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1.
Mol Cancer ; 23(1): 216, 2024 Sep 30.
Article in English | MEDLINE | ID: mdl-39350165

ABSTRACT

Recent advances in cancer research have highlighted the pivotal role of tertiary lymphoid structures (TLSs) in modulating immune responses, particularly in breast cancer (BRCA). Here, we performed an integrated analysis of bulk transcriptome data from over 6000 BRCA samples using biological network-based computational strategies and machine learning (ML) methods, and identified LGALS2 as a key marker within TLSs. Single-cell sequencing and spatial transcriptomics uncover the role of LGALS2 in TLS-associated dendritic cells (DCs) stimulation and reveal the complexity of the tumor microenvironment (TME) at both the macro and micro levels. Elevated LGALS2 expression correlates with prolonged survival, which is associated with a robust immune response marked by diverse immune cell infiltration and active anti-tumor pathways leading to a 'hot' tumor microenvironment. The colocalization of LGALS2 with TLS-associated DCs and its role in immune activation in BRCA were confirmed by hematoxylin-eosin (HE), immunohistochemistry (IHC), and in vivo validation analyses. The identification of LGALS2 as a key factor in BRCA not only highlights its therapeutic potential in novel TLS-directed immunotherapy but also opens new avenues in patient stratification and treatment selection, ultimately improving clinical management.


Subject(s)
Breast Neoplasms , Dendritic Cells , Galectin 2 , Immunotherapy , Tertiary Lymphoid Structures , Tumor Microenvironment , Humans , Dendritic Cells/immunology , Dendritic Cells/metabolism , Breast Neoplasms/immunology , Breast Neoplasms/pathology , Breast Neoplasms/therapy , Breast Neoplasms/metabolism , Breast Neoplasms/genetics , Female , Tumor Microenvironment/immunology , Immunotherapy/methods , Tertiary Lymphoid Structures/immunology , Tertiary Lymphoid Structures/pathology , Galectin 2/genetics , Galectin 2/metabolism , Animals , Biomarkers, Tumor , Gene Expression Regulation, Neoplastic , Mice , Single-Cell Analysis , Prognosis
2.
Int J Mol Sci ; 25(16)2024 Aug 10.
Article in English | MEDLINE | ID: mdl-39201412

ABSTRACT

Galectins are ß-galactoside-binding animal lectins involved in various biological functions, such as host defense. Galectin-2 and -3 are members of the galectin family that are expressed in the stomach, including the gastric mucosa and surface mucous cells. Galectin-3 exhibits aggregation and bactericidal activity against Helicobacter pylori in a ß-galactoside-dependent manner. We previously reported that galectin-2 has the same activity under neutral pH conditions. In this study, the H. pylori aggregation activity of galectin-2 was examined under weakly acidic conditions, in which H. pylori survived. Galectin-2 agglutinated H. pylori even at pH 6.0, but not at pH 5.0, correlating with its structural stability, as determined using circular dichroism. Additionally, galectin-2 binding to the lipopolysaccharide (LPS) of H. pylori cultured under weakly acidic conditions was investigated using affinity chromatography and Western blotting. Galectin-2 could bind to H. pylori LPS containing H type I, a Lewis antigen, in a ß-galactoside-dependent manner. In contrast, galectin-3 was structurally more stable than galectin-2 under acidic conditions and bound to H. pylori LPS containing H type I and Lewis X. In conclusion, galectin-2 and -3 might function cooperatively in the defense against H. pylori in the stomach under different pH conditions.


Subject(s)
Galectin 2 , Helicobacter pylori , Lipopolysaccharides , Helicobacter pylori/metabolism , Lipopolysaccharides/metabolism , Lipopolysaccharides/chemistry , Hydrogen-Ion Concentration , Galectin 2/metabolism , Galectin 2/chemistry , Humans , Galectin 3/metabolism , Galectin 3/chemistry , Protein Binding , Agglutination , Galectins/metabolism , Galectins/chemistry
3.
Biol Pharm Bull ; 46(12): 1676-1682, 2023.
Article in English | MEDLINE | ID: mdl-38044091

