Galectin-3 and the skin

Staphylococcus aureus Proteases: Orchestrators of Skin Inflammation

Skin homeostasis relies on a delicate balance between host proteases and protease inhibitors along with those secreted from microbial communities, as disruption to this harmony contributes to the pathogenesis of inflammatory skin disorders, including atopic dermatitis and Netherton's syndrome. In addition to being a prominent cause of skin and soft tissue infections, the gram-positive bacterium Staphylococcus aureus is a key player in inflammatory skin conditions due to its array of 10 secreted proteases. Herein we review how S. aureus proteases augment the development of inflammation in skin disorders. These mechanisms include degradation of skin barrier integrity, immune dysregulation and pruritis, and impairment of host defenses. Delineating the diverse roles of S. aureus proteases has the potential to reveal novel therapeutic strategies, such as inhibitors of proteases or their cognate target, as well as neutralizing vaccines to alleviate the burden of inflammatory skin disorders in patients.

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

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

TNF-α promotes CXCL-1/8 production in keratinocytes by downregulating galectin-3 through NF-κB and hsa-miR-27a-3p pathway to contribute psoriasis development

OBJECTIVE

Treatment with TNF-α inhibitors improve psoriasis with minimize/minor neutrophils infiltration and CXCL-1/8 expression in psoriatic lesions. However, the fine mechanism of TNF-α initiating psoriatic inflammation by tuning keratinocytes is unclear. Our previous research identified the deficiency of intracellular galectin-3 was sufficient to promote psoriasis inflammation characterized by neutrophil accumulation. This study aims to investigate whether TNF-α participated in psoriasis development through dysregulating galectin-3 expression.

METHODS

mRNA levels were assessed through quantitative real-time PCR. Flow cytometry was used to detect cell cycle/apoptosis. Western blot was used to evaluate the activation of the NF-κB signaling pathway. HE staining and immunochemistry were used to detect epidermal thickness and MPO expression, respectively. Specific small interfering RNA (siRNA) was used to knock down hsa-miR-27a-3p while plasmids transfection was used to overexpress galectin-3. Further, the multiMiR R package was utilized to predict microRNA-target interaction.

RESULTS AND DISCUSSION

We found that TNF-α stimulation altered cell proliferation and differentiation and promoted the production of psoriasis-related inflammatory mediators along with the inhibition of galectin-3 expression in keratinocytes. Supplement of galectin-3 could counteract the rise of CXCL-1/8 but not the other phenotypes of keratinocytes induced by TNF-α. Mechanistically, inhibition of the NF-κB signaling pathway could counteract the decrease of galectin-3 and the increase of hsa-miR-27a-3p expression whereas silence of hsa-miR-27a-3p could counteract the decrease of galectin-3 expression induced by TNF-α treatment in keratinocytes. Intradermal injection of murine anti-CXCL-2 antibody greatly alleviated imiquimod-induced psoriasis-like dermatitis.

CONCLUSION

TNF-α initiates psoriatic inflammation by increasing CXCL-1/8 in keratinocytes mediated by the axis of NF-κB-hsa-miR-27a-3p-galectin-3 pathway.

Navigating the landscape of psoriasis therapy: novel targeted pathways and emerging trends

INTRODUCTION

Psoriasis is a chronic, inflammatory, non-communicable skin disorder that affects a patient's social and emotional well-being. It is characterized by hyperproliferation of keratinocytes, irregular shedding of skin cells, and abnormal invasion of inflammatory mediators. The treatment strategy is designed based on the severity of the disease condition starting from topical, phototherapy, systemic, and biologics. In recent years, extensive research into the underlying mechanisms of psoriasis has led to significant advancement in treatment options from small molecules to biologics.

AREA COVERED

This review focuses on intracellular and molecular mechanisms such as AhR, A3AR, RIP1, CGRP, and S1P that serve as novel pharmacological targets for psoriasis. Moreover, new molecules are approved or are under clinical investigation to interfere with these target mechanisms.

EXPERT OPINION

A detailed understanding of signaling pathways provides potential targets and molecular mechanisms for the inflammatory cascade in psoriasis. This has led to the development of small molecules targeting specific pathways. Further, the combination of nanotechnology can assist in dose reduction leading to reduced adverse effects in the management of psoriasis.

Integrative analysis of gene expression and DNA methylation to identify biomarkers of non-genital warts induced by low-risk human papillomaviruses infection

Background

Human papillomaviruses have been shown to dysregulate the gene expression and DNA methylation profiles of their host cells over the course of infection. However, there is a lack of information on the impact of low-risk HPV infection and wart formation on host cell's expression and methylation patterns. Therefore, the objective of this study is to analyse the genome and methylome of common warts using an integrative approach.

Methods

In the present study, gene expression (GSE136347) and methylation (GSE213888) datasets of common warts were obtained from the GEO database. Identification of the differentially expressed and differentially methylated genes was carried out using the RnBeads R package and the edgeR Bioconductor package. Next, functional annotation of the identified genes was obtained using the Database for Annotation, Visualization, and Integrated Discovery (DAVID). Network construction and analyses of the gene-gene, protein-protein, and signaling interactions of the differentially expressed and differentially methylated genes was performed using the GeneMANIA web interface, the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database, and the Signaling Network Open Resource 2.0 (SIGNOR 2.0), respectively. Lastly, significant hub genes were identified using the Cytoscape application CytoHubba.

Results

A total of 276 genes were identified as differentially expressed and differentially methylated in common warts, with 52% being upregulated and hypermethylated. Functional enrichment analysis identified extracellular components as the most enriched annotations, while network analyses identified ELN, ITGB1, TIMP1, MMP2, LGALS3, COL1A1 and ANPEP as significant hub genes.

Conclusions

To the best knowledge of the authors, this is the first integrative study to be carried out on non-genital warts induced by low-risk HPV types. Future studies are required to re-validate the findings in larger populations using alternative approaches.

