Effect Of Gal-1 Research Articles

Anti-inflammatory Property of Galectin-1 in a Murine Model of Allergic Airway Inflammation.

Galectin-1 (Gal-1) has immunomodulatory activities in various allergic inflammatory disorders, but its potential anti-inflammatory properties on allergic airway diseases have not been confirmed. We explored the pharmacological effects of Gal-1 on the progression of allergic airway inflammation and investigated the underlying mechanism. Female C57BL/6 mice were sensitized on day 0 and challenged with ovalbumin (OVA) on days 14-17 to establish an allergic airway inflammation model. In the challenge phase, a subset of mice was treated intraperitoneally with recombinant Gal-1 (rGal-1) or dexamethasone (Dex). We found that rGal-1 inhibited pulmonary inflammatory cell recruitment, mucus secretion, bronchoalveolar lavage fluid (BALF) inflammatory cell infiltration, and cytokine production. The treatment also suppressed the infiltration of eosinophils into the allergic lung as indicated by decreased expression levels of eotaxin and eosinophil peroxidase (EPX). However, only the expression levels of IL-25, neither IL-33 nor TSLP, were significantly decreased in the lung by rGal-1 treatment. These immunomodulatory effects in the allergic lung were correlated with the activation of extracellular signal-regulated kinase (ERK) signaling pathway and downregulation of endogenous Gal-1. In addition, rGal-1 reduced the plasma concentrations of anti-OVA immunoglobulin E (IgE) and IL-17. Our findings suggest that rGal-1 is an effective therapy for allergic airway inflammation in a murine model and may be a potential pharmacological target for allergic airway inflammatory diseases.

Pharmacological treatment with galectin-1 protects against renal ischaemia-reperfusion injury

Galectin-1 protein (GAL-1) has important anti-inflammatory properties, but related pharmacologic approaches to effectively treat or prevent renal ischaemia and reperfusion injury are highly limited. Here, we investigated the effect of GAL-1 in a renal ischaemia-reperfusion injury rat model and an in vitro hypoxia-reoxygenation model with a proximal renal tubular epithelial cell line. In vivo, pretreatment with GAL-1 attenuated the renal parameters changed by ischaemia-reperfusion/hypoxia-reoxygenation, with recovery of renal function, protecting against influx of leukocytes, cell death and oxidative stress. Ischaemia-reperfusion/hypoxia-reoxygenation was also associated with increased renal endogenous expression of GAL-1 and intercellular adhesion molecule 1 (ICAM-1) plus augmented levels of proinflammatory cytokines IL-1β, TNF-α and MCP-1 and decreased anti-inflammatory IL-10 in urine, all of which were abrogated by GAL-1 treatment. In vitro studies demonstrated renal tubular epithelial cells as an important source of GAL-1 during hypoxia-reoxygenation and confirmed the protective effects of exogenous GAL-1 through downregulation of proinflammatory cytokine release by proximal renal tubular epithelial cells. Collectively, our findings confirm the important anti-inflammatory role of GAL-1 in kidney ischaemia and reperfusion injury and indicate its promising use as a therapeutic approach.

Galectin-1 Influences Breast Cancer Cell Adhesion to E-selectin Via Ligand Intermediaries.

Invasion of other tissues during bloodborne metastasis in part requires adhesion of cancer cells to vascular endothelium by specific fluid shear-dependent receptor-ligand interactions. This study investigates the hypothesis that the adhesion is mediated by ligands shared between endothelial E-selectin and Galectin-1 (Gal-1), both of which are upregulated during inflammation and cancer. Flow chamber adhesion and dynamic biochemical tissue analysis (DBTA) assays were used to evaluate whether Gal-1 modulates E-selectin adhesive interactions of breast cancer cells and tissues under dynamic flow conditions, while immunocytochemistry, immunohistochemistry, western blotting, and fluorescence anisotropy were used to study molecular interactions under static conditions. Dynamic adhesion assays revealed a shear-dependent binding interaction between Gal-1hFc treated breast cancer cells and tissues and E-selectin-coated beads, causing~300% binding increase of the beads compared to negative controls. Immunocyto- and immunohistochemical analyses showed that Gal-1 and E-selectin fluorescent signals colocalized on cells and tissues at~75% for each assay. Immunoprecipitation and Western blotting of Mac-2BP from breast cancer cell lysates revealed that Gal-1 and E-selectin share Mac-2BP as a ligand, while fluorescence anisotropy and circulating tumor cell model systems exhibited competitive or antagonistic binding between Gal-1 and E-selectin for shared ligands, including Mac-2BP. Furthermore, Mac-2BP functional blockade inhibited the effects of Gal-1 on E-selectin binding. In summary, this investigation reveals a shear-dependent interaction between E-selectin and Gal-1 that may be due to intermediation by a similar or shared ligand(s), including Mac-2BP, which may provide a rational basis for development of novel diagnostics or therapeutics for breast cancer.

