Curvature and Rho activation differentially control the alignment of cells and stress fibers

• DOI: 10.1126/sciadv.1700150
• Publication Date: 2017-09-07T04:29:59Z
• Authors: Nathan D. Bade; Randall D. Kamien; Richard K. Assoian; Kathleen J. Stebe
• Keywords: rho GTP-Binding Proteins; 0301 basic medicine; Myocytes, Smooth Muscle; Fibroblasts; Actins; Enzyme Activation; Actin Cytoskeleton; Mice; 03 medical and health sciences; Stress Fibers; Animals; Humans; Cell Shape; Research Articles; Cell Size

In vivo, cells respond to a host of physical cues ranging from substrate stiffness the organization micro- and nanoscale fibrous networks. We show that macroscale substrates with radii curvature tens hundreds micrometers influence cell alignment. model system fibroblasts, isolated aligned strongly in axial direction on cylinders similar length more weakly much larger radius. Isolated vascular smooth muscle did not align as effectively fibroblasts. However, both types robustly weak fields when confluent monolayers. identified two distinct populations stress fibers types: long, apical axially short, basal circumferentially. Circumferential alignment is apparent disagreement long-standing hypothesis energetic penalties for bending enforce cylinders. To explore this phenomenon, we manipulated by activating Rho, small guanosine triphosphatase regulates fiber assembly. response, disassembled, whereas thickened circumferential direction. By Rho monolayers cells, recapitulated pattern F-actin within these observed cylindrical vessels vivo. agreement recent theory, results suggest are overcome contractility enhanced motivate deeper study mechanics populations.