Gal-3 Protein Expression and Localization in Prostate Tumours

Gal-3 plays an important role in cell survival, mRNA splicing, and cell–cell and cell–matrix interactions. Depending on its cellular localization and cancer type, Gal-3 may have tumour-suppressive or tumour-promoting activities. Given the promising diagnostic role of Gal-3 in the urine of PCa patients found in our previous study, its concordant gene and protein expression levels, and its involvement in PCa-related biological processes (e.g., morphogenesis of the prostate gland epithelium), we aimed to investigate this protein immunohistochemically in tumour and normal prostate tissues. Gal-3 protein expression was evaluated in 48 tumour prostate tissues, eight normal prostate tissues and 14 adjacent-normal prostate tissues. Decreased Gal-3 staining was detected in tumour tissues compared with normal tissues. Although Gal-3 staining was decreased in tumour tissues with GS 5-8 and pT2 and pT3 stages compared with normal prostate tissue, no correlation was found between Gal-3 expression and PCa progression. In the present study, the pattern of cellular localization differed between groups, as Gal-3 was predominantly excluded from the nucleus in tumour tissues. Furthermore, Gal-3 had no significant effect on survival and relapse in these PCa patients. This work confirms Gal-3 as a promising marker for PCa diagnosis.

Transcriptional Heterogeneity and the Microbiome of Cutaneous T-Cell Lymphoma

Cutaneous T-Cell Lymphomas (CTCL) presents with substantial clinical variability and transcriptional heterogeneity. In the recent years, several studies paved the way to elucidate aetiology and pathogenesis of CTCL using sequencing methods. Several T-cell subtypes were suggested as the source of disease thereby explaining clinical and transcriptional heterogeneity of CTCL entities. Several differentially expressed pathways could explain disease progression. However, exogenous triggers in the skin microenvironment also seem to affect CTCL status. Especially Staphylococcus aureus was shown to contribute to disease progression. Only little is known about the complex microbiome patterns involved in CTCL and how microbial shifts might impact this malignancy. Nevertheless, first hints indicate that the microbiome might at least in part explain transcriptional heterogeneity and that microbial approaches could serve in diagnosis and prognosis. Shaping the microbiome could be a treatment option to maintain stable disease. Here, we review current knowledge of transcriptional heterogeneity of and microbial influences on CTCL. We discuss potential benefits of microbial applications and microbial directed therapies to aid patients with CTCL burden.

Galectin-3 as a Novel Multifaceted and Not Only Cardiovascular Biomarker in Patients with Psoriasis with Regard to Systemic Treatment-Preliminary Data

Simple Summary

Galectin-3 (gal-3) regulates many different biological processes and diseases, which are common accompanying diseases of psoriasis. Psoriasis is one of the most common skin diseases. There is little information about potential diagnostic role of gal-3 in psoriasis. Serum gal-3 concentrations were measured before and after twelve weeks of antipsoriatic treatment in patients with psoriasis and compared to 11 persons without psoriasis (control group). Serum gal-3 level in patients with psoriasis was significantly higher compared to the control group. In obese patients and long-lasting psoriasis positive relations of gal-3 and index of psoriasis severity were noted. In psoriatics with low gal-3 levels, it was noted that the higher the gal-3, the higher the BMI and glucose level. In patients with long history of psoriasis it was observed that the higher gal-3, the lower the lipids levels. The Gal-3 level might be a factor affecting the course of psoriasis and useful in prediction of cardiometabolic comorbidities, especially in patients with a long history of the disease or obesity. Patients with low serum gal-3 and a short history of psoriasis may have greater risk of diabetes. In obese patients with long-lasting psoriasis, gal-3 may have a beneficial influence against abnormal lipid profiles or perhaps further cardiovascular disorder development.

Abstract

Galectin-3 (gal-3) is a multifunctional regulator of various biological processes and diseases, which are common comorbidities in psoriasis. Data regarding potential diagnostic role of gal-3 in psoriasis are insufficient. Serum gal-3 levels were evaluated before and after twelve weeks of treatment with acitretin or methotrexate in 31 patients with plaque-type psoriasis and compared to 11 healthy control group. The mean serum galectin-3 level in patients with psoriasis was significantly higher compared to the control group (p < 0.01). In patients with obesity and long-lasting psoriasis (>20 years) positive relations of gal-3 and PASI were noted. In psoriatics with low gal-3 levels, positive correlations between the gal-3 and BMI, glucose level, and with the latter in short-lasting psoriasis (<20 years) were noted. In the long history of psoriasis, gal-3 was negatively correlated with lipids levels. The Gal-3 level might be a multifaceted modulator of the course of psoriasis and predictive factor of cardiometabolic comorbidities’ development, especially in patients with a long history of the disease or obesity. Patients with low serum gal-3 and short history of psoriasis are presumably at greater risk of diabetes. In patients with long-lasting psoriasis and concomitant obesity, gal-3 may exert a protective role against dyslipidemia or perhaps further CMD development.

Immunohistochemical Expression of Galectin-3 in Pemphigus Vulgaris

ABSTRACT

Pemphigus vulgaris (PV) is an autoimmune bullous disorder related to immunoglobulin-G autoantibodies against desmoglein-3. Galectin-3 is one of the main elements of the immunoglobulin-E group which is essential in the cell-cell or cell-matrix adhesion. Although the presence of immunoglobulin-E autoantibodies in PV has been observed, no studies have been performed to describe the role of galectin-3 in PV. We evaluated galectin-3 expression in PV as a first step in assessing its impact in the pathogenesis of this autoimmune blistering process. In a retrospective study, 56 specimens from 45 patients diagnosed with PV were stained with antibodies to galectin-3. The percentages of nuclear and cytoplasmic galectin-3 expression as well as staining intensity were evaluated around blisters and adjacent unaffected skin. We observed a significant decrease in galectin-3 cytoplasmic and nuclear expression as well as stain intensity around blisters compared with adjacent unaffected skin. Although autoantibodies against desmogleins trigger the blister formation in PV patients, loss of galectin-3 may play a role in the extension of blister formation by initiating cell-cell disassembly at the level of the intercellular keratinocyte desmosome. We demonstrated a lower expression of galectin-3 around the blisters in PV. The pathogenesis of the blister formation may be related to lower expression of galectin-3. Additional studies are necessary to clarify the result of this outcome and determine the accurate pathogenesis of blister formation in PV.

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.

