Galectins form a protein family with a conserved carbohydrate-binding domain that specifically interacts with β-galactoside-containing glycoconjugates, which are found abundantly on mammalian cell surfaces. These proteins play crucial roles in various physiological and pathological processes including immune responses, cell adhesion, inflammation, and apoptosis. During tuberculosis infection, galectins exert diverse impacts on pathogenesis. The interaction between host and pathogen during TB involves intricate mechanisms influencing disease outcomes, where the pathogen exploits host glycosylation patterns to evade immune detection, underscoring the significant role of galectins in regulating these crucial host-pathogen interactions. Galectins facilitate pathogen recognition, enhance the phagocytosis of mycobacteria, support the formation of granuloma, and carefully balance the protective immunity against potential tissue damage. Additionally, galectins have an impact on the cytokine milieu by regulating the levels of pro-inflammatory cytokines and chemokines, essential for orchestrating granuloma formation and maintaining tuberculosis-associated homeostasis. This review delves into the intricate connection between galectins and tuberculosis; uncovering essential molecular mechanisms that deepen our understanding of how these proteins contribute to combating this pervasive infectious disease. Here we discuss the multifaceted roles that galectins play to uniquely and critically influence the core dynamics of host-pathogen interactions in tuberculosis.

Galectins play vital roles in cellular processes such as adhesion, communication, and survival, yet the mechanisms underlying their unconventional secretion remain poorly understood. This study identifies ATG9A, a core autophagy protein, as a key regulator of galectin-9 secretion via a mechanism independent of classical autophagy, secretory autophagy, or the LC3-dependent extracellular vesicle loading and secretion pathway. ATG9A vesicles function as specialized carriers, with the N-terminus of ATG9A and both carbohydrate recognition domains of galectin-9 being critical for the process. TMED10 mediates the incorporation of galectin-9 into ATG9A vesicles, which then fuse with the plasma membrane via the STX13-SNAP23-VAMP3 SNARE complex. Furthermore, ATG9A regulates the secretion of other proteins, including galectin-4, galectin-8, and annexin A6, but not IL-1β, galectin-3, or FGF2. This mechanism is potentially conserved across other cell types, including monocytic cells, which underscores its broader significance in unconventional protein secretion.

Galectins are β-galactoside-binding proteins with numerous functions. Some of them are involved in proliferation and metastasis of cancer, making them promising therapeutic targets. As different plant glycans have been shown to bind to galectins, plant saccharides might be potential galectin inhibitors. To produce plant galactans rich in galactose and smaller in size, we degraded arabinogalactan-proteins from Echinacea purpurea and Zostera marina as well as arabinogalactan from larch. As galectin (Gal)-3 and -9 both have been described to be involved in cancer development, we quantified the binding capacities of the different galactans to both galectins by biolayer-interferometry. Our results revealed that all plant-derived galactans and Yariv reagents with terminal galactose and lactose residues bind to Gal-3 in micromolar ranges. Surprisingly, only the higher charged galactans from Zostera marina showed affinity to Gal-9. Investigations of two different pancreatic cancer cell lines (Panc1 and Panc89) and different cell variants thereof revealed that Gal-3 was expressed by both cell lines with a significantly higher Gal-3 level in Panc1 cells compared to Panc89 cells. Conversely, Gal-9 was only detected in Panc89 cells. The findings revealed that galactans are promising sources to develop galectin antagonists and plant galactans from different species express specificities for distinct galectins.

This review provides a comprehensive analysis of the biosynthetic pathways of various oligosaccharides in Escherichia coli, structural characteristics, and bioactive mechanisms of human milk oligosaccharides (HMOs), with a particular emphasis on their roles in gut health, immune modulation, and neurodevelopment. HMOs primarily function as prebiotics, facilitating the growth of beneficial bacteria such as Bifidobacterium to maintain microbial homeostasis, with a discussion on the synergistic role of carbohydrate-binding modules (CBMs). In immune modulation, HMOs interact with lectins on immune and epithelial cells, influencing immune responses via pathways such as Toll-like receptors (TLRs). Additionally, HMOs have been linked to enhanced cognitive, motor, and language development in infants, influencing genes such as GABRB2, SLC1A7, GLRA4, and CHRM3. The review also examines commercially available HMO-containing products and highlights future research directions and potential applications in nutrition and healthcare.

The cell surface proteome, or surfaceome, is the hub for cells to interact and communicate with the outside world. Many disease-associated changes are hard-wired within the surfaceome, yet approved drugs target less than 50 cell surface proteins. In the past decade, the proteomics community has made significant strides in developing new technologies tailored for studying the surfaceome in all its complexity. In this review, we first dive into the unique characteristics and functions of the surfaceome, emphasizing the necessity for specialized labeling, enrichment, and proteomic approaches. An overview of surfaceomics methods is provided, detailing techniques to measure changes in protein expression and how this leads to novel target discovery. Next, we highlight advances in proximity labeling proteomics (PLP), showcasing how various enzymatic and photoaffinity proximity labeling techniques can map protein-protein interactions and membrane protein complexes on the cell surface. We then review the role of extracellular post-translational modifications, focusing on cell surface glycosylation, proteolytic remodeling, and the secretome. Finally, we discuss methods for identifying tumor-specific peptide MHC complexes and how they have shaped therapeutic development. This emerging field of neo-protein epitopes is constantly evolving, where targets are identified at the proteome level and encompass defined disease-associated PTMs, complexes, and dysregulated cellular and tissue locations. Given the functional importance of the surfaceome for biology and therapy, we view surfaceomics as a critical piece of this quest for neo-epitope target discovery.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive cancers, primarily due to its complex tumor microenvironment (TME), which drives both disease progression and therapy resistance. Understanding the molecular mechanisms governing TME dynamics is essential for developing new treatment strategies for this devastating disease. In this study, we uncover an oncogenic role for Galectin-1 (Gal1), a glycan-binding protein abundantly expressed by activated pancreatic stellate cells (PSCs), a key component of the PDAC TME that orchestrates tumor progression. Our findings reveal that Gal1 expression is elevated in the nucleus of human PSCs in both tissue samples and cultured cell lines. Using chromatin immunoprecipitation followed by sequencing analysis (ChIP-seq), we identify Gal1 occupancy at the promoters of several cancer-associated genes, including KRAS, a pivotal oncogene involved in PDAC pathogenesis. We demonstrate that Gal1 binds to the KRAS promoter, sustaining KRAS expression in PSCs, which, in turn, maintains PSC activation and promotes the secretion of protumorigenic cytokines. Mechanistically, Gal1 is required to preserve histone H3 lysine 4 monomethylation levels and to recruit the histone methyltransferase MLL1 to target promoters. Collectively, our findings define a nuclear function of Gal1 in modulating the transcriptional landscape of cancer-associated genes in PSCs within the PDAC TME, mediated through an epigenetic mechanism. These insights enhance our understanding of PDAC pathology and open potential avenues for therapeutic interventions targeting intracellular Gal1.

