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Lorenz L, Amann B, Hirmer S, Degroote RL, Hauck SM, Deeg CA. NEU1 is more abundant in uveitic retina with concomitant desialylation of retinal cells. Glycobiology 2021; 31:873-883. [PMID: 33677598 DOI: 10.1093/glycob/cwab014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 02/05/2021] [Accepted: 02/05/2021] [Indexed: 12/16/2022] Open
Abstract
Desialylation of cell surface glycoproteins carried out by sialidases affects various immunological processes. However, the role of neuraminidase 1 (NEU1), one of four mammalian sialidases, in inflammation and autoimmune disease is not completely unraveled to date. In this study, we analyzed retinal expression of NEU1 in equine recurrent uveitis (ERU), a spontaneous animal model for autoimmune uveitis. Mass spectrometry revealed significantly higher abundance of NEU1 in retinal Müller glial cells (RMG) of ERU-diseased horses compared to healthy controls. Immunohistochemistry uncovered NEU1 expression along the whole Müller cell body in healthy and uveitic state and confirmed higher abundance in inflamed retina. Müller glial cells are the principal macroglial cells of the retina and play a crucial role in uveitis pathogenesis. To determine whether higher expression levels of NEU1 in uveitic RMG correlate with desialylation of retinal cells, we performed lectin binding assays with sialic acid-specific lectins. Through these experiments we could demonstrate a profound loss of both α2-3- and α2-6-linked terminal sialic acids in uveitis. Hence, we hypothesize that higher abundance of NEU1 in uveitic RMG plays an important role in the pathogenesis of uveitis by desialylation of retinal cells. As RMG become activated in the course of uveitis and actively promote inflammation, we propose that NEU1 might represent a novel activation marker for inflammatory RMG. Our data provide novel insights in the expression and implication of NEU1 in inflammation and autoimmune disease.
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Affiliation(s)
- Lea Lorenz
- Chair of Physiology, Department of Veterinary Sciences, LMU Munich, 82152 Martinsried, Germany
| | - Barbara Amann
- Chair of Physiology, Department of Veterinary Sciences, LMU Munich, 82152 Martinsried, Germany
| | - Sieglinde Hirmer
- Chair of Physiology, Department of Veterinary Sciences, LMU Munich, 82152 Martinsried, Germany
| | - Roxane L Degroote
- Chair of Physiology, Department of Veterinary Sciences, LMU Munich, 82152 Martinsried, Germany
| | - Stefanie M Hauck
- Research Unit Protein Science, Helmholtz Center Munich, German Research Center for Environmental Health (GmbH), 80939 Munich, Germany
| | - Cornelia A Deeg
- Chair of Physiology, Department of Veterinary Sciences, LMU Munich, 82152 Martinsried, Germany
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Hernandez-R J, Boyzo A, Mercadoc R. Activity of sialidases in fetal brain axonal growth cones and during postnatal development. Int J Dev Neurosci 1999; 17:15-20. [PMID: 10219956 DOI: 10.1016/s0736-5748(98)00061-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In the present work the cytosolic, membrane-bound and the total activities of brain sialidases were measured in fetal axonal growth cone particles and in various brain regions during brain development. The developmental profile showed an important activity in the prenatal and perinatal periods as well as in specific differentiating structures like the axonal growth cones from the fetal brain. Interestingly membrane-bound activity was higher than the cytosolic activity, starting from 50-60% at birth and increasing thereafter. Cytosolic activity was almost at adult levels at birth and did not show a further significant increase thereafter. Our results strongly suggest the commitment of membrane-bound sialidase activity in early neurodifferentiating phenomena like axogenesis, probably regulating the turnover of glycoconjugates like gangliosides at the presynaptic period, since high activity was observed in neuroblast's derived membranes and in the perinatal period.
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Affiliation(s)
- J Hernandez-R
- Department of Physiology, Biophysics and Neurosciences, Centro de Investigacion y de Estudios Avanzados del IPN, Universidad Autonoma de Queretaro, Mexico.
