Integrin alpha-9 beta-1 (Integrin α9β1) (ITGA9/ITGB1)

Integrin α9β1 is a heterodimeric transmembrane receptor composed of the α9 (ITGA9) and β1 (ITGB1) subunits, belonging to the integrin family of cell adhesion molecules [1, 8]. It is widely expressed in various tissues, including airway epithelium, smooth muscle, and neutrophils, where it mediates critical interactions between cells and the extracellular matrix [1, 11]. The receptor recognizes a diverse array of ligands, such as tenascin-C, osteopontin, and VCAM-1, and is essential for physiological processes like lymphangiogenesis, angiogenesis, and hematopoietic stem cell maintenance [2, 7, 11]. In pathological contexts, Integrin α9β1 is significantly involved in cancer metastasis, autoimmune diseases like rheumatoid arthritis, and inflammatory conditions such as thrombosis and stroke [1, 6, 24]. Therapeutic strategies have focused on blocking this receptor with monoclonal antibodies, such as ASP5094, or small molecule antagonists to inhibit disease-associated cell migration and signaling [14, 17]. Although clinical trials for some candidates have faced challenges in efficacy, the target remains a high-interest area for treating refractory inflammatory and oncological diseases [17, 19].

Other names

ITGA9ITGB1alpha9beta1CD49iVLA-9

Antagonism of ligand binding (e.g., VCAM-1, Tenascin-C, Osteopontin, VEGF-C/D) to inhibit cell adhesion, migration, and downstream signaling pathways such as FAK/Src and MAPK/ERK [1, 8, 11, 23].