Immune checkpoints, such as PD-1 and CTLA-4, are crucial regulators of immune responses, acting as gatekeepers to balance immunity against foreign antigens and self-tolerance. These checkpoints play a key role in maintaining cardiac homeostasis by preventing immune-mediated damage to critical organs like the heart. In this study, we explored the involvement of PD-1 and CTLA-4 in cardiovascular complications, particularly atherosclerosis and myocarditis, which can lead to heart failure. We conducted a comprehensive analysis using animal models and clinical data to assess the effects of immune checkpoint inhibition on cardiac function. Our findings indicate that disruption of PD-1 and CTLA-4 pathways exacerbates myocardial inflammation, accelerates atherosclerotic plaque formation, and promotes the development of heart failure. Additionally, we observed that immune checkpoint inhibition in these models led to increased infiltration of T lymphocytes, higher levels of pro-inflammatory cytokines, and enhanced tissue damage. These results suggest that PD-1 and CTLA-4 are critical in preserving cardiac health, and their inhibition can result in severe cardiovascular toxicity. Our study emphasizes the need for careful monitoring of cardiovascular health in patients undergoing immune checkpoint inhibitor therapies.

Ultraviolet light (UV) can cause serious damage to human skin. The inflammatory reaction arising from repeated UV exposure leads to severe skin lesions and even promotes photo-carcinogenesis. Iron overload is featured by excessive iron intake and deposition and will promote inflammatory response inside cells. However, the core molecules involved in UV radiation induced iron overload and related anti-inflammatory strategies remain unclear. Signature genes involved in UV-irradiated skin were filtered through integrated datasets from the Gene Expression Omnibus (GEO) database. Subsequently, immune cell infiltration analysis was carried out to examine the relationship between signature gene expression and immune cell abundance. Single cell RNA-seq matrix data implicated in UV-irradiated skin was then applied to assess the expression level of signature genes in different cell clusters and to find out the core cell type and the key signaling pathway involved in UV radiation. Finally, cytological and animal experiments were conducted to investigate the potential of signature genes as therapeutic targets. SAT1 and RBMS1 were screened and validated as signature genes of UV irradiation. Immune cell infiltration analysis demonstrated that SAT1 and RBMS1 expression were associated closely with immune cell abundance, and skin fibroblasts were identified as the central cell type to communicate with other cell clusters in UV-irradiated skin. Disturbance of SAT1 exerted observably more suppressive effects on the release of inflammatory cytokines than overexpression of RBMS1. Two small molecule drugs targeting SAT1, namely Argatroban and Menadione, were predicted. Moreover, their therapeutic potentials in the treatment of UV-irradiated skin injury were confirmed experimentally.

Mitochondria adapt to the cell proliferative demands induced by growth factors through dynamic changes in morphology, distribution, and metabolic activity. Galectin-8 (Gal-8), a carbohydrate-binding protein that promotes cell proliferation by transactivating the EGFR-ERK signaling pathway, is overexpressed in several cancers. However, its impact on mitochondrial dynamics during cell proliferation remains unknown. Using MDCK and RPTEC kidney epithelial cells, we demonstrate that Gal-8 induces mitochondrial fragmentation and perinuclear redistribution. Additionally, mitochondria adopt donut-shaped morphologies, and live-cell imaging with two Keima-based reporters demonstrates Gal-8-induced mitophagy. ERK signaling inhibition abrogates all these Gal-8-induced mitochondrial changes and cell proliferation. Studies with established mutant versions of Gal-8 and CHO cells reveal that mitochondrial changes and proliferative response require interactions between the N-terminal carbohydrate recognition domain of Gal-8 and α-2,3-sialylated N-glycans at the cell surface. DRP1, a key regulator of mitochondrial fission, becomes phosphorylated in MDCK cells or overexpressed in RPTEC cells in an ERK-dependent manner, mediating mitochondrial fragmentation and perinuclear redistribution. Bafilomycin A abrogates Gal-8-induced cell proliferation, suggesting that mitophagy serves as an adaptation to cell proliferation demands. Functional analysis under Gal-8 stimulation shows that mitochondria maintain an active electron transport chain, partially uncoupled from ATP synthesis, and an increased membrane potential, indicative of healthy mitochondria. Meanwhile, the cells exhibit increased extracellular acidification rate and lactate production via aerobic glycolysis, a hallmark of an active proliferative state. Our findings integrate mitochondrial dynamics with metabolic adaptations during Gal-8-induced cell proliferation, with potential implications for physiology, disease, and therapeutic strategies.

