Galectin-3 Expression Research Articles

RAGE ablation attenuates glioma progression and enhances tumor immune responses by suppressing galectin-3 expression.

Malignant gliomas consist of heterogeneous cellular components that have adopted multiple overlapping escape mechanisms that overcome both targeted and immune-based therapies. The receptor for advanced glycation end products (RAGE) is a member of the immunoglobulin superfamily that is activated by diverse proinflammatory ligands present in the tumor microenvironment. Activation of RAGE by its ligands stimulates multiple signaling pathways that are important in tumor growth and invasion. However, treatment strategies that only target the interaction of RAGE with its ligands are ineffective as cancer therapies due to the abundance and diversity of exogenous RAGE ligands in gliomas. As an alternative approach to RAGE ligand inhibition, we evaluated the genetic ablation of RAGE on the tumorigenicity of 2 syngeneic murine glioma models. RAGE expression was inhibited in the GL261 and K-Luc gliomas by shRNA and CRSPR/Cas9 techniques prior to intracranial implantation. Tumor growth, invasion, and inflammatory responses were examined by histology, survival, Nanostring, and flow cytometry. Intracellular RAGE ablation abrogated glioma growth and invasion by suppressing AKT and ERK1/2 activities and by downregulating MMP9 expression. Interestingly, RAGE inhibition in both glioma models enhanced tumor inflammatory responses by downregulating the expression of galectin-3 and potentiated immunotherapy responses to immune checkpoint blockade. We demonstrated that intracellular RAGE ablation suppresses multiple cellular pathways that are important in glioma progression, invasion, and immune escape. These findings strongly support the development of RAGE ablation as a treatment strategy for malignant gliomas.

Lyt-200, a Humanized Anti-Galectin-9 Antibody, Exhibits Preclinical Efficacy in Models of Hematological Malignancies

Patients with relapse and refractory (R/R) hematological malignancies typically have 5-year overall survival rates of less than 50% when receiving chimeric antigen receptor (CAR) T-cell therapy and less than 30% after receiving hematopoietic stem cell transplantation (HSCT). Human leukemia cells utilize a variety of biochemical mechanisms, which allow them to escape host immune surveillance. These molecular pathways cause impairment of the anti-cancer activities of immune cells, which could attack and kill leukemia cells. These dismal outcomes for patients with R/R disease highlight the need for novel treatment regimens when current therapeutic options are exhausted. Galectins are s-type lectins that promote diverse biological processes including adhesion, signaling, and immunosuppression. In acute myeloid leukemia (AML), galectin-9 (GAL-9) maintains the leukemia initiating cell (LIC) population and plays an important role in treatment resistance. We recently tested LYT-200, a fully humanized IgG4 αGAL-9 monoclonal antibody, developed by PureTech Health, which has so far been well tolerated with no dose limiting toxicities in a Phase I clinical trial for solid tumors (NCT04666688). We tested LYT-200 in vitro and in vivo across multiple hematological malignancies. Flow cytometry was used to assess the surface expression of GAL-9 on human B-ALL, AML, T-cell acute lymphoblastic leukemia (T-ALL), and diffuse large B-cell lymphoma (DLBCL) cell lines relative to receptor T-cell immunoglobulin and mucin domain-containing protein-3 (TIM-3) and Programmed cell death protein-1 (PD-1) expression. Compared to healthy human peripheral blood mononuclear cells (PBMCs), where GAL-9 surface expression was low or absent depending on the immune cell, GAL-9 was highly expressed on the surface of all human blood cancer cell lines tested (>100-fold increase). Notably, GAL-9 expression was comparable to PD-1 surface expression and higher than that of TIM-3 on AML, B-ALL, T-ALL, and DLBCL cells. Treating all cell lines with LYT-200 relative to control immunoglobulin resulted in extensive cell death, which occurred after 48 and 72 hours of treatment. Furthermore, a side-by-side comparison with αTIM-3 antibody treatment at equivalent concentrations, revealed that LYT-200 treatment was significantly more effective at killing blood cancer cells at low doses of 10-100 ng/mL in vitro. The in vitro efficacy of LYT-200 against multiple blood cancer subtypes extended to in vivo protection and survival benefit in murine models of T-ALL and AML, both in immunocompromised and immunocompetent mice. When immunocompromised mice were transplanted with human T-ALL cell lines or patient-derived samples, single-agent treatment with LYT-200 (1.5 mg/kg/weekly) was comparable to survival results obtained with methotrexate (0.75 mg/kg/weekly) administration. Notably, the combination of LYT-200 and methotrexate treatments led to the best survival outcomes in both contexts. Similar results were obtained in xenograft studies of AML, where single-agent LYT-200 (1.5 mg/kg/weekly) treatment was more effective at protecting mice than cytarabine (100 mg/kg/weekly). However, combining both treatments resulted in the best survival outcomes with greater than 80% of mice surviving over 2 months after disease appearance. In all, our results demonstrate that GAL-9 is an important driver of multiple blood cancer subtypes and that targeting GAL-9 with LYT-200 represents a potential novel treatment strategy which warrants additional pre-clinical and clinical testing.