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Tarnowski BI, McLaughlin BJ. Phagocytic interactions of sialated glycoprotein, sugar, and lectin coated beads with rat retinal pigment epithelium. Curr Eye Res 1987; 6:1079-89. [PMID: 3665564 DOI: 10.3109/02713688709034880] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Latex beads coated with mucin (a sialic acid containing glycoconjugate), N-acetylglucosamine (GlcNAc), or with the lectins, succinylated wheat germ agglutinin (sWGA) (binds to GlcNAc) or Limax flavus agglutinin (LFA) (binds to sialic acid residues) were used as phagocytic particles. Phagocytosis of these coated beads by retinal pigment epithelial (RPE) explants was determined by bead uptake in normal (Long Evans) and dystrophic (Royal College of Surgeons, RCS/p+) rat retinas. Electron microscopy showed that beads coated with mucin or LFA lectin were not phagocytized by either dystrophic or normal RPE. sWGA-coated beads were phagocytized by both dystrophic and normal RPE, while GlcNAc-coated beads were taken up by dystrophic RPE only. Specificity of uptake for sWGA and GlcNAc bead coatings was shown by the reduction in the number of beads phagocytized in the presence of the appropriate competing sugar or lectin. The lack of phagocytic uptake of beads coated with a sialated glycoprotein or a sialic acid binding lectin suggests that sialic acid residues are not recognized as particulate ligands in this phagocytic assay. The data which show the uptake of beads coated with sWGA (binds only GlcNAc) together with results which showed WGA (binds both GlcNAc and sialic acid)-coated beads were not taken up, further suggest that GlcNAc residues may be involved in bead phagocytosis. The most striking difference between normal and dystrophic RPE engulfment of coated beads is the uptake of GlcNAc-coated beads by dystrophic RPE only. These results suggest that the receptor molecules on dystrophic RPE cell surface membranes may be different from those on normal RPE membranes.
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Affiliation(s)
- B I Tarnowski
- Department of Anatomy and Neurobiology, University of Tennessee, Memphis 38163
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Leskawa KC, Agranoff BW. Properties of endogenous, membrane-associated sialidase activity (N-acetylneuraminidase) of the goldfish visual system. Neurochem Res 1983; 8:99-112. [PMID: 6856020 DOI: 10.1007/bf00965657] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The endogenous sialidase (N-acetylneuraminidase) activity of membranes prepared from goldfish retina and optic tectum displays characteristics similar to those reported for neural plasma membrane sialidases of other organisms. Endogenous membrane sialidase activity was found to be optimal at ph 4.0, and maximal release was obtained at 37-50 degrees C, above which temperature thermal instability of the preparations was observed. Optic nerve crush, which results in regeneration of retinal ganglion cell axons, did not result in significant changes in measured endogenous membrane sialidase activity in either the retina or the optic tectum. Enzymatic hydrolysis of membrane sialoglycolipid (ganglioside) accounted for about 70% of the total sialic acid released. Ganglioside GM1 accumulated as the major lipid product in both retina and tectum, indicating that the inner sialosylgalactosyl linkage in the ganglio oligosaccharide series was resistant to hydrolysis by the endogenous enzyme.
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Dreyfus H, Preti A, Harth S, Pellicone C, Virmaux N. Neuraminidase in calf retinal outer segment membranes. J Neurochem 1983; 40:184-8. [PMID: 6848659 DOI: 10.1111/j.1471-4159.1983.tb12669.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
An enzyme catalyzing the hydrolysis of sialic acid (N-acetylneuraminic acid: NeuNAc)-containing glycoconjugates has been found in bovine retinal rod outer segment (ROS) membranes. The enzymatic activity is optimal at pH 4.0 and is stimulated by 0.15% Triton X-100. Total activity was determined by the release of NeuNac from endogenous and exogenous substrates (GD1a). The ROS enzyme preferentially hydrolyses the ROS gangliosides, possibly because they are more accessible than the glycoproteins as substrates for the neuraminidase. Release of NeuNAc from gangliosides leads to important changes in the ganglioside patterns; whereas the amounts of GM1 increased throughout the incubation, the levels of polysialogangliosides GT1b and GD3 diminished owing to their rapid hydrolysis. The finding that gangliosides are hydrolysed more extensively than glycoproteins suggests that endogenous ROS gangliosides may be the principal source of metabolically available sialic acid in ROS. It was also observed that the activity of ROS neuraminidase is not affected by illumination of the membranes.
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Massarelli R, Wong TY, Harth S, Louis JC, Freysz L, Dreyfus H. Possible role of sialocompounds in the uptake of choline into synaptosomes and nerve cell cultures. Neurochem Res 1982; 7:301-16. [PMID: 7110505 DOI: 10.1007/bf00965642] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Incubation of primary nerve cell cultures and of crude synaptosomal preparations with neuraminidase released sialic acid from both gangliosides and sialoglycoproteins. After this treatment, the pattern of ganglioside distribution was severely modified with a decrease of polysialogangliosides (GD1b, GT1b, Gt1L, GQ1) and a dramatic increase in monosialoganglioside GM1. The choline influx into neuraminidase treated cells and organelles was reduced by 30--50% but the efflux was unmodified. In particular the high affinity mechanism of choline uptake disappeared and the low affinity mechanism was modified in both cases. The disappearance of the high affinity uptake mechanism was not followed by a decreased acetylcholine synthesis as it should be if the current theories on choline uptake and acetylcholine synthesis are correct. Our present data thus confirm our previous hypothesis that choline metabolism regulates choline uptake rather than the other way round as is suggested by the theories most widely accepted at present. Choline uptake was unaffected by pretreatment of cells and organelles with tetanus toxin suggesting that the effect of neuraminidase on the choline uptake were either mediated through glycoproteins or through gangliosides other than those which bind to tetanus toxin (GD1b and GT1b). Several speculative models for explaining the effect of neuraminidase on choline uptake are proposed.