ABSTRACT

Galectin-2 (Gal-2) is an animal lectin with specificity for ß-galactosides. It is predominantly expressed and suggested to play a protective function in the gastrointestinal tract; therefore, it can be used as a protein drug. Recombinant proteins have been expressed using Escherichia coli and used to study the function of Gal-2. The recombinant human Gal-2 (hGal-2) protein purified via affinity chromatography after being expressed in E. coli was not completely homogeneous. Mass spectrometry confirmed that some recombinant Gal-2 were phosphogluconoylated. In contrast, the recombinant mouse Gal-2 (mGal-2) protein purified using affinity chromatography after being expressed in E. coli contained a different form of Gal-2 with a larger molecular weight. This was due to mistranslating the original mGal-2 stop codon TGA to tryptophan (TGG). In this report, to obtain a homogeneous Gal-2 protein for further studies, we attempted the following methods: for hGal-2, 1) replacement of the lysine (Lys) residues, which was easily phosphogluconoylated with arginine (Arg) residues, and 2) addition of histidine (His)-tag on the N-terminus of the recombinant protein and cleavage with protease after expression; for mGal-2, 3) changing the stop codon from TGA to TAA, which is commonly used in E. coli. We obtained an almost homogeneous recombinant Gal-2 protein (human and mouse). These results have important implications for using Gal-2 as a protein drug.


Subject(s)
Escherichia coli , Galectin 2 , Mice , Animals , Humans , Galectin 2/chemistry , Escherichia coli/genetics , Escherichia coli/metabolism , Codon, Terminator/metabolism , Recombinant Proteins/metabolism , Protein Processing, Post-Translational
4.
Int J Mol Sci ; 23(23)2022 Nov 30.
Article in English | MEDLINE | ID: mdl-36499335

ABSTRACT

Acute myocardial infarction occurs when blood supply to a particular coronary artery is cut off, causing ischemia or hypoxia and subsequent heart muscle destruction in the vascularized area. With a mortality rate of 17% per year, myocardial infarction (MI) is still one of the top causes of death globally. Numerous studies have been done to identify the genetic risk factors for myocardial infarction, as a positive family history of heart disease is one of the most potent cardiovascular risk factors. The goal of this review is to compile all the information currently accessible in the literature on the genes associated with AMI. We performed a big data analysis of genes associated with acute myocardial infarction, using the following keywords: "myocardial infarction", "genes", "involvement", "association", and "risk". The analysis was done using PubMed, Scopus, and Web of Science. Data from the title, abstract, and keywords were exported as text files and imported into an Excel spreadsheet. Its analysis was carried out using the VOSviewer v. 1.6.18 software. Our analysis found 28 genes which are mostly likely associated with an increased risk for AMI, including: PAI-1, CX37, IL18, and others. Also, a correlation was made between the results obtained in the big data analysis and the results of the review. The most important genes increasing the risk for AMI are lymphotoxin-a gene (LTA), LGALS2, LDLR, and APOA5. A deeper understanding of the underlying functional genomic circuits may present new opportunities for research in the future.


Subject(s)
Myocardial Infarction , Humans , Lymphotoxin-alpha , Galectin 2/genetics , Data Analysis , Risk Factors
5.
Int J Mol Sci ; 24(1)2022 Dec 25.
Article in English | MEDLINE | ID: mdl-36613785

ABSTRACT

Galectin-2 is a prototype member of the galactoside-binding galectin family. It is predominately expressed in the gastrointestinal tract but is also detected in several other tissues such as the placenta and in the cardiovascular system. Galectin-2 expression and secretion by epithelial cells has been reported to contribute to the strength of the mucus layer, protect the integrity of epithelia. A number of studies have also suggested the involvement of galectin-2 in tissue inflammation, immune response and cell apoptosis. Alteration of galectin-2 expression occurs in inflammatory bowel disease, coronary artery diseases, rheumatoid arthritis, cancer, and pregnancy disorders and has been shown to be involved in disease pathogenesis. This review discusses our current understanding of the role and actions of galectin-2 in regulation of these pathophysiological conditions.


