Exploring Mechanical Niches Identified by Hair Follicle Compression and How These Transduce Proliferation and Differentiation Cues in Epidermally Derived Cells

This study investigated the mechanical properties of hair follicles and surrounding tissues during the shaving process to understand how these structures influence cell proliferation and differentiation. By applying weights to mimic shaving forces, researchers observed changes in nuclear morphology as indicators of force transduction. They identified distinct mechanical compartments in the hair follicle and used multiphoton microscopy to analyze collagen bundling in these regions. The study found that high-density (HD) collagen matrices, which have smaller bundles and are less stiff, promoted higher proliferation rates in HaCaT cells compared to low-density (LD) matrices. This proliferation advantage was mediated by MAPKs, with JNK playing a key role in linking nuclear dynamics with collagen density-mediated proliferation and differentiation.