The average number of galectin-3 + cells in various organs of IgG4-RD patients, including salivary glands, lungs, and lymph nodes, was higher than in controls. Galectin-3 was detectable in macrophages, dendritic cells, and stromal myofibroblast-like cells, but not in lymphocytes by immunofluorescence staining. Serum galectin-3 levels were higher in patients with IgG4-RD compared with healthy donors and remained high during steroid therapy.

Conclusion

Galectin-3 was overexpressed in IgG4-RD and the levels were indirectly related to clinical activity.

Galectin-3 is an independent predictor of survival in systemic sclerosis

BACKGROUND

Galectin-3 is a beta-galactoside-binding lectin that may be related to tissue sclerosis or aberrant activation of angiogenesis in systemic sclerosis (SSc). The aim of our study was to determine the associations between galectin-3 levels and patient characteristics, as well as to investigate the long term prognostic value of galectin-3 in a large cohort of SSc patients.

METHODS

152 patients with SSc (55±11years, 138 female) were included in our follow-up study. Blood samples and clinical data were collected at baseline. Primary and secondary outcomes were all-cause and cardiovascular mortality, respectively.

RESULTSS

Galectin-3 levels showed positive correlation with the grade of left ventricular diastolic function (r=0.193; p=0.026), erythrocyte sedimentation rate (r=0.172; p=0.036) and serum level of C-reactive protein (r=0.200; p=0.015) while negative correlation with diffusing capacity for carbon monoxide (r=-0.228; p=0.006), in age, gender and BSA adjusted analyses. During the follow-up of 7.2±2.3years, 35 SSc patients (23%) died. In multivariate Cox regression analyses adjusted for age, gender, BSA, creatinine and NT-proBNP levels, galectin-3 was an independent predictor both of the all-cause mortality (HR: 2.780, 95% CI: 1.320-5.858, p=0.007) and cardiovascular mortality (HR: 3.346, 95% CI: 1.118-10.012, p=0.031). Using receiver-operating characteristic analysis, galectin-3>10.25ng/ml was found to be the best predictor of the all-cause mortality.

CONCLUSIONS

Our results suggest that galectin-3 is an independent predictor of all-cause and cardiovascular mortality in SSc. Validation studies are required to establish whether galectin-3 may be proposed as simple biomarker for identifying patients with high mortality risk in SSc.

Prognostic value of plasma galectin-3 levels after aneurysmal subarachnoid hemorrhage

BACKGROUND

Inflammatory responses are correlated with secondary brain injury after aneurysmal subarachnoid hemorrhage (aSAH). Galectin-3 (Gal-3) is a novel biomarker reflecting inflammation status, and its elevated circulating levels are associated with poor prognosis of some inflammatory diseases. The aim of this study was to evaluate the relationship between Gal-3 plasma levels and prognosis in a group of aSAH patients.

MATERIALS AND METHODS

We assessed plasma Gal-3 levels in 120 patients and 120 healthy individuals. 6-month clinical outcomes included mortality and unfavorable outcome (Glasgow Outcome Scale score of 1-3). Associations of plasma Gal-3 levels with clinical outcomes were investigated using multivariate analysis.

RESULTS

Patients showed significantly higher Gal-3 levels as compared to controls. Circulating Gal-3 was significantly and independently associated with 6-month clinical outcomes in the logistic regression analysis. Moreover, we observed a significant correlation between circulating Gal-3 and World Federation of Neurological Surgeons scores and modified Fisher scores. Furthermore, Gal-3 possessed high area under receiver operating characteristic curve for prognostic assessment.

CONCLUSION

Our findings indicate the associations between Gal-3 levels and the severity and poor prognosis following aSAH. This suggests the possible role of Gal-3 in the prognostic prediction after aSAH.

