Clinical Significance of Serum Galectin-9 and Soluble CD155 Levels in Patients with Systemic Sclerosis

Relationships between systemic sclerosis and atherosclerosis: screening for mitochondria-related biomarkers

Background

Patients with systemic sclerosis (SSc) are known to have higher incidence of atherosclerosis (AS). Mitochondrial injuries in SSc can cause endothelial dysfunction, leading to AS; thus, mitochondria appear to be hubs linking SSc to AS. This study aimed to identify the mitochondria-related biomarkers of SSc and AS.

Methods

We identified common differentially expressed genes (DEGs) in the SSc (GSE58095) and AS (GSE100927) datasets of the Gene Expression Omnibus (GEO) database. Considering the intersection between genes with identical expression trends and mitochondrial genes, we used the least absolute shrinkage and selection operator (LASSO) as well as random forest (RF) algorithms to identify four mitochondria-related hub genes. Diagnostic nomograms were then constructed to predict the likelihood of SSc and AS. Next, we used the CIBERSORT algorithm to evaluate immune infiltration in both disorders, predicted the transcription factors for the hub genes, and validated these genes for the two datasets.

Results

A total of 112 genes and 13 mitochondria-related genes were identified; these genes were then significantly enriched for macrophage differentiation, collagen-containing extracellular matrix, collagen binding, antigen processing and presentation, leukocyte transendothelial migration, and apoptosis. Four mitochondria-related hub DEGs (IFI6, FSCN1, GAL, and SGCA) were also identified. The nomograms showed good diagnostic values for GSE58095 (area under the curve (AUC) = 0.903) and GSE100927 (AUC = 0.904). Further, memory B cells, γδT cells, M0 macrophages, and activated mast cells were significantly higher in AS, while the resting memory CD4+ T cells were lower and M1 macrophages were higher in SSc; all of these were closely linked to multiple immune cells. Gene set enrichment analysis (GSEA) showed that IFI6 and FSCN1 were involved in immune-related pathways in both AS and SSc; GAL and SGCA are related to mitochondrial metabolism pathways in both SSc and AS. Twenty transcription factors (TFs) were predicted, where two TFs, namely BRCA1 and PPARγ, were highly expressed in both SSc and AS.

Conclusion

Four mitochondria-related biomarkers were identified in both SSc and AS, which have high diagnostic value and are associated with immune cell infiltration in both disorders. Hence, this study provides new insights into the pathological mechanisms underlying SSc and AS. The specific roles and action mechanisms of these genes require further clinical validation in SSc patients with AS.

Advancing Treatment in Bullous Pemphigoid: A Comprehensive Review of Novel Therapeutic Targets and Approaches

Bullous pemphigoid is one of the most common autoimmune bullous diseases occurring primarily in the elderly. Pathogenic autoantibodies against BP180 and BP230 at the dermal-epidermal junction cause subepidermal blisters, erosions, and intense pruritus, all of which adversely affect the patients' quality of life and may increase their morbidity and mortality. Current systemic treatment options for bullous pemphigoid are limited to corticosteroids and immunosuppressants, which can have substantial side effects on these vulnerable patients that even exceed their therapeutic benefits. Therefore, more precisely, targeting therapies to the pathogenic cells and molecules in bullous pemphigoid is an urgent issue. In this review, we describe the pathophysiology of bullous pemphigoid, focusing on autoantibodies, complements, eosinophils, neutrophils, proteases, and the T helper 2 and 17 axes since they are crucial in promoting proinflammatory environments. We also highlight the emerging therapeutic targets for bullous pemphigoid and their latest discoveries in clinical trials or experimental studies. Further well-designed studies are required to establish the efficacy and safety of these prospective therapeutic options.

