Figure 4.

Cdc42 Downstream of Fibronectin and Integrin Activation Is Required to Organize Desmin in Myofibers

(A) Quantification of peripheral nuclei in 10-day myofibers treated with vehicle, PPi (Src inhibitor), or FAK inhibitor. Data from three independent experiments were combined and error bars represent SEM from indicated number of nuclei (n) for each cohort. Unpaired t test was used to determine statistical significance, where ^∗∗∗p < 0.001.

(B) Representative immunofluorescence image of 10-day myofibers treated with vehicle, Cdc42 inhibitor (ML141), Rac1 inhibitor, or Rock inhibitor (Y-27632) and stained for F-actin (myofibrils, green) and DAPI (nucleus, blue). Scale bar, 10 μm.

(C) Quantification of peripheral nuclei in 10-day myofibers treated with vehicle, ML141, Rac1 inhibitor, or Y-27632. Data from three independent experiments were combined and error bars represent SEM from indicated number of nuclei (n) for each cohort. Unpaired t test was used to determine statistical significance, where ^∗∗∗p < 0.001.

(D) Representative immunofluorescence image of 10-day myofibers treated with vehicle or ML141 and stained for F-actin (myofibrils, green), desmin (magenta), and DAPI (nucleus, blue). Scale bar, 10 μm.

(E and F) Quantification of transverse desmin organization in 10-day myofibers from cultures treated with and knocked down for indicated conditions. Data from three independent experiments were combined and error bars represent SEM from at least 30 myofibers for each cohort. Unpaired t test was used to determine statistical significance, where ^∗p < 0.05, ^∗∗p < 0.01, ^∗∗∗p < 0.001.