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Dual Recognition of Sialic Acid and αGal Epitopes by the VP8* Domains of the Bovine Rotavirus G6P[5] WC3 and of Its Mono-reassortant G4P[5] RotaTeq Vaccine Strains. J Virol 2019; 93:JVI.00941-19. [PMID: 31243129 PMCID: PMC6714814 DOI: 10.1128/jvi.00941-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 06/18/2019] [Indexed: 01/02/2023] Open
Abstract
Group A rotaviruses initiate infection through the binding of the VP8* domain of the VP4 protein to sialic acids (SAs) or histo-blood group antigens (HBGAs). Although the bovine G6P[5] WC3 strain is an important animal pathogen and is used as the backbone in the bovine-human reassortant RotaTeq vaccine, the receptor(s) for their P[5] VP8* domain has remained elusive. Using a variety of approaches, we demonstrated that the WC3 and bovine-human mono-reassortant G4P[5] vaccine strains recognize both α2,6-linked SA and αGal HBGA as ligands. Neither ligand is expressed on human small intestinal epithelial cells, explaining the absence of natural human infection by P[5]-bearing strains. However, we observed that the P[5]-bearing WC3 and G4P[5] RotaTeq vaccine strains could still infect human intestinal epithelial cells. Thus, the four P[5] RotaTeq vaccine strains potentially binding to additional alternative receptors may be efficient and effective in providing protection against severe rotavirus disease in human. Group A rotaviruses, an important cause of severe diarrhea in children and young animals, initiate infection via interactions of the VP8* domain of the VP4 spike protein with cell surface sialic acids (SAs) or histo-blood group antigens (HBGAs). Although the bovine G6P[5] WC3 strain is an important animal pathogen and is also used in the bovine-human reassortant RotaTeq vaccine, the receptor(s) for the VP8* domain of WC3 and its reassortant strains have not yet been identified. In the present study, HBGA- and saliva-binding assays showed that both G6P[5] WC3 and mono-reassortant G4P[5] strains recognized the αGal HBGA. The infectivity of both P[5]-bearing strains was significantly reduced in αGal-free MA-104 cells by pretreatment with a broadly specific neuraminidase or by coincubation with the α2,6-linked SA-specific Sambucus nigra lectin, but not by the α2,3-linked specific sialidase or by Maackia amurensis lectin. Free NeuAc and the αGal trisaccharide also prevented the infectivity of both strains. This indicated that both P[5]-bearing strains utilize α2,6-linked SA as a ligand on MA104 cells. However, the two strains replicated in differentiated bovine small intestinal enteroids and in their human counterparts that lack α2,6-linked SA or αGal HBGA, suggesting that additional or alternative receptors such as integrins, hsp70, and tight-junction proteins bound directly to the VP5* domain can be used by the P[5]-bearing strains to initiate the infection of human cells. In addition, these data also suggested that P[5]-bearing strains have potential for cross-species transmission. IMPORTANCE Group A rotaviruses initiate infection through the binding of the VP8* domain of the VP4 protein to sialic acids (SAs) or histo-blood group antigens (HBGAs). Although the bovine G6P[5] WC3 strain is an important animal pathogen and is used as the backbone in the bovine-human reassortant RotaTeq vaccine, the receptor(s) for their P[5] VP8* domain has remained elusive. Using a variety of approaches, we demonstrated that the WC3 and bovine-human mono-reassortant G4P[5] vaccine strains recognize both α2,6-linked SA and αGal HBGA as ligands. Neither ligand is expressed on human small intestinal epithelial cells, explaining the absence of natural human infection by P[5]-bearing strains. However, we observed that the P[5]-bearing WC3 and G4P[5] RotaTeq vaccine strains could still infect human intestinal epithelial cells. Thus, the four P[5] RotaTeq vaccine strains potentially binding to additional alternative receptors may be efficient and effective in providing protection against severe rotavirus disease in human.
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Fraser NS, Knauth CM, Schoeman EM, Moussa A, Perkins AC, Walsh T, Millard GM, Dean MM, Hyland CA, Flower RL. Investigation of the variable In(Lu) phenotype caused by KLF1 variants. Transfusion 2018; 58:2414-2420. [PMID: 30222867 DOI: 10.1111/trf.14926] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 07/19/2018] [Accepted: 07/20/2018] [Indexed: 01/31/2023]
Abstract
INTRODUCTION KLF1 is an essential transcriptional activator that drives erythropoiesis. KLF1 variants can result in the Inhibitor of Lutheran, or In(Lu), phenotype where red blood cells (RBCs) have reduced BCAM (LU) and CD44 (IN). Other RBC surface molecules also have changed expression; however, there is controversy in the literature regarding which are truly impacted. We aimed to investigate KLF1 variants in the Australian population. STUDY DESIGN AND METHODS In(Lu) samples were sourced through screening and through the RBC reference laboratory. Blood donor samples (8036) were screened to identify weakened/absent Lub antigen. Samples were genotyped by massively parallel sequencing, while surface carbohydrates and blood group molecules were assessed by flow cytometry. Hemoglobin (Hb) types were analyzed by high-performance liquid chromatography. RESULTS Four of 8036 donors were identified to be In(Lu), and two previously identified In(Lu) samples were provided from the RBC reference laboratory. Five different KLF1 variants were identified; two were novel: c.954G>C/p.Trp318Cys and c.421C>T/p.Arg141*. BCAM and CD44 were reduced in all samples, consistent with previous reports. As a group, In(Lu) RBCs had reduced CD35 (KN), ICAM4 (LW), and CD147 (OK), and demonstrated increased binding of lectins ECA and SNAI. One In(Lu) sample had elevated HbF and another elevated HbA2. CONCLUSION Different KLF1 variants may potentially produce variable phenotypes. A framework for investigating KLF1 variants and their phenotypic impact has been provided. In the future, given available international databases, further testing algorithms (as advocated here) will allow for correlation of phenotype with genotype and therefore accurately document this variability between KLF1 variants.