IMMU-08. RAGE ABLATION ATTENUATES GLIOMA PROGRESSION AND ENHANCES TUMOR IMMUNE RESPONSES BY SUPPRESSING GALECTIN-3 EXPRESSION

Abstract INTRODUCTION Malignant gliomas consist of heterogenous cellular components that have adopted multiple overlapping escape mechanisms that overcome both targeted and immune-based therapies. The receptor for advanced glycation end products (RAGE) is a member of the immunoglobulin superfamily that is activated by diverse proinflammatory ligands present in the tumor microenvironment (TME). Activation of RAGE by its ligands stimulates multiple signaling pathways that are important in tumor growth, invasion, and immune escape. OBJECTIVE We aimed to demonstrate that blockade of RAGE expression may tackle resistance pathways by inhibiting GBM progression, invasion, and immune evasion. METHODS We evaluated genetic ablation of RAGE on the tumorigenicity of two syngeneic murine glioma models. RAGE expression was inhibited in the GL261 and K-Luc gliomas by shRNA and CRSPR/Cas9 techniques prior to intracranial implantation. Tumor growth, invasion, and inflammatory responses were examined by immunohistochemistry, qPCR, ELISA, western blotting, NanoString, flow cytometry, and in vivo survival analysis. RESULTS Intracellular RAGE ablation abrogated glioma growth and invasion by suppressing AKT and ERK1/2 activities and by downregulating MMP9 expression. Interestingly, RAGE inhibition also enhanced tumor inflammatory responses by downregulating the expression of galectin-3, rendered the immunotherapy resistant K-Luc gliomas responsive to immune checkpoint blockade therapy, and significantly increased survival. CONCLUSION This study is the first to link RAGE expression with galactin-3 as an immune modulator in glioblastoma and revealed that the effect of glioma RAGE expression on TME was mediated through downregulation of Gal-3 and subsequent polarization of Tumor-associated macrophages. The therapeutic significance of RAGE downregulation was demonstrated by sensitizing a highly invasive and immune-resistant glioma model to immune checkpoint blockade and strongly supports the development of RAGE ablation as a complementary treatment strategy for malignant gliomas.

EXTH-73. A NOVEL ANTI-GALECTIN-3 MONOCLONAL ANTIBODY THERAPEUTIC DIMINISHES MIGRATION AND SLOWS TUMOR GROWTH TO PROLONG SURVIVAL IN GLIOBLASTOMA

Abstract Glioblastoma (GBM) is the most aggressive, invasive, and malignant primary brain cancer with a standard of care that hasn’t been improved in over 15 years. Heterogenous tumor cell populations that evade resection and develop resistance to chemoradiation highlight the need for novel therapies that can target both the migratory and proliferative nature of GBM cells. Galectin-3, a carbohydrate-binding protein overexpressed in the GBM parenchyma and stromal astrocytes and microglia/macrophages, is a potent modulator of cell proliferation, migration, angiogenesis, T-cell inhibition, and M2 macrophage polarization. Increased Galectin-3 expression levels correlate to lower survival in glioma patients, and these levels further increase following exposure to temozolomide or radiation alone or in combination, thus more greatly emphasizing the need to target Galectin-3 in GBM patients following initial standard-of-care treatment. Here, we characterize the therapeutic effects of a monoclonal anti-Galectin-3 antibody (Gal3 Ab) we have developed for its ability to inhibit GBM tumorigenic and metastatic potential in several in vitro assays and in vivo heterotopic and orthotopic mouse models. We find that Galectin-3 directly binds to EGFR, the most commonly amplified gene locus in GBM affecting roughly 40% of patients, and our Gal3 Ab can block this binding. Human GBM cells treated with Gal3 Ab show a significant decrease in migration and invasion and reduction in EGFR activation in vitro. In vivo, the Gal3 Ab additionally decreases tumor burden and provides a survival benefit in combination with temozolomide compared to the current standard-of-care treatment alone. Our studies indicate the potential for our novel anti-Galectin-3 antibody to further benefit GBM patients receiving chemoradiation treatment by diminishing tumor cell migration and slowing tumor growth.

Identification of Galectin-7 as a crucial metastatic enhancer of squamous cell carcinoma associated with immunosuppression.