Role of galectin-3 in plasma as a predictive biomarker of outcome after acute intracerebral hemorrhage

OBJECTIVE

Inflammation is involved in pathophysiological mechanisms underlying secondary brain injury after intracerebral hemorrhage. Enhanced circulating levels of galectin-3, a proinflammatory cytokine, have close relation to poor prognosis of some inflammatory illnesses. This study was designed to investigate whether plasma galectin-3 levels are related to the inflammation, severity and prognosis following intracerebral hemorrhage.

METHODS

In this observational, prospective study, plasma galectin-3 levels of 110 patients and 110 controls were determined. We further assessed the association of galectin-3 levels with inflammation reflected by systemic C-reactive protein levels, severity indicated by hematoma volumes and National Institutes of Health Stroke Scale (NIHSS) scores, and endpoints including 1-week mortality, 6-month mortality, 6-month overall survival and 6-month unfavorable outcome (modified Rankin Scale score>2).

RESULTS

Plasma galectin-3 levels of patients were significantly higher than those of controls. Galectin-3 was identified as an independent prognostic predictor for 1-week mortality, 6-month mortality, 6-month overall survival and 6-month unfavorable outcome, as well as had strong relation to C-reactive protein levels, hematoma volumes and NIHSS scores. Compared with NIHSS scores and hematoma volumes, plasma galectin-3 levels had similar areas under receiver operating characteristic curve (AUC). Moreover, galectin-3 levels significantly improved AUCs of NIHSS scores or hematoma volumes alone for prediction of 6-month mortality and 6-month unfavorable outcome.

CONCLUSIONS

Elevated plasma galectin-3 levels are strongly associated with the inflammation, severity and poor prognosis after intracerebral hemorrhage, indicating galectin-3, involved in brain inflammation, might have the potential to be a prognostic biomarker for hemorrhagic stroke.

Vesicular Galectin-3 levels decrease with donor age and contribute to the reduced osteo-inductive potential of human plasma derived extracellular vesicles

Aging results in a decline of physiological functions and in reduced repair capacities, in part due to impaired regenerative power of stem cells, influenced by the systemic environment. In particular osteogenic differentiation capacity (ODC) of mesenchymal stem cells (MSCs) has been shown to decrease with age, thereby contributing to reduced bone formation and an increased fracture risk. Searching for systemic factors that might contribute to this age related decline of regenerative capacity led us to investigate plasma-derived extracellular vesicles (EVs). EVs of the elderly were found to inhibit osteogenesis compared to those of young individuals. By analyzing the differences in the vesicular content Galectin-3 was shown to be reduced in elderly-derived vesicles. While overexpression of Galectin-3 resulted in an enhanced ODC of MSCs, siRNA against Galectin-3 reduced osteogenesis. Modulation of intravesicular Galectin-3 levels correlated with an altered osteo-inductive potential indicating that vesicular Galectin-3 contributes to the biological response of MSCs to EVs. By site-directed mutagenesis we identified a phosphorylation-site on Galectin-3 mediating this effect. Finally, we showed that cell penetrating peptides comprising this phosphorylation-site are sufficient to increase ODC in MSCs. Therefore, we suggest that decrease of Galectin-3 in the plasma of elderly contributes to the age-related loss of ODC.

Galectin-3 in autoimmunity and autoimmune diseases

Galectin-3 (gal-3) is a β-galactoside-binding lectin, which regulates cell-cell and extracellular interactions during self/non-self-antigen recognition and cellular activation, proliferation, differentiation, migration and apoptosis. It plays a significant role in cellular and tissue pathophysiology by organizing niches that drive inflammation and immune responses. Gal-3 has some therapeutic potential in several diseases, including chronic inflammatory disorders, cancer and autoimmune diseases. Gal-3 exerts a broad spectrum of functions which differs according to its intra- or extracellular localization. Recombinant gal-3 strategy has been used to identify potential mode of action of gal-3; however, exogenous gal-3 may not reproduce the functions of the endogenous gal-3. Notably, gal-3 induces monocyte-macrophage differentiation, interferes with dendritic cell fate decision, regulates apoptosis on T lymphocytes and inhibits B-lymphocyte differentiation into immunoglobulin secreting plasma cells. Considering the influence of these cell populations in the pathogenesis of several autoimmune diseases, gal-3 seems to play a role in development of autoimmunity. Gal-3 has been suggested as a potential therapeutic agent in patients affected with some autoimmune disorders. However, the precise role of gal-3 in driving the inflammatory process in autoimmune or immune-mediated disorders remains elusive. Here, we reviewed the involvement of gal-3 in cellular and tissue events during autoimmune and immune-mediated inflammatory diseases.

