Linker histone H1 determines cell stiffness and differentiation

ABSTRACTThe flexibility or stiffness, one mechanical property of cells, is a promising label-free biomarker for underlying cytoskeletal or nuclear changes associated with various disease processes and changes in cell state. However, the molecular changes responsible for the whole-cell mechanical stiffness remain to be clarified. Recently, it was shown that the deterministic lateral displacement (DLD) microfluidic device, originally developed for size fractionation of some particles, might be applied to distinguish cells according to their stiffness. In this experiment, using the DLD device and various cell lines differentially expressing histone H1, a positively-charged protein localized in the linker region of chromatin, we found linear relationships between histone H1 quantity and cell stiffness. We also found that the histone H1 quantity affected cell size and even cell differentiation.