Novel archetype in psoriasis management bridging molecular dynamics in exploring novel therapies

Psoriasis is an autoimmune chronic inflammatory condition of skin affecting 125 million populaces around the globe. It is implicated as a result of multifaceted phenomena involving various cell and subcell activities with the aid of numerous cellular and molecular components including signaling aisle and regulatory proteins owing to the development of such hyperproliferative dermatological conditions. This involves a deeply complex and conflicting pathology owing to genetic and immunological deviations resulting from the unusual presentation of different signaling pathways and regulatory proteins. Explorations of these biomarkers and intervention of molecular and cellular processes in psoriasis are yet to be investigated and could be an exceptional aspect for understanding pathology with successful targeting of disease. In the presented study, we have integrated molecular insights, including signaling molecules, pathways, and proteins implicated in pathogenesis, and we have attempted to link this knowledge to the targeting of these phenomena in order to manage the conditions precisely. Further, therapeutic delivery approaches for targeting distinct layers of skin have also been investigated based on the application of different nanocarriers for successful psoriasis treatment.

Weak immunohistochemical expression of galectin-3 near blisters in Hailey-Hailey disease

BACKGROUND

Hailey-Hailey disease (HHD) is an uncommon hereditary and benign skin condition characterized by blisters and erosions on intertriginous areas. It is related to a mutation of the ATP2C1 gene, which encodes a Ca²⁺ pump. It is characterized by multiple foci of skin acantholysis in the epidermis, with dyskeratosis and suprabasilar clefting. Galectin-3 is a beta-galactoside-binding protein that has an essential role in cell-to-cell and cell-to-matrix adhesion. We assessed galectin-3 immunohistochemical expression in HHD to explore its impact on the pathogenesis of this hereditary blistering disorder.

METHOD

In a retrospective study, seven specimens from seven patients diagnosed with HHD were stained with antibodies to galectin-3. We evaluated the nuclear and cytoplasmic expression of galectin-3, as well as the staining intensity around blisters and distant normal skin.

RESULTS

We observed a significant decrease in cytoplasmic and nuclear expression of galectin-3 as well as stain intensity around blisters compared with distant normal skin.

CONCLUSIONS

While the acantholysis process in HHD is related to abnormality in cadherin expression caused by altered Ca²⁺ pump concentration, lower expression of galectin-3 may cause the extension of blisters by initiating cell-to-cell disassembly in the epidermis.

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.

Plump endothelial cells integrated into pre-existing venules contribute to the formation of 'mother' and 'daughter' vessels in pyogenic granuloma: possible role of galectin-1, -3 and -8

INTRODUCTION

Pyogenic granuloma (PG) is a reactive inflammatory vascular lesion of the skin and mucous membranes, characterised by the presence of enlarged venules and seamed and seamless capillaries with plump endothelial cells (EC), and numerous macrophages. EC activation upregulates the synthesis of galectins and induces their translocation to the EC surface promoting angiogenesis and lymphangiogenesis, particularly galectin-1 (Gal-1), Gal-3 and Gal-8. However, the presence and distribution of Gal-1, -3 and -8, as well as their implications in the pathogenesis of PG, has not been considered.

MATERIALS AND METHODS

Eight biopsies from patients diagnosed with PG were selected. The presence of PECAM-1/CD31, IL-1β, VEGF-C, VEGFR-2, VEGFR-3, integrin β1, CD44, fibronectin and Gal-1, -3 and -8 was assessed by immunofluorescence staining using confocal laser scanning microscopy.

RESULTS AND DISCUSSION

Immunostaining revealed that these molecules were present in the enlarged venules with plump ECs, in some macrophages and other immune cells. We propose that macrophages release VEGF-A and VEGF-C inducing VEGFR-2/VEGFR-3 expression and activation, leading macrophages to transdifferentiate into plump ECs that might integrate into pre-existing venules, contributing to the formation of enlarged venules with transluminal bridges and capillaries. EC activation, induced by certain cytokines, has been shown to stimulate galectin expression and changes in the cellular localisation through association and activation of specific EC surface glycoproteins. Therefore, it is plausible that Gal-1, -3 and -8, acting in a concerted manner, could be mediating the transdifferentiation of macrophages into plump ECs and facilitating their migration and incorporation into the new vessels.

LAY SUMMARY

In this study, immunostaining of pyogenic granuloma (PG) tissue sections showed immunoreactivity for PECAM-1/CD31, IL-1β, VEGF-C, VEGFR-2 and VEGFR-3, and galectin-1, -3 and -8 in enlarged venules with plump endothelial cells (EC), as well as in some macrophages and other immune cells. Interestingly, enlarged and thin-walled transient vessels lined by PECAM-1/CD31 and VEGFR-2 immunopositive ECs that form from pre-existing normal venules in response to VEGF-A (called 'mother' vessels [MV]) and that undergo intraluminal bridging evolving into various types of capillaries (called 'daughter' vessels [DV]) have been observed in benign and malignant tumours, in physiological and pathological angiogenesis as well as in vascular malformations, suggesting an important role for VEGF-A and VEGFR-2 in such a process. However, it is not only the mechanisms by which the MVs evolve in different types of DVs that remains to be elucidated, but also whether the cells that form intraluminal bridges proceed from locally activated ECs or whether they are derived from bone marrow precursors or from resident macrophages.Given that the formation of homodimers by Gal-1 and Gal-8 and pentamers by Gal-3 to generate gal-glycan lattices at the cell surface and in the extracellular space has been shown, it is possible that in PG tissue Gal-1, -3 and -8, through their binding partners, form a supramolecular structure at the surface of ECs and plump ECs, macrophages and in the extracellular space that might be mediating the transdifferentiation of macrophages into plump ECs and facilitating the migration and incorporation of these cells into the pre-existing venules, thus contributing to the formation of MVs and DVs.

Human galectin‑3: Molecular switch of gene expression in dermal fibroblasts in vitro and of skin collagen organization in open wounds and tensile strength in incisions in vivo

Understanding the molecular and cellular processes in skin wound healing can pave the way for devising innovative concepts by turning the identified natural effectors into therapeutic tools. Based on the concept of broad-scale engagement of members of the family of galactoside-binding lectins (galectins) in pathophysiological processes, such as cancer or tissue repair/regeneration, the present study investigated the potential of galectins-1 (Gal-1) and −3 (Gal-3) in wound healing. Human dermal fibroblasts, which are key cells involved in skin wound healing, responded to galectin exposure (Gal-1 at 300 or Gal-3 at 600 ng/ml) with selective changes in gene expression among a panel of 84 wound-healing-related genes, as well as remodeling of the extracellular matrix. In the case of Gal-3, positive expression of Ki67 and cell number increased when using a decellularized matrix produced by Gal-3-treated fibroblasts as substrate for culture of interfollicular keratinocytes. In vivo wounds were topically treated with 20 μg/ml Gal-1 or −3, and collagen score was found to be elevated in excisional wound repair in rats treated with Gal-3. The tensile strength measured in incisions was significantly increased from 79.5±17.5 g/mm² in controls to 103.1±21.4 g/mm² after 21 days of healing. These data warrant further testing mixtures of galectins and other types of compounds, for example a combination of galectins and TGF-β1.