Glycosylation is the process by which glycans (i.e. 'sugars') are enzymatically attached to proteins or lipids to form glycoconjugates. Growing evidence points to glycosylation playing a central role in atherosclerosis. Glycosylation occurs in all human cells and post-translationally modifies many signalling molecules that regulate cardiovascular disease, affecting their binding and function. Glycoconjugates are present in abundance on the vascular endothelium and on circulating lipoproteins, both of which have well-established roles in atherosclerotic plaque development. Sialic acid is a major regulator of glycan function and therefore the process of sialylation, in which sialic acid is added to glycans, is likely to be entwined in any regulation of atherosclerosis. Glycans and sialylation regulators have the potential to present as new biomarkers that predict atherosclerotic disease or as targets for pharmacological intervention, as well as providing insights into novel cardiovascular mechanisms. Moreover, the asialoglycoprotein receptor 1 (ASGR1), a glycan receptor, is emerging as an exciting new regulator of lipid metabolism and coronary artery disease. This review summarises the latest advances in the growing body of evidence that supports an important role for glycosylation and sialylation in the regulation of atherosclerosis.

Galectins are a family of galactoside-binding proteins involved in various pathophysiological processes, which makes them attractive targets for drug discovery. The derivatization of d-galactose at C3 and C1 positions has been shown to increase the affinity of synthetic galectin antagonists. In this study, two small libraries of d-galactose derivatives have been designed and synthesized. The first series involved the development of novel aromatic 3-azolyl-3-deoxy-d-galactopyranoses. The second series consisted of epimeric analogs of glyceryl β-S-d-galactopyranosides, which were also derivatized. Binding-affinity evaluations for galectin-1 and galectin-3 have revealed that galactose analogs from both series have potential for further optimization. Notably, a combination of modifications at the C3 position of the galactose ring and on the aglycone has led to the identification of promising galectin inhibitors, specifically the compounds 29R and 32S.

Galectins, a family of carbohydrate-binding proteins, regulate immune responses, neuroinflammation, and neurogenesis within the central nervous system (CNS). Among the 15 known galectins, galectins-1, -3, -4, -8, and -9 play significant roles in neuroinflammation and have been investigated in the context of CNS pathologies. This review synthesizes recent advancements in understanding galectins' involvement in the neurobiology of brain disorders, focusing on their interplay with signaling pathways underlying major depressive disorder (MDD). It explores their impact on neuroinflammation, neurogenesis, and brain signaling, highlighting the therapeutic potential of targeting galectins while addressing challenges in translating these findings into clinical practice. Comprehensive studies are essential to unravel the complex mechanisms of galectin-mediated pathways and unlock their full potential for managing neuropsychiatric conditions.

In this review, we aim to explore the multifaceted roles of galectins in host defense from a broader perspective, particularly regarding their functions when host integrity is compromised. Numerous comprehensive reviews on galectin functions in immunity have already been published. For researchers new to the field, this wealth of information may create an impression of galectins as proteins involved in a wide array of biological processes. Furthermore, due to the heterogeneity of galectin ligands, glycans, there is a risk of perceiving galectin-specific functions as ambiguous, potentially obscuring their core biological significance. To address this, we revisit foundational aspects, focusing on the significance of the recognition of galactose, a "late-comer" monosaccharide in evolutionary terms, provide an overview of galectin glycan binding specificity, with emphasis on the potential biological importance of each carbohydrate-recognition domain. We also discuss the biological implications of the galectin location paradox wherein these cytosolic lectins function in host defense despite their glycan ligands being synthesized in the secretory pathway. Additionally, we examine the role of galectins in liquid-liquid phase separation on membranes, which may facilitate their diverse functions in cellular responses. Through this approach, we aim to re-evaluate the complex and diverse biological roles of galectins in host defense.

Glycolipid-lectin-driven endocytosis controls the formation of clathrin-independent carriers and the internalization of various cargos such as β1 integrin. Whether this process is regulated in a dynamic manner remained unexplored. Here we demonstrate that, within minutes, the epidermal growth factor triggers the galectin-driven endocytosis of cell-surface glycoproteins, such as integrins, that are key regulators of cell adhesion and migration. The onset of this process-mediated by the Na+/H+ antiporter NHE1 as well as the neuraminidases Neu1 and Neu3-requires the pH-triggered enzymatic removal of sialic acids whose presence otherwise prevents galectin binding. De-sialylated glycoproteins are then retrogradely transported to the Golgi apparatus where their glycan make-up is reset to regulate EGF-dependent invasive-cell migration. Further evidence is provided for a role of neuraminidases and galectin-3 in acidification-dependent bone resorption. Glycosylation at the cell surface thereby emerges as a dynamic and reversible regulatory post-translational modification that controls a highly adaptable trafficking pathway.

Bovine alphaherpesvirus-1 (BoAHV-1) causes several symptoms in cattle, leading to significant costs for the livestock industry. In this study, we used a plasmid encoding a secreted form of BoAHV-1 glycoprotein D (pCIgD) as a DNA vaccine. To enhance the potency of the pCIgD vaccine, we used Montanide™ GEL01 PR (GEL01) and introduced Galectin-8 (Gal-8), a lectin considered a novel adjuvant due to its immunostimulatory effects, into the formulation. Animals were vaccinated with pCIgD, pCIgD with Gal-8 (pCIgD-Gal-8), pCIgD with Gal-8 and GEL01 (pCIgD-Gal-8-GEL01), or the control plasmid pCIneo. The immune response was first assessed in a mouse model and then in bovines. The results showed that combining Gal-8 and GEL01 with pCIgD modulated immune responses at both the humoral and cellular levels in both animal models. This study evaluates the efficacy of a DNA vaccine with Gal-8 and GEL01 as potential adjuvants to enhance immune protection against BoAHV-1.