Metastasis predicts poor prognosis in cancer patients. It has been recognized that specific tumor microenvironment defines cancer cell metastasis, whereas the underlying mechanisms remain elusive. Here we show that Galectin-7 is a crucial mediator of metastasis associated with immunosuppression. In a syngeneic mouse squamous cell carcinoma (SCC) model of NR-S1M cells, we isolated metastasized NR-S1M cells from lymph nodes in tumor-bearing mice and established metastatic NR-S1M cells in in vitro culture. RNA-seq analysis revealed that interferon gene signature was markedly downregulated in metastatic NR-S1M cells compared with parental cells, and in vivo NR-S1M tumors heterogeneously developed focal immunosuppressive areas featured by deficiency of anti-tumor immune cells. Spatial transcriptome analysis (Visium) for the NR-S1M tumors revealed that various pro-metastatic genes were significantly upregulated in immunosuppressive areas when compared to immunocompetent areas. Notably, Galectin-7 was identified as a novel metastasis-driving factor. Galectin-7 expression was induced during tumorigenesis particularly in the microenvironment of immunosuppression, and extracellularly released at later stage of tumor progression. Deletion of Galectin-7 in NR-S1M cells significantly suppressed lymph node and lung metastasis without affecting primary tumor growth. Therefore, Galectin-7 is a crucial mediator of tumor metastasis of SCC, which is educated in the immune-suppressed tumor areas, and may be a potential target of cancer immunotherapy.

Melatonin ameliorates bleomycin-induced pulmonary fibrosis via activating NRF2 and inhibiting galectin-3 expression.

Pulmonary fibrosis (PF) is a chronic interstitial lung disease with no effective therapies. Galectin-3 (Gal-3), a marker of oxidative stress, plays a key role in the pathogenesis of PF. Fibroblast-myofibroblast differentiation (FMD) is an important source of fibrotic cells in PF. Previous studies showed that melatonin (MT) exerted anti-fibrotic effect in many diseases including PF through its antioxidant activity. In the present study we investigated the relationships among Gal-3, NRF2, ROS in FMD and their regulation by MT. We established an in vitro model of FMD in TGF-β1-treated human fetal lung fibroblast1 (HFL1) cells and a PF mouse model via bleomycin (BLM) intratracheal instillation. We found that Gal-3 expression was significantly increased both in vitro and in vivo. Knockdown of Gal-3 in HFL1 cells markedly attenuated TGF-β1-induced FMD process and ROS accumulation. In TGF-β1-treated HFL1 cells, pretreatment with NRF2-specific inhibitor ML385 (5 μM) significantly increased the levels of Gal-3, α-SMA and ROS, suggesting that the expression of Gal-3 was regulated by NRF2. Treatment with NRF2-activator MT (250 μM) blocked α-SMA and ROS accumulation accompanied by reduced Gal-3 expression. In BLM-induced PF model, administration of MT (5 mg·kg-1·d-1, ip for 14 or 28 days) significantly attenuated the progression of lung fibrosis through up-regulating NRF2 and down-regulating Gal-3 expression in lung tissues. These results suggest that Gal-3 regulates TGF-β1-induced pro-fibrogenic responses and ROS production in FMD, and MT activates NRF2 to block FMD process by down-regulating Gal-3 expression. This study provides a useful clue for a clinical strategy to prevent PF. Graphic abstract of the mechanisms. MT attenuated BLM-induced PF via activating NRF2 and inhibiting Gal-3 expression.

The Expression of IL-1β Correlates with the Expression of Galectin-3 in the Tissue at the Maternal-Fetal Interface during the Term and Preterm Labor.

The inflammatory processes that occur at the maternal-fetal interface are considered one of the factors that are responsible for preterm birth. The pro-inflammatory roles of the Gal-3-induced activation of NLRP3 inflammasome and the consecutive production of IL-1β have been described in several acute and chronic inflammatory diseases, but the role of this inflammatory axis in parturition has not been studied. The aim of this study was to analyze the protein expression of Gal-3, NLRP3, and IL-1β in the decidua, villi, and fetal membranes, and to analyze their mutual correlation and correlation with the clinical parameters of inflammation in preterm birth (PTB) and term birth (TB). The study included 40 women that underwent a preterm birth (gestational age of 25.0-36.6) and histological chorioamnionitis (PTB) and control subjects, 22 women that underwent a term birth (gestational age of 37.0-41.6) without histological chorioamnionitis (TB). An analysis of the tissue sections that were stained with anti- Gal-3, -NLRP3, and -IL-1β antibodies was assessed by three independent investigators. The expression levels of Gal-3 and IL-1β were significantly higher (p < 0.001) in the decidua, villi, and fetal membranes in the PTB group when they compared to those of the TB group, while there was no difference in the expression of NLRP3. A further analysis revealed that there was no correlation between the protein expression of NLRP3 and the expression of Gal-3 and IL-1β, but there was a correlation between the expression of Gal-3 and IL-1β in decidua (R = 0.401; p = 0.008), villi (R = 0.301; p = 0.042) and the fetal membranes (R = 0.428; p = 0.002) in both of the groups, PTB and TB. In addition, the expression of Gal-3 and IL-1β in decidua and the fetal membranes was in correlation with the parameters of inflammation in the maternal and fetal blood (C-reactive protein, leukocyte number, and fibrinogen). The strong correlation between the expression of Gal-3 and IL-1β in the placental and fetal tissues during labor indicates that Gal-3 may participate in the regulation of the inflammatory processes in the placenta, leading to increased production of IL-1β, a cytokine that plays the main role in both term and preterm birth.

