S100-alarmins: potential therapeutic targets for arthritis

ABSTRACT

Introduction: In arthritis, inflammatory processes are triggered by numerous factors that are released from joint tissues, promoting joint destruction and pathological progression. During inflammation, a novel family of pro-inflammatory molecules called alarmins is released, amplifying inflammation and joint damage.

Areas covered: With regard to the role of the alarmins S100A8 and S100A9 in the pathogenesis of arthritis, recent advances and the future prospects in terms of therapeutic implications are considered.

Expert opinion: There is still an urgent need for novel treatment strategies addressing the local mechanisms of joint inflammation and tissue destruction, offering promising therapeutic alternatives. S100A8 and S100A9, which are the most up-regulated alarmins during arthritis, are endogenous triggers of inflammation, defining these proteins as promising targets for local suppression of arthritis. In murine models, the blockade of S100A8/S100A9 ameliorates inflammatory processes, including arthritis, and there are several lines of evidence that S100-alarmins may already be targeted in therapeutic approaches in man.

KEYWORDS:

• Alarmins
• new diagnostic tools
• rheumatoid arthritis
• S100A8
• S100A9

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Erratum

Article highlights

• Alarmins drive local inflammatory processes.

• S100A8 and S100A9 are the most abundant alarmins in many forms of arthritis.

• Murine models and human data point to an active role of S100 alarmins in the destructive pathogenesis of arthritis.

• Inhibitors of S100A8/S100A9 have effectively been used in clinical trials for chronic inflammatory diseases.

• The immune-modulatory effects of alarmins, such as S100 proteins, HMGB1, and HSPs, may also be therapeutically useful.

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Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Additional information

Funding

This work was supported by Grants of the Interdisciplinary Center of Clinical Research at the University of Münster (Ro2/003/15), the German Research Foundation (DFG) [CRC 1009 B9], the Federal Ministry of Education and Research (BMBF) project AID-NET, the Innovative Medical Research at the University of Münster [AU121327 and AU211603] and Cells-in-Motion Cluster of Excellence (CIM) at the University of Münster [PP-2016-11].