Substrate engagement of integrins α5β1 and αvβ3 is necessary, but not sufficient, for high directional persistence in migration on fibronectin.

Dimitris Missirlis,Florian Rechenmacher,Carolina Diaz,Tamás Haraszti,Stefanie Neubauer,Catharina V C Scheele,Tina Wiegand,Joachim P Spatz,Horst Kessler

doi:10.1038/srep23258

Abstract

The interplay between specific integrin-mediated matrix adhesion and directional persistence in cell migration is not well understood. Here, we characterized fibroblast adhesion and migration on the extracellular matrix glycoproteins fibronectin and vitronectin, focusing on the role of α5β1 and αvβ3 integrins. Fibroblasts manifested high directional persistence in migration on fibronectin-, but not vitronectin-coated substrates, in a ligand density-dependent manner. Fibronectin stimulated α5β1-dependent organization of the actin cytoskeleton into oriented, ventral stress fibers, and assembly of dynamic, polarized protrusions, characterized as regions free of stress fibers and rich in nascent adhesions at their edge. Such protrusions correlated with persistent, local leading edge advancement, but were not sufficient, nor necessary for directional migration over longer times. Selective blocking of αvβ3 or α5β1 integrins using small molecule integrin antagonists reduced directional persistence on fibronectin, indicating integrin cooperativity in maintaining directionality. On the other hand, patterned substrates, designed to selectively engage either integrin, or their combination, were not sufficient to establish directional migration. Overall, our study demonstrates adhesive coating-dependent regulation of directional persistence in fibroblast migration and challenges the generality of the previously suggested role of β1 and β3 integrins in directional migration.

Highlights

Mesenchymal cell migration involves a complex, yet tightly regulated control over actin polymerization, adhesion dynamics and actomyosin contractility to enable cell translocation in its environment
Our results demonstrate that α5β1 and αvβ[3] integrins are necessary but not sufficient for directional persistence in fibroblast migration
In this study we have demonstrated that fibroblasts exhibit high directional persistence in migration on FNbut not VN-coated substrates and that engagement of both αvβ[3] and α5β1 integrins is necessary for directional

Summary

Introduction

Mesenchymal cell migration involves a complex, yet tightly regulated control over actin polymerization, adhesion dynamics and actomyosin contractility to enable cell translocation in its environment. While integrins are probably not the sole receptor family responsible in regulating cell migration, understanding how cells respond to differential integrin engagement in respect to their motility, and in particular their directional persistence is a major open question[9,10], and constitutes the underlying motivation of this study. We presented fibroblasts with substrates coated with plasma fibronectin (FN) or vitronectin (VN), both ECM glycoproteins containing the integrin-binding RGD sequence[16,17]. In this manner, we studied how differential ECM receptor engagement affects single cell adhesion and migration avoiding genetic manipulation of cells. Our results demonstrate that α5β1 and αvβ[3] integrins are necessary but not sufficient for directional persistence in fibroblast migration

Methods

Results

Conclusion