The Role of Galectin 3 in the Pathogenesis of Diabetes Mellitus: Focus on Β-Cell Function and Survival

Abstract Galectin 3 is a lectin expressed in many tissues with a significant biological role in physiological and pathological processes. Our review aims to sublimate the effects of galectin 3 on the β-cells function and survival. Data about the effect of galectin 3 on β- cells are scarce and contradictory. Several studies have shown that reduced activity of the galectin 3 gene reduces the risk of developing type 1 diabetes in an experimental model of diabetes in galectin 3 deficient mice. On the other side, in an experimental model of type 1 diabetes with mice with selectively enhanced expression of galectin 3 in β-cells, was shown that increased expression of this lectin has a protective role. Unlike type 1 diabetes where the autoimmune process plays a dominant role in pathogenesis, the pathogenesis of type 2 diabetes is multifactorial. One of the main factors which contribute to type 2 diabetes, the insulin resistance, is related to the concentration of soluble galectin 3. The effect of galectin 3 is very important for β-cell function. When a harmful factor acts on a β-cell, its intracellular concentration increases to preserve the function of β-cells and prevent their apoptosis, by blocking the internal path of apoptosis. However, excessive accumulation of galectin 3 inside the cell leads to its secretion, which encourages tissue inflammation. Based on all the above, galectin 3 has a double effect on β-cells.

Western Diet-Fed ApoE Knockout Male Mice as an Experimental Model of Non-Alcoholic Steatohepatitis.

One of the consequences of the Western lifestyle and high-fat diet is non-alcoholic fatty liver disease (NAFLD) and its aggressive form, non-alcoholic steatohepatitis (NASH), which can progress to cirrhosis and hepatocellular carcinoma (HCC) and is rapidly becoming the leading cause of end-stage liver disease or liver transplantation. Currently, rodent NASH models lack significant aspects of the full NASH spectrum, representing a major problem for NASH research. Therefore, this work aimed to characterize a fast rodent model with all characteristic features of NASH. Eight-week-old male ApoE KO mice were fed with Western diet (WD), high fatty diet (HFD) or normal chow (Chow) for 7 weeks. Whole-body fat was increased by ~2 times in WD mice and HFD mice and was associated with increased glucose intolerance, hepatic triglycerides, and plasma ALT and plasma AST compared with Chow mice. WD mice also showed increased galectin-3 expression compared with Chow or HFD mice and increased plasma cholesterol compared with Chow mice. WD and HFD displayed increased hepatic fibrosis and increased F4/80 expression. WD mice also displayed increased levels of plasma MCP-1. Hepatic inflammatory markers were evaluated, and WD mice showed increased levels of TNF-α, MCP-1, IL-6 and IFN-γ. Taken together, these data demonstrated that the ApoE KO mouse fed with WD is a great model for NASH research, once it presents the fundamental parameters of the disease, including hepatic steatosis, fibrosis, inflammation, and metabolic syndrome.

Sex related difference in heart failure development in patients after first myocardial infarction; role of galectine-3

Abstract Cardiac remodeling after the first myocardial infarction (MI) appears to be more successful in women than in men, but more frequently associated with heart failure (HF) development. Galectin-3 expression is upregulated in remodeling and failing myocardium and circulatory level is activated in hypertrophy, fibrosis and inflammation. This study aimed to investigate the potential role of sex differences in the following: risk factors, structural and functional left ventricle (LV) changes, coronary angiography, expression of Galectin-3 and it's circulating level for HF occurrence during 6 months in patients after first MI. Material and methods The prospective study included patients with the first MI treated with the primary percutaneous coronary intervention (p PCI) who underwent Doppler echocardiography within 2±1 days of MI and after 6 months. Relative LGALS-3 mRNA expression in peripheral blood were detected by TaqMan® technology. Expression and concentration of Galectin-3 was obtained by ELISA method. Presence of HF was confirmed by clinical examination and Doppler echocardiography. Assessment of p PCI and description of coronary angiography was performed at the patient's admission time. Results The study included 137 men and 44 women, who were significantly older (57.8 vs. 54.4, p=0.034), with higher LDL cholesterol (3.54±0.93 vs. 4.03±1.27, p=0.027) without differences among angiographic characteristics and medications. In the acute phase of MI, the significantly lower indexed LV volumes were found in women compared to men (EDLVI: 58.3 vs. 49.6, p<0.001, ESLVI: 33.84 vs. 26.83, p<0.001), but the grade of LV remodeling (delta LVDVI, delta LVESVI) during 6 months and changes in LV ejection fraction (deltaLVEF) were similar (p=ns). Incidence of LV hypertrophy and HF development was significantly higher in women 70% vs. 44.6%, p=0.034, 37.5% vs.19.3%, p=0.02). Females have had a higher degree of LV diastolic dysfunction (DD) in the early and late phase after MI (p=0.038, p=0.027). There were significant correlations between grade of DD and level of Gal-3 expression (p=0.001). The relative expression of LGALS-3 mRNA in peripheral blood was higher in females (p=0.007) with upregulation of circulating Gal-3 in females (44.66 vs. 16.30, p<0.001) and in HF patients (31.1 vs. 21.2, p=0.025). Conclusion Sex specific actions such as LV hypertrophy, diastolic dysfunction, upregulation of Galectin-3 expression and higher circulating level may explain more incidence of HF in female. Difference in model and determinants of HF between men and women can be important for further therapy including Gelectin-3 inhibition. Funding Acknowledgement Type of funding sources: None.

