Microscale geometrical modulation of PIEZO1 mediated cell mechanosensing via cytoskeletal redistribution buckle

Abstract

Microgeometry profoundly impacts cellular behaviors, yet the link between it and the ubiquitously expressed mechanosensitive ion channel PIEZO1 remains enigmatic. We introduce a fluorescent micropipette aspiration assay to concurrently observe intracellular calcium mobilization and cytoskeletal restructuring in real-time under distinct microscale geometric alterations. Utilizing finite element analyses, coupled with PIEZO1-specific transgenic models, we discern that steeper micropipette tip angles markedly enhance PIEZO1-mediated calcium influx. This mechanical stress on the aspirated cell induces a significant F-actin reorganization, resulting in a "mechanical buckle" that amplifies PIEZO1 activity within the aspirated region. Remarkably, when this F-actin network is disrupted, PIEZO1 gating is significantly inhibited, signifying its indispensable role in mechanosensing under geometrical changes. This mechanobiology study illuminates the profound relationship between biomechanical microenvironment, cytoskeletal adaptation, and PIEZO1 activation, inspiring future bioengineering applications.

Investigating mechanosensitive channels activation in concert with the mechanical properties of red blood cells

“…Recently, we have introduced a bimodal imaging approach enclosing fluorescence and brightfield imaging to monitor calcium transients and stimulus probe position on the cell and study the activation of mechanosensitive channels in neuronal cells by piconewton forces applied by optical tweezers [34,35]. Moreover, a micropipette aspiration technique with concurrent RBC morphology imaging and intracellular calcium has also been reported by another group for the determination of the RBC calcium dynamic range [36,37]. Here we implement a similar bimodal imaging in combination with the micropipette aspiration technique, however our approach is characterized by the multiple complementary information achievable at the same time from single cells.…”