Analysis of long- and short-range contribution to adhesion work in cardiac fibroblasts: An atomic force microscopy study

Atomic force microscopy (AFM) for single-cell force spectroscopy (SCFS) and Poisson statistic were used to analyze the detachment work recorded during the removal of gold-covered microspheres from cardiac fibroblasts. The effect of Cytochalasin D, a disruptor of the actin cytoskeleton, on cell adhesion was also tested. The adhesion workwas assessed using a Poisson analysis also derived fromsingle-cell force spectroscopy retracting curves. The use of Poisson analysis to get adhesionwork fromAFM curves is quite a novel method, and in this case, proved to be effective to study the short-range and long-range contributions to the adhesion work. This method avoids the difficult identification of minor peaks in the AFMretracting curves by creating what can be considered an average adhesionwork. Even though the effect of actin depolymerisation iswell documented, its use revealed that control cardiac fibroblasts (CT) exhibit a work of adhesion at least 5 times higher than that of the Cytochalasin treated cells. However, our results indicate that in both cells short-range and long-range contributions to the adhesion work are nearly equal and the same heterogeneity index describes both cells. Therefore, we infer that the different adhesion behaviors might be explained by the presence of fewer membrane adhesion molecules available at the AFM tip–cell interface under circumstances where the actin cytoskeleton has been disrupted.