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

PurposeCervical cancer (CC) is the second most frequent cancer in undeveloped countries. Serum biomarkers could be useful for evaluation of the treatment response and as a complementary means to improve diagnosis. The expression of galectin-9 is altered in cancer tissue, and higher concentrations are found in the serum of cancer patients. The objectives of this study were (a) to determine the serum galectin-9 concentration in patients with intraepithelial lesions and CC, (b) to determine if the concentration was related to the clinicopathological characteristics and (c) to determine if the galectin-9 concentration was related to its expression level in tumour tissue.Patients and MethodsIn all, 222 serum samples from women with different diagnoses, including premalignant lesions and CC, as well as samples from women with normal cytology were included in the study. The serum galectin-9 concentration was determined by ELISA. To evaluate the expression level of galectin-9 in CC tissue, immunohistochemistry was performed in 34 CC biopsy specimens.ResultsThe galectin-9 concentration in the serum of CC patients (8.171 ng/mL) was increased compared with serum from women with normal epithelia (4.654 ng/mL) and those with low-grade (4.806 ng/mL) and high-grade (5.354 ng/mL) intraepithelial lesions (p value < 0.0001). The area under the ROC curve considering the CC group and the control group was 0.882. The optimal cut-off value was ≥6.88 ng/mL, the specificity obtained was 100%, and the sensitivity was 68.2%. In the CC group, the analysis of the clinical stage showed an increase of galectin-9 in the advanced stage IV group. Serum galectin-9 was not related to the level of galectin-9 expression in tissue, which suggests that galectin-9 is not secreted by tumour cells.ConclusionThe serum galectin-9 concentration is related to cancer progression, as the level of this protein is higher in patients with advanced-stage disease.

Influence of myelin basic protein charge isomers on IL-33 and galectin-3 expression in astrocytes

Influence of myelin basic protein charge isomers on IL-33 and galectin-3 expression in astrocytes

Galectin-1 in Obesity and Type 2 Diabetes.

Galectin-1 is a carbohydrate-binding protein expressed in many tissues. In recent years, increasing evidence has emerged for the role of galectin-1 in obesity, insulin resistance and type 2 diabetes. Galectin-1 has been highly conserved through evolution and is involved in key cellular functions such as tissue maturation and homeostasis. It has been shown that galectin-1 increases in obesity, both in the circulation and in the adipose tissue of human and animal models. Several proteomic studies have independently identified an increased galectin-1 expression in the adipose tissue in obesity and in insulin resistance. Large population-based cohorts have demonstrated associations for circulating galectin-1 and markers of insulin resistance and incident type 2 diabetes. Furthermore, galectin-1 is associated with key metabolic pathways including glucose and lipid metabolism, as well as insulin signalling and inflammation. Intervention studies in animal models alter animal weight and metabolic profile. Several studies have also linked galectin-1 to the progression of complications in diabetes, including kidney disease and retinopathy. Here, we review the current knowledge on the clinical potential of galectin-1 in obesity and type 2 diabetes.

Involvement of Galectin-3 in neurocognitive impairment in obstructive sleep apnea via regulating inflammation and oxidative stress through NLRP3