Expression of Gal-9 on Dendritic Cells and Soluble Forms of TIM-3/Gal-9 in Patients Suffering from Endometriosis

Immune system dysregulation is clinically evident in the pathogenesis of endometriosis (EMS). Changes in the dendritic cells (DCs) activity or phenotype may be involved in the implantation and growth of endometrial tissue outside the uterus in the disease. The TIM-3/Gal-9 axis is implicated in the development of immune tolerance. However, the knowledge about the exact role of this pathway in the EMS is extremely poor. In the present study, we evaluated the expression of Gal-9 on myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) in the peripheral blood (PB) and peritoneal fluid (PF) of both EMS patients (n = 82) and healthy subjects (n = 10) via flow cytometry. We also investigated the concentrations of soluble Gal-9 and TIM-3 in the plasma and PF of EMS patients and the control group using ELISA. We showed significantly elevated percentages of mDCs-Gal-9⁺ and pDCs-Gal-9⁺, and significantly higher concentrations of the soluble form of Gal-9 and TIM-3 in the PF of EMS patients than in circulation. Our results led us to conclude that the accumulation of Gal-9 expressing mDCs and pDCs in the PF and high sTIM-3/Gal-9 production in the peritoneal cavity could represent the hallmark of immune regulation in EMS patients, which may augment the inflammatory process and development/maintenance of local immunosuppression.

Human poliovirus receptor contributes to biliary atresia pathogenesis by exacerbating natural-killer-cell-mediated bile duct injury

BACKGROUND AND AIMS

Natural killer (NK) cells play an important role in biliary atresia (BA) pathogenesis; human poliovirus receptor (PVR) is an important NK-cell modulator. Here, we explored the role of PVR in BA pathogenesis.

METHODS

Poliovirus receptor expression and NK cell-associated genes were detected in human BA samples and a rotavirus-induced BA mouse model using quantitative PCR and immunofluorescence staining. Chemically modified small interfering RNA silenced PVR expression in the BA model, and its effects on the population and function of intrahepatic NK cells were investigated using flow cytometry (FCM). The effects of PVR overexpression and knockdown on proliferation, apoptosis and NK-cell-mediated lysis of cultured human cholangiocytes were analysed using FCM and cell viability assays. Serum PVR, high-mobility group box 1 (HMGB1), and interleukin-1beta (IL-1beta) levels were measured in a cohort of 50 patients using ELISA.

RESULTS

Poliovirus receptor expression was upregulated in the biliary epithelium of BA patients and BA model and was positively correlated with the population and activation of intrahepatic NK cells. Silencing of PVR expression impaired the cytotoxicity of NK cells, reduced inflammation and protected mice from rotavirus-induced BA. Activation of the TLR3-IRF3 signalling pathway induced PVR expression in cultured cholangiocytes. PVR overexpression promoted proliferation and inhibited the apoptosis of cholangiocytes but exacerbated NK cell-mediated cholangiocyte lysis. Serum PVR levels were elevated in BA patients and were positively correlated with HMGB1 and IL-1beta levels.

CONCLUSIONS

Poliovirus receptor contributes to BA pathogenesis by regulating NK cell-mediated bile duct injury; PVR has the value as a biomarker of BA.

Galectin-9: A novel promoter of atherosclerosis progression

BACKGROUND AND AIMS

Atherosclerosis is widely accepted to be an inflammatory disease driven by lipid accumulation and leukocyte recruitment. More recently, galectins, a family of β-galactoside binding proteins, have been shown to play a role in leukocyte recruitment among other immunomodulatory functions. Galectin (Gal) -9, a tandem repeat type galectin expressed by the endothelium in inflammatory environments, has been proposed to promote leukocyte recruitment. However, the role of Gal-9 in the context of monocyte recruitment remains elusive.

METHODS AND RESULTS

Here, we characterise the immunomodulatory role of Gal-9 in context of atherosclerosis. We show that ApoE-/-Gal-9-/- mice have a significantly reduced aortic plaque burden compared to their ApoE-/- littermate controls after 12 weeks of high fat diet. RNA sequencing data from two independent studies reveal Lgals9 expression in leukocyte clusters isolated from murine atherosclerotic plaques. Additionally, soluble Gal-9 protein induces monocyte activation and a pro-inflammatory phenotype in macrophages. Furthermore, we show that immobilised recombinant Gal-9 acts as capture and adhesion molecule for CD14+ monocytes in a β2-integrin and glycan dependent manner, while adhesion of monocytes to stimulated endothelium is reduced when Gal-9 is knocked down. Gal-9 also facilitates enhanced recruitment of leukocytes from peripheral arterial disease (PAD) patients compared to healthy young and aged controls. We further characterise the endothelium as source of circulating Gal-9, which is increased in plasma of PAD patients compared to healthy controls.