Abstract 4328: Galectin-3 mediates tumor-stromal interaction by activating pancreatic stellate cell through integrinβ1/ILK/NF-κB signaling

Abstract Background: Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive tumor with poor survival in PDAC patients. Proinflammatory cytokines/chemokines play an essential role in tumor microenvironments associated with its invasive and aggressive phenotype. Galectin-3 (Gal-3), a member of a family of β-galactoside-specific lectins, has been found to be involved in tumor progression and tissue fibrosis. However, the precise molecular mechanisms of Gal-3 mediate tumor-stromal interaction and abundant cytokine production is unknown. Methods: The effects of Gal-3 on secretion of cytokines/chemokines from stromal cells (HPSC) were assessed by cytokine array. HPSC proliferation and invasion were assessed by the MTS and Matrigel invasion assays. Co-culture and Conditional medium from PDAC tumor cells with genetic alterations of Gal-3 levels were used to study the interaction between tumor cell and stromal cells. IL-8 production in both tumor cells and stromal cells was confirmed by ELISA. Transcriptional activities of NF-κB and IL-8 were determined by transient transfection. An IKB mutant construct (IKBM), Mutation of the IL-8 promoter at the NF-κB site, and inhibitors of NF-κB (Bay11), ILK and neutral antibody of Integrinβ1 were used to determine the signaling pathways evoked by Gal-3. Results: Gal-3 expression is in both tumor cells and stromal cells of human and genetic mouse model. Secretion of cytokines such as IL-8, GM-CSF, CXCL1, CCL2 and IL6 were significantly increased in HPSC cells treated with rGal-3 which is concomitant with activation of HPSC. Conditioned medium or co-culture from Panc-1 cells in which Gal-3 was down-regulated inhibited the growth and invasion capacity of HPSC cells compared with the vector controls. rGal-3 dramatically induced production and secretion of IL-8 in HPSCs. Mechanistically, Gal-3 stimulates IL-8 secretion at the level of transcription and through Integrinβ1/ILK/NF-kB signaling. rGal-3 strongly stimulated integrin β1 expression and NF-κB transcriptional activity; and inhibitors of ILK inhibitor or NF-κB or neutral antibody of integrin β1 blocked IL-8 transcriptional activity and its secretion. NF-κB mutant construct IKBM or mutation of the NF-κB site in the IL-8 promoter completely block the induction of IL-8 activity by Gal-3. GEO data and our own patients’ cohort analysis of pancreatic tumor samples demonstrated that the level of Gal-3, IL-8 and other cytokines is significantly higher in tumor tissues than those of normal and pancreatitis. Conclusion: Collectively, these data suggest that Gal-3 secreted from tumor cells activate HPSC cells and induce many inflammatory cytokines including IL-8 production via Integrinβ1/ILK/NF-κB signaling. Thus, Gal-3 may play a critical role in mediating tumor-stromal interaction and remodeling tumor associated microenvironments. Citation Format: Wei Zhao, Yan Xu, Guha Sushovan, Rosa Hwang, Nobuo Ochi, Margarete Hafley, Robert Bresalier, Craig Logsdon, Zhenning Wang, Jaffer Ajani, Shumei Song. Galectin-3 mediates tumor-stromal interaction by activating pancreatic stellate cell through integrinβ1/ILK/NF-κB signaling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4328. doi:10.1158/1538-7445.AM2017-4328

Silencing of galectin-1 inhibits retinal neovascularization and ameliorates retinal hypoxia in a murine model of oxygen-induced ischemic retinopathy