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Affiliation(s)
- Nicole S Fraser
- Research and Development, Australian Red Cross Blood Service.,School of Biomedical Science, Faculty of Health, Queensland University of Technology, Brisbane, Australia
| | - Christine M Knauth
- Research and Development, Australian Red Cross Blood Service.,School of Biomedical Science, Faculty of Health, Queensland University of Technology, Brisbane, Australia
| | | | - Assia Moussa
- Research and Development, Australian Red Cross Blood Service.,School of Biomedical Science, Faculty of Health, Queensland University of Technology, Brisbane, Australia
| | - Andrew C Perkins
- Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
| | - Terry Walsh
- School of Biomedical Science, Faculty of Health, Queensland University of Technology, Brisbane, Australia
| | | | - Melinda M Dean
- Research and Development, Australian Red Cross Blood Service.,School of Biomedical Science, Faculty of Health, Queensland University of Technology, Brisbane, Australia
| | - Catherine A Hyland
- Research and Development, Australian Red Cross Blood Service.,School of Biomedical Science, Faculty of Health, Queensland University of Technology, Brisbane, Australia
| | - Robert L Flower
- Research and Development, Australian Red Cross Blood Service.,School of Biomedical Science, Faculty of Health, Queensland University of Technology, Brisbane, Australia
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Dougher CWL, Buffone A, Nemeth MJ, Nasirikenari M, Irons EE, Bogner PN, Lau JTY. The blood-borne sialyltransferase ST6Gal-1 is a negative systemic regulator of granulopoiesis. J Leukoc Biol 2017; 102:507-516. [PMID: 28550122 PMCID: PMC5505748 DOI: 10.1189/jlb.3a1216-538rr] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 04/26/2017] [Accepted: 04/27/2017] [Indexed: 12/25/2022] Open
Abstract
Responding to systemic demands in producing and replenishing end-effector blood cells is predicated on the appropriate delivery and interpretation of extrinsic signals to the HSPCs. The data presented herein implicate the systemic, extracellular form of the glycosyltransferase ST6Gal-1 in the regulation of late-stage neutrophil development. ST6Gal-1 is typically a membrane-bound enzyme sequestered within the intracellular secretory apparatus, but an extracellular form is released into the blood from the liver. Both human and murine HSPCs, upon exposure to extracellular ST6Gal-1 ex vivo, exhibited decreased proliferation, diminished expression of the neutrophilic primary granule protein MPO, and decreased appearance of CD11b+ cells. HSPC suppression was preceded by decreased STAT-3 phosphorylation and diminished C/EBPα expression, without increased apoptosis, indicating attenuated G-CSF receptor signaling. A murine model to raise systemic ST6Gal-1 level was developed to examine the role of the circulatory enzyme in vivo. Our results show that systemic ST6Gal-1 modified the cell surface of the GMP subset of HSPCs and decreased marrow neutrophil reserves. Acute airway neutrophilic inflammation by LPS challenge was used to drive demand for new neutrophil production. Reduced neutrophil infiltration into the airway was observed in mice with elevated circulatory ST6Gal-1 levels. The blunted transition of GMPs into GPs in vitro is consistent with ST6Gal-1-attenuated granulopoiesis. The data confirm that circulatory ST6Gal-1 is a negative systemic regulator of granulopoiesis and moreover suggest a clinical potential to limit the number of inflammatory cells by manipulating blood ST6Gal-1 levels.
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Affiliation(s)
| | - Alexander Buffone
- Department of Molecular and Cellular Biology, Roswell Park Cancer Institute, Buffalo, New York, USA; and
| | - Michael J Nemeth
- Department of Immunology, Roswell Park Cancer Institute, Buffalo, New York, USA
| | - Mehrab Nasirikenari
- Department of Molecular and Cellular Biology, Roswell Park Cancer Institute, Buffalo, New York, USA; and
| | - Eric E Irons
- Department of Molecular and Cellular Biology, Roswell Park Cancer Institute, Buffalo, New York, USA; and
| | - Paul N Bogner
- Department of Pathology, Roswell Park Cancer Institute, Buffalo, New York, USA
| | - Joseph T Y Lau
- Department of Molecular and Cellular Biology, Roswell Park Cancer Institute, Buffalo, New York, USA; and
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Park JJ, Yi JY, Jin YB, Lee YJ, Lee JS, Lee YS, Ko YG, Lee M. Sialylation of epidermal growth factor receptor regulates receptor activity and chemosensitivity to gefitinib in colon cancer cells. Biochem Pharmacol 2012; 83:849-57. [PMID: 22266356 DOI: 10.1016/j.bcp.2012.01.007] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Revised: 01/04/2012] [Accepted: 01/05/2012] [Indexed: 12/14/2022]
Abstract
β-Galactoside α2,6-sialyltransferase (ST6Gal-I) has been shown to catalyze α2,6 sialylation of N-glycan, an action that is highly correlated with colon cancer progression and metastasis. We have recently demonstrated that ST6Gal-I-induced α2,6 sialylation is critical for adhesion and migration of colon cancer cells. Increase of α2,6 sialylation also contributes to radioresistance of colon cancer. A number of studies have focused on the involvement of sialylation in tumorigenesis, but the mechanism underlying ST6Gal-I-induced cancer progression and the identity of enzyme substrates has received scant research attention. To provide further support for the relevance of ST6Gal-I in the malignancy of colon cancer, we prepared and characterized a ST6Gal-I-knockdown SW480 colorectal carcinoma cell line. We found that inhibition of ST6Gal-I expression increased cell proliferation and tumor growth in vitro and in vivo. An examination of the effect of sialylation on epidermal growth factor receptor (EGFR) activity and downstream signaling, which are highly correlated with cell proliferation, showed that the loss of ST6Gal-I augmented EGF-induced EGFR phosphorylation and activation of extracellular signal-regulated kinase (ERK) in colon cancer cells. Moreover, ST6Gal-I induced sialylation of both wild type and mutant EGFR. These studies provide the first demonstration that ST6Gal-I induces EGFR sialylation in human colon cancer cell lines. Importantly, the anticancer effect of the EGFR kinase inhibitor, gefitinib, was increased in ST6Gal-I-deficient colon cancer cells. In contrast, overexpression of ST6Gal I decreased the cytotoxic effect of gefitinib. These results suggest that sialylation of the EGFR affects EGF-mediated cell growth and induces chemoresistance to gefitinib in colon cancer cells.
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Affiliation(s)
- Jung-Jin Park
- Division of Radiation Effects, Korea Institute of Radiological and Medical Sciences, Seoul 139-706, Republic of Korea
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Swindall AF, Bellis SL. Sialylation of the Fas death receptor by ST6Gal-I provides protection against Fas-mediated apoptosis in colon carcinoma cells. J Biol Chem 2011; 286:22982-90. [PMID: 21550977 PMCID: PMC3123066 DOI: 10.1074/jbc.m110.211375] [Citation(s) in RCA: 146] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Revised: 04/28/2011] [Indexed: 01/28/2023] Open
Abstract
The glycosyltransferase, ST6Gal-I, adds sialic acid in an α2-6 linkage to the N-glycans of membrane and secreted glycoproteins. Up-regulation of ST6Gal-I occurs in many cancers, including colon carcinoma, and correlates with metastasis and poor prognosis. However, mechanisms by which ST6Gal-I facilitates tumor progression remain poorly understood due to limited knowledge of enzyme substrates. Herein we identify the death receptor, Fas (CD95), as an ST6Gal-I substrate, and show that α2-6 sialylation of Fas confers protection against Fas-mediated apoptosis. Intriguingly, differences in ST6Gal-I activity do not affect the function of DR4 or DR5 death receptors upon treatment with TRAIL, implicating a selective effect of ST6Gal-I on the Fas receptor. Using ST6Gal-I knockdown and forced overexpression colon carcinoma cell models, we find that α2-6 sialylation of Fas prevents apoptosis stimulated by FasL as well as the Fas-activating antibody, CH11, as evidenced by decreased activation of caspases 8 and 3. We also show that α2-6 sialylation of Fas does not alter the binding of CH11, but rather inhibits the capacity of Fas to induce apoptosis by blocking the association of FADD with Fas cytoplasmic tails, an event that initiates death-inducing signaling complex formation. Furthermore, α2-6 sialylation of Fas inhibits Fas internalization, which is required for apoptotic signaling. Although dysregulated Fas activity is a well known mechanism through which tumors evade apoptosis, the current study is the first to link Fas insensitivity to the actions of a specific sialyltransferase. This finding establishes a new paradigm by which death receptor function is impaired for the self-protection of tumors against apoptosis.