Inflammatory bowel disease (IBD) is a multifaceted disease characterised by compromised integrity of the epithelial barrier, the gut microbiome, and mucosal inflammation. While leukocyte recruitment and infiltration into intestinal tissue are well-studied and targeted in clinical practice, the role of galectins in modulating mucosal immunity remains underexplored. Galectins, a family of lectin-binding proteins, mediate critical interactions between immune cells and the intestinal epithelium. This study investigated the effect of endogenous Galectin-9 (Gal-9), as well as the combined effects with Galectin-3 (Gal-3), in modulating disease progression in murine models of colitis, using global knockout (KO) models for Gal-3, Gal-9, and Gal-3/Gal-9. Global deficiency in both galectins demonstrated improved disease parameters in Dextran sodium sulfate (DSS)-driven colitis. In contrast, in a model of adoptive T cell driven colitis, the addition of recombinant Gal-9 (rGal-9) was associated with reduced intestinal inflammation and an improvement in disease parameters. Further in vitro studies revealed no change in bone marrow-derived macrophage cytokine production in the absence of endogenous Gal-9, whereas the addition of rGal-9 to human macrophages stimulated pro-inflammatory cytokine production. Collectively, these findings demonstrate that Gal-9 plays distinct, context-dependent effects in intestinal inflammation, with both pro-inflammatory and anti-inflammatory effects. The contrasting functions of endogenous and exogenous Gal-9 underscore its complex involvement in IBD pathogenesis and highlight the need to differentiate its physiological function from therapeutic applications.

Cells contain a plethora of structurally diverse lipid species, which are unevenly distributed across the different cellular membrane compartments. Some of these lipid species require vesicular trafficking to reach their subcellular destinations. Here, we review recent advances made in the field that contribute to understanding lipid sorting during endomembrane trafficking.

Endometriosis, a benign, chronic gynecological disorder characterized by the presence of endometrial-like tissue outside the uterine cavity, affects 15% of women of reproductive age. Galectins, a family of beta-galactoside-binding proteins, regulate inflammation and autoimmunity and are widely expressed in reproductive tissues. This study aimed to assess Galectin-3 (Gal-3) levels in the serum of patients with endometriosis compared to asymptomatic controls and investigate serum Gal-3 level changes over a one-year follow-up period of patients with endometriosis. To determine the levels of soluble Gal-3 in the serum of women with endometriosis or gynecological tumors as well as healthy controls, a human Gal-3-specific ELISA was used. Our findings revealed significantly elevated serum Gal-3 levels in patients with endometriosis compared with healthy controls. Furthermore, Gal-3 concentrations were markedly higher in patients with malignant gynecological transformation of the endometrium than in patients with or without endometriosis. During the one-year follow-up, patients with endometriosis exhibited a progressive increase in serum Gal-3 levels. These findings highlight the potential of Gal-3 as a biomarker for endometriosis and related gynecological conditions. However, further prospective studies with larger, more representative patient cohorts are needed to validate its clinical value.

Background/Objectives: Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) is commonly considered as a hepatic manifestation of metabolic syndrome, posing considerable public health and economic challenges due to its high prevalence. This study investigates the diagnostic potential of serum galectin-1 levels in MASLD patients. Methods: A total of 128 participants were analyzed for this study, comprising 68 healthy controls and 60 MASLD patients. The hepatic steatosis index (HSI) and fatty liver index (FLI) were calculated to evaluate the liver steatosis. Serum galectin-1 levels were measured using an enzyme-linked immunosorbent assay. We additionally conducted a comparative analysis of galectin-1 mRNA and protein expression levels in the liver tissue between the mouse models of MASLD, including ob/ob mice (n = 6), high-fat diet-fed C57 mice (n = 6), and the control group (n = 6). Results: Average serum galectin-1 levels significantly differed between groups, with lower values in the controls (p < 0.01). The frequency of MASLD increased with higher quartiles of galectin-1 levels (p < 0.01). The correlation analysis showed a positive relationship between serum galectin-1 and both HSI and FLI (p < 0.01). The multivariate logistic regression indicated that elevated galectin-1 was associated with an increased risk of MASLD (p < 0.01), yielding an area under the receiver operating characteristic curve for predicting MASLD at 0.745 (95% CI: 0.662-0.829). Hepatic galectin-1 levels were also elevated in the MASLD mouse model at both transcript and protein levels (p < 0.01). Conclusions: Serum galectin-1 can be used as a potential biomarker to help diagnose MASLD.