Aberrant neovascularization is a consequence of inappropriate angiogenic signaling and contributes to several diseases. Although many regulators of pathogenic angiogenesis have been identified, the understanding of this process remains incomplete. Galectin-1 (Gal-1), as a homodimeric protein with a single carbohydrate-recognition domain, is implicated in several pathologic processes, including angiogenesis; however, its involvement in retinal neovascularization (RNV) remains unknown. Here, we investigated the anti-angiogenic effect of silencing Gal-1 through intravitreal injection in a mouse model of oxygen-induced retinopathy (OIR). Our results revealed that Gal-1 was overexpressed and closely related to retinal neo-vessels in OIR retinas. After silencing Gal-1 via intravitreal injection of adenoviral-Gal-1-RNA interference (Ad-Gal-1-RNAi), RNV and retinal hypoxia were significantly attenuated, indicating the anti-angiogenic effect of Gal-1 inhibition. Western blot analysis and real-time polymerase chain reaction indicated that the expression of both neuropilin-1 (Nrp-1) and B cell lymphoma-2 (Bcl-2) decreased after intravitreal injection of Ad-Gal-1-RNAi, implying the possible involvement of Nrp-1 and Bcl-2 in Gal-1-related angiogenic processes. Additionally, whole-mount fluorescence and hematoxylin and eosin staining showed that intravitreal injection of Ad-Gal-1-RNAi did not significantly disrupt the retinal vasculature and neuronal structure of room air mice. Moreover, Ad-Gal-1-RNAi transfer promoted retinal vascular sprouting and increased retinal vascular perfusion, likely through decreased phosphorylation of myosin phosphatase target protein-1. Collectively, our results demonstrated that Gal-1 functions as an important regulator in RNV and offers a promising strategy for the treatment of RNV diseases, such as proliferative diabetic retinopathy and retinopathy of prematurity.

Galectin-1 knockdown improves drug sensitivity of breast cancer by reducing P-glycoprotein expression through inhibiting the Raf-1/AP-1 signaling pathway.

Galectin-1 (Gal-1), a member of the galectin family of carbohydrate binding proteins, plays a pivotal role in various cellular processes of tumorigenesis. The regulatory effect of Gal-1 on multidrug resistance (MDR) breast cancer cells is still unclear. qRT-PCR and western blot showed that Gal-1 and MDR gene 1 (MDR1) were both highly expressed in breast tumor tissues and cell lines. MTT assay and flow cytometry revealed that Gal-1 knockdown improved sensitivity to paclitaxel (PTX) and adriamycin (ADR) in MCF-7/PTX and MCF-7/ADR cells via inhibition of cell viability and promotion of cell apoptosis, while MDR1 overexpression weakened the sensitivity to PTX and ADR induced by Gal-1 knockdown. Furthermore, the negative effects of Gal-1 knockdown on sensitivity to PTX and ADR in MCF-7/PTX and MCF-7/ADR cells were revealed to be mediated via the suppression of Raf-1/AP-1 pathway. In conclusion, Gal-1 knockdown dramatically improved drug sensitivity of breast cancer by reducing P-glycoprotein (P-gp) expression via inhibiting the Raf-1/AP-1 pathway, providing a novel therapeutic target to overcome MDR in breast cancer.

Galectin-1 promotes tumor progression via NF-κB signaling pathway in epithelial ovarian cancer.

Purpose: We previously reported that Galectin-1 (Gal-1) played a role in epithelial ovarian cancer (EOC) progression. In this study, we aimed to further investigate the association between Gal-1 expression and prognosis in EOC patients and tried to reveal some novel potential mechanisms of Gal-1 in EOC invasion and migration.Materials and Methods: Gal-1 and nucleus NF-κBp65 expression in 109 human epithelial ovarian cancer tissue specimens were evaluated by immunohistochemistry. The Cox model and survival curves were used to investigate the effect of Gal-1 on EOC prognosis. Correlation between Gal-1 expression and NF-κB activation in EOC patients was also analyzed. In vitro experiments were further performed to reveal the function and mechanisms of Gal-1 in invasion and migration of EOC cells.Results: Expression level of Gal-1 in EOC tissue was an independent prognostic factor on overall survival (p<0.05) and progression-free survival (p<0.05). Patients with high Galectin-1 expression had shorter overall survival (OS, p<0.05)) and progression-free survival (PFS, p<0.05). Immunohistochemistry revealed that expression of Gal-1 was positively associated with activation of NF-κBp65 in EOC tissues (Kappa coefficient=0.458, p<0.001). Patients with tumors concomitantly co-over-expressing Gal-1 and NF-κBp65 had the worse OS (p<0.001) and PFS (p<0.001). The abilities of migration and invasion for EOC cells were significantly reduced after Gal-1 knocked-down in human EOC cell line HO8910, which was accompanied with the suppression of NF-κb pathway activation and with the matrix metalloproteinase-2 and matrix metalloproteinase-9 down-regulation.Conclusions: Our results suggest that Gal-1 is associated with poor outcome in EOC and Galectin-1 promotes tumor progression via NF-κB pathway activation in EOC.

