PIEZO1 and PECAM1 interact at cell-cell junctions and partner in endothelial force sensing

Abstract

Two prominent concepts for the sensing of shear stress by endothelium are the PIEZO1 channel as a mediator of mechanically activated calcium ion entry and the PECAM1 cell adhesion molecule as the apex of a triad with CDH5 and VGFR2. Here, we investigated if there is a relationship. By inserting a non-disruptive tag in native PIEZO1 of mice, we reveal in situ overlap of PIEZO1 with PECAM1. Through reconstitution and high resolution microscopy studies we show that PECAM1 interacts with PIEZO1 and directs it to cell-cell junctions. PECAM1 extracellular N-terminus is critical in this, but a C-terminal intracellular domain linked to shear stress also contributes. CDH5 similarly drives PIEZO1 to junctions but unlike PECAM1 its interaction with PIEZO1 is dynamic, increasing with shear stress. PIEZO1 does not interact with VGFR2. PIEZO1 is required in Ca2+-dependent formation of adherens junctions and associated cytoskeleton, consistent with it conferring force-dependent Ca2+ entry for junctional remodelling. The data suggest a pool of PIEZO1 at cell junctions, the coming together of PIEZO1 and PECAM1 mechanisms and intimate cooperation of PIEZO1 and adhesion molecules in tailoring junctional structure to mechanical requirement.

PIEZO Ion Channels in Cardiovascular Functions and Diseases

“…50 dynamics. 55,61,67,68 By initiating localized force-dependent Ca 2+ entry at cell-cell junction, PIEZO1 channels participate in the formation and remodeling of adherens junctions. 61 PIEZO1 channels are also required for leukocyte diapedesis, the movement of leukocytes out of the vascular system.…”

“…55,61,67,68 By initiating localized force-dependent Ca 2+ entry at cell-cell junction, PIEZO1 channels participate in the formation and remodeling of adherens junctions. 61 PIEZO1 channels are also required for leukocyte diapedesis, the movement of leukocytes out of the vascular system. 67 Leukocyte-induced clustering of ICAM-1 (intercellular adhesion molecule-1) at EC surface generates mechanical forces that synergize with low shear stress to activate endothelial PIEZO1.…”

“…Indeed, PIEZO1 channels are present both in the apical endothelial membrane and at the inter-endothelial junction complexes where they interact with PECAM1 (platelet EC adhesion molecule-1). 27,29,61 At these sites, PIEZO1 channels are activated by shear stress and could sense stretch/membrane tension, respectively. Constitutive PIEZO1 ablation in mice causes embryonic lethality before E14.5 due to impaired vasculature development and defective circulation, including vasculature disorganization and major pericardial effusion.…”

“…An important function of endothelial PIEZO1 channels is their contribution to alignment of ECs to the direction of fluid flow 27,29,66 and adherens junction dynamics. 55,61,67,68 By initiating localized force-dependent Ca 2+ entry at cell-cell junction, PIEZO1 channels participate in the formation and remodeling of adherens junctions. 61 PIEZO1 channels are also required for leukocyte diapedesis, the movement of leukocytes out of the vascular system.…”

Light‐Induced Nanoscale Deformation in Azobenzene Thin Film Triggers Rapid Intracellular Ca2+ Increase via Mechanosensitive Cation Channels

“…Apical shear forces are known to be present for example in the endothelium from blood and lymph flow, and Piezo1 channels have been shown to sense these apical shear forces. [68,84] Basal mechanical cell-ECM interactions are known to play a role in, for example, cancer progression and development, but the details of this mechanical coupling are mostly unknown. In recent work, Ellefsen et al [83] showed that Piezo1 channels are localized evenly throughout the basal membrane but show most activity near focal adhesions.…”