Gaunt, H. J. | bioRxiv Science

bioRxiv2023

PIEZO1 force sensing controls global lipid homeostasis

How cardiovascular activity beneficially regulates lipid homeostasis is unclear. Here we hypothesise a mechanism in which mechanical force sensed by PIEZO1 ion channels in endothelium links blood flow to lipid regulation. We engineered mice for conditional deletion of PIEZO1 in endothelium and determined consequences for lipid regulation. Prominent are upregulated expression of hepatic Cyp7a1 and intestinal Ldlr genes, which are pivotal in cholesterol catabolism and excretion. Consistent with such regulation is endothelial PIEZO1-dependence of hepatic, intestinal and whole body cholesterol and bile homeostasis. There is organ perfusion-dependent gene regulation via endothelial PIEZO1 and downstream nitric oxide synthase. Endothelial PIEZO1-deleted mice are protected against hyperlipidaemia and ectopic fat deposition. Human PIEZO1 gene variants and a recapitulated human PIEZO1 gain-of-function variant in mice associate with dyslipidaemia. The data suggest lipid-promoting effects of endothelial force sensing and new opportunity for understanding and addressing problems of hyperlipidaemia.

physiology↗

bioRxiv2019

Cell adhesion molecule interaction with Piezo1 channels is a mechanism for sub cellular regulation of mechanical sensitivity

The discovery of Piezo1 channels as force sensors with roles in the endothelial response to fluid flow has appeared contradictory to earlier work suggesting mediation by a triad of cell adhesion molecules (CD31 and VE-cadherin) and vascular endothelial growth factor receptor 2 (VEGFR2). Here we propose an explanation. Stimulated emission depletion microscopy revealed physical proximity between Piezo1 and CD31 primarily at cell junctions. Forster resonance energy transfer measured by fluorescence lifetime imaging showed that the proteins approached to less than 10 nm. Substitution of a tyrosine residue at the distal C-terminus of CD31 prevented the interaction, suggesting intracellular association. The extracellular N-terminus also interacted, but exclusively at cell junctions. There was proximity between Piezo1 and VE-cadherin but not VEGFR2. Interaction with VE-cadherin was flow-dependent, consistent with additional recruitment after flow-sensing. CD31 suppressed mechanical sensitivity of Piezo1 channels and interacted with N-terminal Piezo1 propeller arms implicated in force sensing. The data suggest partnership between Piezo1 and adhesion molecules for sub cellular tuning of force response.

cell biology↗