SPRED1 Interferes with K-ras but Not H-ras Membrane Anchorage and Signaling.

The Ras/mitogen-activated protein kinase (MAPK) signaling pathway is tightly controlled by negative feedback regulators, such as the tumor suppressor SPRED1. The SPRED1 gene also carries loss-of-function mutations in the RASopathy Legius syndrome. Growth factor stimulation translocates SPRED1 to the plasma membrane, triggering its inhibitory activity. However, it remains unclear whether SPRED1 there acts at the level of Ras or Raf. We show that pharmacological or galectin-1 (Gal-1)-mediated induction of B- and C-Raf-containing dimers translocates SPRED1 to the plasma membrane. This is facilitated in particular by SPRED1 interaction with B-Raf and, via its N terminus, with Gal-1. The physiological significance of these novel interactions is supported by two Legius syndrome-associated mutations that show diminished binding to both Gal-1 and B-Raf. On the plasma membrane, SPRED1 becomes enriched in acidic membrane domains to specifically perturb membrane organization and extracellular signal-regulated kinase (ERK) signaling of active K-ras4B (here, K-ras) but not H-ras. However, SPRED1 also blocks on the nanoscale the positive effects of Gal-1 on H-ras. Therefore, a combinatorial expression of SPRED1 and Gal-1 potentially regulates specific patterns of K-ras- and H-ras-dependent signaling output. More broadly, our results open up the possibility that related SPRED and Sprouty proteins act in a similar Ras and Raf isoform-specific manner.

Nuclear repartitioning of galectin-1 by an extracellular glycan switch regulates mammary morphogenesis

Branching morphogenesis in the mammary gland is achieved by the migration of epithelial cells through a microenvironment consisting of stromal cells and extracellular matrix (ECM). Here we show that galectin-1 (Gal-1), an endogenous lectin that recognizes glycans bearing N-acetyllactosamine (LacNAc) epitopes, induces branching migration of mammary epithelia in vivo, ex vivo, and in 3D organotypic cultures. Surprisingly, Gal-1's effects on mammary patterning were independent of its glycan-binding ability and instead required localization within the nuclei of mammary epithelia. Nuclear translocation of Gal-1, in turn, was regulated by discrete cell-surface glycans restricted to the front of the mammary end buds. Specifically, α2,6-sialylation of terminal LacNAc residues in the end buds masked Gal-1 ligands, thereby liberating the protein for nuclear translocation. Within mammary epithelia, Gal-1 localized within nuclear Gemini bodies and drove epithelial invasiveness. Conversely, unsialylated LacNAc glycans, enriched in the epithelial ducts, sequestered Gal-1 in the extracellular environment, ultimately attenuating invasive potential. We also found that malignant breast cells possess higher levels of nuclear Gal-1 and α2,6-SA and lower levels of LacNAc than nonmalignant cells in culture and in vivo and that nuclear localization of Gal-1 promotes a transformed phenotype. Our findings suggest that differential glycosylation at the level of tissue microanatomy regulates the nuclear function of Gal-1 in the context of mammary gland morphogenesis and in cancer progression.

Regulation of eosinophilia and allergic airway inflammation by the glycan-binding protein galectin-1

