Directional Change Produced by Perpendicularly-Oriented Microgrooves is Microtubule-Dependent for Fibroblasts and Epithelium

Anisotrophic substrata such as micromachined grooves can control can control cell shape, orientation, and the direction of cell movement, a phenomena termed topographic guidance. Although many types of cells exhibit topographic guidance little is known regarding cell responses to conflicting topographic cues. We employed a substratum With interesting grooves in order to present fibroblasts and epithelial cells with conflicting topographic cues. Using time-lapse and confocal microscopy, we examined cell behavior at groove intersections. Migrating fibroblasts and epithelial cells typically extended a cell process into the intersection ahead of the cell body. After travelling along, the X groove to enter the intersection, the leading lamellipodia of the cell body encountered the perpendicular Y groove, mid spread latterly along the Y groove. The formation of lateral lamellipodia resulted in cells forming T or morphologies, which were characterized by the Formation of phosphotyrosine-rich local adhesions at the leading edges. The Y groove did not prove an absolute barrier to cell migration,. particularly epithelial cells. Analysis of cytoskeletal distribution revealed that F-actin bundles did not adapt closely to the groove patterns. but typically did align to either the or Y grooves. In contrast microtubules (MT) adapted closely to the walls. inhibition of microtubule nucleation attenuated fibroblast and epithelial cell orientation within the intersection of the perpendicular grooves. We conclude that MT may be the prime determinant of fibroblast and epithelial cell Coll formation to conflicting, topographies. Cell Motif. Cytoskeleton 66: 260-271, 2009. (C) 2009 Wiley-Liss, Inc.