Functions of galectin-3 and its role in fibrotic diseases

Fibrotic diseases occur in a variety of organs and lead to continuous organ injury, function decline, and even failure. Currently effective treatment options are limited. Galectin-3 (Gal-3) is a pleiotropic lectin that plays an important role in cell proliferation, adhesion, differentiation, angiogenesis, and apoptosis. Accumulating evidence indicates that Gal-3 activates a variety of profibrotic factors, promotes fibroblast proliferation and transformation, and mediates collagen production. Recent studies have defined key roles for Gal-3 in fibrogenesis in diverse organ systems, including liver, kidney, lung, and myocardial. To help set the stage for future research, we review recent advances about the role played by Gal-3 in fibrotic diseases. Herein we discuss the potential profibrotic role of Gal-3, inhibition of which may represent a promising therapeutic strategy against tissue fibrosis.

Alternations of galectin levels after renal transplantation

OBJECTIVES

Galectins (gals), a growing family of β-galactoside-binding animal lectins, have been implicated in a variety of biological processes including fibrosis, angiogenesis, and immune activation, all of which are involved in hemodialysis (HD) and renal transplantation (RTx). In this study, we aimed to investigate serum gal levels in HD and RTx recipients.

DESIGN AND METHODS

41 normal subjects, 41 RTx recipients and 32 HD patients were recruited for this study. RTx recipients were evaluated before transplantation as well as 3 months afterwards. Serum gals-1, 2, 3, 4, 8, and 9 were measured both at baseline and 3 months later in each group.

RESULTS

At baseline, there were no differences in gals-1, 2, 3, 4, 8, and 9 between the RTx and HD groups. However, the levels of gals-1, 2, 3, 8, and 9 in the RTx and HD groups were higher than that of normal subjects. In paired analyses, gals-1, 2, and 3 were significantly decreased in RTx patients (P<0.0001) at 3 months, while there was no change in the HD group. However, levels of gals-4, 8, and 9 did not significantly change in either the HD or RTx group.

CONCLUSION

Gal-1, 2, and 3 levels were high in maintenance HD patients. Kidney transplantation improved gal-1, 2, and 3 levels.

Galectin-3 drives glycosphingolipid-dependent biogenesis of clathrin-independent carriers

Several cell surface molecules including signalling receptors are internalized by clathrin-independent endocytosis. How this process is initiated, how cargo proteins are sorted and membranes are bent remains unknown. Here, we found that a carbohydrate-binding protein, galectin-3 (Gal3), triggered the glycosphingolipid (GSL)-dependent biogenesis of a morphologically distinct class of endocytic structures, termed clathrin-independent carriers (CLICs). Super-resolution and reconstitution studies showed that Gal3 required GSLs for clustering and membrane bending. Gal3 interacted with a defined set of cargo proteins. Cellular uptake of the CLIC cargo CD44 was dependent on Gal3, GSLs and branched N-glycosylation. Endocytosis of β1-integrin was also reliant on Gal3. Analysis of different galectins revealed a distinct profile of cargoes and uptake structures, suggesting the existence of different CLIC populations. We conclude that Gal3 functionally integrates carbohydrate specificity on cargo proteins with the capacity of GSLs to drive clathrin-independent plasma membrane bending as a first step of CLIC biogenesis.