Subject(s)
Arthritis, Rheumatoid , Neoplasms , Pregnancy , Female , Humans , Galectin 2/genetics , Galectins , Neoplasms/metabolism , Placenta/metabolism
6.
Int J Mol Sci ; 23(3)2022 Feb 07.
Article in English | MEDLINE | ID: mdl-35163802

ABSTRACT

There are several open questions to be answered regarding the pathophysiology of the development of preeclampsia (PE). Numerous factors are involved in its genesis, such as defective placentation, vascular impairment, and an altered immune response. The activation of the adaptive and innate immune system represents an immunologic, particularity during PE. Proinflammatory cytokines are predominantly produced, whereas immune regulatory and immune suppressive factors are diminished in PE. In the present study, we focused on the recruitment of regulatory T cells (Tregs) which are key players in processes mediating immune tolerance. To identify Tregs in the decidua, an immunohistochemical staining of FoxP3 of 32 PE and 34 control placentas was performed. A clearly reduced number of FoxP3-positive cells in the decidua of preeclamptic women could be shown in our analysis (p = 0.036). Furthermore, CCL22, a well-known Treg chemoattractant, was immunohistochemically evaluated. Interestingly, CCL22 expression was increased at the maternal-fetal interface in PE-affected pregnancies (psyncytiotrophoblast = 0.035, pdecidua = 0.004). Therefore, the hypothesis that Tregs undergo apoptosis at the materno-fetal interface during PE was generated, and verified by FoxP3/TUNEL (TdT-mediated dUTP-biotin nick end labeling) staining. Galectin-2 (Gal-2), a member of the family of carbohydrate-binding proteins, which is known to be downregulated during PE, seems to play a pivotal role in T cell apoptosis. By performing a cell culture experiment with isolated Tregs, we could identify Gal-2 as a factor that seems to prevent the apoptosis of Tregs. Our findings point to a cascade of apoptosis of Tregs at the materno-fetal interface during PE. Gal-2 might be a potential therapeutic target in PE to regulate immune tolerance.


Subject(s)
Decidua/immunology , Down-Regulation , Galectin 2/metabolism , Pre-Eclampsia/metabolism , T-Lymphocytes, Regulatory/cytology , Adolescent , Adult , Apoptosis , Case-Control Studies , Cells, Cultured , Chemokine CCL22/metabolism , Female , Forkhead Transcription Factors/metabolism , Humans , Maternal Age , Pregnancy , T-Lymphocytes, Regulatory/metabolism , Up-Regulation , Young Adult
7.
Mamm Genome ; 32(3): 153-172, 2021 06.
Article in English | MEDLINE | ID: mdl-33880624

ABSTRACT

Type 2 diabetes (T2D) has a strong genetic component. Most of the gene variants driving the pathogenesis of T2D seem to target pancreatic ß-cell function. To identify novel gene variants acting at early stage of the disease, we analyzed whole transcriptome data to identify differential expression (DE) and alternative exon splicing (AS) transcripts in pancreatic islets collected from two metabolically diverse mouse strains at 6 weeks of age after three weeks of high-fat-diet intervention. Our analysis revealed 1218 DE and 436 AS genes in islets from NZO/Hl vs C3HeB/FeJ. Whereas some of the revealed genes present well-established markers for ß-cell failure, such as Cd36 or Aldh1a3, we identified numerous DE/AS genes that have not been described in context with ß-cell function before. The gene Lgals2, previously associated with human T2D development, was DE as well as AS and localizes in a quantitative trait locus (QTL) for blood glucose on Chr.15 that we reported recently in our N2(NZOxC3H) population. In addition, pathway enrichment analysis of DE and AS genes showed an overlap of only half of the revealed pathways, indicating that DE and AS in large parts influence different pathways in T2D development. PPARG and adipogenesis pathways, two well-established metabolic pathways, were overrepresented for both DE and AS genes, probably as an adaptive mechanism to cope for increased cellular stress. Our results provide guidance for the identification of novel T2D candidate genes and demonstrate the presence of numerous AS transcripts possibly involved in islet function and maintenance of glucose homeostasis.


Subject(s)
Diabetes Mellitus, Type 2/genetics , Galectin 2/genetics , Insulin/genetics , PPAR gamma/genetics , Adipogenesis/genetics , Alternative Splicing/genetics , Animals , Blood Glucose/genetics , CD36 Antigens/genetics , Diabetes Mellitus, Type 2/pathology , Exons/genetics , Gene Expression Regulation/genetics , Humans , Insulin-Secreting Cells/metabolism , Insulin-Secreting Cells/pathology , Islets of Langerhans/growth & development , Islets of Langerhans/pathology , Metabolic Networks and Pathways/genetics , Mice , Quantitative Trait Loci/genetics , Retinal Dehydrogenase/genetics , Transcriptome/genetics
8.
Cell Immunol ; 368: 104419, 2021 10.
Article in English | MEDLINE | ID: mdl-34371260