ObjectiveAccumulated studies have revealed that oxidative stress and inflammation play important roles in the development of OSA related cognitive dysfunction. Galectin-3, a member of the galectin family, has been reported to be involved in the neuroinflammatory diseases. However, the relationship between Galectin-3 and cognitive impairment in OSA remains ambiguous. Materials and methods47 new diagnosed OSA patients and 18 age-, gender-, education- and body mass index-matched healthy control subjects were enrolled in the present study. All subjects underwent whole-night in-laboratory polysomnography (PSG). Montreal Cognitive Assessment (MoCA) was used to evaluated the cognitive function of OSA patients. Serum Galectin-3, interleukin (IL)-1β and IL-8 were examined by enzyme-linked immunosorbent assay (ELISA). The levels of malonaldehyde (MDA), superoxide dismutase (SOD) and catalase (CAT) were measured to evaluate oxidative stress. Protein level of Galectin-3 and NLRP3 in peripheral blood mononuclear cells (PBMCs) and human microglial clone 3 (HMC3) cells were measured by Western Blot. ResultsSerum Galectin-3 level in severe OSA patients (2.31 ± 0.43 ng/m) was higher than those in mild-moderate OSA patients (1.87 ± 0.32 ng/m, p < 0.001) and those in the healthy controls (1.56 ± 0.22 ng/ml, p < 0.001). Similarly, Galectin-3 level in PBMCs was increased with disease severity (p < 0.01). In addition, OSA patients also showed higher levels of inflammation and oxidative stress (p < 0.01). Patients with OSA scored significantly lower than healthy controls on the MoCA test after controlling for age, gender, education, and BMI. CPAP treatment for 12 weeks effectively reduced the levels of Galectin-3, inflammation and oxidative stress, as well as improved cognitive function of severe OSA patients. Closed correlations were observed between Galectin-3 with sleep respiratory parameters and cognitive dysfunction. In addition, we explored the underlying mechanism of Galectin-3 in neuroinflammation and oxidative stress. We treated HMC3 cells with LPS to mimic neuroinflammatory response in vitro. The results showed that LPS treatment led to a dose-dependent increase in Galectin-3 expression, meanwhile induced inflammation and oxidative stress. Inhibiting Galectin-3 with a specific Galectin-3 inhibitor, TD139, significantly ameliorated LPS-induced neuroinflammation and oxidative stress via suppressing NLRP3. ConclusionCurrent findings suggest that increased Galectin-3 might be involved in the cognitive impairment of OSA patients by promoting neuroinflammation and oxidative stress via regulating NLRP3. These results suggested that Galectin-3 inhibition may exert a protective role against the neurocognitive dysfunction associated with OSA.

Galectin-3 as a biomarker in breast neoplasms: Mechanisms and applications in patient care.

Galectin-3 is a member of the lectin family encoded by the LGALS3 gene on chromosome 14. It is secreted by a wide range of immune cells and mammary tumor cells. Through its activity on the tumor microenvironment, in particular on tumor-infiltrating leukocytes, galectin-3 improves the proliferation, survival, and colonizing ability of mammary neoplastic cells. Consequently, galectin-3 expression in the tumor microenvironment could worsen therapeutic outcomes of breast neoplasms and become a biomarker and a therapeutic target in combined immunotherapy in breast neoplasms. There is a limited amount of information that is available on galectin-3 in breast cancer in Africa. In this review, we analyze how galectin-3 influences the tumor microenvironment and its potential as a biomarker and therapeutic target in breast neoplasms. We aim to emphasize the significance of investigating galectin-3 in breast neoplasms in Africa based on the results of studies conducted elsewhere.

Genetic targeting or pharmacological inhibition of galectin-3 dampens microglia reactivity and delays retinal degeneration

BackgroundDysfunctional humoral and cellular innate immunity are key components in the development and progression of age-related macular degeneration (AMD). Specifically, chronically activated microglia and their disturbed regulatory system contribute to retinal degeneration. Galectin-3, a β-galactose binding protein, is a potent driver of macrophage and microglia activation and has been implicated in neuroinflammation, including neurodegenerative diseases of the brain. Here, we hypothesized that genetic deficiency of galectin-3 or its modulation via TD139 dampens mononuclear phagocyte reactivity and delays retinal degeneration.MethodsGalectin-3 expression in AMD patients was analyzed by immunohistochemical stainings. Galectin-3 knockout and BALB/cJ mice were exposed to white bright light with an intensity of 15,000 lux for 1 h and Cx3cr1GFP/+ mice to focal blue light of 50,000 lux for 10 min. BALB/cJ and Cx3cr1GFP/+ mice received intraperitoneal injections of 15 mg/kg TD139 or vehicle for five consecutive days, starting one day prior to light exposure. The effects of galectin-3 deficiency or inhibition on microglia were analyzed by immunohistochemical stainings and in situ hybridization of retinal sections and flat mounts. Pro-inflammatory cytokine levels in the retina and retinal pigment epithelium (RPE) were quantified by qRT-PCR and transcriptomic changes were analyzed by RNA-sequencing. Retinal thickness and structure were evaluated by optical coherence tomography.ResultsWe found that galectin-3 expression was strongly upregulated in reactive retinal mononuclear phagocytes of AMD patients and in the two related mouse models of light-induced retinal degeneration. The experimental in vivo data further showed that specific targeting of galectin-3 by genetic knockout or administration of the small-molecule inhibitor TD139 reduced microglia reactivity and delayed retinal damage in both light damage conditions.ConclusionThis study defines galectin-3 as a potent driver of retinal degeneration and highlights the protein as a drug target for ocular immunomodulatory therapies.