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Freysz L, Harth S, Dreyfus H. Topographic distribution of enzymes synthesizing phosphatidylcholine and phosphatidylethanolamine in chicken brain microsomes. J Neurochem 1982; 38:582-7. [PMID: 7108558 DOI: 10.1111/j.1471-4159.1982.tb08666.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The localization of phosphatidylethanolamine and phosphatidylcholine biosynthetic enzymes within the transverse plane of chicken brain microsomes was investigated by using proteases (trypsin and pronase) and neuraminidase. Treatment of intact microsomes with the proteases inactivated the phosphocholine transferase completely and the ethanolamine phosphotransferase only slightly. This latter enzyme was, however, completely inactivated when deoxycholate-treated microsomes were exposed to proteases. Treatment of intact microsomes with neuraminidase had no effect on both phosphotransferases, although 65% of the sialic acid of sialoglycoproteins and 37% of that of gangliosides were removed. With deoxycholate-disrupted microsomes nearly all sialic acid from the sialoglycoproteins and about 70% of that of gangliosides were released. In parallel, the phosphoethanolamine transferase was 90% inactivated. It is suggested that phosphocholine transferase is localized on the outer face of the microsomal vesicle, whereas the phosphoethanolamine transferase could be a sialoglycoprotein, possibly situated on the inner face of the vesicle, or perhaps a transmembrane protein.
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Abstract
Embryonic retina cells incorporated radioactivity from D-[6-3H]glucosamine into gangliosides in vitro. The incorporation was higher in retinas from younger embryos. The pattern of labeling of individual gangliosides of the retina changed gradually from a predominant labeling of gangliosides running chromatographically as GD3 (nomenclature of Svennerholm) and GM3 in retinas from 8-day-old embryos to a predominant labeling of those running as GD1a and GT1 in retinas from 13--18-day-old embryos and newly hatched chicks. The shift in the pattern of labeling correlated with a temporary increase of about sixfold of the activity of UDP-N-acetylgalactosamine:GM3 N-acetylgalactosaminyltransferase occurring between days 8 and 14 of embryonic development and with a regular increase of the activity of the UDP-galactose:GM2 galactosyltransferase occurring from day 8 until hatching. The activities of the CMP-NeuAc:lactosylceramide-, CMP-NeuAc:GM3-, and CMP-NeuAc:GM1-sialosyltransferases in the retinas of newly hatched chicks were 40, 20, and 40% in comparison with the corresponding activities determined in retinas of the 8-day-old embryo.
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Schiller H, Seagler K, Jeserich G, Rösner H, Rahmann H. Properties of membrane-bound neuraminidase in the developing trout brain. Life Sci 1979; 25:2029-33. [PMID: 43941 DOI: 10.1016/0024-3205(79)90193-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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10
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Preti A, Fiorilli A, Dreyfus H, Harth S, Urban PF, Mandel P. Developmental studies of the catabolism of sialocompounds by endogenous neuraminidase in the chick retina. Exp Eye Res 1978; 26:621-8. [PMID: 680019 DOI: 10.1016/0014-4835(78)90096-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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11
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Sieber-Blum M, Cohen AM. Lectin binding to neural crest cells. Changes of the cell surface during differentiation in vitro. J Biophys Biochem Cytol 1978; 76:628-38. [PMID: 632323 PMCID: PMC2110013 DOI: 10.1083/jcb.76.3.628] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
To examine possible changes in cell surface carbohydrates, fluorescent lectins were applied at various times during differentiation of neural crest cells in vitro. The pattern and intensity of binding of several lectins changed as the crest cells developed into melanocytes and adrenergic cells. Considerable amounts of concanavalin A (Con A) and wheat germ agglutinin (WGA) bound to all unpigmented cells throughout the culture period. Melanocytes, however, bound much less of these lectins. Soy bean agglutinin (SBA), unlike Con A and WGA, only bound later in development to unpigmented cells at about the time when catecholamines were detected histochemically. Binding of SBA could be induced in younger cultures by pretreating the cells with neuraminidase. Melanocytes, however, did not bind detectable amounts of SBA even if treated with neuraminidase. The SBA-binding sites were often concentrated on cytoplasmic extensions and on contact points between neighboring cells, even when receptor mobility was restricted by prefixation of the cells or adsorption of lectin at 0 degrees C. All three lectins bound to cell processes resembling nerve fibers in particularly high amounts.
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12
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Dreyfus H, Harth S, Preti A, Urban PF, Mandel P. Studies on retinal ganglioside metabolism. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1978; 101:655-65. [PMID: 665385 DOI: 10.1007/978-1-4615-9071-2_61] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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13
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Lipids of Chick Retina during Ontogenesis. Brain 1977. [DOI: 10.1007/978-94-011-8884-5_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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