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European Journal of Histochemistry : EJH Sep 2019In mammals, the alveolarization process develops predominantly after birth. Airway cells display a complex assemblage of glycans on their surface. These glycans,...
In mammals, the alveolarization process develops predominantly after birth. Airway cells display a complex assemblage of glycans on their surface. These glycans, particularly terminal glycan extensions, are important effective carriers of information that change during the differentiation process. Nevertheless, few systematic data are reported about the cell surface sugar residue content during post-natal lung development. In the present work, we aimed to identify and semi-quantify N-acetylgalactosamine (GalNAc)/galactose (Gal) residues on the bronchioloalveolar cell surface in rat lung sections from 1-, 4-, 8- day old and adult animals and link these data with the lung glycocalyx composition. Horseradish peroxidase-conjugated lectin from Glycine max (soybean agglutinin, SBA) was used, and light microscopy methodologies were performed. SBA labelling intensity was studied before and after sialidase pre-treatment, at one-, four- and eight-day-old animals and adult animals. For semi-quantitative evaluation of SBA binding intensity, two investigators performed the analysis independently, blinded to the type of experiment. Reactivity of the lectin was assessed in bronchiolar and respiratory portion/alveolar epithelial cell surfaces. We evidenced a stronger positive reaction when lung sections were pre-treated with neuraminidase before incubation with the lectin in one- and four-day-old animals and adult animals. These results were not so manifest in eight-day-old animals. This binding pattern, generally points towards the presence of terminal but mainly sub-terminal GalNAc/Gal residues probably capped by sialic acids on the rat bronchiolar/respiratory tract epithelial cells. As this glycan extension is common in O- and N-glycans, our results suggest that these glycan classes can be present in bronchioloalveolar cells immediately after birth and exist during the postnatal period. The results observed in eight-day-old rat lung sections may be due to the dramatic lung morphologic changes and the possible underlying biological mechanisms that occur during this age-moment.
Topics: Acetylgalactosamine; Animals; Bronchi; Epithelial Cells; Female; Galactose; Histocytochemistry; Horseradish Peroxidase; Neuraminidase; Plant Lectins; Pregnancy; Pulmonary Alveoli; Rats, Wistar; Soybean Proteins
PubMed: 31505925
DOI: 10.4081/ejh.2019.3040 -
The Journal of Comparative Neurology Apr 2018Perineuronal nets (PNs) are aggregates of extracellular matrix molecules that surround some neurons in the brain. While PNs occur widely across many cortical areas,...
Perineuronal nets (PNs) are aggregates of extracellular matrix molecules that surround some neurons in the brain. While PNs occur widely across many cortical areas, subcortical PNs are especially associated with motor and auditory systems. The auditory system has recently been suggested as an ideal model system for studying PNs and their functions. However, descriptions of PNs in subcortical auditory areas vary, and it is unclear whether the variation reflects species differences or differences in staining techniques. Here, we used two staining techniques (one lectin stain and one antibody stain) to examine PN distribution in the subcortical auditory system of four different species: guinea pigs (Cavia porcellus), mice (Mus musculus, CBA/CaJ strain), Long-Evans rats (Rattus norvegicus), and naked mole-rats (Heterocephalus glaber). We found that some auditory nuclei exhibit dramatic differences in PN distribution among species while other nuclei have consistent PN distributions. We also found that PNs exhibit molecular heterogeneity, and can stain with either marker individually or with both. PNs within a given nucleus can be heterogeneous or homogenous in their staining patterns. We compared PN staining across the frequency axes of tonotopically organized nuclei and among species with different hearing ranges. PNs were distributed non-uniformly across some nuclei, but only rarely did this appear related to the tonotopic axis. PNs were prominent in all four species; we found no systematic relationship between the hearing range and the number, staining patterns or distribution of PNs in the auditory nuclei.
Topics: Acetylgalactosamine; Animals; Auditory Cortex; Auditory Pathways; Guinea Pigs; Hearing; Male; Mice; Moles; Nerve Net; Rats; Rats, Long-Evans; Rodentia; Species Specificity
PubMed: 29277975
DOI: 10.1002/cne.24383 -
The Journal of Biological Chemistry Mar 1957
Topics: Acetylgalactosamine; Galactose; Liver; Nucleotides
PubMed: 13416241
DOI: No ID Found -
The Journal of Cell Biology Oct 1977The preferential adhesion of chick neural retina cells to surfaces of intact optic tecta has been investigated biochemically. The study uses a collection assay in which...
