Mechanical Stimulation of Piezo1 Receptors Depends on Extracellular Matrix Proteins and Directionality of Force.
Piezo receptors convert mechanical forces into electrical signals. In mammals, they play important roles in basic physiological functions including proprioception, sensation of touch, and vascular development. However, basic receptor properties like the gating mechanism, the interaction with extracellular matrix (ECM) proteins, and the response to mechanical stimulation, remain poorly understood. Here, we establish an atomic force microscopy (AFM)-based assay to mechanically stimulate Piezo1 receptors in living animal cells, while monitoring receptor activation in real-time using functional calcium imaging. Our experiments show that in the absence of ECM proteins Piezo1 receptors are relatively insensitive to mechanical forces pushing the cellular membrane, whereas they can hardly be activated by mechanically pulling the membrane. Yet, if conjugated with Matrigel, a mix of ECM proteins, the receptors become sensitized. Thereby, forces pulling the cellular membrane activate the receptor much more efficiently compared to pushing forces. Finally, we found that collagen IV, a component of the basal lamina, which forms a cohesive network and mechanical connection between cells, sensitizes Piezo1 receptors to mechanical pulling.
Department of Biosystems Science and Engineering, ETH Zurich , 4058 Basel, Switzerland.
Benjamin M
BM
Gaub
Department of Biosystems Science and Engineering, ETH Zurich , 4058 Basel, Switzerland.
Daniel J
0000-0003-3075-0665
DJ
Müller
D000818:Animals; D001696:Biomechanical Phenomena; D002118:Calcium / Q000378:metabolism; D045744:Cell Line, Tumor; D024141:Collagen Type IV / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D007473:Ion Channels / Q000378:metabolism*; D040542:Mechanotransduction, Cellular; D051379:Mice; D018625:Microscopy, Atomic Force / Q000379:methods; D018613:Microscopy, Confocal / Q000379:methods; D013314:Stress, Mechanical
D024141:Collagen Type IV; D016326:Extracellular Matrix Proteins; D007473:Ion Channels; C515204:PIEZO1 protein, human; C552920:Piezo1 protein, mouse; D002118:Calcium
Mechanosensation; Piezo receptors; atomic force microscopy; extracellular matrix; single-cell force spectroscopy