Fig. 4

Analysis of hiPS-EV-H5 impact on the actin cytoskeleton, focal contacts, and mechanical properties of human cardiac fibroblasts (hCFs) stimulated with TGFβ (1 ng/ml). EV-H5 from hiPSC-L3 were used. A Representative fluorescence microscopy images of hCFs. The insets in the upper corners of the images are zoomed areas marked with white rectangles showing mature focal contacts (FCs). Quantitative data of FC measurements are shown in the graphs below: FCs length (B) and area (C) (n = 105). D Analysis of transcript levels of genes associated with the formation of FCs (PFN, PXN, TLN1) by real-time qPCR (n = 4). E Optical microscopy images of cells during AFM analysis, followed by high-resolution morphology images (F) as well as elasticity maps (G) of the cells. Dash squares in the optical images indicate scanning areas covered by AFM. Black and red horizontal lines in (F) and (G) indicate cross-sections and the corresponding cross-section analyses are shown in (H). I Scatter graph showing values of the Young’s modulus determined with AFM force spectroscopy (n = 30). All data are presented as the mean ± SD. Statistical significance was tested using Kruskal–Wallis with Dunn’s post hoc test (B–D, I). *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001