The preferential adhesion of chick neural retina cells to surfaces of intact optic tecta has been investigated biochemically. The study uses a collection assay in which single cells from either dorsal or ventral halves of neural retain adhere preferentially to ventral or dorsal halves of optic tecta respectively. The data presented support the following conclusions: (a) The adhesion of ventral retina to dorsal tecta seems to depend on proteins located on ventral retina and on terminal beta-N-acetylgalactosamine residues on dorsal tecta. (b) The adhesion of dorsal retina to ventral tecta seems to depend on proteins located on ventral tecta and on terminal beta- N-acetylgalactosamine residues on dorsal retina. (c) A double gradient model for retinotectal adhesion along the dorsoventral axis is consistent with the data presented. The model utilizes only two complementary molecules. The molecule suggested to be concentrated dorsally in both retina and tectum seems to require terminal beta-N-acetylgalactosamine residues for adhesion. Its activity is not affected by protease. A molecule fitting these qualifications, the ganglioside GM(2), could not be detected in a gradient, but lecithin vesicles containing GM(2) adhered preferentially to ventral tectal surfaces. The second molecule, concentrated ventrally in both retina and tectum, is a protein and seems capable of binding terminal beta-N- acetylgalactosamine residues. One enzyme, UDP-galactose:GM(2) galactosyltransferase, has been found to be more concentrated in ventral retina than dorsal, but only by 30 percent.
Topics: Acetylgalactosamine; Animals; Cell Adhesion; Chick Embryo; Cold Temperature; Cycloheximide; Dinitrophenols; Eye Proteins; Galactosamine; Galactosyltransferases; Gangliosides; Glycoside Hydrolases; Models, Biological; Peptide Hydrolases; Phosphatidylcholines; Puromycin; Retina; Superior Colliculi
PubMed: 562348
DOI: 10.1083/jcb.75.1.237 -
Molecular Microbiology Jul 2000Among enteric bacteria, the ability to grow on N-acetyl-galactosamine (GalNAc or Aga) and on D-galactosamine (GalN or Gam) differs. Thus, strains B, C and EC3132 of...
Among enteric bacteria, the ability to grow on N-acetyl-galactosamine (GalNAc or Aga) and on D-galactosamine (GalN or Gam) differs. Thus, strains B, C and EC3132 of Escherichia coli are Aga+ Gam+ whereas E. coli K-12 is Aga- Gam-, similarly to Klebsiella pneumoniae KAY2026, Klebsiella oxytoca M5a1 and Salmonella typhimurium LT2. The former strains carry a complete aga/kba gene cluster at 70.5 min of their gene map. These genes encode an Aga-specific phosphotransferase system (PTS) or IIAga (agaVWE) and a GalN-specific PTS or IIGam (agaBCD). Both PTSs belong to the mannose-sorbose family, i.e. the IIB, IIC and IID domains are encoded by different genes, and they share a IIA domain (agaF). Furthermore, the genes encode an Aga6P-deacetylase (agaA), a GalN6P deaminase (agaI), a tagatose-bisphosphate aldolase comprising two different peptides (kbaYZ) and a putative isomerase (agaS), i.e. complete pathways for the transport and degradation of both amino sugars. The genes are organized in two adjacent operons (kbaZagaVWEFA and agaS kbaYagaBCDI) and controlled by a repressor AgaR. Its gene agaR is located upstream of kbaZ, and AgaR responds to GalNAc and GalN in the medium. All Aga- Gam- strains, however, carry a deletion covering genes agaW' EF 'A; consequently they lack active IIAga and IIGam PTSs, thus explaining their inability to grow on the two amino sugars. Remnants of a putative recombination site flank the deleted DNA in the various Aga- Gam- enteric bacteria. Derivatives with an Aga+ Gam- phenotype can be isolated from E. coli K-12. These retain the DeltaagaW' EF 'A deletion and carry suppressor mutations in the gat and nag genes for galactitol and N-acetyl-glucosamine metabolism, respectively, that allow growth on Aga but not on GalN.
Topics: Acetylgalactosamine; Amino Acid Sequence; Base Sequence; Cloning, Molecular; Culture Media; Escherichia coli; Fructose-Bisphosphate Aldolase; Galactosamine; Genes, Bacterial; Genes, Regulator; Molecular Sequence Data; Mutation; Phenotype; Phosphotransferases; Regulon; Sequence Analysis, DNA
PubMed: 10931310
DOI: 10.1046/j.1365-2958.2000.01969.x -
ACS Chemical Biology Jan 2017Capsular polysaccharide A (CPSA) is a four-sugar repeating unit polymer found on the surface of the gut symbiont Bacteroides fragilis that has therapeutic potential in...
