Different glycoforms of alpha-1-acid glycoprotein contribute to its functional alterations in platelets and neutrophils

Sumanth, M. S. and Shancy P. Jacob and Abhilasha, K. V. and Manne, Bhanu Kanth and Venkatesha, B. and Lehoux, Sylvain and Campbell, Robert A. and Yost, Christian C. and McIntyre, Thomas M. and Cummings, Richard D. and Weyrich, Andrew S. and Rondina, Matthew T. and Marathe, Gopal K. (2021) Different glycoforms of alpha-1-acid glycoprotein contribute to its functional alterations in platelets and neutrophils. Journal of Leukocyte Biology, 109 (5). pp. 915-930. ISSN 1938-3673

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Official URL: https://doi.org/10.1002/JLB.3A0720-422R


Alpha-1-acid glycoprotein (AGP-1) is a positive acute phase glycoprotein with uncertain functions. Serum AGP-1 (sAGP-1) is primarily derived from hepatocytes and circulates as 12-20 different glycoforms. We isolated a glycoform secreted from platelet-activating factor (PAF)-stimulated human neutrophils (nAGP-1). Its peptide sequence was identical to hepatocyte-derived sAGP-1, but nAGP-1 differed from sAGP-1 in its chromatographic behavior, electrophoretic mobility, and pattern of glycosylation. The function of these 2 glycoforms also differed. sAGP-1 activated neutrophil adhesion, migration, and neutrophil extracellular traps (NETosis) involving myeloperoxidase, peptidylarginine deiminase 4, and phosphorylation of ERK in a dose-dependent fashion, whereas nAGP-1 was ineffective as an agonist for these events. Furthermore, sAGP-1, but not nAGP-1, inhibited LPS-stimulated NETosis. Interestingly, nAGP-1 inhibited sAGP-1-stimulated neutrophil NETosis. The discordant effect of the differentially glycosylated AGP-1 glycoforms was also observed in platelets where neither of the AGP-1 glycoforms alone stimulated aggregation of washed human platelets, but sAGP-1, and not nAGP-1, inhibited aggregation induced by PAF or ADP, but not by thrombin. These functional effects of sAGP-1 correlated with intracellular cAMP accumulation and phosphorylation of the protein kinase A substrate vasodilator-stimulated phosphoprotein and reduction of Akt, ERK, and p38 phosphorylation. Thus, the sAGP-1 glycoform limits platelet reactivity, whereas nAGP-1 glycoform also limits proinflammatory actions of sAGP-1. These studies identify new functions for this acute phase glycoprotein and demonstrate that the glycosylation of AGP-1 controls its effects on 2 critical cells of acute inflammation.

Item Type: Article
Subjects: C Chemical Science > Biochemistry
Divisions: Department of > Biochemistry
Depositing User: Mr Umendra uom
Date Deposited: 10 Mar 2021 06:18
Last Modified: 24 Jun 2022 10:52
URI: http://eprints.uni-mysore.ac.in/id/eprint/15490

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