Redox modifications of cysteine residues regulate the cytokine activity of HMGB1.

Yang, Huan, Lundbäck, Peter, Ottosson, Lars, Erlandsson-Harris, Helena, Venereau, Emilie, Bianchi, Marco E, Al-Abed, Yousef, Andersson, Ulf, Tracey, Kevin J (June 2021) Redox modifications of cysteine residues regulate the cytokine activity of HMGB1. Molecular Medicine, 27 (1). p. 58. ISSN 1076-1551

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Abstract

BACKGROUND: High mobility group box 1 (HMGB1) is a nuclear protein with extracellular inflammatory cytokine activity. It is passively released during cell death and secreted by activated cells of many lineages. HMGB1 contains three conserved redox-sensitive cysteine residues: cysteines in position 23 and 45 (C23 and C45) can form an intramolecular disulfide bond, whereas C106 is unpaired and is essential for the interaction with Toll-Like Receptor (TLR) 4. However, a comprehensive characterization of the dynamic redox states of each cysteine residue and of their impacts on innate immune responses is lacking. METHODS: Primary human macrophages or murine macrophage-like RAW 264.7 cells were activated in cell cultures by redox-modified or point-mutated (C45A) recombinant HMGB1 preparations or by lipopolysaccharide (E. coli.0111: B4). Cellular phosphorylated NF-κB p65 subunit and subsequent TNF-α release were quantified by commercial enzyme-linked immunosorbent assays. RESULTS: Cell cultures with primary human macrophages and RAW 264.7 cells demonstrated that fully reduced HMGB1 with all three cysteines expressing thiol side chains failed to generate phosphorylated NF-КB p65 subunit or TNF-α. Mild oxidation forming a C23-C45 disulfide bond, while leaving C106 with a thiol group, was required for HMGB1 to induce phosphorylated NF-КB p65 subunit and TNF-α production. The importance of a C23-C45 disulfide bond was confirmed by mutation of C45 to C45A HMGB1, which abolished the ability for cytokine induction. Further oxidation of the disulfide isoform also inactivated HMGB1. CONCLUSIONS: These results reveal critical post-translational redox mechanisms that control the proinflammatory activity of HMGB1 and its inactivation during inflammation.

Item Type:	Paper
Subjects:	bioinformatics diseases & disorders bioinformatics > genomics and proteomics > genetics & nucleic acid processing bioinformatics > genomics and proteomics Investigative techniques and equipment bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification Investigative techniques and equipment > biomarker organs, tissues, organelles, cell types and functions > cell types and functions > cell types organs, tissues, organelles, cell types and functions > cell types and functions > cell types organs, tissues, organelles, cell types and functions > cell types and functions > cell types organs, tissues, organelles, cell types and functions > cell types and functions diseases & disorders > inflammation > cytokines diseases & disorders > inflammation organs, tissues, organelles, cell types and functions > cell types and functions > cell types > macrophages organs, tissues, organelles, cell types and functions > cell types and functions > cell types > macrophages organs, tissues, organelles, cell types and functions > cell types and functions > cell types > macrophages organs, tissues, organelles, cell types and functions bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein expression > phosphorylation bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein expression organs, tissues, organelles, cell types and functions > tissues types and functions > signal transduction organs, tissues, organelles, cell types and functions > tissues types and functions
CSHL Authors:	Tracey, Kevin
Communities:	CSHL labs > Tracey lab
SWORD Depositor:	CSHL Elements
Depositing User:	CSHL Elements
Date:	7 June 2021
Date Deposited:	05 Aug 2021 14:42
Last Modified:	25 Jan 2024 21:11
PMCID:	PMC8185929
URI:	https://repository.cshl.edu/id/eprint/40309

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