CONCLUSIONS

These results highlight a pathological role for Gal-9 as promoter of monocyte recruitment and atherosclerotic plaque progression, making it a novel target in the prevention of plaque formation and progression.

Serum Levels of Galectin-9 are Increased in Cervical Cancer Patients and are Higher in Advanced Clinical Stages

Purpose

Cervical cancer (CC) is the second most frequent cancer in undeveloped countries. Serum biomarkers could be useful for evaluation of the treatment response and as a complementary means to improve diagnosis. The expression of galectin-9 is altered in cancer tissue, and higher concentrations are found in the serum of cancer patients. The objectives of this study were (a) to determine the serum galectin-9 concentration in patients with intraepithelial lesions and CC, (b) to determine if the concentration was related to the clinicopathological characteristics and (c) to determine if the galectin-9 concentration was related to its expression level in tumour tissue.

Patients and Methods

In all, 222 serum samples from women with different diagnoses, including premalignant lesions and CC, as well as samples from women with normal cytology were included in the study. The serum galectin-9 concentration was determined by ELISA. To evaluate the expression level of galectin-9 in CC tissue, immunohistochemistry was performed in 34 CC biopsy specimens.

Results

The galectin-9 concentration in the serum of CC patients (8.171 ng/mL) was increased compared with serum from women with normal epithelia (4.654 ng/mL) and those with low-grade (4.806 ng/mL) and high-grade (5.354 ng/mL) intraepithelial lesions (p value < 0.0001). The area under the ROC curve considering the CC group and the control group was 0.882. The optimal cut-off value was ≥6.88 ng/mL, the specificity obtained was 100%, and the sensitivity was 68.2%. In the CC group, the analysis of the clinical stage showed an increase of galectin-9 in the advanced stage IV group. Serum galectin-9 was not related to the level of galectin-9 expression in tissue, which suggests that galectin-9 is not secreted by tumour cells.

Conclusion

The serum galectin-9 concentration is related to cancer progression, as the level of this protein is higher in patients with advanced-stage disease.

Galectin-9 Regulates Monosodium Urate Crystal-Induced Gouty Inflammation Through the Modulation of Treg/Th17 Ratio

Gout is caused by depositing monosodium urate (MSU) crystals within the articular area. The infiltration of neutrophils and monocytes drives the initial inflammatory response followed by lymphocytes. Interestingly, emerging evidence supports the view that in situ imbalance of T helper 17 cells (Th17)/regulatory T cells (Treg) impacts the subsequent damage to target tissues. Galectin-9 (Gal-9) is a modulator of innate and adaptive immunity with both pro- and anti-inflammatory functions, dependent upon its expression and cellular location. However, the specific cellular and molecular mechanisms by which Gal-9 modulates the inflammatory response in the onset and progression of gouty arthritis has yet to be elucidated. In this study, we sought to comprehensively characterise the functional role of exogenous Gal-9 in an in vivo model of MSU crystal-induced gouty inflammation by monitoring in situ neutrophils, monocytes and Th17/Treg recruited phenotypes and related cyto-chemokines profile. Treatment with Gal-9 revealed a dose-dependent reduction in joint inflammation scores, knee joint oedema and expression of different pro-inflammatory cyto-chemokines. Furthermore, flow cytometry analysis highlighted a significant modulation of infiltrating inflammatory monocytes (CD11b⁺/CD115⁺/LY6-C^hi) and Th17 (CD4⁺/IL-17⁺)/Treg (CD4⁺/CD25⁺/FOXP-3⁺) cells following Gal-9 treatment. Collectively the results presented in this study indicate that the administration of Gal-9 could provide a new therapeutic strategy for preventing tissue damage in gouty arthritic inflammation and, possibly, in other inflammatory-based diseases.