Diminished Expression of Galectin-3 Around Blisters in Bullous Pemphigoid: An Immunohistochemistry Study

Background

Bullous pemphigoid (BP) is a subepidermal blistering disorder caused by autoantibodies directed against hemidesmosomal proteins. Many patients with BP demonstrate circulating IgE autoantibodies. Although the role of IgE in the pathogenesis of BP is unknown, a correlation between IgE antibodies and eosinophilia has been observed. Soluble CD23 and galectin-3 are the main elements of the IgE group. The roles for CD23 in BP as a potential biomarker and IgE production regulator have been characterized, but no studies have evaluated any roles for galectin-3 in this disease.

Objective

In this study, we evaluated galectin-3 expression in BP as a first step in assessing its role in the pathogenesis of this autoimmune blistering process.

Patients and Methods

Sixty specimens diagnosed as BP were stained with antibodies to galectin-3. The percentages of nuclear and cytoplasmic galectin-3 expression and staining intensity were evaluated.

Results

There was a significant difference in galectin-3 cytoplasmic and nuclear expression within keratinocytes immediately surrounding and above the blisters: (1) cytoplasmic (mean = 17.2% ± 2.4%) vs adjacent unaffected skin (mean = 66.7% ± 2.0%, P < 0.0001) and (2) nuclear (mean = 1.9% ± 0.4%) vs adjacent unaffected skin (mean = 13.2% ± 1.2%, P < 0.0001).

Conclusions

Lower expression of galectin-3 around blisters in BP may suggest a role as an adhesion molecule. Loss of galectin-3 may add to the extension of blister formation by initiating cell-extracellular matrix disassembly and may be involved with the associated dermal inflammation and the eosinophil chemotaxis. Further studies will be necessary to elucidate the result of this observed loss on disease pathogenesis.

Changes in Proteome of Fibroblasts Isolated from Psoriatic Skin Lesions

The dermal fibroblasts are in constant contact with the cells of the immune system and skin epidermis. Therefore, they are essential for the development of lesions in psoriasis. The aim of this study was to assess the changes in the proteomic profile of fibroblasts in the dermis of psoriasis patients, and to discuss the most significant changes and their potential consequences. The proteomic results indicate that fibroblast dysfunction arises from the upregulation of proinflammatory factors and antioxidant proteins, as well as those involved in signal transduction and participating in proteolytic processes. Moreover, downregulated proteins in psoriatic fibroblasts are mainly responsible for the transcription/translation processes, glycolysis/ adenosine triphosphate synthesis and structural molecules. These changes can directly affect intercellular signaling and promote the hyperproliferation of epidermal cells. A better understanding of the metabolic effects of the proteomic changes observed could guide the development of new pharmacotherapies for psoriasis.

Relationship of Galectin-3 Expression in Canine Cutaneous Squamous Cell Carcinomas with Histopathological Grading and Proliferation Indices

Squamous cell carcinoma (SCC) is a frequent malignant neoplasm of the skin that usually arises from areas of solar dermatosis. It is characterized by local invasiveness and regional lymph node metastasis, mainly in poorly differentiated tumours. Galectin-3 (Gal-3) is a lectin that is expressed in the nucleus or cytoplasm and has been identified as a prognostic tool for human neoplasms. The purpose of this study was to characterize Gal-3 expression in canine cutaneous SCCs and to investigate its relationship with tumour differentiation and cell proliferation indices. Immunohistochemical analysis of 50 SCCs for Gal-3 revealed no correlation between the localization or intensity of immunolabelling, or number of immunopositive cells, with histological grade of tumour or proliferative activity. The results suggest that Gal-3 expression is not a reliable prognostic marker for cutaneous SCC in dogs.

Cutaneous wound healing in aged, high fat diet-induced obese female or male C57BL/6 mice

Since there are limited studies analyzing the impact of age, sex and obesity on cutaneous repair, the current study evaluated excisional skin wound healing as a function of age, sex and diet in C57BL/6 mice subjected to either low (LFD) or high (HFD) fat diet. Older mice accumulated increased body fat relative to younger mice under HFD. Skin wound healing at particular stages was affected by age in the aspect of Tgfβ-1, MCP-1, Mmp-9 and Mmp-13 expression. The most profound, cumulative effect was observed for the combination of two parameters: age and sex. While skin of younger males displayed extremely high collagen 1 and collagen 3 expression, younger females showed exceptionally high Mmp-13 expression at day 3 and 7 after injury. Diet as a single variable modified the thickness of dermis due to increased dermal White Adipose Tissue (dWAT) accumulation in mice fed HFD. The combination of age and diet affected the re-epithelialization and inflammatory response of injured skin. Overall, our data indicate that age has the most fundamental impact although all components (age, sex and diet) contribute to skin repair.

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.

Galectin-3 regulates UVB-induced inflammation in skin

BACKGROUND

Galectin-3 is widely expressed in many immunocytes and epithelial cells including skin keratinocytes. Galectin-3 can regulate immunological or inflammatory processes and plays a proinflammatory role in some disease models. Galectin-3 has a role in disorders related to ultraviolet (UV) photodamage such as apoptosis, skin squamous cell carcinoma and basal cell carcinoma. However, the evidence of galectin-3 in UVB-induced skin inflammation is still limited and the underlying molecular mechanism remains elusive.

OBJECTIVE

We aimed to investigate the effects of galectin-3 in human epidermal keratinocytes and in mice after UVB irradiation.

METHODS

Primary human epidermal keratinocytes with galectin-3 knockdown were used as the in vitro model. ELISA, QPCR, and western blotting were applied to evaluate the released cytokine, mRNA and protein expression. Histologic analysis, measurement of erythema and transepidermal water loss (TEWL) were applied to evaluate UVB-induced skin damage in galectin-3 knockout mice.