The third most prevalent type of cancer in the world, colorectal cancer, poses a significant treatment challenge due to the nonspecific distribution, low efficacy, and high systemic toxicity associated with chemotherapy. To overcome these limitations, a targeted drug delivery system with a high cytotoxicity against cancer cells while maintaining a minimal systemic side effects represents a promising therapeutic approach. Therefore, the aim of this study was to develop an efficient gold nanocarrier for the targeted delivery of the anticancer agent everolimus to Caco-2 cells. A novel gold nanocomposite (EV-β-CD-HA-Chi-AuNCs) functionalized with a targeting ligand (hyaluronic acid), a permeation enhancement excipient (chitosan), and an anticancer inclusive compound consisting of beta-cyclodextrin and everolimus was proposed and prepared via Turkevich method. Characterization was performed with a UV spectrometer, FTIR, Zetasizer, and HRTEM. Its drug release profile was also evaluated in media with three different pH values. Cytotoxicity and biocompatibility studies were performed on a colorectal cancer cell line (Caco-2) and a normal fibroblast line (MRC-5), respectively, via xCELLigence real-time cellular analysis (RTCA) technology. The inhibitory effect on migration was also further tested via the xCELLigence RTCA technique and a scratch assay. Characterization studies revealed the successful formation of EV-β-CD-HA-Chi-AuNCs with a size and charge which are suitable for the use as targeted drug delivery carrier. In the cytotoxic study, the EV-β-CD-HA-Chi-AuNCs showed a lower IC50 (16 ± 1 µg/ml) than the pure drug (25 ± 3 µg/ml) toward a colorectal cell line (Caco-2). In the biocompatibility study, the EV-β-CD-HA-Chi-AuNCs have minimal toxicity, while the pure drug has severe toxicity toward healthy fibroblasts (MRC-5) despite its low concentration. In the cell migration study, the EV-β-CD-HA-Chi-AuNCs also showed a greater inhibitory effect than the pure drug. Compared with the pure drug, the EV-β-CD-HA-Chi-AuNCs exhibit an excellent selective cytotoxicity between cancerous colorectal Caco-2 cells and healthy MRC-5 cells, making it a potential carrier to carry the drug to the cancerous site while maintaining its low toxicity to the surrounding environment. In addition, an increase in the cytotoxic activity of the EV-β-CD-HA-Chi-AuNCs toward cancerous colorectal Caco-2 cells was also observed, which can potentially improve the treatment of colorectal cancer.

Lysophagy eliminates damaged lysosomes and is crucial to cellular homeostasis; however, its underlying mechanisms are not entirely understood. We screen a ubiquitination-related compound library and determine that the substrate recognition component of the SCF-type E3 ubiquitin ligase complex, SCFFBXO3(FBXO3), which is a critical lysophagy regulator. Inhibition of FBXO3 reduces lysophagy and lysophagic flux in response to L-leucyl-L-leucine methyl ester (LLOMe). Furthermore, FBXO3 interacts with TMEM192, leading to its ubiquitination in LLOMe-treated cells. We also identify TAX1BP1 as a critical autophagic adaptor that recognizes ubiquitinated TMEM192 during lysophagy and find that TBK1 activation is crucial for lysophagy, as it phosphorylates FBXO3 in response to lysosomal damage. Knockout of FBXO3 significantly impairs lysophagy, and its reconstitution with a loss-of-function mutant (V221I) further confirms its essential role in lysophagy regulation. Collectively, our findings highlight the significance of the TBK1-FBXO3-TMEM192-TAX1BP1 axis in lysophagy and emphasize the critical role of FBXO3 in lysosomal integrity.

Galectins are widely distributed throughout the animal kingdom, from marine sponges to mammals. Galectins are a family of soluble lectins that specifically recognize β-galactoside-containing glycans and are categorized into three subgroups based on the number and function of their carbohydrate recognition domains (CRDs). The interaction of galectins with specific ligands mediates a wide range of biological activities, depending on the cell type, tissue context, expression levels of individual galectin, and receptor involvement. Galectins affect various immune cell processes through both intracellular and extracellular mechanisms and play roles in processes, such as apoptosis, angiogenesis, and fibrosis. Their importance has increased in recent years because they are recognized as biomarkers, therapeutic agents, and drug targets, with many other applications in conditions such as cardiovascular diseases and cancer. However, little is known about the involvement of galectins in liver diseases. Here, we review the functions of various galectins and evaluate their roles in liver diseases.

Hyaluronic acid (HA) is a natural and biocompatible polysaccharide that is able to interact with CD44 receptors to regulate inflammation, fibrosis, and tissue reconstruction. It is a suitable chemical scaffold for drug delivery that can be functionalized with pharmacophores and/or vectorizable groups. The derivatization of HA is achieved to varying extents by reacting 1-amino-1-deoxy-lactitol via the carboxyl group to form amide linkages, giving rise to the grafted polymer, HYLACH. This retains the broad properties of HA, even though, as in most HA-grafted polymers, the detailed conformational effects of such substitutions, while crucial in the design or optimization of drug delivery systems, remain unknown. Here, the conformation, size, secondary structure, hydrogen bond network, and hydration features of lactosylated HA derivatives were evaluated by using multiple independent molecular dynamics simulations. This revealed subtle but nevertheless significant changes in the HA scaffold, establishing the density of grafting as the key parameter determining its properties.

Background: Prostate cancer remains one of the leading causes of cancer-related mortality in men worldwide. The treatment of it is currently based on surgical removal, radiotherapy, and hormone therapy. It is crucial to improve therapeutic prospects for the diagnosis and treatment of prostate cancer via drug target screening. Methods: We integrated eQTL data from the eQTLGen Consortium and pQTL data from UK Biobank Proteome Plasma Proteins (UKB-PPP) and deCODE health datasets. MR analyses (SMR, heterogeneity in dependent instruments (HEIDI), IVW, Wald ratio, weighted median, and MR-Egger) were used to screen candidate genes associated with prostate adenocarcinoma (PRAD) risk. Candidate genes were further verified through TCGA-based gene expression profile, survival analysis, and immune microenvironment evaluations. TIDE analysis was utilized to investigate gene immunotherapy response. Single-cell RNA sequencing data from the GSE176031 dataset were used to investigate the gene expression patterns. The Drug Bank, Therapeutic Target Database and Drug Signatures Database were utilized to predict targeted drugs for candidate genes. Results: MTHFD1 and LGALS4 were identified as promising therapeutic targets for PRAD, with evidence provided at multi-omics levels. LGALS4 was predominantly expressed in malignant cells and was correlated with enhanced immune checkpoint pathways, increased TIDE scores, and immunotherapy resistance. In contrast, MTHFD1was expressed in both tumor and microenvironmental cells and was associated with poor survival. Drug target prediction suggested that there are no currently approved drugs specifically targeting MTHFD1 and LGALS4. Conclusions: Our study identified MTHFD1 and LGALS4 as potential preventive targets for PRAD. However, future experiments are warranted to assess the utility and effectiveness of these candidate proteins.