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Affiliation(s)
- Amanda F. Swindall
- From the Department of Physiology and Biophysics, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Susan L. Bellis
- From the Department of Physiology and Biophysics, University of Alabama at Birmingham, Birmingham, Alabama 35294
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Lee CL, Chiu PC, Pang PC, Chu IK, Lee KF, Koistinen R, Koistinen H, Seppälä M, Morris HR, Tissot B, Panico M, Dell A, Yeung WS. Glycosylation failure extends to glycoproteins in gestational diabetes mellitus: evidence from reduced α2-6 sialylation and impaired immunomodulatory activities of pregnancy-related glycodelin-A. Diabetes 2011; 60:909-17. [PMID: 21300843 PMCID: PMC3046852 DOI: 10.2337/db10-1186] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
OBJECTIVE Gestational diabetes mellitus (GDM) is a common metabolic disorder of pregnancy. Patients with GDM are at risk for high fetal mortality and gestational complications associated with reduced immune tolerance and abnormal carbohydrate metabolism. Glycodelin-A (GdA) is an abundant decidual glycoprotein with glycosylation-dependent immunomodulatory activities. We hypothesized that aberrant carbohydrate metabolism in GDM was associated with changes in glycosylation of GdA, leading to defective immunomodulatory activities. RESEARCH DESIGN AND METHODS GdA in the amniotic fluid from women with normal (NGdA) and GDM (DGdA) pregnancies was purified by affinity chromatography. Structural analysis of protein glycosylation was preformed by lectin-binding assay and mass spectrometry. Cytotoxicity, cell death, cytokine secretion, and GdA binding of the GdA-treated lymphocytes and natural killer (NK) cells were determined. The sialidase activity in the placental tissue from normal and GDM patients was measured. RESULTS GDM affected the glycosylation but not the protein core of GdA. Specifically, DGdA had a lower abundance of α2-6-sialylated and high-mannose glycans and a higher abundance of glycans with Sda (NeuAcα2-3[GalNAcβ1-4]Gal) epitopes compared with NGdA. DGdA had reduced immuosuppressive activities in terms of cytotoxicity on lymphocytes, inhibitory activities on interleukin (IL)-2 secretion by lymphocytes, stimulatory activities on IL-6 secretion by NK cells, and binding to these cells. Desialylation abolished the immunomodulation and binding of NGdA. Placental sialidase activity was increased in GDM patients, which may account for the reduced sialic acid content of DGdA. CONCLUSIONS Taken together, this study provides the first direct evidence for altered enzymatic glycosylation and impaired bioactivity of GdA in GDM patients.
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Affiliation(s)
- Cheuk-Lun Lee
- Department of Obstetrics and Gynaecology, University of Hong Kong, Hong Kong, China
- Department of Chemistry, University of Hong Kong, Hong Kong, China
- Centre for Reproduction, Development, and Growth, University of Hong Kong, Hong Kong, China
| | - Philip C.N. Chiu
- Department of Obstetrics and Gynaecology, University of Hong Kong, Hong Kong, China
- Centre for Reproduction, Development, and Growth, University of Hong Kong, Hong Kong, China
- Corresponding author: Philip C.N. Chiu,
| | - Poh-Choo Pang
- Division of Molecular Biosciences, Faculty of Natural Sciences, Imperial College London, London, U.K
| | - Ivan K. Chu
- Department of Chemistry, University of Hong Kong, Hong Kong, China
| | - Kai-Fai Lee
- Department of Obstetrics and Gynaecology, University of Hong Kong, Hong Kong, China
- Centre for Reproduction, Development, and Growth, University of Hong Kong, Hong Kong, China
| | - Riitta Koistinen
- Department of Clinical Chemistry, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland
| | - Hannu Koistinen
- Department of Clinical Chemistry, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland
| | - Markku Seppälä
- Department of Clinical Chemistry, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland
| | - Howard R. Morris
- Division of Molecular Biosciences, Faculty of Natural Sciences, Imperial College London, London, U.K
| | - Bérangère Tissot
- Division of Molecular Biosciences, Faculty of Natural Sciences, Imperial College London, London, U.K
| | - Maria Panico
- Division of Molecular Biosciences, Faculty of Natural Sciences, Imperial College London, London, U.K
| | - Anne Dell
- Division of Molecular Biosciences, Faculty of Natural Sciences, Imperial College London, London, U.K
| | - William S.B. Yeung
- Department of Obstetrics and Gynaecology, University of Hong Kong, Hong Kong, China
- Centre for Reproduction, Development, and Growth, University of Hong Kong, Hong Kong, China
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Lehoux S, Groux-Degroote S, Cazet A, Dhaenens CM, Maurage CA, Caillet-Boudin ML, Delannoy P, Krzewinski-Recchi MA. Transcriptional regulation of the human ST6GAL2 gene in cerebral cortex and neuronal cells. Glycoconj J 2009; 27:99-114. [PMID: 19768537 DOI: 10.1007/s10719-009-9260-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2009] [Revised: 08/26/2009] [Accepted: 09/01/2009] [Indexed: 11/27/2022]
Abstract
The second human beta-galactoside alpha-2,6-sialyltransferase (hST6Gal II) differs from hST6Gal I, the first member of ST6Gal family, in substrate specificity and tissue expression pattern. While ST6GAL1 gene is expressed in almost all human tissues, ST6GAL2 shows a restricted tissue-specific pattern of expression, mostly expressed in embryonic and adult brain. In order to understand the mechanisms involved in the transcriptional regulation of ST6GAL2, we first characterized the transcription start sites (TSS) in SH-SY5Y neuroblastoma cells. 5' RACE experiments revealed multiple TSS located on three first alternative 5' exons, termed EX, EY and EZ, which are unusually close on the genomic sequence and are all located more than 42 kbp upstream of the first common coding exon. Using Taqman duplex Q-PCR, we showed that the ST6GAL2 transcripts initiated by EX or EY are mainly expressed in both brain-related cell lines and human cerebral cortex, testifying for the use of a similar transcriptional regulation in vivo. Furthermore, we also showed for the first time hST6Gal II protein expression in the different lobes of the human cortex. Luciferase reporter assays allowed us to define two sequences upstream EX and EY with a high and moderate promoter activity, respectively. Bioinformatics analysis and site-directed mutagenesis showed that NF-kappaB and NRSF are likely to act as transcriptional repressors, whereas neuronal-related development factors Sox5, Puralpha and Olf1, are likely to act as transcriptional activators of ST6GAL2. This suggests that ST6GAL2 transcription could be potentially activated for specific neuronal functions.
