Figure 7
Immobilized α5β1 and αvβ3 integrin selective ligands on patterned substrates do not promote high directional persistence in fibroblast migration.
(A) REFYFP-PAX actin cytoskeleton and YFP-paxillin clustering 6 hours post-seeding on patterned gold particles with a 50 nm average inter-particle distance and functionalized with the indicated ligands. Stress fiber morphology on α5β1- and αvβ3-selective surfaces resembles that on FN and VN, respectively. FAs, but not NAs nor polarized protrusions, are present on patterned substrates, independent of the type of immobilized ligands. (B,C) Quantification of REFWT projected cell area (B) and aspect ratio (C) 6 hours post-seeding on patterned gold particles with a 50 nm average inter-particle distance (n > 100 cells). (D) Cell speed increased on patterned substrates with a 50 nm inter-particle distance presenting both α5β1- and αvβ3-selective ligands (1:1 ratio) compared to substrates presenting these ligands alone (n = 60 cells from Nexp = 3). Decreasing the inter-particle distance to 30 nm resulted in a slight decrease in cell speed when both ligands were present (n = 60 cells from Nexp = 2). (E) DI remained very low for REFWT on all substrates, independent of integrin ligand type or density, indicating random migration on patterned substrates. The middle line in box plots indicates the median, the box indicates the interquartile range, the whiskers the 5th and 95th percentiles and the cross the mean. Experimental data were compared using one-way ANOVA with Tukey’s post-test analysis. Only statistically significant differences are shown: *P < 0.05; **P < 0.01, ***P < 0.001, ****P < 0.0001. Scale bars: 10 μm.
