Fluid shear magnitude, mechanical history and actin-sensitive coupling shape Piezo1 signalling
Mechanical forces shape cell behaviour, yet how Piezo1-associated responses encode force magnitude, recent mechanical history and cytoskeletal context under repeated fluid shear remains unclear. We combined defined fluid shear stress (FSS) with GenEPi, a genetically encoded reporter of Piezo1-proximal Ca2+ entry, in engineered XLGenEPi-HEK293T monolayers to resolve mechanically evoked responses at single-cell and population scales. GenEPi responses increased with FSS magnitude but showed diminishing response gain at higher shear. Repeated submaximal FSS produced history-dependent attenuation and reduced temporal coordination, with higher FSS accelerating the early phase of attenuation. Low-dose Latrunculin A, without significantly reducing bulk F-actin abundance, converted sustained FSS-evoked signalling into a brief, decay-dominated response while largely preserving peak responses to Yoda1. These findings show that Piezo1-associated signalling is shaped over minutes by force magnitude, recent mechanical history and actin-sensitive mechanical coupling, providing a quantitative framework for understanding mechanotransduction under sustained and repeated mechanical stimulation.