Galectin-1 (Gal-1), a glycan-binding protein with broad antiinflammatory activities, functions as a proresolving mediator in autoimmune and chronic inflammatory disorders. However, its role in allergic airway inflammation has not yet been elucidated. We evaluated the effects of Gal-1 on eosinophil function and its role in a mouse model of allergic asthma. Allergen exposure resulted in airway recruitment of Gal-1-expressing inflammatory cells, including eosinophils, as well as increased Gal-1 in extracellular spaces in the lungs. In vitro, extracellular Gal-1 exerted divergent effects on eosinophils that were N-glycan- and dose-dependent. At concentrations ≤0.25 µM, Gal-1 increased eosinophil adhesion to vascular cell adhesion molecule-1, caused redistribution of integrin CD49d to the periphery and cell clustering, but inhibited ERK(1/2) activation and eotaxin-1-induced migration. Exposure to concentrations ≥1 µM resulted in ERK(1/2)-dependent apoptosis and disruption of the F-actin cytoskeleton. At lower concentrations, Gal-1 did not alter expression of adhesion molecules (CD49d, CD18, CD11a, CD11b, L-selectin) or of the chemokine receptor CCR3, but decreased CD49d and CCR3 was observed in eosinophils treated with higher concentrations of this lectin. In vivo, allergen-challenged Gal-1-deficient mice exhibited increased recruitment of eosinophils and CD3(+) T lymphocytes in the airways as well as elevated peripheral blood and bone marrow eosinophils relative to corresponding WT mice. Further, these mice had an increased propensity to develop airway hyperresponsiveness and displayed significantly elevated levels of TNF-α in lung tissue. This study suggests that Gal-1 can limit eosinophil recruitment to allergic airways and suppresses airway inflammation by inhibiting cell migration and promoting eosinophil apoptosis.

ASPP2 Is a Novel Pan-Ras Nanocluster Scaffold.

Ras-induced senescence mediated through ASPP2 represents a barrier to tumour formation. It is initiated by ASPP2’s interaction with Ras at the plasma membrane, which stimulates the Raf/MEK/ERK signaling cascade. Ras to Raf signalling requires Ras to be organized in nanoscale signalling complexes, called nanocluster. We therefore wanted to investigate whether ASPP2 affects Ras nanoclustering. Here we show that ASPP2 increases the nanoscale clustering of all oncogenic Ras isoforms, H-ras, K-ras and N-ras. Structure-function analysis with ASPP2 truncation mutants suggests that the nanocluster scaffolding activity of ASPP2 converges on its α-helical domain. While ASPP2 increased effector recruitment and stimulated ERK and AKT phosphorylation, it did not increase colony formation of RasG12V transformed NIH/3T3 cells. By contrast, ASPP2 was able to suppress the transformation enhancing ability of the nanocluster scaffold Gal-1, by competing with the specific effect of Gal-1 on H-rasG12V- and K-rasG12V-nanoclustering, thus imposing ASPP2’s ERK and AKT signalling signature. Similarly, ASPP2 robustly induced senescence and strongly abrogated mammosphere formation irrespective of whether it was expressed alone or together with Gal-1, which by itself showed the opposite effect in Ras wt or H-ras mutant breast cancer cells. Our results suggest that Gal-1 and ASPP2 functionally compete in nanocluster for active Ras on the plasma membrane. ASPP2 dominates the biological outcome, thus switching from a Gal-1 supported growth-promoting setting to a senescence inducing and stemness suppressive program in cancer cells. Our results support Ras nanocluster as major integrators of tumour fate decision events.

Immune response modulation by Galectin-1 in a transgenic model of neuroblastoma

ABSTRACTGalectin-1 (Gal-1) has been described to promote tumor growth by inducing angiogenesis and to contribute to tumor immune escape by promoting apoptosis of activated T cells. We had previously identified upregulation of Gal-1 in preclinical models of aggressive neuroblastoma (NB), a solid tumor of childhood. However, the clinical and biological relevance of Gal-1 in this tumor entity is unclear. Here, the effect of Gal-1 on the immune system and tumorigenesis was assessed using modulation of Gal-1 expression in immune effector cells and in a transgenic NB model, designated TH-MYCN. The fraction of CD4+ T cells was decreased in tumor-bearing TH-MYCN mice compared to tumor-free littermates, while both CD4+ T cells as well as CD8+ T cells were less activated, compatible with a reduced immune response in tumor-bearing mice. Tumor incidence was not significantly altered by decreasing Gal-1/LGALS1 gene dosage in TH-MYCN mice, but TH-MYCN/Gal-1−/− double transgenic mice displayed impaired tumor angiogenesis, splenomegaly, and impaired T cell tumor-infiltration with no differences in T cell activation and apoptosis rate. Additionally, a lower migratory capacity of Gal-1 deficient CD4+ T cells toward tumor cells was observed in vitro. Transplantation of TH-MYCN-derived tumor cells into syngeneic mice resulted in significantly reduced tumor growth and elevated immune cell infiltration when Gal-1 was downregulated by shRNA. We therefore conclude that T cell-derived Gal-1 mediates T cell tumor-infiltration, whereas NB-derived Gal-1 promotes tumor growth. This opposing effect of Gal-1 in NB should be considered in therapeutic targeting strategies, as currently being developed for other tumor entities.

