Protein S100-A8 (S100A8) (S100A8)

Protein S100-A8 (S100A8), also known as MRP8, is a calcium-binding protein that acts as a potent alarmin or damage-associated molecular pattern (DAMP) in the innate immune system (UniProt P05109). It is primarily expressed in neutrophils and monocytes and is released into the extracellular environment during tissue injury or infection (PubMed: 29038500). While it can form homodimers, it most commonly functions as a heterodimer with S100A9, a complex known as calprotectin (PubMed: 21903672). Extracellular S100A8 dimers signal through receptors such as Toll-like receptor 4 (TLR4) and the Receptor for Advanced Glycation End-products (RAGE) to promote leukocyte recruitment and cytokine production (PubMed: 25610005). This protein plays a critical role in the progression of chronic inflammatory diseases, including rheumatoid arthritis, psoriasis, and inflammatory bowel disease (PubMed: 22410872). In oncology, S100A8 is involved in creating a pre-metastatic niche and promoting tumor cell migration and survival (PubMed: 28277538). Therapeutic targeting of S100A8 often involves small molecules like quinoline-3-carboxamides, such as Paquinimod and Tasquinimod, which inhibit its interaction with pro-inflammatory receptors (PubMed: 26361057). Clinical monitoring of S100A8/A9 levels is widely used as a biomarker for assessing disease activity and response to therapy in inflammatory conditions (PubMed: 23446639).

Other names

MRP8Calgranulin-AMigration inhibitory factor-related protein 8CAGAP8CP-10

Inhibition of S100A8/A9 complex binding to TLR4 and RAGE receptors (PubMed: 22410872)