The Vasculopathy of Juvenile Dermatomyositis: Endothelial Injury, Hypercoagulability, and Increased Arterial Stiffness

OBJECTIVE

Vasculopathy is considered central to the pathogenesis of juvenile dermatomyositis (DM) and is associated with severe extramuscular manifestations. We undertook this study to investigate the hypothesis that the vasculopathy of juvenile DM can be noninvasively tracked by examining biomarkers of endothelial injury, subclinical inflammation, hypercoagulability, and vascular arterial stiffness.

METHODS

The study population was a UK cohort of children with juvenile DM. Circulating endothelial cells (CECs) and microparticles (MPs) were identified using immunomagnetic bead extraction and flow cytometry, respectively. Plasma thrombin generation was determined using a fluorogenic assay. Cytokine and chemokine levels were measured by electrochemiluminescence. Arterial stiffness was assessed using pulse wave velocity (PWV). Results were expressed as the median and interquartile range (IQR), and statistical significance was assessed using nonparametric analyses.

RESULTS

Ninety patients with juvenile DM and 79 healthy control subjects were included. The median age of the patients was 10.21 years (IQR 6.68-13.40), and the median disease duration was 1.63 years (IQR 0.28-4.66). CEC counts were higher in all patients with juvenile DM compared to controls (median 96 cells/ml [IQR (40-192] and 12 cells/ml [IQR 8-24], respectively; P < 0.0001). Circulating MP numbers were also significantly higher in patients with active juvenile DM compared to controls (median 204.7 × 103 /ml [IQR 87.9-412.6] and 44.3 × 103 /ml [IQR 15.0-249.1], respectively; P < 0.0001). MPs were predominantly of platelet and endothelial origin. Enhanced plasma thrombin generation was demonstrated in patients with active juvenile DM compared to those with inactive disease (P = 0.0003) and controls (P < 0.0001). Carotid-radial PWV adjusted for age was increased in patients with juvenile DM compared to controls (P = 0.003).

CONCLUSION

We observed increased endothelial injury and increased levels of proinflammatory cytokines in patients with active juvenile DM. MP profiles reflected distinct disease activity status in juvenile DM and are markers of vascular pathology, platelet activation, and thrombotic propensity. Ongoing long-term vascular injury may result in increased arterial stiffness in patients with juvenile DM.

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.

A potential contribution of decreased serum galectin-10 levels to systemic inflammation and pulmonary vascular involvement in systemic sclerosis

OBJECTIVE

Galectin-10 (Gal-10) is a key molecule involved in eosinophil-mediated suppression of T-cell immune response. Systemic sclerosis (SSc) is characterized by T helper (Th) 2/Th17 immune response and impaired function of regulatory T cells, but the pathological role of Gal-10 has not been studied so far. Therefore, we investigated the clinical correlation of serum Gal-10 levels in SSc patients.

METHODS

Serum Gal-10 levels were determined by enzyme-linked immunosorbent assay in 38 patients with diffuse cutaneous SSc (dcSSc), 30 with limited cutaneous SSc and 20 healthy controls. Clinical correlations of serum Gal-10 levels were examined.

RESULTS

Serum Gal-10 levels were significantly lower in SSc patients than in healthy controls, especially in dcSSc patients, and inversely correlated with skin score, the percentage of predicted diffusion lung capacity for carbon monoxide and estimated right ventricular systolic pressure (RVSP). Furthermore, serum Gal-10 levels had negative correlations with leucocyte counts and inflammatory parameters. Multivariate regression analysis identified C-reactive protein and RVSP as explanatory parameters for serum Gal-10 levels.

CONCLUSION

Decreased serum Gal-10 levels may reflect the impairment of eosinophil-mediated regulatory system for T-cell immune response in SSc, possibly contributing to pulmonary vascular involvement leading to pulmonary arterial hypertension.