Galectin-3 inhibition prevents adipose tissue remodelling in obesity.

Extracellular matrix remodelling of the adipose tissue has a pivotal role in the pathophysiology of obesity. Galectin-3 (Gal-3) is increased in obesity and mediates inflammation and fibrosis in the cardiovascular system. However, the effects of Gal-3 on adipose tissue remodelling associated with obesity remain unclear. Male Wistar rats were fed either a high-fat diet (33.5% fat) or a standard diet (3.5% fat) for 6 weeks. Half of the animals of each group were treated with the pharmacological inhibitor of Gal-3, modified citrus pectin (MCP; 100 mg kg(-1) per day) in the drinking water. In adipose tissue, obese animals presented an increase in Gal-3 levels that were accompanied by an increase in pericellular collagen. Obese rats exhibited higher adipose tissue inflammation, as well as enhanced differentiation degree of the adipocytes. Treatment with MCP prevented all the above effects. In mature 3T3-L1 adipocytes, Gal-3 (10(-8 )m) treatment increased fibrosis, inflammatory and differentiation markers. In conclusion, Gal-3 emerges as a potential therapeutic target in adipose tissue remodelling associated with obesity and could have an important role in the development of metabolic alterations associated with obesity.

Elevated interictal serum galectin-3 levels in intractable epilepsy.

Intractable epilepsy is defined as the occurrence of seizures that cannot be controlled with medical treatment. The discovery of epilepsy biomarkers is increasingly attracting more attention from both clinical physicians as well as neuroscientists. Increased levels of soluble and/or cellular galectin-3 (Gal-3) have been associated with various diseases. However, the effects of Gal-3 in epilepsy are still unknown. In this study, we evaluated the association of higher interictal serum Gal-3 protein levels in patients diagnosed with intractable epilepsy. A group of 38 patients with intractable epilepsy and 26 healthy age-matched control subjects were included in this study. A commercially available electrochemiluminescence immunoassay (ECLIA) kit was used to determine serum Gal-3 protein levels. Our results indicated that serum Gal-3 protein level in the patient group was 6.67 ± 0.34 ng/ml, and in the age-matched control group was 5.40 ± 0.34 ng/ml. The difference between the two groups was found to be statistically significant (P = 0.003). This study found a detectable elevation in serum Gal-3 concentration in patients with focal epilepsy. Given its secretory nature and detectable levels in the serum, Gal-3 could be a potential biomarker for intractable epilepsy.

Prognostic value of the interaction between galectin-3 and antigen carbohydrate 125 in acute heart failure.

AimsGalectin-3 (Gal-3) and carbohydrate antigen 125 (CA125) have emerged as robust prognostic biomarkers in heart failure. Experimental data have also suggested a potential molecular interaction between CA125 and Gal-3; however, the biological and clinical relevance of this interaction is still uncertain. We sought to evaluate, in patients admitted for acute heart failure, the association between plasma Gal-3 with all-cause mortality and the risk for rehospitalizations among high and low levels of CA125.Methods and ResultsWe included 264 consecutive patients admitted for acute heart failure to the Cardiology Department in a third-level center. Both biomarkers were measured on admission. Negative binomial and Cox regression models were used to evaluate the prognostic effect of the interaction between Gal-3 and CA125 (dichotomized by its median) with hospital readmission and all-cause mortality, respectively. During a median follow-up of 2 years (IQR = 1-2.8), 108 (40.9%) patients deaths and 365 rehospitalizations in 171 (69.5%) patients were registered. In a multivariable setting, the effect of Gal-3 on mortality and rehospitalization was differentially mediated by CA125 (p = 0.007 and p<0.001, respectively). Indeed, in patients with CA125 above median (>67 U/ml), values across the continuum of Gal-3 showed a positive and almost linear relationship with either the risk of death or rehospitalization. Conversely, when CA125 was below median (≤67 U/ml), Gal-3 lacked any prognostic effect on both endpoints.ConclusionIn patients with acute heart failure, Gal-3 was strongly associated with higher risk of long-term mortality and repeated rehospitalizations, but only in those patients exhibiting higher values of CA125 (above 67 U/ml).

