Peptidyl Arginine Deiminase 4 and Rheumatoid Arthritis at the 2017 EULAR Annual Meeting in Madrid

Peptidyl arginine deiminase type 4 (PADI4) converses arginine residues to citrulline [1]. PADI4 is normally expressed in the cytoplasm, nucleus and in cytoplasmic granules of eosinophils and neutrophils. And, now we become vigilant, PADI4 is also expressed in rheumatoid arthritis synovial tissues.

There had been just one study at the 2017 EULAR Annual Meeting in Madrid addressing peptidyl arginine deiminase 4 (PADI4).

K. Yamamoto presented [2]: “PEPTIDYL ARGININE DEIMINASE 4 AND RHEUMATOID ARTHRITIS: FROM HUMAN GENETICS TO MURINE MODELS”. The idea is that increased PADI4 is associated with increased citrullinated proteins like ACPA. PADI4 polymorphisms highly predispose male smokers to rheumatoid arthritis. As “the mechanisms of PAD4 involvement turned out to be more complex than previously thought in animal models”, PADI4 knockout mice were created to investigate the pathological process in detail. Dr. Yamamoto sees different roles for PADI4 in the immune system, when he compared neutrophil extracellular traps (NETs), which rewuire PADI4 to be generated, in rheumatoid arthritis and systemic lupus erythematodes.

So we see the advent of more basic research to elucidate the pathogenesis of inflammatory rheumatic diseases.

Links and References:

[1] https://en.wikipedia.org/wiki/PADI4

[2] DOI: 10.1136/annrheumdis-2017-eular.7136

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