Glycan-mediated recognition plays a critical role in facilitating cell-cell and cell-matrix interactions. Galectin-8 (Gal-8), classified as a 'tandem-repeat' type of galectin, binds to cell surface glycans to modulate various cellular functions, including cell adhesion, migration, apoptosis, pathogen recognition, autophagy, and immunomodulation. Despite the known function of Gal-8 in binding to various glycosylated proteins, only a few interactions have been reported to date. In this study, mass spectrometry is used to identify CD98hc as a novel binding partner for Gal-8. Both the N-terminal and C-terminal carbohydrate recognition domains (CRDs) of Gal-8 (Gal-8N and Gal-8C) bind to CD98hc, an interaction that is specifically inhibited by lactose but not sucrose, as confirmed by pull-down assays. The binding affinity between CD98hc and Gal-8 measured by microscale thermophoresis (MST) is 1.51 ± 0.17 μM. In addition, Gal-8N and Gal-8C have the binding affinities of 0.22 ± 0.03 μM and 10.68 ± 1.69 μM, respectively. Gal-8N and Gal-8C are both involved in the recognition and binding process of CD98hc. Furthermore, both full-length Gal-8 and its individual CRDs bind specifically to N-glycosylated glycans on CD98hc, as demonstrated by the use of tunicamycin to inhibit N-glycosylation in cells. In addition, Gal-8 and its individual CRDs can pull down glycosylated CD98hc-ED but not free CD98hc-ED in vitro, indicating that the binding of Gal-8 to glycosylated CD98hc-ED is N-glycosylation-dependent. Overall, our findings establish CD98hc as a novel binding partner for Gal-8 and provide insights for further exploration of the diverse biological functions of Gal-8.

A captivating challenge in chemistry lies in achieving robust and precise binding of uncharged, hydrophilic carbohydrate entities. Although past decades have provided a variety of excellent molecular architectures tailored for carbohydrate recognition, including acyclic receptors, macrocycles and foldamers, recent advances have highlighted the potential of synthetic molecular cages. These structures are equipped with intricately designed cavities that contain bespoke noncovalent binding sites for carbohydrate interactions. Constructed with the principles of complementarity and preorganization, these cage receptors demonstrate high affinity and exquisite selectivity in carbohydrate recognition through noncovalent interactions, capitalizing on multivalency and cooperativity. This Review highlights recent advances in the design and application of molecular cages with diverse structures, interactions and binding capacities for carbohydrate recognition. In the concluding remarks, we discuss future avenues for further exploration.

Galectins, glycan-binding proteins, have been identified as critical regulators of the immune system. Recently, Galectin-9 (Gal-9) has emerged as biomarker that correlates with disease severity in a range of inflammatory conditions. However, Gal-9 has highly different roles in the context of immunoregulation, with the potential to either stimulate or suppress the immune response. Neutralizing antibodies targeting Gal-9 have been developed and are in early test phase investigating their therapeutic potential in cancer. Despite ongoing research, the mechanisms behind Gal-9 action remain not fully understood, and extrapolating the implications of targeting this molecule from previous studies is challenging. Here, we examine the pleiotropic function of Gal-9 focusing on conventional T lymphocytes, providing a current overview of its immunostimulatory and immunosuppressive roles. In particular, we highlight that Gal-9 differentially regulates immune responses depending on the context. Considering this complexity, further investigation of Gal-9's intricate biology is necessary to define therapeutic strategies in immune disorders and cancer treatment aimed at inducing or inhibiting Gal-9 signaling.

The interest in galectin-3 as a drug target in the cancer and fibrosis space has grown during the past few years with several new classes of compounds being developed. The first orally available galectin-3 inhibitor, GB1211 (h-galectin-3 Kd = 0.025 μM), is currently in phase 2 clinical trials. Due to structural differences between human and mouse galectin-3 a significant reduction in mouse galectin-3 affinity is observed for most highly potent human galectin-3 inhibitors including GB1211 (m-galectin-3 Kd = 0.77 μM). Pharmacokinetic experiments in mouse dosing GB1211 up to 100 mg/kg results in free plasma levels below m-galectin-3 Kd, which is not comparable to the data observed in humans. To better support translation into clinical studies, a new improved mouse galectin-3 tool compound, GB2095, was developed. Dosing this new compound in in vivo syngeneic mouse models of cancer resulted in reduction of the growth of breast and melanoma cancers.

Kaposi sarcoma-associated herpesvirus (KSHV) is an oncogenic γ-herpesvirus. Autophagy during KSHV entry has remained unexplored. We show that LC3 lipidation as a hallmark of autophagy is induced shortly after KSHV entry. LC3 co-localizes with KSHV in amphisomes during entry and loss of LC3 lipidation increases infection. Accordingly, NDP52, a receptor of selective autophagy, was recruited to endocytosed viral particles, and its reduction increased KSHV infection. Additionally, virus particles co-localized with the endolysosome damage sensor galectin-8 upon KSHV entry and depletion of galectin-8 promoted KSHV infection. Compared with herpes simplex virus, listeriolysin, adenovirus, and influenza virus, and in contrast to what was previously thought about enveloped viruses, KSHV binding to EphA2 by its envelope protein gH causes endolysosomal membrane damage, akin to non-enveloped viruses and bacteria. Taken together, our study identifies an important anti-viral role for galectin-8, NDP52, and the autophagy machinery at virus-damaged endosomes, restricting KSHV entry by selective autophagy.

