Periostin

Periostin is a secreted extracellular matrix protein of the fasciclin domain-containing family that functions as a matricellular protein. In humans it is encoded by the POSTN gene. Periostin is produced mainly by periosteal fibroblasts and osteoblasts, as well as by fibroblasts in various tissues, and is secreted into the extracellular matrix where it interacts with collagen I, fibronectin, and tenascin-C. It binds to cell-surface integrins, particularly αVβ3 and αVβ5, to regulate cell adhesion, migration, survival, and differentiation. Through these interactions, periostin contributes to tissue remodeling and repair in development and adulthood, including cardiac valve formation and bone remodeling, as well as wound healing and angiogenesis.

Expression of periostin is regulated by mechanical stress and signaling factors such as transforming growth factor-β (TGF-β) and Th2 cytokines such as interleukin-4 and interleukin-13, leading to increased levels in remodeling and inflammatory tissues. Clinically, periostin is associated with fibrotic diseases (for example, lung, skin, and liver fibrosis) and with type 2 inflammatory conditions such as asthma, where it can serve as a biomarker of airway remodeling and eosinophilic inflammation. In cancer and other contexts, periostin can support tumor cell invasion and angiogenesis, though its role is complex and context-dependent. Research ongoing to evaluate anti-periostin approaches in models of fibrosis and asthma.