RESULTS

In UVB-irradiated human keratinocytes, galectin-3 knockdown downregulated the UVB-induced ASC crosslinking, cleavage of caspase-1, and formation of active IL-1β. Galectin-3 knockdown also decreased UVB-induced production of reactive oxygen species, p38 phosphorylation, and COX2 expression in human keratinocytes. After four days of UVB irradiation, galectin-3 knockout mice showed reduced gross erythema, histologic features of tissue inflammation, quantified levels of erythema and TEWL compared to wild type mice. The skin tissue lysate also showed less expression of active IL-1β and COX2 in galectin-3 knockout mice.

CONCLUSION

Galectin-3 may play a positive regulatory role in UVB-induced skin inflammation.

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.

Neonatal Antibiotic Treatment Is Associated With an Altered Circulating Immune Marker Profile at 1 Year of Age

Background: Neonatal antibiotics disturb the developing gut microbiome and are therefore thought to influence the developing immune system, but exact mechanisms and health consequences in later life still need to be elucidated. Therefore, we investigated whether neonatal antibiotics influence inflammatory markers at 1 year of age. In addition, we determined whether health problems during the first year of life, e.g., allergic disorders (eczema and wheezing) or infantile colics, were associated with changes in the circulating immune marker profile at 1 year of age. Methods: In a subgroup (N = 149) of the INCA-study, a prospective birth-cohort study, a blood sample was drawn from term born infants at 1 year of age and analyzed for 84 immune related markers using Luminex. Associations of antibiotic treatment, eczema, wheezing, and infantile colics with immune marker concentrations were investigated using a linear regression model. The trial is registered as NCT02536560. Results: The use of broad-spectrum antibiotics in the first week of life, was significantly associated with different levels of inflammatory markers including sVCAM-1, sCD14, sCD19, sCD27, IL-1RII, sVEGF-R1, and HSP70 at 1 year of age. Eczema was associated with decreased concentrations of IFNα, IFNγ, TSLP, CXCL9, and CXCL13, but increased concentrations of CCL18 and Galectin-3. Wheezing, independent of antibiotic treatment, was positively associated to TNF-R2 and resistin. Infantile colics were positively associated to IL-31, LIGHT, YKL-40, CXCL13, sPD1, IL1RI, sIL-7Ra, Gal-1, Gal-9, and S100A8 at 1 year of age, independent of early life antibiotic treatment. Conclusion: In this explorative study, we identified that neonatal antibiotics are associated with immunological alterations at 1 year of age and that, independent of the antibiotic treatment, infantile colics were associated with alterations within gut associated markers. These findings support the importance of the first host microbe interaction in early life immune development.

Animal Galectins and Plant Lectins as Tools for Studies in Neurosciences

Lectins are proteins or glycoproteins of non-immunological origin capable of reversibly and specifically binding to glycoconjugates. They exist in free form or associated with cells and are widely distributed in nature, being found in plants, microorganisms, and animals. Due to their characteristics and mainly due to the possibility of reversible binding to glycoconjugates, lectins have stood out as important tools in research involving Neurobiology. These proteins have the ability to modulate molecular targets in the central nervous system (CNS) which may be involved with neuroplasticity, neurobehavioral effects, and neuroprotection. The present report integrates existing information on the activity of animal and plant lectins in different areas of Neuroscience, presenting perspectives to direct new research on lectin function in the CNS, providing alternatives for understanding neurological diseases such as mental disorders, neurodegenerative, and neuro-oncological diseases, and for the development of new drugs, diagnoses and therapies in the field of Neuroscience.

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.

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.

Protein biomarker for psoriasis: A systematic review on their role in the pathomechanism, diagnosis, potential targets and treatment of psoriasis

Psoriasis is defined as a long-lasting multifactorial inflammatory autoimmune skin condition precisely characterized by delimited, erythematic papules with adherent shiny scales. The conditions are led by hyperproliferative responses of epidermis due to hyperactivation and immature keratinocytes production. The psoriatic skin consists of the thickened epidermal layer, in concurrence with inflammatory exudates in the dermis mainly of dendritic cells, neutrophils, T cells, and macrophages, contributing to the distinct manifestation of psoriatic lesions. It consents to multifaceted and discrete pathology due to the genetic and immunological alteration resulting from abnormal expression of various regulatory and structural proteins. These proteins are associated with various cellular and sub-cellular activities. Therefore, the presence of protein in a pathological cellular environment in the psoriatic lesions as well as in serum could be a great avenue for the insight of pathomechanism, anticipation and diagnosis of psoriasis. Research of protein biomarker in psoriasis is yet a developing realm to be explored by both fundamental and clinical researchers. This review is an attempt to assimilate the current discoveries and revelations of different proteins as a biomarker and their importance in pathogenesis, diagnosis, treatment, and anticipation of both the inflammatory and other dermatological aspects of psoriasis.

Basidiomycetes-X, an edible mushroom, alleviates the development of atopic dermatitis in NC/Nga mouse model

Basidiomycetes-X (BDM-X) is a novel edible mushroom recently identified as a new fungi species and is effective against oxidative stress and anti-inflammation associated with immune response. However the effect of BDM-X on atopic dermatitis (AD) has not been elucidated. In this study, we have investigated the effect of BDM-X on AD skin lesions in NC/Nga mouse model. AD-like lesion was induced by the application of house dust mite extract (DfE) to the dorsal skin of NC/Nga mouse. After AD induction, BDM-X was administered once daily for 2 weeks. We have analyzed the effects of BDM-X on dermatitis severity, histopathological changes and changes in inflammatory and proinflammatory proteins expressions in DfE induced AD mice skin. Treatment with BDM-X attenuated the development of AD-like clinical symptoms and effectively inhibited hyperkeratosis, parakeratosis, acanthosis and mast cells in AD mice skin. Furthermore, BDM-X treatment inhibited DfE induced tumor necrosis factor (TNF)α, high mobility group protein (HMG)B1, nuclear factor kappa (NFκ)B and inflammatory cytokines. These results indicate that BDM-X inhibits AD through modulating Th1 and Th2 responses and diminishing the mast cells infiltration in the skin lesions in NC/Nga mice.

