Cellular Responses to Substrate Topography: Role of Myosin II and Focal Adhesion Kinase

Abstract

Although two-dimensional cultures have been used extensively in cell biological research, most cells in vivo exist in a three-dimensional environment with complex topographical features, which may account for at least part of the striking differences between cells grown in vivo and in vitro. To investigate how substrate topography affects cell shape and movement, we plated fibroblasts on chemically identical polystyrene substrates with either flat surfaces or micron-sized pillars. Compared to cells on flat surfaces, 3T3 cells on pillar substrates showed a more branched shape, an increased linear speed, and a decreased directional stability. These responses may be attributed to stabilization of cell adhesion on pillars coupled to myosin II-dependent contractions toward pillars. Moreover, using FAK-/- fibroblasts we showed that focal adhesion kinase, or FAK, is essential for the responses to substrate topography. We propose that increased surface contact provided by topographic features guides cell migration by regulating the strength of local adhesions and contractions, through a FAK- and myosin II-dependent mechanism.

Topography Design Concept of a Tissue Engineering Scaffold for Controlling Cell Function and Fate Through Actin Cytoskeletal Modulation

“…3B, Micropillar-1, top). [80][81][82] On the other hand, if there is enough spacing between the pillars, actin filaments are constrained between the pillars, and the focal adhesions are present only on the side and/or the bottom of the pillars (Fig. 3B, Micropillar-1, bottom).…”

“…The resulting collective migration forms a multicellular spherical acinus or tube inside a structural constraint with a curved surface. 63,64,119 Control of cell migration through actin modulation has been well characterized based on contact guidance by means of simple synthetic 2.5D microtopographical features, such as parallel ridges and grooves, 73,96,[120][121][122][123][124] arrays of micropillars, 14,22,80,81 and asymmetric microchannels (Fig. 5B).…”

Distinct Apical and Basolateral Membrane Requirements for Stretch-induced Membrane Traffic at the Apical Surface of Bladder Umbrella Cells

“…The increase may represent a slowing in the endocytic rate or an increase in exocytic rate. Additional mechanosensors may include the actomyosin cytoskeleton, which in conjunction with integrins is required for mechanosensation in both anchored and nonanchored cells (Gillespie and Walker, 2001;Frey et al, 2006;Ingber, 2006;Effler et al, 2007) and is prominently associated with the basolateral membrane of the umbrella cell (Acharya et al, 2004). Treatment with cytochalasin D or latrunculin impairs exocytosis and endocytosis in umbrella cells (Lewis and de Moura, 1982).…”

Machine grinding as an alternative method for creating functional surfaces for controlling cell behaviour

“…This has since evolved to see the design of a range of surface features including islands [7], pits [23], grooves [1] and pillars [11], all of which have been shown to have an effect on cell behaviour. Such design features have been incorporated into the development of biomedical implant technology.…”