Galectin-3 critically mediates the hepatoprotection conferred by M2-like macrophages in ACLF by inhibiting pyroptosis but not necroptosis signalling

We previously documented that M2-like macrophages exert a hepatoprotective effect in acute-on-chronic liver failure (ACLF) by inhibiting necroptosis signalling. Nevertheless, the molecular mechanism behind this hepatoprotection still needs to be further dissected. Galectin-3 (GAL3) has been reported to be critically involved in the pathogenesis of multiple liver diseases, whereas the potential role of GAL3 in ACLF remains to be explored. Herein, we hypothesised that GAL3 plays a pivotal role in the hepatoprotection conferred by M2-like macrophages in ACLF by inhibiting necroptosis. To test this hypothesis, we first assessed the expression of GAL3 in control and fibrotic mice with or without acute insult. Second, loss- and gain-of-function experiments of GAL3 were performed. Third, the correlation between GAL3 and M2-like macrophage activation was analysed, and the potential role of GAL3 in M2-like macrophage-conferred hepatoprotection was confirmed. Finally, the molecular mechanism underlying GAL3-mediated hepatoprotection was dissected. GAL3 was found to be obviously upregulated in fibrotic mice with or without acute insult but not in acutely injured mice. Depletion of GAL3 aggravated hepatic damage in fibrotic mice upon insult. Conversely, adoptive transfer of GAL3 provided normal mice enhanced resistance against acute insult. The expression of GAL3 is closely correlated with M2-like macrophage activation. Through adoptive transfer and depletion experiments, M2-like macrophages were verified to act as a major source of GAL3. Importantly, GAL3 was confirmed to hold a pivotal place in the hepatoprotection conferred by M2-like macrophages through loss- and gain-of-function experiments. Unexpectedly, the depletion and adoptive transfer of GAL3 resulted in significant differences in the expression levels of pyroptosis but not necroptosis signalling molecules. Taken together, GAL3 plays a pivotal role in the hepatoprotection conferred by M2-like macrophages in ACLF by inhibiting pyroptosis but not necroptosis signalling. Our findings provide novel insights into the pathogenesis and therapy of ACLF.

Immune checkpoint inhibitor therapy increases systemic SDF-1, cardiac DAMPs Fibronectin-EDA, S100/Calgranulin, galectine-3, and NLRP3-MyD88-chemokine pathways.

BackgroundImmune checkpoint inhibitors (ICIs) have significantly changed the oncology clinic in recent years, improving survival expectations in cancer patients. ICI therapy have a broad spectrum of side effects from endocrinopathies to cardiovascular diseases. In this study, pro-inflammatory and pro-fibrotic effects of short-term ICIs therapy in preclinical models were analyzed.MethodsFirstly, in a human in vitro model, human cardiomyocytes co-cultured with hPBMC were exposed to ICIs (with CTLA-4 or PD-1 blocking agents, at 200 nM) for 72 h. After treatment, production of DAMPs and 12 cytokines were analyzed in the supernatant through colorimetric and enzymatic assays. C57/Bl6 mice were treated with CTLA-4 or PD-1 blocking agents (15 mg/kg) for 10 days. Before (T0), after three days (T3) and after treatments (T10), ejection fraction, fractional shortening, radial and longitudinal strain were calculated by using bidimensional echocardiography (Vevo 2100, Fujfilm). Fibrosis, necrosis, hypertrophy and vascular NF-kB expression were analyzed through Immunohistochemistry. Myocardial expression of DAMPs (S100- Calgranulin, Fibronectin and Galectine-3), MyD88, NLRP3 and twelve cytokines have been analyzed. Systemic levels of SDF-1, IL-1β, and IL-6 were analyzed before, during and after ICIs therapy.ResultsRadial and longitudinal strain were decreased after 10 days of ICIs therapy. Histological analysis of NF-kB expression shows that short-term anti-CTLA-4 or anti-PD-1 treatment increased vascular and myocardial inflammation. No myocardial hypertrophy was seen with the exception of the pembrolizumab group. Myocardial fibrosis and expression of galectin-3, pro-collagen 1-α and MMP-9 were increased after treatment with all ICIs. Both anti-CTLA-4 or anti-PD-1 treatments increased the expression of DAMPs, NLRP3 inflammasome and MyD88 and induced both in vitro and in vivo the secretion of IL-1β, TNF-α and IL-6. Systemic levels of SDF-1, IL-1β and IL-6 were increased during and after treatment with ICIs.ConclusionsShort therapy with PD-1 and CTLA-4 blocking agents increases vascular expression of NF-kB, systemic SDF-1, IL-1β, IL-6 levels and myocardial NLRP3, MyD88 and DAMPs expression in preclinical models. A pro-inflammatory cytokine storm was induced in myocardial tissues and in cultured cardiac cells after ICIs therapy. The overall picture of the study suggests new putative biomarkers of ICIs-mediated systemic and myocardial damages potentially useful in clinical cardioncology.