Galectin-3-Mediated Glial Crosstalk Drives Oligodendrocyte Differentiation and (Re)myelination

Galectin-3 (Gal-3) is the only chimeric protein in the galectin family. Gal-3 structure comprises unusual tandem repeats of proline and glycine-rich short stretches bound to a carbohydrate-recognition domain (CRD). The present review summarizes Gal-3 functions in the extracellular and intracellular space, its regulation and its internalization and secretion, with a focus on the current knowledge of Gal-3 role in central nervous system (CNS) health and disease, particularly oligodendrocyte (OLG) differentiation, myelination and remyelination in experimental models of multiple sclerosis (MS). During myelination, microglia-expressed Gal-3 promotes OLG differentiation by binding glycoconjugates present only on the cell surface of OLG precursor cells (OPC). During remyelination, microglia-expressed Gal-3 favors an M2 microglial phenotype, hence fostering myelin debris phagocytosis through TREM-2b phagocytic receptor and OLG differentiation. Gal-3 is necessary for myelin integrity and function, as evidenced by myelin ultrastructural and behavioral studies from LGALS3^-/- mice. Mechanistically, Gal-3 enhances actin assembly and reduces Erk 1/2 activation, leading to early OLG branching. Gal-3 later induces Akt activation and increases MBP expression, promoting gelsolin release and actin disassembly and thus regulating OLG final differentiation. Altogether, findings indicate that Gal-3 mediates the glial crosstalk driving OLG differentiation and (re)myelination and may be regarded as a target in the design of future therapies for a variety of demyelinating diseases.

Galectin-3 Expression in Benign and Malignant Skin Diseases With Epidermal Hyperplasia

Galectin-3 has been suggested relative to tumor genesis, progression, and metastasis in basal cell carcinoma and squamous cell carcinoma that are the most common skin cancers characterized by malignant epidermal proliferation. In this study, we evaluated galectin-3 expression in seborrheic keratosis, keratoacanthoma, and infectious diseases including verruca vulgaris, condyloma acuminatum, and chromoblastomycosis that are pathologically featured by benign epidermal proliferation. Galectin-3 expression was shown by immunohistochemical staining and quantified using the Image Pro Plus V6.0. We found that galectin-3 distributed evenly in normal skin around the body decreased significantly in all selected diseases compared with healthy controls, but it was comparable among each disease. These findings imply that galectin-3 do not differentiate between benign and malignant proliferation of keratinocytes.

Fecal Galectin-3: A New Promising Biomarker for Severity and Progression of Colorectal Carcinoma

Background and Objectives

The aim of the study was to determine systemic and fecal values of galectin-3 and pro- and anti-inflammatory cytokines in patients with CRC and the relationship with clinicopathological aspects.

Methods

Concentrations of galectin-3, TNF-α, TGF-β, IL-10, and IL-1β were analyzed in samples of blood and stool of 60 patients with CRC.

Results

Systemic concentration of TNF-α was significantly lower in patients with severe diseases (advanced TNM stage, nuclear grade, and poor histological differentiation) as in patients with more progressive CRC (lymph and blood vessel invasion, presence of metastasis). Fecal values of anti-inflammatory cytokines TGF-β and IL-10 were increased in patients with severe stadium of CRC. Fecal concentration of Gal-3 was enhanced in CRC patients with higher nuclear grade, poor tumor tissue differentiation, advanced TNM stage, and metastatic disease. Gal-3/TNF-α ratio in sera and feces had a higher trend in patients with severe and advanced diseases. Positive correlation between fecal Gal-3 and disease severity, tumor progression, and biomarkers AFP and CEA, respectively, was also observed.

Conclusions

Predomination of Gal-3 in patients with advanced diseases may implicate on its role in limiting ongoing proinflammatory processes. The fecal values of Gal-3 can be used as a valuable marker for CRC severity and progression.

The effects of galectin-3 depletion apheresis on induced skin inflammation in a porcine model

Galectin-3 (Gal-3), a β-galactoside-binding lectin that is expressed in mammalian cells, is known to modulate several biological functions such as cell-cell adhesion, macrophage activation, angiogenesis, metastasis, and fibrosis. The goal of this study was to evaluate the ability of Gal-3 depletion apheresis using an adsorption column with immobilized anti-Gal-3-antibody to reduce inflammation induced by Complete Freund's Adjuvant injection in a skin inflammation porcine model. Here, we report that plasma perfusion by apheresis through a Gal-3 binding immuno-affinity column reduces plasma Gal-3 levels to below limits of quantitative detection, and results in significant decrease in skin inflammation, including degree and duration of inflammatory lesions. Human plasma was tested ex vivo and found to be efficiently depleted using the anti-Gal-3 affinity column. This study demonstrates the potential of Gal-3 depletion apheresis as a therapeutic method for inflammation-mediated disease, supporting continued research in this area for clinical application.

Galectin-3 is an amplifier of the interleukin-1β-mediated inflammatory response in corneal keratinocytes

Interleukin-1β (IL-1β) is a potent mediator of innate immunity commonly up-regulated in a broad spectrum of inflammatory diseases. When bound to its cell surface receptor, IL-1β initiates a signalling cascade that cooperatively induces the expression of canonical IL-1 target genes such as IL-8 and IL-6. Here, we present galectin-3 as a novel regulator of IL-1β responses in corneal keratinocytes. Using the SNAP-tag system and digitonin semi-permeabilization, we show that recombinant exogenous galectin-3 binds to the plasma membrane of keratinocytes and is internalized into cytoplasmic compartments. We find that exogenous galectin-3, but not a dominant negative inhibitor of galectin-3 polymerization lacking the N-terminal domain, exacerbates the response to IL-1β by stimulating the secretion of inflammatory cytokines. The activity of galectin-3 could be reduced by a novel d-galactopyranoside derivative targeting the conserved galactoside-binding site of galectins and did not involve interaction with IL-1 receptor 1 or the induction of endogenous IL-1β. Consistent with these observations, we demonstrate that small interfering RNA-mediated suppression of endogenous galectin-3 expression is sufficient to impair the IL-1β-induced secretion of IL-8 and IL-6 in a p38 mitogen-activated protein kinase-independent manner. Collectively, our findings provide a novel role for galectin-3 as an amplifier of IL-1β responses during epithelial inflammation through an as yet unidentified mechanism.

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.