Capsular polysaccharide A (CPSA) is a four-sugar repeating unit polymer found on the surface of the gut symbiont Bacteroides fragilis that has therapeutic potential in animal models of autoimmune disorders. This therapeutic potential has been credited to its zwitterionic character derived from a positively charged N-acetyl-4-aminogalactosamine (AADGal) and a negatively charged 4,6-O-pyruvylated galactose (PyrGal). In this report, using a fluorescent polyisoprenoid chemical probe, the complete enzymatic assembly of the CPSA tetrasaccharide repeat unit is achieved. The proposed pyruvyltransferase, WcfO; galactopyranose mutase, WcfM; and glycosyltransferases, WcfP and WcfN, encoded by the CPSA biosynthesis gene cluster were heterologously expressed and functionally characterized. Pyruvate modification, catalyzed by WcfO, was found to occur on galactose of the polyisoprenoid-linked disaccharide (AADGal-Gal), and did not occur on galactose linked to uridine diphosphate (UDP) or a set of nitrophenyl-galactose analogues. This pyruvate modification was also found to be required for the incorporation of the next sugar in the pathway N-acetylgalactosamine (GalNAc) by the glycosyltransferase WcfP. The pyruvate acetal modification of a galactose has not been previously explored in the context of a polysaccharide biosynthesis pathway, and this work demonstrates the importance of this modification to repeat unit assembly. Upon production of the polyisoprenoid-linked AADGal-PyrGal-GalNAc, the proteins WcfM and WcfN were found to work in concert to form the final tetrasaccharide, where WcfM formed UDP-galactofuranose (Galf) and WcfN transfers Galf to the AADGal-PyrGal-GalNAc. This work demonstrates the first enzymatic assembly of the tetrasaccharide repeat unit of CPSA in a sequential single pot reaction.
Topics: Acetylgalactosamine; Aldehyde-Ketone Transferases; Animals; Bacteroides fragilis; Biosynthetic Pathways; Gene Expression; Glycosyltransferases; Multigene Family; Polysaccharides, Bacterial
PubMed: 28103676
DOI: 10.1021/acschembio.6b00931 -
The Journal of Experimental Medicine Apr 2000The macrophage and epithelial cell mannose receptor (MR) binds carbohydrates on foreign and host molecules. Two portions of MR recognize carbohydrates: tandemly arranged...
The macrophage and epithelial cell mannose receptor (MR) binds carbohydrates on foreign and host molecules. Two portions of MR recognize carbohydrates: tandemly arranged C-type lectin domains facilitate carbohydrate-dependent macrophage uptake of infectious organisms, and the NH(2)-terminal cysteine-rich domain (Cys-MR) binds to sulfated glycoproteins including pituitary hormones. To elucidate the mechanism of sulfated carbohydrate recognition, we determined crystal structures of Cys-MR alone and complexed with 4-sulfated-N-acetylgalactosamine at 1.7 and 2.2 A resolution, respectively. Cys-MR folds into an approximately three-fold symmetric beta-trefoil shape resembling fibroblast growth factor. The sulfate portions of 4-sulfated-N-acetylgalactosamine and an unidentified ligand found in the native crystals bind in a neutral pocket in the third lobe. We use the structures to rationalize the carbohydrate binding specificities of Cys-MR and compare the recognition properties of Cys-MR with other beta-trefoil proteins.
Topics: Acetylgalactosamine; Amino Acid Sequence; Animals; Carbohydrate Conformation; Carbohydrate Metabolism; Carbohydrates; Cell Line, Transformed; Crystallography, X-Ray; Cysteine; Humans; Lectins, C-Type; Ligands; Mannose Receptor; Mannose-Binding Lectins; Mice; Molecular Sequence Data; Protein Conformation; Receptors, Cell Surface; Recombinant Fusion Proteins
PubMed: 10748229
DOI: 10.1084/jem.191.7.1105 -
Journal of Virology Mar 2004Filoviruses cause lethal hemorrhagic disease in humans and nonhuman primates. An initial target of filovirus infection is the mononuclear phagocytic cell....
Filoviruses cause lethal hemorrhagic disease in humans and nonhuman primates. An initial target of filovirus infection is the mononuclear phagocytic cell. Calcium-dependent (C-type) lectins such as dendritic cell- or liver/lymph node-specific ICAM-3 grabbing nonintegrin (DC-SIGN or L-SIGN, respectively), as well as the hepatic asialoglycoprotein receptor, bind to Ebola or Marburg virus glycoprotein (GP) and enhance the infectivity of these viruses in vitro. Here, we demonstrate that a recently identified human macrophage galactose- and N-acetylgalactosamine-specific C-type lectin (hMGL), whose ligand specificity differs from DC-SIGN and L-SIGN, also enhances the infectivity of filoviruses. This enhancement was substantially weaker for the Reston and Marburg viruses than for the highly pathogenic Zaire virus. We also show that the heavily glycosylated, mucin-like domain on the filovirus GP is required for efficient interaction with this lectin. Furthermore, hMGL, like DC-SIGN and L-SIGN, is present on cells known to be major targets of filoviruses (i.e., macrophages and dendritic cells), suggesting a role for these C-type lectins in viral replication in vivo. We propose that filoviruses use different C-type lectins to gain cellular entry, depending on the cell type, and promote efficient viral replication.