Galectin-3 predicts long-term cardiovascular death in high-risk patients with coronary artery disease.

Galectin-3 (Gal-3) can affect atherogenesis by multiple mechanisms, but it remains scarcely known whether plasma Gal-3 levels predict cardiovascular events in patients with coronary artery disease. Therefore, we investigated if Gal-3 predicts cardiovascular death in patients with coronary artery disease of the Genetic and ENvironmental factors In Coronary Artery disease study. In a prospective cohort study, we measured the plasma levels of Gal-3 in 1013 randomly selected patients who underwent coronary angiography and long-term follow-up to assess incident cardiovascular events. The primary end points were (1) cardiovascular death and (2) a composite of cardiovascular death, acute coronary syndrome, and stroke. Secondary end points entailed (1) acute myocardial infarction, (2) stroke, and (3) a composite fatal ischemic event including fatal myocardial infarction and stroke. The effect of Gal-3 on prognosis was assessed using Kaplan-Meier analysis and multivariate Cox's regression. During long-term follow-up (median, 7.2 years), 115 cardiovascular deaths occurred (15.2%), more commonly in the high Gal-3 tertile (25.2%) than in the intermediate and the low tertiles (13.6% versus 7.5%, respectively; P<0.001). The adverse prognostic effect of high Gal-3 was confirmed in subgroup analysis of the patients with angiographically documented coronary artery disease and also of those with a normal left ventricular ejection fraction. At multivariate analysis, Gal-3 was a predictor of cardiovascular mortality (hazard ratio, 1.79; 95% confidence interval, 1.10-2.93; P=0.020) along with age, left ventricular ejection fraction, and coronary atherosclerotic burden. In high cardiovascular risk patients referred for coronary angiography Gal-3 is a strong independent predictor of cardiovascular death.

Galectin-1 induces vascular permeability through the neuropilin-1/vascular endothelial growth factor receptor-1 complex

Galectin-1 (Gal-1) is a β-galactoside-binding lectin that regulates endothelial cell migration, proliferation, and adhesion. However, the effect of Gal-1 on vascular permeability and the underlying mechanisms are unclear. We found that high Gal-1 expression was associated with elevated tumor vascular permeability in specimens of oral squamous cell carcinoma. Using transendothelial passage of FITC-dextran and a Miles assay, we demonstrated that Gal-1 increased vascular permeability extracellularly through its carbohydrate recognition domain. Mechanism dissection revealed that the neuropilin (NRP)-1/vascular endothelial growth factor receptor- (VEGFR)-1 complex was required for Gal-1-regulated vascular permeability. Activation of VEGFR-1 triggered activation of Akt which led to a reduction in vascular endothelial-cadherin at cell-cell junctions and resulted in cytoskeletal rearrangement. Both inhibition of Gal-1 secreted from cancer cells and administration of an anti-Gal-1 antibody in the tumor microenvironment suppressed tumor growth and vascular permeability in xenograft models. In conclusion, our results demonstrate a novel function of Gal-1 of increasing vascular permeability through the NRP-1/VEGFR1 and Akt signaling pathway and indicate that targeting Gal-1 by an anti-Gal-1 antibody is a feasible therapy for vascular hyperpermeability and cancer.

Elevated Galectin-3 Levels in the Serum of Patients With Alzheimer's Disease.

Alzheimer's disease (AD) is a neurodegenerative disorder of the central nervous system. Galectin-3 (Gal-3) is characterized by a conserved sequence within the carbohydrate recognition domain. The effect of Gal-3 in AD is presently unknown. In this study, we found significantly increased Gal-3 serum levels in patients with AD compared to control participants (P=.017). There was no significant difference between patients with mild cognitive impairment (MCI) and healthy controls (P=.143) or between patients with AD and MCI (P=.688). The degree of cognitive impairment, as measured by the Mini-Mental Status Examination score, was found to have a significant correlation with the Gal-3 serum levels in all patients and healthy controls. These data suggest that Gal-3 potentially plays a role in the neuropathogenesis of AD. The Gal-3 found in serum could be a potential candidate for a biomarker panel for AD diagnosis.

