Lower shear stress exacerbates atherosclerosis by inducing the generation of neutrophil extracellular traps via Piezo1-mediated mechanosensation

BACKGROUNDAtherosclerosis is a chronic lipid-driven inflammatory disease, largely influenced by hemodynamics. Neutrophil extracellular traps (NETs)-mediated inflammation plays an important role in atherosclerosis. However, little is known about the mechanism of the generation of NETs under different shear stress and subsequent damage to endothelial cells. We sought to identify a novel mechanical signal provokes NETs generation and to investigate its potential role in atherosclerosis. METHODSApoE-/- mice were fed with high-fat diet (HFD) to induce atherosclerosis. The model of lower shear stress (LSS) with a partial ligation of the left carotid artery was established to assess the role of LSS in NETs generation and atherosclerotic lesions development. Furthermore, the underlying mechanism of LSS promoting NETs generation and injuring endothelial cells was deciphered in neutrophil-like human promyelocytic leukemia (HL-60) cells in parallel-plate flow chamber. RESULTSWe found that LSS correlated spatially with both NETs and atherosclerosis, while inhibition of NETosis could significantly reduce plaque formation in ApoE-/- mice. In vitro, LSS could promote NETs generation directly through down-regulation of Piezo1, a mechanosensitive ion channel. downexpression of Piezol could activate neutrophils and promote NETosis in static. Conversely, Yoda1-evoked activation of Piezo1 attenuated LSS-induced NETosis. Mechanistically, the downexpression of Piezo1 resulted in decreased Ca2+ influx and increased histone deacetylase 2 (HDAC2), which increase reactive oxygen species levels, then led to NETosis. LSS-induced NETs generation promoted the apoptosis and adherence of endothelial cells. CONCLUSIONSLSS directly promotes NETosis through piezo1-HDAC2 axis in atherosclerosis progression. This study uncovers the essential role of Piezo1-mediated mechanical signaling in NETs generation and plaque formation, which provides a promising therapeutic strategy for atherosclerosis. Graphic Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=131 SRC="FIGDIR/small/529165v1_ufig1.gif" ALT="Figure 1"> View larger version (52K): org.highwire.dtl.DTLVardef@583911org.highwire.dtl.DTLVardef@aa3e2org.highwire.dtl.DTLVardef@8d83e5org.highwire.dtl.DTLVardef@ce55a0_HPS_FORMAT_FIGEXP M_FIG C_FIG Proposed mechanism for lower shear stress LSS exacerbating atherosclerosis. LSS stimuli decrease Piezo1 expression in the neutrophils, resulting in decreased intracellular Ca2+ concentration, as well as the higher expression level of HDAC2, which could activate oxidative stress and promote intracellular reactive oxygen species formation, and ultimately lead to NETs generation. NETs could aggravate endothelial cells injury and exasperate atherosclerosis. Highlights{blacksquare} Lower shear stress (LSS) promotes Neutrophil extracellular traps (NETs) formation, which is critical for lipid deposits and plaque formation in Atherosclerosis. {blacksquare}Atherosclerotic plaque formation was significantly reduced in the aorta of high fat diet fed ApoE-/- mice intraperitoneal injected with NETs inhibitor, GSK484, especially in the lower shear stress regions. {blacksquare}Piezo1 is a key molecule in the process of neutrophils sense lower shear stress. {blacksquare}lower shear stress inhibits the activation of Piezo1 and promotes NETosis through piezo1-HDAC2 axis. {blacksquare}LSS-induced NETs promote the apoptosis and adhesion of endothelial cells.