Fig. 4.

The nanomechanical fingerprint of RPE cells overexpressing HrA1 and S328A variant. (A/B, left panels) The cell viability and position of the AFM probe is monitored in the brightfield signal for each experiment. Live-Fluorescence imaging allowed for identifying the overexpressing cells (white insert). AFM topography and stiffness data belonging to the measurements (white insert). (A, right panel) Stiffness data, S328A variant cells exhibit similar properties when compared to the neighboring negative cells. (B, right panel) Stiffness data, HtrA1 overexpressing cells showed a 2-fold decrease for RPEs overexpressing HtrA1 (red line) when compared to cells having a low HtrA1 content (green line). (C) Quantitative stiffness analysis over multiple measurements. N = 9 maps (n = 92 cells) for S328A and N = 17 maps (n = 168 cells) for HtrA1, *p < 0.05. (D) Live cell imaging Halotag TMR ligand for HtrA1 (red), SiR-Tubulin (green) and Hoechst (blue). Scale bar, 20 μm.