Galectin-3 regulates p21 stability in human prostate cancer cells

Galectin-3 (Gal-3) is a multifunctional protein involved in cancer through regulation of cell adhesion, cell growth, apoptosis, and metastasis, while p21 (Cip1/WAF1) is a negative regulator of the cell cycle, involved in apoptosis, transcription, DNA repair and metastasis. The results presented here demonstrate for the first time that the level of Gal-3 protein is associated with the level of p21 protein expression in human prostate cancer cells and the effects of Gal-3 on cell growth and apoptosis were reversed by modulating p21 expression level. Furthermore, Gal-3 regulates p21 expression at the post-translational level by stabilizing p21 protein via the carbohydrate-recognition domain (CRD). This is the first report suggesting a molecular function not yet described for Gal-3 as the regulator of p21 protein stability. This study provides a unique insight into the relationship of these two molecules during prostate cancer progression, and may provide a novel therapeutic target.

Knockdown of Shwachman-Diamond Syndrome Gene, SBDS, Induces Increased Expression of Galectin-1 and Impaired Cell Growth.

AbstractAbstract 2360Shwachman-Diamond syndrome (SDS) is an autosomal-recessive disorder characterized by exocrine pancreatic insufficiency and bone marrow failure. The SDS disease locus was mapped to chromosome 7q11. We have previously reported the Shwachman-Bodian-Diamond syndrome (SBDS) gene is not required for neutrophil maturation. However, SBDS knockdown cells which established by SBDS shRNAi were sensitive to apoptotic stimuli, and led to growth inhibition, indicating that SBDS acts to maintain survival of granulocyte precursor cells (Exp Hematol 35;579,2007). The precise mechanism by which the loss of SBDS inhibits growth of cells remains elusive. In order to clarify the impaired cell growth of SBDS knockdown cells, we analyzed two SDS patients (c.183_184TA>CT and c.258+2T>C) derived EB virus transformed lymphoblast cells (LCL). The growth of both LCL-SDS cell lines was considerably lower than control donor cells (LCL-C) which occurred in within 3 days of culture (1.4×106 cells/ml in LCL-C vs 5×105 cells/lm in LCL-SDS). LCL-C cells divided until 5 days, however, growth of LCL-SDS cells was saturated in 3days. When LCL-SDS cells were seeded to the fresh medium, LCL-SDS cells proliferated again. Conditional medium from 5 days SDS-LCL cell culture was then added to the culture of both LCL-C and LCL-SDS cell. This LCL-SDS conditional medium inhibited both LCL-C and LCL-SDS cell growth (50% and 60%, respectively), suggesting that growth inhibitors were secreted from LCL-SDS cells. In order to find growth inhibitors, we performed differential display. By annealing control primer based GeneFishing PCR screening, we found galectin-1 mRNA level was increased in LCL-SDS cells. We also confirmed that Galectin-1(Gal1) protein expression was markedly increased in LCL-SDS cells by western blot and conforcal microscopy. Gal1 was found to membrane bound, and it is plausible that Gal1 was secreted to the medium. In order to isolate Gal1 protein from medium, medium was passed through lactose agarose. Gal1 protein was purified from LCL-SDS cell culture medium, not from LCL-C cells. The inhibitory effect of Gal1 was confirmed using recombinant human Galectin-1 (rhGal1), which had similar dynamics to that of conditional medium from LCL-SDS cells. rhGal1 the proliferation of both LCL-C and LCL-SDS cells in a dose dependent manner. After exposure to rhGal1, Annexin V positive cells were increased in LCL-C cells (13.78±2.09% in control vs 16.83±2.81% in rhGal1, p=0.02). However, there was no difference in Gal1 induced apoptosis between LCL-C and LCL-SDS cells. In order to rescue growth failure of LCL-SDS cells, lactose, which modulates the binding between galectin and its substrate, was supplemented to the medium. Though lactose showed the growth inhibition of LCL cells, the viability of LCL-SDS cells was much higher than LCL-C cells. LCL-SDS cells were easily aggregated, however, the colony of LCL-SDS cell was much smaller in the presence of lactose. We also confirmed that Gal1 protein was overexpressed in SBDS knockdown 32Dcl3 cells, which were established by SBDS shRNAi. Conclusion:Overexpressed Gal1 was found from SDS patient's derived LCL cells and SBDS shRNAi knockdown 32Dcl3 cells. Gal1 was also found in the conditional medium of LCL-SBDS cells, and secreted Gal1 inhibited the cell proliferation. These results indicated that Galectin-1 partially involved in growth failure of SBDS deficient cells. Disclosures:No relevant conflicts of interest to declare.