Journal: bioRxiv
Article Title: Fibrillar adhesions are the primary integrin complexes shaped by matrix topography
doi: 10.1101/2025.11.26.690075
Figure Lengend Snippet: (A) HUVECs grown on plasma fibronectin-coated flexible PDMS in a stretching device, subjected to 0% stretch or a rapid 16% stretch and further incubation for 10 min. Cells visualized for F-actin (magenta) and α5-integrin (fibrillar adhesions, green, left) or vinculin (focal adhesions, green, right). Boxed areas shown with high magnification in a greyscale. Fibrillar adhesions decrease after substrate stretching while focal adhesions remain intact. Scale bar, 10µm. (B) Quantification of ratio of fibrillar adhesion area to total cell area (FB Area/Cell Area) for HUVEC under 0% stretch ( n =46) or 16% stretch ( n =47), N =3, box-and-whiskers plot (min, median, max) with all data points shown, P -values calculated using unpaired t-test, **** P < 0.0001. (C) Scatterplot showing pixel intensity correlations between myosin-IIA heavy chain (red) and α5-integrin (green), showing a strong relative mutual exclusivity ( n =10 regions of interest from 10 cells). Representative images of myosin-IIA (red) and α5-integrin (green) in a region of interest of a HUVEC cell are shown. (D) HUVECs plated overnight on planar glass coverslips and stained for myosin-IIA heavy chain (magenta) and α5-integrin (green) under control conditions or after treatment with 5µg/ml Rho activator CNO3 for 3 hours, 1nM of MLCP inhibitor calyculin A (15 min) or 1 µM nocodazole (which increases Rho activity due to release of GEF-H1 upon microtubule disruption) for 1 hour. Note that activation of myosin filament formation results in disruption of fibrillar adhesions. Pre-treatment of cells with 30 µM Y-27632 for 15 min before co-addition of 1 µM nocodazole mostly preserves fibrillar adhesion formation. Scale bar, 10 µm. (E) Quantification of ratio of fibrillar adhesion area to total cell area (FB Area/Cell Area) for control HUVEC ( n =58), cells treated with 5µg/ml CNO3 for 3 hours ( n =51), 1nM calyculin A for 15 min ( n =42), 10 µM nocodazole for 1 hour ( n =59), or 30 µM Y-27632 added for 15 min before co-addition of 1 µM nocodazole for an additional hour (nocodazole and Y-37632) ( n =54), N =3, box-and-whiskers plot (min, median, max) with all data points shown, one way ANOVA comparing means of + CNO3, + Calyculin A and + Nocodazole to control, as well as + Y-27 then Nocodazole to Nocodazole, **** P < 0.0001). (F) Mean intensity of α5-integrin clustering along electrospun nanofibers under control conditions ( n =57) or after incubation with 5µg/ml CNO3 for 3 hours ( n =56) or 1nM calyculin A for 15 min ( n =60), or 10 µM nocodazole for 1 hour ( n =57). ( N =3, Box and whiskers (min, median, max) with all data points shown, P -values calculated using one way ANOVA, **** P < 0.0001. See for representative images. (G) Graph showing measurements of cortical stiffness (Pa) in HUVEC by atomic force microscopy (AFM) in control ( n =33 cells) and cells pre-treated with 30µM Y-27632 for 1 hour ( n =34 cells), N =3 independent experiments, box-and-whiskers plot (min, median, max) with all data points shown, two-tailed unpaired t-test, **** P < 0.0001. (H) Graph showing measurements of cortical stiffness (Pa) of HUVEC by AFM in control ( n =31 cells) and cells pre-treated with 1µM nocodazole for 1 hour ( n =25 cells) N =3 independent experiments, box-and-whiskers plot (min, median, max) with all data points shown, two-tailed unpaired t-test, **** P < 0.0001. (I) Matched cortical stiffness (Pa) AFM measurements in HUVEC before and after treatment with 1 nM calyculin A for 10–20 min (pooled data on n =20 cells, in N =2 independent experiments, paired t-test, ** P < 0.01).
Article Snippet: Human umbilical vein endothelial cells (HUVEC) (ATCC, CRL-1730) were cultured in endothelial growth medium EGM-2 Bulletkit (Lonza) including all provided supplements.
Techniques: Clinical Proteomics, Incubation, Staining, Control, Activity Assay, Disruption, Activation Assay, Microscopy, Two Tailed Test