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Affiliation(s)
- Sylvain Lehoux
- Structural and Functional Glycobiology Unit, UMR CNRS 8576, University of Sciences and Technologies of Lille, 59655, Villeneuve d'Ascq, France
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Bos PD, Zhang XHF, Nadal C, Shu W, Gomis RR, Nguyen DX, Minn AJ, van de Vijver MJ, Gerald WL, Foekens JA, Massagué J. Genes that mediate breast cancer metastasis to the brain. Nature 2009; 459:1005-9. [PMID: 19421193 DOI: 10.1038/nature08021] [Citation(s) in RCA: 1332] [Impact Index Per Article: 88.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2009] [Accepted: 03/26/2009] [Indexed: 12/23/2022]
Abstract
The molecular basis for breast cancer metastasis to the brain is largely unknown. Brain relapse typically occurs years after the removal of a breast tumour, suggesting that disseminated cancer cells must acquire specialized functions to take over this organ. Here we show that breast cancer metastasis to the brain involves mediators of extravasation through non-fenestrated capillaries, complemented by specific enhancers of blood-brain barrier crossing and brain colonization. We isolated cells that preferentially infiltrate the brain from patients with advanced disease. Gene expression analysis of these cells and of clinical samples, coupled with functional analysis, identified the cyclooxygenase COX2 (also known as PTGS2), the epidermal growth factor receptor (EGFR) ligand HBEGF, and the alpha2,6-sialyltransferase ST6GALNAC5 as mediators of cancer cell passage through the blood-brain barrier. EGFR ligands and COX2 were previously linked to breast cancer infiltration of the lungs, but not the bones or liver, suggesting a sharing of these mediators in cerebral and pulmonary metastases. In contrast, ST6GALNAC5 specifically mediates brain metastasis. Normally restricted to the brain, the expression of ST6GALNAC5 in breast cancer cells enhances their adhesion to brain endothelial cells and their passage through the blood-brain barrier. This co-option of a brain sialyltransferase highlights the role of cell-surface glycosylation in organ-specific metastatic interactions.
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Affiliation(s)
- Paula D Bos
- Cancer Biology and Genetics Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA
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Gu J, Xie Z, Gao Z, Liu J, Korteweg C, Ye J, Lau LT, Lu J, Gao Z, Zhang B, McNutt MA, Lu M, Anderson VM, Gong E, Yu ACH, Lipkin WI. H5N1 infection of the respiratory tract and beyond: a molecular pathology study. Lancet 2007; 370:1137-45. [PMID: 17905166 PMCID: PMC7159293 DOI: 10.1016/s0140-6736(07)61515-3] [Citation(s) in RCA: 285] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
BACKGROUND Human infection with avian influenza H5N1 is an emerging infectious disease characterised by respiratory symptoms and a high fatality rate. Previous studies have shown that the human infection with avian influenza H5N1 could also target organs apart from the lungs. METHODS We studied post-mortem tissues of two adults (one man and one pregnant woman) infected with H5N1 influenza virus, and a fetus carried by the woman. In-situ hybridisation (with sense and antisense probes to haemagglutinin and nucleoprotein) and immunohistochemistry (with monoclonal antibodies to haemagglutinin and nucleoprotein) were done on selected tissues. Reverse-transcriptase (RT) PCR, real-time RT-PCR, strand-specific RT-PCR, and nucleic acid sequence-based amplification (NASBA) detection assays were also undertaken to detect viral RNA in organ tissue samples. FINDINGS We detected viral genomic sequences and antigens in type II epithelial cells of the lungs, ciliated and non-ciliated epithelial cells of the trachea, T cells of the lymph node, neurons of the brain, and Hofbauer cells and cytotrophoblasts of the placenta. Viral genomic sequences (but no viral antigens) were detected in the intestinal mucosa. In the fetus, we found viral sequences and antigens in the lungs, circulating mononuclear cells, and macrophages of the liver. The presence of viral sequences in the organs and the fetus was also confirmed by RT-PCR, strand-specific RT-PCR, real-time RT-PCR, and NASBA. INTERPRETATION In addition to the lungs, H5N1 influenza virus infects the trachea and disseminates to other organs including the brain. The virus could also be transmitted from mother to fetus across the placenta.
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Affiliation(s)
- Jiang Gu
- Infectious Disease Centre, Peking University, Beijing, China.
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Siebert HC, Rosen J, Seyrek K, Kaltner H, André S, Bovin NV, Nyholm PG, Sinowatz F, Gabius HJ. α2,3/α2,6-Sialylation of N-glycans: non-synonymous signals with marked developmental regulation in bovine reproductive tracts. Biochimie 2006; 88:399-410. [PMID: 16360259 DOI: 10.1016/j.biochi.2005.09.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2005] [Accepted: 09/23/2005] [Indexed: 10/25/2022]
Abstract
The glycan part endows cellular glycoconjugates with significant potential for biological recognition. N-Glycan branches often end with alpha2,3/alpha2,6-sialylation, posing the question whether and how placement of the sialic acid at 3 - or 6 -acceptor positions of galactose has cell biological relevance. As attractive model to study developmental regulation we monitored the expression of alpha2,3/alpha2,6-sialylated determinants in fetal and adult bovine testes and ovaries by lectin histochemistry. Distinct expression patterns were detected in both organ types. Oocyte staining, as a prominent example, was restricted to the presence of alpha2,6-sialylated glycans. Treatment with sialidase abolished binding and thus excluded sulfate esters as lectin targets. We added computer simulations to rationalize the observed evidence for non-random expression of the two closely related sialylgalactose isomers. Extensive molecular mechanics and molecular dynamics calculations reveal that the seemingly minor shift of the glycosidic bond from the alpha2,3 position to the alpha2,6 configuration causes significant shape and flexibility changes. They give each disaccharide its own characteristic meaning as signal in the sugar code.
