Fig. 3.

Inhibition of αvβ5 integrin interaction with vitronectin increases fibronectin matrix assembly. A - MG-63 cells were pre-incubated for 45 minutes with the cyclic peptide RGDfV (20 μM) or its inactive analog RADfV (20 μM) or for 2 hours with 20 μg/ml of normal mouse IgG, β3 integrin blocking antibody LM609 or β5 integrin blocking antibody P1F6 and then incubated with ¹²⁵I-fibronectin (Fn) for 6 hours. This experiment is representative of three separate experiments. Data are the mean ± S.E. of two different experiments performed in duplicate. *Significantly different than control cells, t test, p < 0.05 (n=4). B - Same as A only under conditions of uPAR stimulation with P25. Cell layers were extracted in 1% DOC, and ¹²⁵I-fibronectin that was incorporated into the detergent-insoluble matrix was recovered by centrifugation and measured by gamma scintillation.. This experiment is representative of three separate experiments. Data are the mean ± S.E. of two experiments performed in duplicate. *Significantly different than P25-treated cells, t test, p < 0.05 (n=4).