Ovarian cancer is a lethal disease with low survival rates for women diagnosed in advanced stages. Current cancer immunotherapies are not efficient in ovarian cancer, and there is therefore a significant need for novel treatment options. The β-galactoside-binding lectin, Galectin-3, is involved in different immune processes and has been associated with poor outcome in various cancer diagnoses. Here, we investigated how Galectin-3 affects the interaction between natural killer (NK) cells and neutrophils in the tumor microenvironment of ovarian cancer.

Ascites from the metastatic tumor microenvironment and cyst fluid from the primary tumor site were collected from patients with high-grade serous carcinoma (HGSC) together with peripheral blood samples. Galectin-3 concentration was measured in ascites, cyst fluid and serum or plasma. Neutrophils isolated from HGSC ascites and autologous blood were analyzed to evaluate priming status and production of reactive oxygen species. In vitro co-culture assays with NK cells, neutrophils and K562 target cells (cancer cell line) were conducted to evaluate NK cell viability, degranulation and cytotoxicity.

High levels of Galectin-3 were observed in cyst fluid and ascites from patients with HGSC. Neutrophils present in HGSC ascites showed signs of priming; however, the priming status varied greatly among the patient samples. Galectin-3 induced production of reactive oxygen species in ascites neutrophils, but only from a fraction of the patient samples, which is in line with the heterogenous priming status of the ascites neutrophils. In co-cultures with NK cells and K562 target cells, we observed that Galectin-3-induced production of reactive oxygen species in neutrophils resulted in decreased NK cell viability and lowered anti-tumor responses.

Taken together, our results demonstrate high levels of Galectin-3 in the tumormicroenvironment of HGSC. High levels of Galectin-3 may induce production of reactiveoxygen species in ascites neutrophils in some patients. In turn, reactive oxygen species produced by neutrophils may modulate the NK cell anti-tumor immunity. Together, this study suggests further investigation to evaluate if a Galectin-3-targeting therapy may be used in ovarian cancer.

Four directional and positional variants of sulfonamide-derivatized galactopyranosides were synthesized and evaluated against human galectin-1, -3, -4C (C-terminal), -7, -8N (N-terminal), -8C (C-terminal), -9N (N-terminal), and -9C (C-terminal), which revealed that one of the sulfonamide positions and directionalities (methyl 3-{4-[2-(phenylsulfonylamino)-phenyl]-triazolyl}-3-deoxy-α-d-galactopyranosides) bound with 6-15 fold higher affinity than the corresponding phenyltriazole (lacking the phenylsulfonamide moiety) for galectin-9N. Molecular dynamic simulations suggested that inhibitor adopted a conformation that is complementary to the galectin-9N binding site and where the sulfonamide moiety protrudes into an unexplored and non-conserved binding site perpendicular to and below the A-B subsite to interact with a His61 NH proton. This resulted in the discovery of galectin-9N inhibitors with unprecedented selectivity over other galectins, thus constituting valuable tools for studies of the biological functions of galectin-9.

Cerebral arteriovenous malformations (AVMs) are intricate vascular anomalies that disrupt normal cerebral blood flow, potentially leading to severe neurological complications. Although the pathology of AVMs is not fully understood, epigenetic mechanisms have been implicated in their formation.

Transcriptional differences between cerebral AVMs and normal tissues were analyzed using RNA sequencing (RNA-seq), identifying IGF2BP2 as a key differentially expressed gene. Comprehensive bioinformatics analysis, integrating multi-omics data such as RNA-seq and methylated RNA immunoprecipitation sequencing (MeRIP-seq), was employed to identify the downstream target gene of IGF2BP2. The roles of specific genes in vascular development were assessed using endothelial cell cultures and zebrafish models.

Our analysis of RNA-seq data from cerebral AVMs and normal tissues identified IGF2BP2, a key N6-methyladenosine (m6A) reader, as significantly downregulated in cerebral AVMs. Functional studies showed that IGF2BP2 knockdown resulted in abnormal angiogenesis in endothelial cells and disrupted vascular development in zebrafish models. Mechanistically, IGF2BP2 regulates LGALS8 expression by modulating mRNA stability through m6A modification, and LGALS8 deficiency severely impairs angiogenesis in vitro and leads to cerebrovascular dysplasia in vivo.

Our findings suggest that IGF2BP2, via m6A-dependent regulation of LGALS8, is crucial for vascular development and presents potential targets for therapeutic intervention in cerebral AVMs.

Fibrosis is defined by the excessive accumulation of extracellular matrix (ECM) and constitutes a central pathophysiological process that underlies tissue dysfunction, across organs, in multiple chronic diseases and during aging. Myocardial fibrosis is a key contributor to dysfunction and failure in numerous diseases of the heart and is a strong predictor of poor clinical outcome and mortality. The excess structural and matricellular ECM proteins deposited by cardiac fibroblasts, is found between cardiomyocytes (interstitial fibrosis), in focal areas where cardiomyocytes have died (replacement fibrosis), and around vessels (perivascular fibrosis). Although myocardial fibrosis has important clinical prognostic value, access to cardiac tissue biopsies for histological evaluation is limited. Despite challenges with sensitivity and specificity, cardiac magnetic resonance imaging (CMR) is the most applicable diagnostic tool in the clinic, and the scientific community is currently actively searching for blood biomarkers reflecting myocardial fibrosis, to complement the imaging techniques. The lack of mechanistic insights into specific pro- and anti-fibrotic molecular pathways has hampered the development of effective treatments to prevent or reverse myocardial fibrosis. Development and implementation of anti-fibrotic therapies is expected to improve patient outcomes and is an urgent medical need. Here, we discuss the importance of the ECM in the heart, the central role of fibrosis in heart disease, and mechanistic pathways likely to impact clinical practice with regards to diagnostics of myocardial fibrosis, risk stratification of patients, and anti-fibrotic therapy.

