A new publication in Biophysical Journal from Franziska Lautenschläger’s group in Saarbrücken demonstrates that myosin II blockage leads to cell stiffening. Three adherent cell lines (3T3 fibroblasts, HeLa cells and TNGA mouse embryonic stem cells) were measured in the Optical Stretcher with and without blebbistatin treatement (causing myosin II blockage) and some other cytoskeleton disturbing drugs. The results are in contrary to findigs measured on adhered cells with stress fibers.
The stiffening effect of blebbistatin was also observed for naturally suspended cells (HL60-derived neutrophiles, HL-60-derived monocytes, NB4). A comparison of the results with two other methods for measuring cell stiffness (Microfluidic microcirculation mimetic, real-time deformability cytometry) confirmed that this effects holds for various time scales down to ms.