ABSTRACT

Rheumatoid arthritis (RA) is a complicated rheumatic autoimmune disease. Lectin, galactoside-binding soluble, 2 (LGALS2), LGALS3 and LGALS9, three members of the galectin family, play potential roles in autoimmune diseases, including RA. However, association of genetic polymorphisms of LGALS2, LGALS3 and LGALS9 with RA risk in a Southern Chinese Han population has not been elucidated. A case-control study was conducted herein, including 500 RA patients and 650 healthy individuals of Southern Chinese Han origin. Twelve single nucleotide polymorphisms (SNPs), including rs7291467 for the LGALS2 gene, rs4644, rs4652, rs1009977, rs2274273 and rs17128183 for the LGALS3 gene, and rs4795835, rs3763959, rs4239242, rs3751093, rs732222 and rs4794976 for the LGALS9 gene, were genotyped. Polymorphisms were genotyped using the KASP method. Frequencies of rs1009977 genotype TG and rs3751093 genotype GA of LGALS3 gene were significantly different between RA patients and healthy controls (P = 0.049, P = 0.033). Allele T and genotypes TT and TT + TG of rs4794976 for LGALS9 gene were significantly correlated with RA risk (P = 0.017, P = 0.012, P = 0.041). Subgroup analysis revealed that rs1009977, rs2274273 and rs17128183 polymorphisms of LGALS3 gene and rs4795835 polymorphism of LGALS9 gene were correlated with several RA clinical manifestations (all P < 0.05). In addition, haplotype GCGTT showed an increased risk for RA (OR = 1.216, 95% CI: 1.028-1.438, P = 0.023), whereas haplotype GCGTG showed a reduced risk for RA susceptibility (OR = 0.779, 95% CI: 0.625-0.971, P = 0.026). In conclusion, LGALS3 and LGALS9 gene polymorphisms may associate with RA predisposition in a Southern Chinese Han population.


Subject(s)
Arthritis, Rheumatoid/genetics , Galectin 2/genetics , Galectin 3/genetics , Galectins/genetics , Genotype , Adult , Aged , China , Female , Gene Frequency , Genetic Association Studies , Genetic Predisposition to Disease , Humans , Male , Middle Aged , Polymorphism, Single Nucleotide , Risk
9.
Fish Shellfish Immunol ; 106: 473-479, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32805415

ABSTRACT

Our previous study has recorded that the recombinant protein of Nile tilapia (Oreochromis niloticus) galectin-2 (rOnGal-2) can enhance immune response against Streptococcus agalactiae (S.agalactiae) infection in vitro. In this study, we further explored the effects of OnGal-2 in immune response against bacterial infection in vivo. The administration of rOnGal-2 could improve serum antibacterial activity (ALKP, ACP, and LZM) and antioxidant capacity (CAT, POD, and SOD). After S. agalactiae infection, rOnGal-2 injection could reduce bacterial burden and decrease tissue damage in head kidney, spleen, and liver of tilapia. Also, rOnGal-2 regulated the inflammatory-related genes expression including IL-6, IL-8 and IL-10 during bacterial infection. Furthermore, rOnGal-2 administration could increase the relative percentage survival of tilapia infected with S.agalactiae. Taken together, our results indicate that OnGal-2 can protect fish from bacterial infection through reducing bacterial burden, impairing tissue damage and modulating anti-bacterial immune response, which also can be applied as a potential vaccine adjuvant in O.niloticus culture.


Subject(s)
Cichlids/immunology , Fish Diseases/immunology , Fish Proteins/immunology , Galectin 2/immunology , Gene Expression Regulation/immunology , Immunity, Innate/genetics , Animals , Cichlids/genetics , Fish Proteins/genetics , Galectin 2/genetics , Gene Expression Profiling/veterinary , Male , Streptococcal Infections/immunology , Streptococcal Infections/veterinary , Streptococcus agalactiae/physiology
10.
Biol Pharm Bull ; 43(2): 356-360, 2020.
Article in English | MEDLINE | ID: mdl-32009121

