741 Structural adaptations of epidermal stem cells to mechanical stress

The skin has a pronounced ability to adapt physical changes in the environment by exhibiting plasticity at cellular level. Transient mechanical deformations applied are accommodated without permanent tissue structure. However, sustained stress induces long-lasting alterations skin, which mediated shifts keratinocyte activity. To elucidate mechanism of epidermal stem cell plasticity, we implemented 2-photon intravital imaging capture response keratinocytes live mouse varying degrees force. We show that formation intracellular vesicles, specifically cells within basal layer interfollicular epidermis. Under force, these vesicles gradually enlarge, leading deformation nucleus. By lineage tracing analysis demonstrate morphological adaptations individual linked their fate. Calcium signaling is critical for regulating activity and commitment terminal differentiation. Utilizing fluorescent vivo reporter, captured calcium dynamics under different conditions. force increase cells. further resolve stress, hypothesized mechanosensitive ion channel, Piezo1 involved mediating observed phenomena. Conditional deletion adult caused an force-induced vesicle formation. Moreover, during loading were disrupted knockout epidermis compared wild type. Subsequently, found myosin required This study uncovers how respond vivo.