Citrus pectin (CP) is a dietary fiber used in animal nutrition with anti-inflammatory properties. CP downregulates chicken immunoregulatory monocytes' functions, like chemotaxis and phagocytosis, in vitro. The molecular underlying background is still unknown. This study investigated the activity of CP on chicken peripheral blood mononuclear cells (PBMC) proteome. An overall number of 1503 proteins were identified and quantified. The supervised sparse variant partial least squares-discriminant analysis (sPLS-DA) for paired data highlighted 373 discriminant proteins between CP-treated and the control group, of which 50 proteins with the highest abundance in CP and 137 in the control group were selected for Gene Ontology (GO) analyses using ProteINSIDE. Discriminant Protein highly abundant in CP-treated cells were involved in actin cytoskeleton organization and negative regulation of cell migration. Interestingly, MARCKSL1, a chemotaxis inhibitor, was upregulated in CP-treated cells. On the contrary, CP incubation downregulated MARCKS, LGALS3, and LGALS8, which are involved in cytoskeleton rearrangements, cell migration, and phagocytosis. In conclusion, these results provide a proteomics background to the anti-inflammatory activity of CP, demonstrating that the in vitro downregulation of phagocytosis and chemotaxis is related to changes in proteins related to the cytoskeleton.

Even though Stellaria dichotoma L. var. lanceolate (S. dichotoma) is a well-known medicinal plant in the family Caryophyllaceae, its oligosaccharides remain unexplored in terms of their potential as bioactive agents. Here, we isolated a mixture of oligosaccharides from S. dichotoma (Yield: 12 % w/w), that are primarily non-classical raffinose family oligosaccharides (RFOs). Nine major oligosaccharides were purified and identified from the mixture, including sucrose, raffinose, 1-planteose, lychnose, stellariose, along with four new non-classical RFOs. Two of the four new oligosaccharides are linear hexose pentamers with α-galactosyl extensions on their lychnose moieties, and the other two are branched hexose hexamers with α-galactosyl extensions on their stellariose groups. Their interactions with galectin-3 (Gal-3) revealed significant binding, with the terminal galactose providing enhanced affinity for the lectin. Notably, Gal-3 residues Arg144, His158, Asn160, Arg162, Asn174, Trp181, Glu184 and Arg186 coordinate with the lychnose. In vivo studies using the dextran sulfate sodium (DSS) mouse model for colitis demonstrated the ability of these carbohydrates in mitigating ulcerative colitis (UC). Overall, our study has provided structural information and potential applications of S. dichotoma oligosaccharides, also offers new approaches for the development of medicinal oligosaccharides.

Adaptive immunity relies on dendritic cell (DC) migration to transport antigens from tissues to lymph nodes. Galectins, a family of β-galactoside-binding proteins, control cell membrane organisation, exerting crucial roles in multiple physiological processes. Here, we report a novel mechanism underlying cell polarity and uropod retraction. We demonstrate that galectin-9 regulates chemokine-driven and basal DC migration both in humans and mice, indicating a conserved function for this lectin. We identified the underlying mechanism, namely a deficiency in cell rear contractility mediated by galectin-9 interaction with CD44 that in turn regulates RhoA activity. Analysis of DC motility in the 3D tumour-microenvironment revealed galectin-9 is also required for DC infiltration. Moreover, exogenous galectin-9 rescued the motility of tumour-immunocompromised human blood DCs, validating the physiological relevance of galectin-9 in DC migration and underscoring its implications for DC-based immunotherapies. Our results identify galectin-9 as a necessary mechanistic component for DC motility and highlight a novel role for the lectin in regulating cell polarity and contractility.

Background:Lgals3/galectin-3 plays a pivotal role in many vascular diseases. However, the involvement of Lgals3/galectin-3 in eyes with neovascular age-related macular degeneration (nAMD) remains unknown. Methods: In the laser-induced CNV model, a whole mount retina stained with Isolectin B4 and collagen type I revealed the vascular bed and CNV-associated subretinal fibrosis on day 7 after laser treatment. Results: We show that the expression levels of Lgals3/galectin-3 were significantly increased in the RPE/choroidal complex of CNV mice. An intravitreal injection of Lgals3-siRNA significantly suppressed the area of CNV and subretinal fibrosis, together with Mcp-1 decline. The mixture of Lgals3-siRNA and Ranibizumab showed more efficiency than each drug used separately. Hypoxia induced Lgals3/galectin-3 production in ARPE-19 cells, which was reduced by the silencing hypoxia-inducible factor -1α (Hif-1a). Conclusions: Our data indicated that Lgals3/galectin-3 is involved in the pathogenesis of CNV and subretinal fibrosis, and Lgals3/galectin-3 could be a potential therapeutic target for nAMD.

Access to defined glycans and glycoconjugates is pivotal for discovery, dissection, and harnessing of a range of biological functions orchestrated by cellular glycosylation processes and the glycome. We previously employed genetic glycoengineering by nuclease-based gene editing to develop sustainable production of designer glycoprotein therapeutics and cell-based glycan arrays that display glycans in their natural context at the cell surface. However, access to human glycans in formats and quantities that allow structural studies of molecular interactions and use of glycans in biomedical applications currently rely on chemical and chemoenzymatic syntheses associated with considerable labor, waste, and costs. Here, we develop a sustainable and scalable method for production of glycans in glycoengineered mammalian cells by employing secreted Glycocarriers with repeat glycosylation acceptor sequence motifs for different glycans. The Glycocarrier technology provides a flexible production platform for glycans in different formats, including oligosaccharides, glycopeptides, and multimeric glycomodules, and offers wide opportunities for use in bioassays and biomedical applications.