ABSTRACT

Galectins are a group of animal lectins characterized by their specificity for ß-galactosides. Of these, galectin-2 (Gal-2) is predominantly expressed in the gastrointestinal tract. In the current study, we used a mouse gastric mucous fraction to investigate whether Gal-2 is secreted from epithelial cells and identify its potential ligands in gastric mucus. Gal-2 was detected in the mouse gastric mucous fraction and could be eluted from it by the addition of lactose. Affinity chromatography using recombinant mouse galectin-2 (mGal-2)-immobilized adsorbent and subsequent LC-MS/MS identified MUC5AC, one of the major gastric mucin glycoproteins, as a potential ligand of mGal-2. Furthermore, MUC5AC was detected in the mouse gastric mucous fraction by Western blotting, and recombinant mGal-2 was adsorbed to this fraction in a carbohydrate-dependent manner. These results suggested that Gal-2 and MUC5AC in mouse gastric mucus interact in a ß-galactoside-dependent manner, resulting in a stronger barrier structure protecting the mucosal surface.


Subject(s)
Galectin 2/chemistry , Gastrointestinal Tract/chemistry , Mucin 5AC/chemistry , Animals , Humans , Lactose , Mice , Mucus , Stomach
11.
Int J Mol Sci ; 21(7)2020 Mar 31.
Article in English | MEDLINE | ID: mdl-32244351

ABSTRACT

Gestational diabetes mellitus (GDM) is the most common pregnancy-associated metabolic disorder that negatively impacts on the health of both mothers and their offspring in the long-term. The molecular mechanisms involved are not fully understood. As in other states of insulin resistance, a disproportionate immune response in GDM leads to a state of chronic low-grade inflammation. Galectin-2 exerts regulatory effects on different immune cells. This study investigated galectin-2 expression in the placenta of 40 GDM patients and 40 controls, in a sex-specific manner. Immunohistochemistry was used for semi-quantitative analysis of expression strength. The phenotypes of galectin-2 expressing cells were characterized through double immunofluorescence. We found a significant up-regulation of galectin-2 in the fetal syncytiotrophoblast, as well as in the maternal decidua of GDM placentas. Double staining showed a strong galectin-2 expression in extra villous trophoblast cells and fetal endothelial cells in GDM. These findings present the first systematic investigation of galectin-2 in GDM. The findings contribute to the emerging understanding of the role of immunomodulation and inflammation in GDM and of galectin-2 itself. This might also have implications for the long-term cardiovascular health of the offspring.


Subject(s)
Diabetes, Gestational/metabolism , Galectin 2/metabolism , Placenta/metabolism , Placenta/pathology , Adult , Colon/pathology , Endothelial Cells/metabolism , Female , Fetus/metabolism , Galectin 2/genetics , Gene Expression Regulation , Humans , Inflammation , Insulin Resistance , Male , Pregnancy , Pregnancy Complications/metabolism , Trophoblasts/metabolism , Trophoblasts/pathology
12.
Int J Mol Sci ; 21(8)2020 Apr 13.
Article in English | MEDLINE | ID: mdl-32295066

ABSTRACT

Helicobacter pylori is associated with the onset of gastritis, peptic ulcers, and gastric cancer. Galectins are a family of ß-galactoside-binding proteins involved in diverse biological phenomena. Galectin-2 (Gal-2), a member of the galectin family, is predominantly expressed in the gastrointestinal tract. Although some galectin family proteins are involved in immunoreaction, the role of Gal-2 against H. pylori infection remains unclear. In this study, the effects of Gal-2 on H. pylori morphology and survival were examined. Gal-2 induced H. pylori aggregation depending on ß-galactoside and demonstrated a bactericidal effect. Immunohistochemical staining of the gastric tissue indicated that Gal-2 existed in the gastric mucus, as well as mucosa. These results suggested that Gal-2 plays a role in innate immunity against H. pylori infection in gastric mucus.


Subject(s)
Galactosides/pharmacology , Galectin 2/pharmacology , Helicobacter pylori/drug effects , Recombinant Proteins/pharmacology , Animals , Helicobacter Infections , Helicobacter pylori/growth & development , Humans , Male , Mice
13.
Glycobiology ; 29(6): 504-512, 2019 06 01.
Article in English | MEDLINE | ID: mdl-30874734