Topics: Acetylgalactosamine; Animals; Cell Line, Tumor; Chlorocebus aethiops; Filoviridae; Galactose; Humans; Lectins, C-Type; Macrophages; Vero Cells
PubMed: 14990712
DOI: 10.1128/jvi.78.6.2943-2947.2004 -
The Journal of Clinical Endocrinology... Mar 2009The gonadotropins are secreted from the human pituitary as spectra of isoforms with different degrees of sulfonation and sialylation of the oligosaccharides,...
CONTEXT
The gonadotropins are secreted from the human pituitary as spectra of isoforms with different degrees of sulfonation and sialylation of the oligosaccharides, modifications suspected to determine their half-lives in the circulation.
OBJECTIVES
Our objectives were to determine the isoform composition of the serum gonadotropins during GnRH receptor blockade, and to estimate the half-lives in circulation of isoforms with 0-1-2-3 sulfonated N-acetylgalactosamine (SO(3)-GalNAc) residues.
DESIGN/PARTICIPANTS
Serum samples were collected in seven healthy women before and up to 20 h after administration of the NAL-GLU GnRH antagonist.
MAIN OUTCOME MEASURES
The number of sialic acid and SO(3)-GalNAc residues per LH and FSH molecule and the distribution of molecules with 0-1-2-3 sulfonated residues were measured. The half-lives were estimated by monoexponential decay.
RESULTS
More sialylated and less sulfonated gonadotropin isoforms remain longer in circulation during GnRH receptor blockade. LH isoforms with two and three sulfonated residues per molecule had shorter half-lives compared with those with zero and one (109 and 80 vs. 196 and 188 min; P < 0.01). FSH isoforms with one and two sulfonated residues had shorter half-lives than those with zero (485 and 358 vs. 988 min; P < 0.01).
CONCLUSIONS
The decline in LH and FSH during GnRH receptor blockade is associated with a decrease in sulfonated and increase in sialylated residues. The rapid disappearance of LH isoforms with two and three SO(3)-GalNAc residues suggests their removal by hepatic SO(3)-GalNAc-receptors similar to those in rodents. Episodical secretion of spectra of isoforms with different half-lives is expected to lead to continuous changes in gonadotropin isoform compositions in blood.
Topics: Acetylgalactosamine; Electrophoretic Mobility Shift Assay; Female; Follicle Stimulating Hormone; Gonadotropin-Releasing Hormone; Half-Life; Humans; Luteinizing Hormone; N-Acetylneuraminic Acid; Protein Isoforms; Sulfonic Acids
PubMed: 19116233
DOI: 10.1210/jc.2008-2070 -
Proceedings of the National Academy of... Aug 2013Invasiveness underlies cancer aggressiveness and is a hallmark of malignancy. Most malignant tumors have elevated levels of Tn, an O-GalNAc glycan. Mechanisms underlying...
Invasiveness underlies cancer aggressiveness and is a hallmark of malignancy. Most malignant tumors have elevated levels of Tn, an O-GalNAc glycan. Mechanisms underlying Tn up-regulation and its effects remain unclear. Here we show that Golgi-to-endoplasmic reticulum relocation of polypeptide N-acetylgalactosamine-transferases (GalNAc-Ts) drives high Tn levels in cancer cell lines and in 70% of malignant breast tumors. This process stimulates cell adhesion to the extracellular matrix, as well as migration and invasiveness. The GalNAc-Ts lectin domain, mediating high-density glycosylation, is critical for these effects. Interfering with the lectin domain function inhibited carcinoma cell migration in vitro and metastatic potential in mice. We also show that stimulation of cell migration is dependent on Tn-bearing proteins present in lamellipodia of migrating cells. Our findings suggest that relocation of GalNAc-Ts to the endoplasmic reticulum frequently occurs upon cancerous transformation to enhance tumor cell migration and invasiveness through modification of cell surface proteins.
Topics: Acetylgalactosamine; Animals; Antigens, Tumor-Associated, Carbohydrate; Blotting, Western; Cell Line; Cell Movement; Cloning, Molecular; Endoplasmic Reticulum; Fluorescent Antibody Technique; Gene Expression Regulation, Neoplastic; Glycosylation; Glycosyltransferases; Golgi Apparatus; Humans; Kaplan-Meier Estimate; Mice; Mice, Inbred BALB C; Neoplasm Invasiveness; Neoplasms
PubMed: 23912186
DOI: 10.1073/pnas.1305269110