Galectin-3 Activation and Inhibition in Heart Failure and Cardiovascular Disease: An Update

Galectin-3 is a versatile protein orchestrating several physiological and pathophysiological processes in the human body. In the last decade, considerable interest in galectin-3 has emerged because of its potential role as a biotarget. Galectin-3 is differentially expressed depending on the tissue type, however its expression can be induced under conditions of tissue injury or stress. Galectin-3 overexpression and secretion is associated with several diseases and is extensively studied in the context of fibrosis, heart failure, atherosclerosis and diabetes mellitus. Monomeric (extracellular) galectin-3 usually undergoes further "activation" which significantly broadens the spectrum of biological activity mainly by modifying its carbohydrate-binding properties. Self-interactions of this protein appear to play a crucial role in regulating the extracellular activities of this protein, however there is limited and controversial data on the mechanisms involved. We therefore summarize (recent) literature in this area and describe galectin-3 from a binding perspective providing novel insights into mechanisms by which galectin-3 is known to be "activated" and how such activation may be regulated in pathophysiological scenarios.

Activation of Human Basophils by A549 Lung Epithelial Cells Reveals a Novel IgE-Dependent Response Independent of Allergen

Evidence for epithelial cell (EC)-derived cytokines (e.g., thymic stromal lymphopoietin [TSLP]) activating human basophils remains controversial. We therefore hypothesize that ECs can directly activate basophils via cell-to-cell interaction. Basophils in medium alone or with IL-3 ± anti-IgE were coincubated with TSLP, IL-33, or IL-25. Analogous experiments cocultured basophils (1-72 h) directly with EC lines. Supernatants were tested for mediators and cytokines. Abs targeting receptors were tested for neutralizing effects. Lactic acid (pH 3.9) treatment combined with passive sensitization tested the role of IgE. Overall, IL-33 augmented IL-13 secretion from basophils cotreated with IL-3, with minimal effects on histamine and IL-4. Conversely, basophils (but not mast cells) released histamine and marked levels of IL-4/IL-13 (10-fold) when cocultured with A549 EC and IL-3, without exogenous allergen or IgE cross-linking stimuli. The inability to detect IL-33 or TSLP, or to neutralize their activity, suggested a unique mode of basophil activation by A549 EC. Half-maximal rates for histamine (4 h) and IL-4 (5 h) secretion were slower than observed with standard IgE-dependent activation. Ig stripping combined with passive sensitization ± omalizumab showed a dependency for basophil-bound IgE, substantiated by a requirement for cell-to-cell contact, aggregation, and FcεRI-dependent signaling. A yet unidentified IgE-binding lectin associated with A549 EC is implicated after discovering that LacNAc suppressed basophil activation in cocultures. These findings point to a lectin-dependent activation of basophil requiring IgE but independent of allergen or secreted cytokine. Pending further investigation, we predict this unique mode of activation is linked to inflammatory conditions whereby IgE-dependent activation of basophils occurs despite the absence of any known allergen.

Galectin-3 Is a Target for Proteases Involved in the Virulence of Staphylococcus aureus

Staphylococcus aureus is a major cause of skin and soft tissue infection. The bacterium expresses four major proteases that are emerging as virulence factors: aureolysin (Aur), V8 protease (SspA), staphopain A (ScpA), and staphopain B (SspB). We hypothesized that human galectin-3, a β-galactoside-binding lectin involved in immune regulation and antimicrobial defense, is a target for these proteases and that proteolysis of galectin-3 is a novel immune evasion mechanism. Indeed, supernatants from laboratory strains and clinical isolates of S. aureus caused galectin-3 degradation. Similar proteolytic capacities were found in Staphylococcus epidermidis isolates but not in Staphylococcus saprophyticus Galectin-3-induced activation of the neutrophil NADPH oxidase was abrogated by bacterium-derived proteolysis of galectin-3, and SspB was identified as the major protease responsible. The impact of galectin-3 and protease expression on S. aureus virulence was studied in a murine skin infection model. In galectin-3^+/+ mice, SspB-expressing S. aureus caused larger lesions and resulted in higher bacterial loads than protease-lacking bacteria. No such difference in bacterial load or lesion size was detected in galectin-3^-/- mice, which overall showed smaller lesion sizes than the galectin-3^+/+ animals. In conclusion, the staphylococcal protease SspB inactivates galectin-3, abrogating its stimulation of oxygen radical production in human neutrophils and increasing tissue damage during skin infection.

Galectin-7 in the stratum corneum: a biomarker of the skin barrier function

OBJECTIVE

Skin barrier disruption often occurs in diseased and damaged skin conditions such as atopic dermatitis (AD). We focused the galectin-7 protein (Gal-7) as a biomarker of skin condition and assessed whether the content of Gal-7 in stratum corneum (scGal-7) could be used as an indicator of skin barrier disruption and as an index of local skin symptoms in AD patients.

METHODS

Alteration of Gal-7 expression levels in keratinocyte and scGal-7 contents after barrier disruption by sodium dodecyl sulphate were evaluated in vitro and in vivo, respectively. Correlation between scGal-7 content and transepidermal water loss (TEWL) was examined in 126 healthy subjects. We performed single measurements of scGal-7 contents in 34 AD patients and serial measurements of 15 inpatients among them. SC samples were collected by the tape-stripping method, and scGal-7 content was determined using enzyme-linked immunosorbent assay.

RESULTS

Gal-7 expression in keratinocytes increased after barrier disruption. The scGal-7 content reflected the disruption of the skin barrier. The scGal-7 contents and TEWL values correlated in healthy subjects. The scGal-7 level was higher in AD patients than in healthy subjects. The scGal-7 contents in the cheek and neck of AD patients significantly correlated with the total and local skin lesion severity scores. Serial measurements in the inpatients showed that the scGal-7 contents in the cheek and neck decreased in tandem with local severity scores in response to treatment.

CONCLUSION

Measurement of scGal-7 content in tape-stripped samples was useful for the evaluation of the skin barrier function in dry skin conditions such as AD.