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Affiliation(s)
- Hans-Christian Siebert
- Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximilians-University, Veterinärstr. 13, 80539 München, Germany
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Jiménez-Farfán D, Guevara J, Zenteno E, Hernández-Guerrero JC. Alteration of the sialylation pattern of the murine tooth germ after ethanol exposure. ACTA ACUST UNITED AC 2006; 73:980-8. [PMID: 16323169 DOI: 10.1002/bdra.20198] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
BACKGROUND Ethanol consumption during pregnancy leads to changes in murine dental morphogenesis, dental size, cellular differentiation, enamel mineralization, and delayed eruption. It has been proposed that glycoproteins play a role during embryonic dental development that may determine the dental morphological pattern and extracellular matrix secretion. O-glycosylation and sialylation appear to actively participate in the differentiation and maturation processes. Because glycosylation may be affected by teratogens that can alter the maturation of several organisms, in this work we describe the main modifications of the sialylation pattern in prenatal day (PD) 18.5 murine tooth germs exposed to ethanol. METHODS Pregnant female mice were divided into groups that were given 15% or 20% ethanol solutions, or water as a control. The histochemistry of tooth germs from PD 18.5 fetuses was revealed with lectins specific for sialic acid (Neu5Ac), such as Sambucus nigra (SNA), Maackia amurensis (MAA), and Machrobrachium rosenbergii (MRL), and for sialylated-O-glycosidically linked glycans, such as Amaranthus leucocarpus (ALL). RESULTS The basement membrane, preameloblasts, inner-enamel epithelium, preodontoblasts, and subodontoblastic cells of the test groups showed changes in labeling according to the 4 lectins used. Intranuclear staining was observed with SNA (specific for Neu5Acalpha2,6Gal/GalNAc) in the control group, but this was reduced in the test groups. The nuclei of dental papillary cells under the experimental conditions were stained with MAA (Neu5Acalpha2,3Gal). CONCLUSIONS Dental development involves different types of sialylated O-glycosidically linked glycans that are likely to regulate cell-to-cell and cell-to-matrix interactions. Our results suggest that ethanol consumption during pregnancy alters the sialylation pattern during murine dental morphogenesis.
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Affiliation(s)
- Dolores Jiménez-Farfán
- Laboratorio de Inmunología, División de Estudios de Posgrado e Investigación, DEPeI, Facultad de Odontología, Universidad Nacional Autónoma de México, Ciudad de México, México
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12
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Zuber C, Paulson JC, Toma V, Winter HC, Goldstein IJ, Roth J. Spatiotemporal expression patterns of sialoglycoconjugates during nephron morphogenesis and their regional and cell type-specific distribution in adult rat kidney. Histochem Cell Biol 2003; 120:143-60. [PMID: 12898273 DOI: 10.1007/s00418-003-0553-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/27/2003] [Indexed: 01/30/2023]
Abstract
The expression of alpha2,6- and alpha2,3-linked sialic acids on N-glycans was studied in embryonic, postnatal, and adult rat kidney. Histochemistry and blotting using Polyporus squamosus and Sambucus nigra lectins for alpha2,6-linked sialic acids and the Maackia amurensis lectin for alpha2,3-linked sialic acids were performed and sialyltransferase activity was assayed. N-glycans with alpha2,6- and alpha2,3-linked sialic acid were differently expressed in the two embryonic anlagen and early stages of nephron. Metanephrogenic mesenchyme was positive for alpha2,3-linked sialic acid but not for the alpha2,6-linked one, which became detectable initially in the proximal part of S-shaped bodies. Collecting ducts were positive for alpha2,6-linked sialic acid, whereas alpha2,3-linked sialic acid was restricted to their ampullae. Although positive in embryonic kidney, S1 and S2 of proximal tubules became unreactive for alpha2,3-linked sialic acid in postnatal and adult kidneys. In adult kidney, intercalated but not principal cells of collecting ducts were reactive for alpha2,3-linked sialic acid. In contrast, alpha2,6-linked sialic acids were detected in all cells of adult kidney nephron. Blot analysis revealed a different but steady pattern of bands reactive for alpha2,6- and alpha2,3-linked sialic acid in embryonic, postnatal, and adult kidney. Activity of alpha2,6 and alpha2,3 sialyltransferases was highest in embryonic kidney and decreased over postnatal to adult kidney with the activity of alpha2,6 sialyltransferase always being three to fourfold that of alpha2,3 sialyltransferase. Thus, alpha2,6- and alpha2,3-linked sialic acids are differently expressed in embryonic anlagen and mesenchyme-derived early stages of nephron and show regional and cell type-specific differences in adult kidney.
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Affiliation(s)
- Christian Zuber
- Division of Cell and Molecular Pathology, Department of Pathology, University of Zürich, Schmelzbergstrasse 12, 8091 Zürich, Switzerland
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13
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Holíková Z, Hrdlicková-Cela E, Plzák J, Smetana K, Betka J, Dvoránková B, Esner M, Wasano K, André S, Kaltner H, Motlík J, Hercogová J, Kodet R, Gabius HJ. Defining the glycophenotype of squamous epithelia using plant and mammalian lectins. Differentiation-dependent expression of alpha2,6- and alpha2,3-linked N-acetylneuraminic acid in squamous epithelia and carcinomas, and its differential effect on binding of the endogenous lectins galectins-1 and -3. APMIS 2002; 110:845-56. [PMID: 12645662 DOI: 10.1034/j.1600-0463.2002.1101202.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A thorough characterization of the properties of squamous epithelial cells is necessary in order to improve our understanding of the functional aspects of normal development and malignant aberrations. Up to now, studies have focused almost exclusively on monitoring distinct protein markers. With our growing awareness of the coding function of glycan chains of cellular glycoconjugates and their interaction with receptors (lectins) in situ, defining the glycophenotype of these cells has become an important issue. Whereas the commonly applied plant lectins are tools used to map the presence and localization of biochemically defined saccharide epitopes, the introduction of endogenous (mammalian) lectins to this analysis enables us to take the step from monitoring the presence of glycan to understanding the functional implications by revealing ligand properties of the detected epitope for tissue lectin. Thus, in this study we investigated a distinct aspect of glycosylation using plant and mammalian lectins, i.e. the linkage type of sialylation. We first mapped the expression profile of the type of sialylation (alpha2,3- or alpha2,6-linked) by plant lectins. Based on the hypothesis that this factor regulates accessibility of ligands for endogenous lectins we introduced two labeled galectins to this study. Galectin-3 (but not galectin-1) binding was related to cell differentiation in normal adult and developing epithelia, cultured epidermal cells, and carcinomas derived from these epithelia. The presented data suggest that alpha2,6-linked N-acetyl-D-neuraminic acid moieties could serve to mask galectin-3-reactive glycoepitopes. As a consequence, monitoring of the linkage type of sialic acid in glycans by plant lectins therefore has implications for the extent of glycan reactivity with endogenous lectins, pointing to a potential function of changes in sialylation type beyond these cell and lectin systems.
