Psoriasin

Psoriasin (S100A7) is a calcium-binding EF-hand protein that is overexpressed in psoriatic keratinocytes. S100A7 is a member of the S100 gene family located in the S100 gene cluster on chromosome 1q21 and shares the typical calcium binding domains that define this protein family. It was first identified as an 11.4 kDa cytoplasmic and secreted protein isolated from psoriasis-affected skin that can be induced in cultured squamous cells.

It was later revealed to be expressed by normal cultured as well as malignant keratinocytes and malignant mammary epithelial cells in ductal carcinoma in situ, suggesting a link with abnormal differentiation pathways. Psoriasin plays a role in the pathogenesis of inflammatory skin diseases, as a chemotactic factor for hematopoietic cells.

Significantly elevated serum psoriasin concentrations were measured in 53.9% of psoriasis patients. The serum psoriasin concentration correlated with the "Psoriasis Activity and Severity Index (PASI)" in these patients. Patients with an increased psoriasin concentration had a significantly higher PASI than patients without detectable psoriasin.

1. Granata M et al (2019) S100A7, Jab1, and p27kip1 expression in psoriasis and S100A7 CRISPR-activated human keratinocyte cell line. J Cell Biochem 120:3384-3392.
2. Lu Z et al. (2021) S100A7 as a potential diagnostic and prognostic biomarker of esophageal squamous cell carcinoma promotes M2 macrophage infiltration and angiogenesis. Clin Transl Med 11:e459.
3. Watson PH et al (1998) Psoriasin (S100A7). Int J Biochem Cell Biol 30:567-571.