An investigation of the effect of colchicine on living fibroblasts by atomic force and confocal microscopy

Using atomic force and confocal laser scanning microscopy, the effect of colchicine (1$\mu$g/mL) on primary culture of rat fibroblasts, causing depolymerization of tubulin microtubules, was studied. When analyzing the atomic force microscopy data, the sliding type of the probe–cell contact was identified by the increasing apparent deformation in its inclined areas. For an unambiguous interpretation of the observed variations in the mechanical characteristics of fibroblasts, it is necessary to confirm the sliding of the probe along the cell surface. It was found that some fibroblasts are soft and are characterized by a fairly uniform distribution of the apparent Young’s modulus over their surface, whereas others, on the contrary, are much harder, with rigid fibrous structures on the Young’s modulus map. It was shown that colchicine causes significant strengthening of cells in both groups. Confocal microscopy data allowed us to conclude that the observed effect is associated with an increase in the intracellular content of $F$-actin in fibroblasts.