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Affiliation(s)
- Zuzana Holíková
- Charles University, 1st Faculty of Medicine, Institute of Anatomy, Prague, Czech Republic
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14
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Cao Y, Merling A, Crocker PR, Keller R, Schwartz-Albiez R. Differential expression of beta-galactoside alpha2,6 sialyltransferase and sialoglycans in normal and cirrhotic liver and hepatocellular carcinoma. J Transl Med 2002; 82:1515-24. [PMID: 12429811 DOI: 10.1097/01.lab.0000038503.34655.98] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
SUMMARY Sialyltransferases sialylate plasma glycoproteins in hepatocytes and may (as hepatic key enzymes) constitute markers for liver diseases. We examined expression of the prevalent alpha2,6 sialyltransferase (ST6Gal I) and sialoglycans in normal liver, cirrhotic liver, and hepatocellular carcinoma (HCC) using a new ST6Gal I-specific mAb and recombinant fusion proteins of CD22 and sialoadhesin recognizing alpha2,6- or alpha2,3-sialylated glycans in immunohistology and flow cytometry. In normal and cirrhotic liver, ST6Gal I and sialoglycans were localized in the Golgi region of hepatocytes surrounding the bile canaliculi and along the bile canaliculi, respectively. Sialoglycans were additionally recognized in Kupffer cells, bile ducts, endothelial cells, and oval cells. Well-differentiated and moderately differentiated HCC showed Golgi and diffuse cytoplasmic staining of ST6Gal I and sialoglycans, whereas the cytoplasmic staining for ST6Gal I and sialoglycans was decreased or even absent in poorly differentiated HCC. Detection of sialoglycans by the recombinant fusion proteins in Western blots of cell lysates derived from cell lines revealed two major double bands of sialoglycoproteins at 65 and 120 kDa for hepatocytes, three major bands at 54, 49, and 44 kDa for colonic epithelial cells, and one band at 60 kDa for endothelial cells. Our results describe the expression patterns of ST6Gal I and sialoglycans in various liver tissues and demonstrate an altered expression of these structures between benign and malignant hepatocellular lesions.
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Affiliation(s)
- Yi Cao
- Tumor Immunology Program, German Cancer Research Center, Heidelberg, Germany
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15
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Ishii M, Tsukise A, Meyer W. Lectin histochemistry of glycoconjugates in the feline hair follicle and hair. Ann Anat 2001; 183:449-58. [PMID: 11677811 DOI: 10.1016/s0940-9602(01)80203-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The distribution of glycoconjugate in the feline hair follicle and hair was studied by light and electron microscopic histochemical methods. The hair apparatus was found to contain considerable amounts of complex carbohydrates with different saccharide residues (alpha-D-mannose, beta-D-glucose, alpha-L-fucose, beta-N-acetyl-D-glucosamine). Variations of those were detected in the plasma membrane of the hair follicle cells during the course of their differentiation and keratinization, namely, alph-D-glucose, alpha-L-fucose and beta-N-acetyl-D-glucosamine in the suprabulbar and bulbar regions. The reaction level of sialic acid residues in the plasma membrane decreased in some cell layers during the course of differentiation. The results obtained from the present study indicated that interaction between saccharide residues of neutral carbohydrates and sialyl groups during the anagen phase might contribute to cell keratinization in hair follicles and hairs. It is discussed whether the existence of glycogen in outer root sheath cells might enable these cells to provide other hair apparatus cells with energy when necessary. Moreover, it became obvious from variations in sialyl residue distribution that cell differentiation processes terminate first of all in Huxley's and Henle's layers within the suprabulbar region of the hair follicle, as followed by the hair cortex.
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Affiliation(s)
- M Ishii
- Department of Veterinary Anatomy, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa 252-8510, Japan
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16
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Ulloa F, Real FX. Differential distribution of sialic acid in alpha2,3 and alpha2,6 linkages in the apical membrane of cultured epithelial cells and tissues. J Histochem Cytochem 2001; 49:501-10. [PMID: 11259453 DOI: 10.1177/002215540104900410] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
We used lectin cytochemistry and confocal microscopy to examine the distribution of sialic acid in epithelial cells. Maackia amurensis lectin and Sambuccus nigra agglutinin were used to detect alpha2,3 and alpha2,6 sialic acid, respectively. In Caco-2, HT-29 5M12, and MCF-7 cells, which express sialic acid mainly in one type of linkage, the majority of the signal was observed in the apical membrane. In cells that bound both lectins, alpha2,3 sialic acid was distributed apically, whereas alpha2,6 sialic acid showed a broader distribution. In IMIM-PC-1 cultures, alpha2,3 sialic acid was detected mainly in the apical membrane, whereas alpha2,6 sialic acid was more abundant in the basolateral domain of polarized cells. In these cells, treatment with GalNAc-O-benzyl led to reduced alpha2,3 levels and to an increase and redistribution of alpha2,6 to the apical domain. Similarly, sialic acid was predominantly expressed apically in all epithelial tissues examined. In conclusion, (a) sialic acid is mainly distributed to the apical membrane of epithelial cells, (b) there is a hierarchy in the distribution of sialic acids in polarized epithelial cells, i.e., alpha2,3 is preferred to alpha2,6 in the apical membrane, and (c) IMIM-PC-1 cells are a good model in which to study the regulation of the levels and distribution of sialic acids.
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Affiliation(s)
- F Ulloa
- Unitat de Biologia Cel.lular i Molecular, Institut Municipal d'Investigació Mèdica, Universitat Pompeu Fabra, Barcelona, Spain
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17
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Abstract
Sialylation represents one of the most frequently occurring terminations of the oligosaccharide chains of glycoproteins and glycolipids. Sialic acid is commonly found alpha2,3- or alpha2,6-linked to galactose (Gal), alpha2,6-linked to N-acetylgalactosamine (GalNAc) or alpha2,8-linked to another sialic acid. The biosynthesis of the various linkages is mediated by the different members of the sialyltransferase family. The addition of sialic acid in alpha2,6-linkage to the galactose residue of lactosamine (type 2 chains) is catalyzed by beta-galactoside alpha2,6-sialyltransferase (ST6Gal.I). Although expressed by a single gene, this enzyme shows a complex pattern of regulation which allows its tissue- and stage-specific modulation. The cognate oligosaccharide structure, NeuAcalpha2,6Galbeta1,4GlcNAc, is widely distributed among tissues and is involved in biological processes such as the regulation of the immune response and the progression of colon cancer. This review summarizes the current knowledge on the biochemistry of ST6Gal.I and on the functional role of the sialyl-alpha2,6-lactosaminyl structure.
