Nanoscale surface topography reduces focal adhesions and cell stiffness by enhancing integrin endocytosis

Abstract

Both substrate stiffness and surface topography regulate cell behavior through mechanotransduction signaling pathways. Such intertwined effects suggest that engineered surface topographies might substitute or cancel the effects of substrate stiffness in biomedical applications. However, the mechanisms by which cells recognize topographical features are not fully understood. Here we demonstrate that the presence of nanotopography drastically alters cell behavior such that neurons and stem cells cultured on rigid glass substrates behave as if they were on soft hydrogels. We further show that rigid nanotopography resembles the effect of soft hydrogels in reducing cell stiffness and membrane tension as measured by atomic force microscopy. Finally, we demonstrate that nanotopography reduces focal adhesions and cell stiffness by enhancing the endocytosis and the subsequent removal of integrin receptors. This mechanistic understanding will support the rational design of nanotopography that directs cells on rigid materials to behave as if they were on soft ones. TOC graphic O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=104 SRC="FIGDIR/small/448920v1_ufig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@1599ab1org.highwire.dtl.DTLVardef@1bade3corg.highwire.dtl.DTLVardef@1543b28org.highwire.dtl.DTLVardef@f7cc15_HPS_FORMAT_FIGEXP M_FIG C_FIG