DAMP
DAMPs (Damage Associated Molecular Patterns) or alarmins are molecules most often intracellular in the physiological state, which are released into the extracellular environment (passively during cell death or actively during cellular stress).
Examples of DAMP
The intracellular components usually contained in the cytosol (uric acid, ATP, heat shock proteins (HSP), etc.), the nucleus (DNA, RNA, histones, IL-1α, etc.), the mitochondria (mitochondrial DNA, etc.), the endoplasmic reticulum (calreticulin), the plasma membrane (proteoglycans such as glypicans and syndecans) correspond to DAMPs when they are released at the extra-cellular level.
Following tissue injury, molecules derived from the extracellular matrix can also be released and be recognised as DAMPs (hyaluronic acid, heparin, fibrinogen, etc.).
DAMP receptors
The receptors for DAMPs are PRRs (Pattern Recognition Receptors), whose downstream pathways are mainly pro-inflammatory.
What needs to be remembered
DAMPs are non-specific molecular patterns indicating cellular and/or tissue damage. They are recognised by PRRs whose downstream pathways generate pro-inflammatory and chemoattractant cytokines, which will notably recruit the players of innate immunity to set up the inflammatory response.