Galectin expression in healing wounded skin treated with low-temperature plasma: Comparison with treatment by electronical coagulation

Low-temperature plasma is useful for the care of wounded skin. It accelerates wound healing. However, the mechanism of this effect has not been fully elucidated yet. Galectin-1 is reported to accelerate wound healing via the Smad signaling pathway. In the present study to clarify whether or not galectins were expressed during the process of wound healing in the plasma-treated skin, we examined the effect of low-temperature plasma on galectin expression in the healing skin. We compared the effects of low-temperature plasma on the expression of galectin-1, -2, and -3 in the healing skin with those of electrocoagulation conducted with a high-frequency electrical coagulator. Immediately after the start of low-temperature plasma treatment following the incision made in the skin, a membrane-like structure was formed on the surface of the wound. Immunoelectron microscopy showed that these galectins were localized in the membrane-like structure of the plasma-treated skin. The expressions of these galectins were increased by the low-temperature plasma treatment, whereas they were inhibited by the electrocoagulation. These results suggest that galectins were involved in the wound healing of low-temperature plasma-treated skin. Galectins will thus be good markers for further examination of the effects of low-temperature plasma on the healing of wounded skin.

Microbes taming mast cells: Implications for allergic inflammation and beyond

There is increasing awareness of a relationship between our microbiota and the pathogenesis of allergy and other inflammatory diseases. In investigating the mechanisms underlying microbiota modulation of allergy the focus has been on the induction phase; alterations in the phenotype and function of antigen presenting cells, induction of regulatory T cells and shifts in Th1/Th2 balance. However there is evidence that microbes can influence the effector phase of disease, specifically that certain potentially beneficial bacteria can attenuate mast cell activation and degranulation. Furthermore, it appears that different non-pathogenic bacteria can utilize distinct mechanisms to stabilize mast cells, acting locally though direct interaction with the mast cell at mucosal sites or attenuating systemic mast cell dependent responses, likely through indirect signaling mechanisms. The position of mast cells on the frontline of defense against pathogens also suggests they may play an important role in fostering the host-microbiota relationship. Mast cells are also conduits of neuro-immuo-endocrine communication, suggesting the ability of microbes to modulate cell responses may have implications for host physiology beyond immunology. Further investigation of mast cell regulation by non-pathogenic or symbiotic bacteria will likely lead to a greater understanding of host microbiota interaction and the role of the microbiome in health and disease.

History of allergy and atopic dermatitis in relation to squamous cell and Basal cell carcinoma of the skin

BACKGROUND

Little is known about whether history of allergies and atopy is related to the occurrence of keratinocyte cancers. Thus, we evaluated the association between history of allergies and atopy and the incidence of squamous cell carcinoma (SCC) and early onset basal cell carcinoma (BCC).

METHODS

As part of a population-based case-control study, interviews were conducted with 1,050 residents of New Hampshire (375 early onset BCC cases and 251 controls, 254 SCC cases and 432 controls). ORs of SCC and early onset BCC and history of allergy and atopic dermatitis were computed using logistic regression, while controlling for potential confounding factors.

RESULTS

An overall inverse association was observed between a history of allergy and early onset BCC [OR, 0.61; 95% confidence interval (CI), 0.38-0.97] but not SCC (OR, 1.18; 95% CI, 0.78-1.79). Among women, we found reduced ORs of both early onset BCC and of SCC in relation to allergy history (early onset BCC OR, 0.53; 95% CI, 0.31-0.92 and SCC OR, 0.59; 95% CI, 0.29-1.19). Among men, we observed no clear association with early onset BCC (OR, 0.87; 95% CI, 0.39-1.99) and an increased risk of SCC (OR, 1.58; 95% CI, 0.93-2.69).

CONCLUSION

Our findings suggest that allergies and atopy may influence risk of early onset BCC and SCC, and that effects may be gender specific.

IMPACT

A deeper understanding of the immune mechanisms underlying allergies and atopy may provide new routes of preventing keratinocyte cancers.

Structural integrity of the antigen is a determinant for the induction of T-helper type-1 immunity in mice by gene gun vaccines against E. coli beta-galactosidase

The type of immune response is critical for successful protection and typically determined by pathogen-associated danger molecules. In contrast, protein antigens are usually regarded as passive target structures. Here, we provide evidence that the structure of the antigen can profoundly influence the type of response that is elicited under else identical conditions. In mice, gene gun vaccines induce predominantly Th2-biased immune reactions against most antigens. One exception is E. coli beta-galactosidase (βGal) that induces a balanced Th1/Th2 response. Because both, the delivered material (plasmid DNA-coated gold particles) as well as the procedure (biolistic delivery to the skin surface) is the same as for other antigens we hypothesized that Th1 induction could be a function of βGal protein expressed in transfected cells. To test this we examined gene gun vaccines encoding structural or functional variants of the antigen. Employing a series of gene gun vaccines encoding individual structural domains of βGal, we found that neither of them induced IgG2a antibodies. Even disruption of the homo-tetramer association of the native protein by deletion of a few N-terminal amino acids was sufficient to abrogate IgG2a production. However, enzymatically inactive βGal with only one point mutation in the catalytic center retained the ability to induce Th1 reactions. Thus, structural but not functional integrity of the antigen must be retained for Th1 induction. βGal is not a Th1 adjuvant in the classical sense because neither were βGal-transgenic ROSA26 mice particularly Th1-biased nor did co-administration of a βGal-encoding plasmid induce IgG2a against other antigens. Despite this, gene gun vaccines elicited Th1 reactions to antigens fused to the open reading frame of βGal. We interpret these findings as evidence that different skin-borne antigens may be differentially handled by the immune system and that the three-dimensional structure of an antigen is an important determinant for this.

Malignant T cells secrete galectins and induce epidermal hyperproliferation and disorganized stratification in a skin model of cutaneous T-cell lymphoma

Cutaneous T-cell lymphomas (CTCLs) are the most common primary skin lymphomas, which are characterized by an accumulation of malignant T cells in the skin. The early lesion resembles both clinically and histologically benign inflammatory disorders and also presents with hyperproliferative epidermis and T-cell infiltration. Despite considerable progress in understanding the molecular mechanisms involved in the malignant transformation of T cells, the causes of the morphological and histopathological features of the disease are largely unknown. We used an organotypic model of CTCL to show that malignant T cells through the secretion of galectin-1 and -3 stimulate vigorous growth of keratinocytes. In parallel, malignant T cells induce disorganized keratinocyte stratification, resembling the early hyperproliferative stage of CTCL. We also observed a loss of attachment between the epithelial and mesenchymal compartments. In addition, hyperproliferation was followed by a downregulation of differentiation markers, such as keratin 10 and involucrin, and a decrease in barrier formation. In conclusion, we provide evidence that malignant T cells orchestrate the histopathological epidermal changes seen in CTCL.