Glycans and Glycan-Binding Proteins as Regulators and Potential Targets in Leukocyte Recruitment

Leukocyte recruitment is a highly controlled cascade of interactions between proteins expressed by the endothelium and circulating leukocytes. The involvement of glycans and glycan-binding proteins in the leukocyte recruitment cascade has been well-characterised. However, our understanding of these interactions and their regulation has expanded substantially in recent years to include novel lectins and regulatory pathways. In this review, we discuss the role of glycans and glycan-binding proteins, mediating the interactions between endothelium and leukocytes both directly and indirectly. We also highlight recent findings of key enzymes involved in glycosylation which affect leukocyte recruitment. Finally, we investigate the potential of glycans and glycan binding proteins as therapeutic targets to modulate leukocyte recruitment and transmigration in inflammation.

Galectin-9 as a biomarker of disease severity

Galectin-9 (Gal-9) is a β-galactoside binding lectin known for its immunomodulatory role in various microbial infections. Gal-9 is expressed in all organ systems and localized in the nucleus, cell surface, cytoplasm and the extracellular matrix. It mediates host-pathogen interactions and regulates cell signalling via binding to its receptors. Gal-9 is involved in many physiological functions such as cell growth, differentiation, adhesion, communication and death. However, recent studies have emphasized on the elevated levels of Gal-9 in autoimmune disorders, viral infections, parasitic invasion, cancer, acute liver failure, atopic dermatitis, chronic kidney disease, type-2 diabetes, coronary artery disease, atherosclerosis and benign infertility-related gynecological disorders. In this paper we have reviewed the potential of Gal-9 as a reliable, sensitive and non-invasive biomarker of disease severity. Tracking changes in Gal-9 levels and its implementation as a biomarker in clinical practice will be an important tool to monitor disease activity and facilitate personalized treatment decisions.

Prognostic role of galectins expression in patients with hepatic cancer: A meta-analysis

OBJECTIVE

The objective of this study was to illustrate the prognostic value of diversified galectins in patients with hepatic cancer via meta-analysis.

METHODS

We conducted a systematic search on PubMed, Embase, The Cochrane Library, Web of Science, the Chinese National Knowledge Infrastructure (CNKI) database, and Wanfang Data for studies that reported associations between galectin expression and the prognosis for hepatic cancer patients, from the inception of each database to March 20, 2019. The combined hazard ratio (HR) and 95% confidence interval (CI) were estimated to investigate the prognosis.

RESULTS

We collected 11 studies of 1957 patients in our meta-analysis. The pooled results indicated that overall galectin expression was not correlated with OS (HR = 1.23, 95% CI = 0.84-1.79, P = .29) or DFS/RFS (HR = 0.808, 95% CI = 0.376-1.735, P = .42) in liver cancer patients. In stratified analyses, we observed that high galectin-1 and galectin-3 expression was significantly associated with poor OS. The pooled HR of galectin-4 and galectin-9 was correlated with improved OS.

CONCLUSION

Our results indicate that the high expression of galectin-1 and -3 and the low expression of galectin-4 and -9 may be predictive prognostic factors for poor OS in liver cancer patients.

Dynamics of digital ulcers in systemic sclerosis

Systemic sclerosis (SSc) is a collagenosis with insufficiently known etiopathogenesis, characterized by microvasculopathy and excessive fibrosis in the context of an autoimmune disorder. The incompletely elucidated pathogenesis and limited therapeutic options, disabling aspects, skin lesions and pain determine important functional and psychological deficiencies which affect the quality of life. It is imperative to observe and correlate individual clinical and paraclinical data to optimize disease management. A group of 22 patients diagnosed with SSc, hospitalized in a university clinic in Bucharest was included in an observational study. The evolution of digital ulcers was evaluated as an indicator of vasculopathy and their status and dynamics were correlated with clinical elements reflecting the fibrotic aspect of the disease. The present study shows that the Raynaud phenomenon is almost always present during the course of the disease, but its presence is not always associated with digital ulcers. The existing data in the literature show that fibrosis is subsequent to vasculopathy, but this study did not reveal causality between these two aspects of pathogenesis. The presence of microstomia and digital contracture was identified in the presence of digital ulcers, but also in their absence. The etiopathogenic mechanisms with multiple unknown involved factors open the opportunity to investigate many aspects of SSc for optimal aiming of therapeutic interventions.