Figure 6.

The activity of RhoA and Rac1 is time- and cell type-dependent while the localization of membrane protrusions is spatially not changed upon stretching. (a) Analysis of the relative activity of the two small Rho GTPases RhoA and Rac1 in human primary endothelial cells (ECs) and smooth muscle cells (SMCs) using an enzyme linked immunosorbent assay (ELISA). The data were normalized to non-stretched control conditions for each cell type (dotted black line). The cells were exposed for 20 or 60 min to a uniaxial cyclic tensile strain at a frequency of 1 Hz. (b) Analysis of directional protrusion activity over a time course of 300 min. Cell protrusions occurring perpendicular to the direction of uniaxial cyclic tensile strain were determined as “end”; cell protrusions parallel to the axis of uniaxial cyclic tensile strain were called “side”; the direction of cyclic tensile strain is indicated by a black double-headed arrow (see inset). (Student’s t-test; *P < 0.05; +P > 0.05)