Cargando…

Control of Innate Immunity by Sialic Acids in the Nervous Tissue

Sialic acids (Sias) are the most abundant terminal sugar residues of glycoproteins and glycolipids on the surface of mammalian cells. The nervous tissue is the organ with the highest expression level of Sias. The ‘sialylation’ of glycoconjugates is performed via sialyltransferases, whereas ‘desialyl...

Descripción completa

Detalles Bibliográficos
Autores principales: Liao, Huan, Klaus, Christine, Neumann, Harald
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7432451/
https://www.ncbi.nlm.nih.gov/pubmed/32752058
http://dx.doi.org/10.3390/ijms21155494
_version_ 1783571801314426880
author Liao, Huan
Klaus, Christine
Neumann, Harald
author_facet Liao, Huan
Klaus, Christine
Neumann, Harald
author_sort Liao, Huan
collection PubMed
description Sialic acids (Sias) are the most abundant terminal sugar residues of glycoproteins and glycolipids on the surface of mammalian cells. The nervous tissue is the organ with the highest expression level of Sias. The ‘sialylation’ of glycoconjugates is performed via sialyltransferases, whereas ‘desialylation’ is done by sialidases or is a possible consequence of oxidative damage. Sialic acid residues on the neural cell surfaces inhibit complement and microglial activation, as well as phagocytosis of the underlying structures, via binding to (i) complement factor H (CFH) or (ii) sialic acid-binding immunoglobulin-like lectin (SIGLEC) receptors. In contrast, activated microglial cells show sialidase activity that desialylates both microglia and neurons, and further stimulates innate immunity via microglia and complement activation. The desialylation conveys neurons to become susceptible to phagocytosis, as well as triggers a microglial phagocytosis-associated oxidative burst and inflammation. Dysfunctions of the ‘Sia–SIGLEC’ and/or ‘Sia–complement’ axes often lead to neurological diseases. Thus, Sias on glycoconjugates of the intact glycocalyx and its desialylation are major regulators of neuroinflammation.
format Online
Article
Text
id pubmed-7432451
institution National Center for Biotechnology Information
language English
publishDate 2020
publisher MDPI
record_format MEDLINE/PubMed
spelling pubmed-74324512020-08-24 Control of Innate Immunity by Sialic Acids in the Nervous Tissue Liao, Huan Klaus, Christine Neumann, Harald Int J Mol Sci Review Sialic acids (Sias) are the most abundant terminal sugar residues of glycoproteins and glycolipids on the surface of mammalian cells. The nervous tissue is the organ with the highest expression level of Sias. The ‘sialylation’ of glycoconjugates is performed via sialyltransferases, whereas ‘desialylation’ is done by sialidases or is a possible consequence of oxidative damage. Sialic acid residues on the neural cell surfaces inhibit complement and microglial activation, as well as phagocytosis of the underlying structures, via binding to (i) complement factor H (CFH) or (ii) sialic acid-binding immunoglobulin-like lectin (SIGLEC) receptors. In contrast, activated microglial cells show sialidase activity that desialylates both microglia and neurons, and further stimulates innate immunity via microglia and complement activation. The desialylation conveys neurons to become susceptible to phagocytosis, as well as triggers a microglial phagocytosis-associated oxidative burst and inflammation. Dysfunctions of the ‘Sia–SIGLEC’ and/or ‘Sia–complement’ axes often lead to neurological diseases. Thus, Sias on glycoconjugates of the intact glycocalyx and its desialylation are major regulators of neuroinflammation. MDPI 2020-07-31 /pmc/articles/PMC7432451/ /pubmed/32752058 http://dx.doi.org/10.3390/ijms21155494 Text en © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Review
Liao, Huan
Klaus, Christine
Neumann, Harald
Control of Innate Immunity by Sialic Acids in the Nervous Tissue
title Control of Innate Immunity by Sialic Acids in the Nervous Tissue
title_full Control of Innate Immunity by Sialic Acids in the Nervous Tissue
title_fullStr Control of Innate Immunity by Sialic Acids in the Nervous Tissue
title_full_unstemmed Control of Innate Immunity by Sialic Acids in the Nervous Tissue
title_short Control of Innate Immunity by Sialic Acids in the Nervous Tissue
title_sort control of innate immunity by sialic acids in the nervous tissue
topic Review
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7432451/
https://www.ncbi.nlm.nih.gov/pubmed/32752058
http://dx.doi.org/10.3390/ijms21155494
work_keys_str_mv AT liaohuan controlofinnateimmunitybysialicacidsinthenervoustissue
AT klauschristine controlofinnateimmunitybysialicacidsinthenervoustissue
AT neumannharald controlofinnateimmunitybysialicacidsinthenervoustissue