422.2: Investigating Galectin-3 as a Novel Therapeutic Target To Block Inflammation and Reduce Ischemia Reperfusion Injury During Vascular Composite Allograft Transplantation

Introduction: Vascularized Composite Allograft (VCA) transplantation is a treatment option for complex injuries that leave patients with structural and functional deficits that cannot be adequately reconstructed. During transplantation, grafts are subjected to hypoxic/ischemic injury during procurement, storage, and reperfusion. Skin and muscle containing VCA are highly susceptible to ischemia reperfusion injury. Galectin-3 is an endogenous β-galactoside binding lectin known to play a role in driving inflammatory responses in response to hypoxic/ischemic stress. Blocking galectin-3 using known inhibitors including modified citrus pectin (MCP) has been shown in animal models to reduce inflammation and fibrosis. We hypothesized that galectin-3 significantly contributes to VCA IRI and that blocking galectin-3 can serve as a novel therapeutic approach to prevent or reduce IRI. We aimed to determine the role of galectin-3 in VCA ischemia reperfusion injury and the effect of blocking galectin-3 using MCP in syngeneic VCA models. Method: Male Brown Norway rats underwent syngeneic hind limb transplantation following 0, 6 or 24 hours of cold ischemia time. A group of rats receiving hind limbs subjected to 24 hours of static cold storage were treated with MCP (1% w/v) in the drinking water starting one week prior to transplantation. Recipient serum and donor VCA tissues were collected at end-of-study 6 days post transplantation. Sera and tissues collected from naive Brown Norway rats were included as controls. Sera levels of galectin-3 were determined by sandwich ELISA (Novus Biologics, Inc). Galectin-3 expression in the muscle was determined by Western Blotting. The degree of inflammation in the muscle tissue was determined by H&E. Results: Sera galectin-3 levels averaged 0.854±0.557ng/ml in naïve BN rats (n=7), 4.232±2.134ng/ml in recipients of grafts transplanted immediately without static cold storage (n=3), 12.86±1.292ng/ml in recipients of grafts subjected to 6 hours cold storage without MCP treatment (n=3),20.10±3.185ng/ml in recipients of grafts subjected to 24 hours cold storage without MCP treatment (n=6), and 12.77±2.098ng/ml in recipients of grafts subjected to 24 hours cold storage with MCP treatment (n=9) (Figure 1A). Galectin-3 expression in the VCA muscle increased according to the extent of cold ischemia. MCP treatment decreased muscle galectin-3 expression (Figure 1B) and inflammation in the muscle (Figure 2) post transplantation.Conclusion: Galectin-3 levels significantly increased in recipient sera and donor muscle within a week in rats transplanted with donor VCA grafts subjected to prolonged ischemia. Blocking galectin-3 using MCP can reduce the amount of galectin-3 in circulation and muscle tissue post transplantation and may decrease inflammation associated with VCA IRI. Galectin-3 may serve as a novel therapeutic target to reduce inflammation associated with ischemic injury and improve VCA outcomes. DOD CDMRP RTRP W81XWH1910163 RT180168.

Assessment of galectins -1, -3, -4, -8, and -9 expression in ovarian carcinoma patients with clinical implications

Background and aimGalectins have been recently tackled by many researchers in the field of cancer due to their role in tumorigenesis, disease progression, and metastasis. Thus, they are currently involved in biomarkers research on several types of cancer. In ovarian cancers, few studies were carried out to evaluate galectins expression profiling. Hence, our present study was executed to evaluate the mRNA expression of galectins -1, -3, -4, -8, and -9 in epithelial ovarian cancers.MethodsFifty-six tumor samples of ovarian carcinomas were analyzed for mRNA expression using qRT-PCR, and fold-changes were calculated in comparison to tissue samples of 26 women with normal ovaries.ResultsThe results of the present paper emphasize the importance of galectins as predictors for targeted therapy. LGALS1, LGALS3, LGALS4, LGALS8, and LGALS9 were found to be mostly overexpressed in ovarian carcinoma patients with the following percentage: 78.6%, 92.9%, 66.1%, 87.5%, and 85.7% respectively. Moreover, galectins -3 and -9 were found to be significantly elevated with lymph node metastasis (p = 0.044 and p = 0.011). Also, upregulation of galectin-1 and -9 were statistically significant in stages IIB, IIC, and IIIB (p = 0.002) in FIGO staging. CA19.9 is positively correlated to galectin-4 expression (p = 0.039).ConclusionOur findings strengthen the role of galectins in carcinogenesis, disease progression, and lymphnode metastasis in ovarian carcinomas. And since these galectins are mostly overexpressed, they could be promising markers for targeted therapy to reduce disease progression and metastasis process.