Modulation of α(v)β(3) Integrin via Transactivation of β(3) Integrin Gene on Murine Bone Marrow Macrophages by 1,25(OH)(2)D(3), Retinoic Acid and Interleukin-4

The interleukin (IL)-4, 1,25(OH)(2)D(3) and retinoic acid, increase surface expression of functional integrin α(v)β(3) on murine osteoclast precursors. All three agonists stimulate transcription of the β(3) gene, leading to increased steady-state levels of mRNA this protein. By contrast, mRNA levels of α(v) remain unchanged. In each instance, the increase in the surface expression of the integrin results in increased migration of the cells onto an α(v)β(3) substrate. Because β(3) subunit, except platelet where β(3) subunit conform a dimer with α(IIb), associates solely with α(v) subunit monogamously, while promiscuous α(v) subunit combines with various subunit, our present data support the idea that the β(3) subunit governs the surface-expressed functional integrin complex.