Figure 3. Milk fat globule‐epidermal growth factor (MFG‐E8) mediates actin‐related protein 2 (Arp2) expression in a biphasic, dose‐dependent manner in vascular smooth muscle cells (VSMCs).

A through C, A10 VSMCs were treated with either a low (10 ng/mL) or high (1000 ng/mL) concentration of recombinant MFG‐E8 for 16 hours. A, Western blot analysis of the protein expression of Arp2 and actin‐related protein (Arp3) in A10 cells treated with low and high doses of MFG‐E8 for 16 hours. Quantitative analyses of Arp2 (B) and Arp3 (C) levels normalized to those of α‐tubulin were conducted (n=3). Data are presented as mean±SD. Three independent experiments were performed. Each point is derived from each of the 3 repeated experiments. *P<0.05, **P<0.01, ***P<0.001, as obtained using 1‐way ANOVA followed by Tukey multiple comparisons test. D through E, VSMCs isolated from aortas of wild‐type mice were immunostained with antibodies against Arp2 (D) and Arp3 (E) and costained with phalloidin to label filamentous actin (F‐actin). Bar, 50 μm. Three independent experiments were performed and each experiment was repeated with similar results. In a representative experiment, the fluorescence intensities of Arp2 (n=3–5) (D) and Arp3 (n=3) (E) were quantitated. Data are presented as mean±SD. Each point is derived from an assessment of each picture field. *P<0.05 and ****P<0.0001, as obtained using 1‐way ANOVA followed by Tukey multiple comparisons test. DAPI indicates 4',6‐diamidino‐2‐phenylindole.