The involvement of galectin-3 in skin injury in systemic lupus erythematosus patients

Accumulation of Microvascular Target Organ Damage in Systemic Lupus Erythematosus Patients Is Associated with Increased Cardiovascular Risk

Background: Systemic lupus erythematosus (SLE) is a prototype autoimmune disease associated with increased cardiovascular (CV) burden. Besides increased arterial stiffness and subclinical atherosclerosis, microvascular dysfunction is considered an important component in the pathophysiology of CV disease. However, there is a lack of data regarding the effect of multiple target organ damage (TOD) on CV health. Objectives: This study aimed to evaluate (i) the presence of microvascular changes in SLE in various vascular beds, (ii) the possible associations between the accumulation of microvascular TOD and CV risk and (iii) whether Galectin-3 represents a predictor of combined microvascular TOD. Methods: Participants underwent (i) evaluation of skin microvascular perfusion (laser speckle contrast analysis), (ii) fundoscopy (non-mydriatic fundus camera), (iii) indirect assessment of myocardial perfusion (subendocardial viability ratio) and (iv) determination of urine albumin-to-creatinine ratio (UACR). CV risk was calculated using the QResearch Risk Estimator version 3 (QRISK3). Serum Galectin-3 levels were determined. Results: Forty-seven SLE patients and fifty controls were studied. SLE patients demonstrated impaired skin microvascular reactivity (160.2 ± 41.0 vs. 203.6 ± 40.1%), retinal arteriolar narrowing (88.1 ± 11.1 vs. 94.6 ± 13.5 μm) and higher UACR levels compared to controls. Furthermore, SLE individuals had significantly higher Galectin-3 levels [21.5(6.1) vs. 6.6(6.6) ng/dL], QRISK3 scores [7.0(8.6) vs. 1.3(3.6)%] and a greater chance for microvascular dysfunction. In the SLE group, patients with multiple TOD exhibited higher QRISK3. In the multivariate analysis, the accumulation of TOD correlated with disease activity and Galectin-3 (p < 0.05). Conclusions: Our study showed for the first time that SLE patients exhibit a greater number of cases of TOD. The accumulation of TOD was associated with increased CV risk. Clinicians dealing with SLE should be aware and seek microvascular alterations.

Urine proteomics by mass spectrometry identifies proteins involved in key pathogenic pathways in patients with juvenile dermatomyositis

OBJECTIVES

To identify and validate biomarkers in JDM patients using a multiplexing tandem mass tag urine proteome profiling approach.

METHODS

First morning void urine samples were collected from JDM patients (n = 20) and healthy control subjects (n = 21) and processed for analysis using a standardized liquid chromatography-tandem mass spectrometry approach. Biomarkers with significantly altered levels were correlated with clinical measures of myositis disease activity and damage. A subset of candidate biomarkers was validated using commercially available ELISA kits.

RESULTS

In total, 2348 proteins were detected in the samples, with 275 proteins quantified across all samples. Among the differentially altered proteins, cathepsin D and galectin-3 binding protein were significantly increased in the urine of JDM patients (adjusted P < 0.05), supporting previous findings in myositis patients. These two candidate biomarkers were confirmed with ELISAs. Cathepsin D positively correlated with Myositis Damage Index (r = 0.57, P < 0.05) and negatively correlated with the Childhood Myositis Assessment Scale (r = -0.54, P < 0.05). We also identified novel JDM candidate biomarkers involved with key features of myositis, including extracellular matrix remodelling proteins.

CONCLUSION

This study confirmed the presence of several proteins in the urine of JDM patients that were previously found to be elevated in the blood of myositis patients and identified novel candidate biomarkers that require validation. These results support the use of urine as a source for biomarker development in JDM.

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

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

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.

Serum levels of galectin-3 in idiopathic inflammatory myopathies: a potential biomarker of disease activity

OBJECTIVES

Galectin-3 is involved in various biological activities, including immune activations and fibrosis. Idiopathic inflammatory myopathies (IIMs) are autoimmune diseases of unknown aetiology, often complicated by interstitial lung disease (ILD). The aim of this study was to evaluate the expression of galectin-3 in sera and tissues of patients with IIM and assess the associations of galectin-3 with patient characteristics and disease activity.

