Modulation of the expression of the α_vβ₃ complex on human dermal microvascular endothelial cells (HDMEC) may be crucial in wound healing and angiogenesis. Therefore, we examined the influence of basic fibroblast growth factor (bFGF), transforming growth factor β, and interferon-γ (IFN-γ) on the expression of this complex. Stimulation of HDMEC with bFGF increased cell surface expression of both α_v and β₃ in a dose- and time-dependent manner associated with the development of a spindled, elongated cell morphology. Northern blot analysis of HDMEC stimulated with bFGF demonstrated a marked increase in β₃ but not α_v mRNA expression. Incubation of HDMEC with transforming growth factor-β or interferon-γ alone resulted in modest decreases in cell surface α_vβ₃, and co-incubation of HDMEC with bFGF and transforming growth factor-β or interferon-γ inhibited bFGF-induced changes in cell morphology, increases in cell surface α_v&₃ expression, and increases in &₃ mRNA. These data demonstrate that both growth factors and pro-inflammatory cytokines alter the ex- pression of α_vβ₃ on microvascular endothelial cells and that these alterations correlate with changes in cell morphology.