Redox modifications of cysteine residues regulate the cytokine activity of HMGB1

Molecular Medicine

Yousef Al-Abed¹  Helena Erlandsson-Harris²  Peter Lundbäck²  Lars Ottosson³  Ulf Andersson³  Huan Yang⁴  Kevin J. Tracey⁴  Emilie Venereau⁵  Marco E. Bianchi⁶ 

[1] Center for Molecular Innovation, Feinstein Institutes for Medical Research, Northwell Health, Manhasset, NY, USA;Department of Medicine, Center for Molecular Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden;Department of Women’s and Children’s Health, Karolinska Institutet, Stockholm, Sweden;Laboratory of Biomedical Science, The Feinstein Institute for Medical Research, Manhasset, NY, USA;Vita-Salute San Raffaele University, Milan, Italy;Vita-Salute San Raffaele University, Milan, Italy;Division of Genetics and Cell Biology, Chromatin Dynamics Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy;

关键词: HMGB1;    Isoforms;    TLR4;    Redox;    Cytokine;    Receptor;    Inflammation;   

DOI  :  10.1186/s10020-021-00307-1

来源: Springer

【 摘 要 】

BackgroundHigh 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.MethodsPrimary 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.ResultsCell 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.ConclusionsThese results reveal critical post-translational redox mechanisms that control the proinflammatory activity of HMGB1 and its inactivation during inflammation.

【 授权许可】

CC BY