RESULTS

Serum galectin-3 levels were significantly higher in IIM patients than in healthy controls. The serum galectin-3 levels positively correlated with serum levels of inflammatory markers and proinflammatory cytokines/chemokines and the Myositis Intention-to-Treat Activity Index. Stratification analysis revealed that patients with IIM-associated ILD (IIM-ILD) had significantly higher levels of serum galectin-3 than those without IIM-ILD. In addition, patients with acute/subacute interstitial pneumonia had significantly higher levels of serum galectin-3 than those with chronic interstitial pneumonia. Furthermore, serum galectin-3 levels in IIM-ILD patients correlated with the radiological assessments of parenchymal lung involvement and treatment response. Immunohistochemical analysis revealed that galectin-3 was expressed in inflammatory cells of myositis and dermatitis sections, whereas in ILD sections, galectin-3 was expressed in interstitial fibrosis and inflammatory cells.

CONCLUSION

Galectin-3 may be involved in the pathogenesis of inflammatory and fibrotic conditions in IIM and can serve as a potential biomarker of disease activity, especially in patients with IIM-ILD.

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.

Dermatological Implications of Galectin-3 in Circulation: An Evaluation From the Perspective of Patients With Differential Manifestations of Post-Kala-Azar Dermal Leishmaniasis

Galectin-3, a β-galactoside-binding lectin, has been implicated in vast repertoire of inflammatory and immunomodulatory processes including skin diseases. However, galectin-3 has not been comprehensively studied in infectious diseases. This study emphasizes on fascinating aspects of galectin-3 expression in dermal infection by studying post-kala-azar dermal leishmaniasis (PKDL), an intracellular infection caused by Leishmania donovani. Indian PKDL is a well-recognized parasitic dermatosis, with a high risk of anthroponotic transmission of L. donovani in causing leishmaniasis. This study aims to investigate the levels of galectin-3 and galectin-3-binding site expression in circulation of different forms of Indian patients with PKDL. Thirty-seven confirmed untreated PKDL patients, comprising 20 polymorphic and 17 macular PKDL manifestations, were evaluated for the levels of sera galectin-3 with respect to 28 age- and sex-matched healthy controls from endemic areas. Result shows a significant increment (P < 0.001) in circulatory galectin-3 levels in PKDL variants as compared to healthy controls. In addition, there were heightened levels of galectin-3 and galectin-3-binding sites on cellular infiltrates on lesional sites. Furthermore, there was a positive correlation between frequencies of mononuclear cells and galectin-3 during microcirculation in lesions. Data were well corroborated with positive correlation of IL-10 and IFN-γ with sera galectin-3 levels. Moreover, flow cytometry demonstrated the enhanced expression levels of the galectin-3-binding site in circulation in patients with PKDL as compared to healthy controls. Taken together, elevated levels of galectin-3 reflect its involvement in PKDL pathogenesis.

Coordinated Induction of Antimicrobial Response Factors in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by dysregulated autoantibody production and complement activation leading to multi-organ damage. The disease is associated with increased intestinal permeability. In this study, we tested the hypothesis that SLE subjects have increased systemic exposure to bacteria. Since bacteria induce the expression of antimicrobial response factors (ARFs), we measured the levels of a series of clinically relevant ARFs in the plasma of SLE subjects. We found that levels of sCD14, lysozyme, and CXCL16 were significantly elevated in SLE subjects. A strong positive correlation was also observed between sCD14 and SELENA-SLEDAI score. Interestingly, the ratio of EndoCAb IgM:total IgM was significantly decreased in SLE and this ratio was negatively correlated with sCD14 levels. Although, there were no significant differences in the levels of lipopolysaccharide binding protein (LBP) and fatty acid binding protein 2 (FABP2), we observed significant positive correlations between lysozyme levels and sCD14, LBP, and FABP2. Moreover, galectin-3 levels also positively correlate with lysozyme, sCD14, and LBP. Since our SLE cohort comprised 43.33% males, we were able to identify gender-specific changes in the levels of ARFs. Overall, these changes in the levels and relationships between ARFs link microbial exposure and SLE. Approaches to reduce microbial exposure or to improve barrier function may provide therapeutic strategies for SLE patients.