ABSTRACT

Galactoseß1-4Fucose (GalFuc) is a unique disaccharide found in invertebrates including nematodes. A fungal galectin CGL2 suppresses nematode development by recognizing the galactoseß1-4fucose epitope. The Caenorhabditis elegans galectin LEC-6 recognizes it as an endogenous ligand and the Glu67 residue of LEC-6 is responsible for this interaction. We found that mammalian galectin-2 (Gal-2) also has a comparable glutamate residue, Glu52. In the present study, we investigated the potential nematode-suppressing activity of Gal-2 using C. elegans as a model and focusing on Gal-2 binding to the GalFuc epitope. Gal-2 suppressed C. elegans development whereas its E52D mutant (Glu52 substituted by Asp), galectin-1 and galectin-3 had little effect on C. elegans growth. Lectin-staining using fluorescently-labeled Gal-2 revealed that, like CGL2, it specifically binds to the C. elegans intestine. Natural C. elegans glycoconjugates were specifically bound by immobilized Gal-2. Western blotting with anti-GalFuc antibody showed that the bound glycoconjugates had the GalFuc epitope. Frontal affinity chromatography with pyridylamine-labeled C. elegans N-glycans disclosed that Gal-2 (but not its E52D mutant) recognizes the GalFuc epitope. Gal-2 also binds to the GalFuc-bearing glycoconjugates of Ascaris and the GalFuc epitope is present in the parasitic nematodes Nippostrongylus brasiliensis and Brugia pahangi. These results indicate that Gal-2 suppresses C. elegans development by binding to its GalFuc epitope. The findings also imply that Gal-2 may prevent infestations of various parasitic nematodes bearing the GalFuc epitope.


Subject(s)
Caenorhabditis elegans/growth & development , Disaccharides/chemistry , Epitopes/chemistry , Galectin 2/metabolism , Animals , Ascaris suum/growth & development , Ascaris suum/metabolism , Binding Sites , Biomphalaria , Caenorhabditis elegans/metabolism , Disaccharides/metabolism , Epitopes/metabolism , Galectin 2/chemistry , HeLa Cells , Humans , Mice , Mice, Inbred ICR
14.
Fish Shellfish Immunol ; 87: 737-743, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30779996

ABSTRACT

galectin-2 plays important roles in innate and adaptive immunity. In this study, galectin-2 (OnGal-2) was identified from Nile tilapia (Oreochromis niloticus). Its tissue distribution and expression patterns following bacterial infection were also investigated. OnGal-2 is widely distributed in various tissues of healthy tilapia. After Streptococcus agalactiae challenge, OnGal-2 expressions were significantly up-regulated in all tested tissues. Meanwhile, the recombinant OnGal-2 (rOnGal-2) protein showed strong agglutinating activities against both Gram-negative bacteria and Gram-positive bacteria. Moreover, rOnGal-2 could promote phagocytosis of macrophages. Taken together, the present study indicated that OnGal-2 might play roles in the immune responses of Nile tilapia against bacterial pathogens.


Subject(s)
Cichlids/genetics , Cichlids/immunology , Fish Diseases/immunology , Galectin 2/genetics , Galectin 2/immunology , Gene Expression Regulation/immunology , Immunity, Innate/genetics , Agglutination Tests/veterinary , Animals , Fish Proteins/genetics , Fish Proteins/immunology , Gene Expression Profiling/veterinary , Gram-Negative Bacteria/physiology , Gram-Positive Bacteria/physiology , Recombinant Proteins/genetics , Recombinant Proteins/immunology , Sequence Analysis, DNA/veterinary , Streptococcal Infections/immunology , Streptococcus agalactiae/physiology
15.
Fish Shellfish Immunol ; 78: 238-247, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29678793

