Figure 6. β1 integrin is involved in milk fat globule‐epidermal growth factor (MFG‐E8)–mediated actin‐related protein 2 (Arp2) expression and actin polymerization.

A through C, A10 vascular smooth muscle cells (VSMCs) incubated with either 50 μg/mL β1 inhibitory antibody (Itgb1 Ab) or isotype control 4 hours before treatment with either a low or high concentration of recombinant MFG‐E8 for 16 hours. A, Immunoblotting was performed to assess the protein expression of Arp2 and actin‐related protein 3 (Arp3) in A10 cells in a representative experiment. Quantitative analyses of Arp2 (B) and Arp3 (C) normalized to GAPDH were conducted (n=3). Data are presented as mean±SD. Three repeated experiments were performed. Each point is derived from each of the 3 repeated experiments. *P<0.05, **P<0.01, ***P<0.001, ****P<0.0001, as obtained using 1‐way ANOVA followed by Tukey multiple comparisons test. D, Representative confocal fluorescent images of phalloidin for filamentous actin (F‐actin) (green) and DNase I for globular actin (G‐actin) (red) staining of A10 VSMCs stimulated with low (10 ng/mL) and high (1000 ng/mL) doses of MFG‐E8 for 16 hours. Bar, 50 μm. In a representative experiment, corresponding quantification of the mean fluorescence intensity of phalloidin for F‐actin (n=5) and that of DNase I for G‐actin (n=4–6) was performed. Data are presented as mean±SD. Each point is derived from an assessment of each picture field. **P<0.01 and ****P<0.0001, as obtained using 1‐way ANOVA followed by Tukey multiple comparisons test.