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Affiliation(s)
- F Dall'Olio
- Dipartimento di Patologia Sperimentale, Università di Bologna, Italy
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18
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Toma V, Zuber C, Sata T, Roth J. Specialized expression of simple O-glycans along the rat kidney nephron. Glycobiology 1999; 9:1191-7. [PMID: 10536035 DOI: 10.1093/glycob/9.11.1191] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Glycosyltransferases can exhibit tissue-specific expression. By histochemistry glycosyltransferases and their products can be localized to specific cell types in organs of complex cellular composition. We have applied the lectin Amaranthin, having a nominal specificity for Galbeta1,3GalNAcR and Neu5Ac2,3Galbeta1, 3GalNAcalpha-R, and a monoclonal antibody raised against Galbeta1, 3GalNAcalphaR to examine the distribution of these simple O-glycans in adult rat kidney. The monoclonal antibody stained ascending thin limbs of Henle, distal convoluted tubules, and collecting ducts of cortex and outer medulla. Remarkably, the ascending thick limb of Henle, located between ascending thin limb and distal convoluted tubules, was unreactive. However, Amaranthin staining was detectable in ascending thick limbs of Henle, in addition to the structures positive with the monoclonal antibody. In kidney extracts, two bands of approximately 160 kDa and >210 kDa were reactive with both Amaranthin and the monoclonal antibody. One band at approximately 200 kDa, and a smear at approximately 100 kDa, were reactive only with Amaranthin. Our data show that in rat kidney simple O-linked glycans are expressed in a highly specialized manner along the renal tubule and can be detected only on a few glycoproteins. This may reflect a cell-type-specific expression of the corresponding glycosyltransferases.
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Affiliation(s)
- V Toma
- Division of Cell and Molecular Pathology, Department of Pathology, University of Zurich, CH-8091 Zurich, Switzerland
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19
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Le Marer N, Skacel PO. Up-regulation of alpha2,6 sialylation during myeloid maturation: a potential role in myeloid cell release from the bone marrow. J Cell Physiol 1999; 179:315-24. [PMID: 10228950 DOI: 10.1002/(sici)1097-4652(199906)179:3<315::aid-jcp9>3.0.co;2-u] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The mechanisms by which mature myeloid cells are released from the bone marrow into the peripheral blood are not clearly understood. Glycosylation is likely to play an important role, as has been shown in the homing of lymphocytes to lymph nodes and of neutrophils to inflamed endothelia. Cell surface sialylation is an important component of many cellular adhesive interactions, both as ligand-promoting interactions, as occurs in selectin and sialoadhesin-mediated adhesion, and for reducing cell adhesion as in some cancer cells. We have studied the expression of cell surface alpha2,6-linked sialic acid in the maturation of normal bone marrow myeloid cells, the expression of alpha2,6-sialyltransferase mRNA, and the role of sialylation in the adherence of myeloid cells to bone marrow stroma. Our data show that there is a dramatic increase in cell surface alpha2,6-sialylation during the late stage of maturation. This up-regulation is restricted to specific glycoproteins including CD11b and CD18. It is associated with a relative increase in the level of alpha2,6-sialyltransferase mRNA compared with alpha2,3-sialyltransferase mRNA. The changes in mature bone marrow myeloid cells are associated with reduced cell binding to fibronectin and cultured bone marrow stroma. Our data strongly suggest that alpha2,6-sialylation may be important in the interaction between maturing myeloid cells and bone marrow stroma and may govern the release of cells from the bone marrow into the peripheral blood.
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MESH Headings
- Antigens, CD34/analysis
- Antigens, CD34/genetics
- Antigens, CD34/metabolism
- Antigens, Surface/metabolism
- Blotting, Western
- Bone Marrow Cells/chemistry
- Bone Marrow Cells/cytology
- Bone Marrow Cells/enzymology
- CD11 Antigens/analysis
- CD11 Antigens/genetics
- CD11 Antigens/metabolism
- Cell Adhesion/immunology
- Cell Differentiation/immunology
- Cell Movement/immunology
- Fibronectins/metabolism
- Gene Expression Regulation, Enzymologic/immunology
- Glycosylation
- Humans
- Kinetics
- N-Acetylneuraminic Acid/metabolism
- Neutrophils/chemistry
- Neutrophils/cytology
- Neutrophils/enzymology
- RNA, Messenger/analysis
- Receptors, IgG/analysis
- Receptors, IgG/genetics
- Receptors, IgG/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Sialyltransferases/genetics
- Sialyltransferases/metabolism
- Up-Regulation/physiology
- beta-D-Galactoside alpha 2-6-Sialyltransferase
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Affiliation(s)
- N Le Marer
- Department of Haematology, Imperial College School of Medicine, London, United Kingdom
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20
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Keppler OT, Hinderlich S, Langner J, Schwartz-Albiez R, Reutter W, Pawlita M. UDP-GlcNAc 2-epimerase: a regulator of cell surface sialylation. Science 1999; 284:1372-6. [PMID: 10334995 DOI: 10.1126/science.284.5418.1372] [Citation(s) in RCA: 242] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Modification of cell surface molecules with sialic acid is crucial for their function in many biological processes, including cell adhesion and signal transduction. Uridine diphosphate-N-acetylglucosamine 2-epimerase (UDP-GlcNAc 2-epimerase) is an enzyme that catalyzes an early, rate-limiting step in the sialic acid biosynthetic pathway. UDP-GlcNAc 2-epimerase was found to be a major determinant of cell surface sialylation in human hematopoietic cell lines and a critical regulator of the function of specific cell surface adhesion molecules.
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Affiliation(s)
- O T Keppler
- Applied Tumor Virology Program, Tumor Immunology Program, Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany
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21
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Zhang X, Lok SH, Kon OL. Stable expression of human alpha-2,6-sialyltransferase in Chinese hamster ovary cells: functional consequences for human erythropoietin expression and bioactivity. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1425:441-52. [PMID: 9838208 DOI: 10.1016/s0304-4165(98)00095-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Hamster cell lines are common hosts for recombinant protein production, e.g. erythropoietin (Epo). Terminal sialylation of native human proteins is characteristically in both alpha-2,3 and alpha-2,6 linkage to galactose at the termini of N-linked oligosaccharides but only in alpha-2,3 linkage in recombinant proteins expressed in hamster cells which do not express alpha-2, 6-sialyltransferase (ST6GalI) (EC 2.4.99.1). This difference could alter the bioactivity of certain recombinant proteins. Chinese hamster ovary (CHO) cells stably transfected with human ST6GalI cDNA linked to the hamster metallothionein II promoter expressed highly inducible authentic ST6GalI activity. Untransfected CHO cells and CHO cells stably expressing ST6GalI cDNA when transfected with a human Epo cDNA expression cassette secreted immunoreactive Epo. Human Epo from singly transfected Pro-5 CHO cells induced significant reticulocytosis (7.00+/-1.58%; mean+/-S.D. % reticulocytes; control conditioned medium 3.04+/-1.29%; P<0.0024), whereas Epo from Pro-5 cells coexpressing ST6GalI elicited a more modest reticulocytosis (4.62+/-1.02%). Thus for recombinant human Epo, engineering CHO cells to express ST6GalI activity does not enhance Epo bioactivity in vivo in mice. The availability of CHO cells that express high levels of ST6GalI activity now enables systematic studies to determine the functional requirement for this form of sialylation in recombinant human proteins.