ABSTRACT

Galectins are ß-galactoside binding lectins that play crucial roles in innate immunity in vertebrates and invertebrates through their conserved carbohydrate-recognition domains (CRDs). In the present study, single- and four-CRD-containing galectins were identified in oyster Crassostrea gigas (designated CgGal-2 and CgGal-3). The open reading frames (ORFs) of CgGal-2 and CgGal-3 encode polypeptides of 200 and 555 amino acids, respectively. All CRDs of CgGal-3 include two consensus motifs essential for ligand-binding, and a novel motif is present in CgGal-2. Pathogen-associated molecular pattern (PAMP) profiles were determined for recombinant rCgGal-2 and rCgGal-3, and rCgGal-2 displayed low binding affinity for PAMPs, while rCgGal-3 bound various PAMPs including glucan, lipopolysaccharide (LPS), and peptidoglycan (PGN) with relatively high affinity. Furthermore, rCgGal-2 and rCgGal-3 exhibited different microbe binding profiles; rCgGal-2 bound to Gram-negative bacteria (Escherichia coli and Vibrio vulnificus) and fungi (Saccharomyces cerevisiae and Pichia pastoris), while rCgGal-3 bound to these microbes but also to Gram-positive bacteria (Micrococcus luteus). In addition, rCgGal-3 possessed microbial agglutinating activity and coagulation activity against fungi and erythrocytes, respectively, but rCgGal-2 lacked any agglutinating activity. Carbohydrate binding specificity analysis showed that rCgGal-3 specifically bound D-galactose. Furthermore, rCgGal-2 and rCgGal-3 functioned as opsonin participating in the clearance against invaders in C. gigas. Thus, CgGal-2 with one CRD and CgGal-3 with four CRDs are new members of the galectin family involved in immune responses against bacterial infection. Differences in the organisation and amino acid sequences of CRDs may affect their specificity and affinity for nonself substances.


Subject(s)
Crassostrea/genetics , Galectin 2/genetics , Galectin 3/genetics , Gene Expression Regulation/immunology , Immunity, Innate/genetics , Amino Acid Sequence , Animals , Crassostrea/immunology , Fungi/physiology , Galectin 2/chemistry , Galectin 2/immunology , Galectin 3/chemistry , Galectin 3/immunology , Gene Expression Profiling , Gram-Negative Bacteria/physiology , Gram-Positive Bacteria/physiology , Phylogeny , Sequence Alignment
16.
Biol Pharm Bull ; 40(10): 1789-1795, 2017.
Article in English | MEDLINE | ID: mdl-28966253

ABSTRACT

Galectins comprise a group of animal lectins characterized by their specificity for ß-galactosides. Galectin-2 (Gal-2) is predominantly expressed in the gastrointestinal tract and has been identified as one of the main gastric mucosal proteins that are proposed to have a protective role in the stomach. As Gal-2 is known to form homodimers in solution, this may result in crosslinking of macromolecules with the sugar structures recognized by Gal-2. In this study, we report that Gal-2 could interact with mucin, an important component of gastric mucosa, in a ß-galactoside-dependent manner. Furthermore, Gal-2 and mucin could form an insoluble precipitate, potentially through the crosslinking of mucins via Gal-2 and the formation of a lattice, resulting in a large insoluble complex. Therefore, we suggest that Gal-2 plays a role in the gastric mucosa by strengthening the barrier structure through crosslinking the mucins on the mucosal surface.


Subject(s)
Galectin 2/chemistry , Galectin 2/metabolism , Mucins/chemistry , Mucins/metabolism , Animals , Epithelial Cells/metabolism , Galectin 2/genetics , Gastric Mucosa/metabolism , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/metabolism , Lactose/chemistry , Lactose/metabolism , Molecular Weight , Plasmids , Protein Multimerization , Rats , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Swine
17.
J Hum Genet ; 61(1): 71-7, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26134515

ABSTRACT

Coronary artery disease (CAD) including myocardial infarction (MI) is a common disease and among the leading cause of death in the world. The onset of CAD depends on complex interactions of environmental and genetic factors. To clarify the genetic architecture of MI, we started a genome-wide association study (GWAS) using nearly 100 000 gene-based single-nucleotide polymorphisms (SNPs) from 2000, and identified LTA associated with the increased risk of MI in Japanese population. To our knowledge, this is the first study identified a genetic factor for common disease by GWAS in the worldwide. Through examining the LTA cascade by combination of molecular biological and genetic analyses, we have identified additional MI susceptible genes, LGALS2, PSMA6 and BRAP, so far. Nowadays a lot of large-scale GWAS have identified numerous genetic risk factors for common diseases. In CAD, 51 loci with GWAS significance (P<5 × 10(-8)) have collectively identified by recent large-scale GWAS mainly in Caucasian descent. In this review, we discuss recent advances in molecular genetics for CAD.