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Affiliation(s)
- X Zhang
- Department of Biochemistry, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Singapore
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22
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Gangopadhyay A, Perera SP, Thomas P. Differential expression of alpha2,6-sialyltransferase in colon tumors recognized by a monoclonal antibody. Hybridoma (Larchmt) 1998; 17:117-23. [PMID: 9627051 DOI: 10.1089/hyb.1998.17.117] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
It has been reported that alpha2,6-sialyltransferase (alpha2,6-ST; E.C. 2.4.99.1) activity is associated with cellular differentiation. To define its role in colon carcinoma differentiation, we have generated murine monoclonal antibodies (MAb) against alpha2,6-sialyltransferase. The MAb, designated 6B9 of IgM isotype, showed strong reactivity with the purified and crude alpha2,6-ST by ELISA and dot blot assays. Western blotting with MAb 6B9 identified purified alpha2,6-ST of MW 47 kDa and the same MW protein from rat and human liver extracts. The MAb also reacted with two other liver proteins of approximate MW 65 and 100 kDa. Immunoperoxidase studies with formalin-fixed paraffin-embedded tissues showed that MAb 6B9 reacts with liver tissues, the staining of hepatocytes was granular and cytoplasmic. There was a distinct pattern of zonal distribution of this enzyme in hepatocytes located particularly in the portal areas of the liver corresponding to zone 1. Normal colon (100%) and hyperplastic polyps (100%) showed very weak to no reactivity. Adenomas (100%) demonstrated moderate reactivity, while the poor (33%), moderate (100%) and well-differentiated (80%) colon adenocarcinomas showed strong reactivity. Results suggest that alpha2,6-ST is associated with the differentiation state of colon tumors.
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Affiliation(s)
- A Gangopadhyay
- Laboratory of Cancer Biology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA
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23
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Baum LG, Derbin K, Perillo NL, Wu T, Pang M, Uittenbogaart C. Characterization of terminal sialic acid linkages on human thymocytes. Correlation between lectin-binding phenotype and sialyltransferase expression. J Biol Chem 1996; 271:10793-9. [PMID: 8631891 DOI: 10.1074/jbc.271.18.10793] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
T cell surface sialylation changes during maturation in the thymus. We have previously demonstrated increased expression of mRNA encoding the Gal beta 1, 3GalNAc alpha 2,3-sialyltransferase in mature medullary human thymocytes, compared with immature cortical thymocytes. For this enzyme, increased expression of transferase mRNA correlated with increased sialylation of O-glycans. We have now examined the pattern of expression in the human thymus of two additional sialyltransferases, the Gal beta 1,4GlcNAc alpha 2,6-sialyltransferase (ST6N) and the Gal beta 1,3/4GlcNAc alpha 2,3-sialyltransferase (ST3N). The patterns of mRNA expression were compared with the pattern of binding of two sialic acid-specific plant lectins, Sambucus nigra agglutinin and Maackia amurensis agglutinin, which preferentially recognize alpha 2,6- and alpha 2,3-linked sialic acids, respectively, on N-glycans. By in situ hybridization, mRNA encoding ST3N was detected uniformly throughout the thymus. All thymocytes bound M. amurensis agglutinin, demonstrating a direct correlation between the level of ST3N mRNA expression and cell-surface glycosylation. In contrast, mRNA encoding ST6N was also expressed uniformly throughout the thymus; however, only mature (CD3hi) medullary thymocytes bound S. nigra agglutinin. On mature thymocytes, S. nigra agglutinin appeared to bind primarily to the cell-surface glycoprotein CD45; since only the mature thymocytes expressed the CD45RA isoform, while both mature and immature populations expressed the CD45R0 isoform, CD45RA may be a preferred substrate for ST6N. These results demonstrate that glycoprotein sialylation is tightly regulated during T cell development and that the developmentally regulated expression of specific oligosaccharide structures on the cell surface may be influenced by expression of both the relevant glycosyltransferase and specific acceptor substrates.
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Affiliation(s)
- L G Baum
- Department of Pathology, UCLA School of Medicine 90024-1732, USA
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24
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Yamamoto H, Kaneko Y, Vandermulen D, Kersey D, Mkrdichian E, Cerullo L, Leestma J, Moskal JR. The expression of CMP-NeuAc: Gal beta 1,4GlcNAc alpha 2,6 sialyltransferase [EC 2.4.99.1] and glycoproteins bearing alpha 2,6-linked sialic acids in human brain tumours. Glycoconj J 1995; 12:848-56. [PMID: 8748163 DOI: 10.1007/bf00731247] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The expression of CMP-NeuAc: Gal beta 1,4GlcNAc alpha 2,6 sialyltransferase (alpha 2,6-ST) [EC 2.4.99.1] and glycoproteins bearing alpha 2,6-linked sialic acids were examined in primary human brain tumours and cell lines. 79% (19/24) of the meningiomas expressed alpha 2,6-ST mRNA, 42% (10/24) of which showed very high expression. alpha 2,6-ST mRNA expression was undetectable in normal brain tissue. In contrast, only 1/13 of the gliomas examined expressed detectable alpha 2,6-ST mRNA. Metastases to the brain did not express measurable amounts of alpha 2,6-ST mRNA. Less expression was found in malignant (i.e. anaplastic) compared to benign (i.e. meningothelial) meningiomas. Two-dimensional SDS-PAGE of glioma and meningioma proteins, followed by Sambucus nigra lectin staining, revealed the presence of a glycoprotein bearing alpha 2,6-linked sialic acids, M(r) = 53 kDa and a pI = 7.0 (MEN-1) that appeared in all seven of the meningiomas examined, but was expressed at barely detectable levels, if at all, in seven out of the seven glioblastomas examined. Thus, decreased alpha 2,6-ST expression may play a role in the aggressive nature of anaplastic meningiomas, but appears to be virtually absent in all tumours of glial origin.
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Affiliation(s)
- H Yamamoto
- Chicago Institute of Neurosurgery and Neuroresearch, IL 60614, USA
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