Subject(s)
Coronary Artery Disease/genetics , Galectin 2/genetics , Genetic Loci , Genetic Predisposition to Disease , Genetic Variation , Genome-Wide Association Study , Humans , Lymphotoxin-alpha/genetics , Myocardial Infarction/genetics , Proteasome Endopeptidase Complex/genetics , Ubiquitin-Protein Ligases/genetics
18.
Arch Biochem Biophys ; 605: 86-94, 2016 09 01.
Article in English | MEDLINE | ID: mdl-26827730

ABSTRACT

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


Subject(s)
Galectin 1/metabolism , Galectin 2/metabolism , Galectin 3/metabolism , Plasma Gases/therapeutic use , Wound Healing , Animals , Cold Temperature , Electrocoagulation , Female , Gene Expression Regulation , Immunohistochemistry , Mice , Mice, Inbred C57BL , Microscopy, Electron, Transmission , Microscopy, Immunoelectron , Signal Transduction , Skin/metabolism , Skin/pathology , Smad Proteins/metabolism
19.
Acta Biochim Biophys Sin (Shanghai) ; 48(10): 939-947, 2016 Oct.
Article in English | MEDLINE | ID: mdl-27563008

ABSTRACT

Galectin-2 (Gal-2) plays a role in cancer, myocardial infarction, immune response, and gastrointestinal tract diseases. The only reported crystal structure of Gal-2 shows that it is a dimer in which the monomer subunits have almost identical structures, each binding with one molecule of lactose. In this study, we crystallized Gal-2 under new conditions that produced three crystal structures. In each Gal-2 dimer structure, lactose was shown to be bound to only one of the carbohydrate recognition domain subunits. In solution studies, the thermal shift assay demonstrated that inequivalent monomer subunits in the Gal-2 dimer become equivalent upon ligand binding. In addition, galectin-mediated erythrocyte agglutination assays using lactose and larger complex polysaccharides as inhibitors showed the structural differences between Gal-1 and Gal-2. Overall, our results reveal some novel aspects to the structural differentiation in Gal-2 and expand the potential for different types of molecular interactions that may be specific to this lectin.


Subject(s)
Galectin 2/chemistry , Lactose/chemistry , Peptides/chemistry , Amino Acids/chemistry , Amino Acids/genetics , Amino Acids/metabolism , Binding Sites/genetics , Crystallography, X-Ray , Galectin 2/genetics , Galectin 2/metabolism , Hemagglutination/drug effects , Hemagglutination Tests , Humans , Lactose/metabolism , Models, Molecular , Peptides/metabolism , Polysaccharides/pharmacology , Protein Binding , Protein Conformation , Protein Domains , Protein Multimerization
20.
Int J Mol Sci ; 17(4): 523, 2016 Apr 07.
Article in English | MEDLINE | ID: mdl-27070577

ABSTRACT

Galectins (gal) are members of the mammalian ß-galactoside-binding proteins and recognize Galß1-4GlcNAc and Galß1-4GalNac (Thomsen-Friedenreich antigen (TF)) sequences of several cell surface oligosaccharides. In this study, gal-1, -2, -3 and -13 were investigated systematically in the trophoblast and decidua compartment of intrauterine growth restriction (IUGR) placentas and normal third trimester control placentas and stratified by fetal gender and gestational age. Within this study, 29 third trimester placentas after delivery were analyzed. Fetal gender was equally divided within both groups, and immunohistochemical staining was analyzed according to fetal gender and gestational age. Double immune-fluorescence with trophoblast-specific markers was used to identify galectin-expressing cells at the feto-maternal interface in the decidua. Gal-3 was significantly downregulated only in the extravillous trophoblast of IUGR placentas. In contrast, expressions of gal-2 and gal-13 were downregulated in both villous and extravillous trophoblast cells of IUGR placentas. In addition, gal-2 and gal-13 showed a highly correlated expression scheme in the placenta. There are significant gender-specific expression patterns for single prototype galectins with downregulation of gal-2 and gal-13 of male gender placentas in cases of IUGR. Gal-3 as the chimera type galectin shows only little gender-specific differences in expression, which disappear in IUGR cases.


Subject(s)
Fetal Growth Retardation/pathology , Galectin 1/analysis , Galectin 2/analysis , Galectin 3/analysis , Galectins/analysis , Placenta/pathology , Pregnancy Proteins/analysis , Decidua/metabolism , Decidua/pathology , Down-Regulation , Female , Fetal Growth Retardation/genetics , Fluorescent Antibody Technique , Galectin 2/genetics , Humans , Male , Placenta/metabolism , Pregnancy , RNA, Messenger/genetics , Trophoblasts/metabolism , Trophoblasts/pathology
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