Inhibition of Shear-Induced Platelet Aggregation by Xueshuantong via Targeting Piezo1 Channel-Mediated Ca2+ Signaling Pathway.

Zhengxiao Sun,Yun You,Mei Xue,Ying Chen,Qiongling Zhang,Shunli Xiao,Lei Liu,Lin-Hua Jiang,Fulong Liao,Shilan Ding,Lan Wang,Xiaojie Yin

doi:10.3389/fphar.2021.606245

Abstract

XueShuanTong (XST) comprising therapeutically active ginsenosides, a lyophilized extract of Panax notoginseng roots, is extensively used in traditional Chinese medicine to treat ischemic heart and cerebrovascular diseases. Our recent study shows that treatment with XST inhibits shear-induced thrombosis formation but the underlying mechanism remained unclear. This study aimed to investigate the hypothesis that XST inhibited shear-induced platelet aggregation via targeting the mechanosensitive Ca2+-permeable Piezo1 channel by performing platelet aggregation assay, Ca2+ imaging and Western blotting analysis. Exposure to shear at physiologically (1,000–2000 s−1) and pathologically related rates (4,000–6,000 s−1) induced platelet aggregation that was inhibited by treatment with GsMTx-4. Exposure to shear evoked robust Ca2+ responses in platelets that were inhibited by treatment with GsMTx-4 and conversely enhanced by treatment with Yoda1. Treatment with XST at a clinically relevant concentration (0.15 g L−1) potently inhibited shear-induced Ca2+ responses and platelet aggregation, without altering vWF-mediated platelet adhesion and rolling. Exposure to shear, while resulting in no effect on the calpain-2 expression in platelets, induced calpain-2-mediated cleavage of talin1 protein, which is known to be critical for platelet activation. Shear-induced activation of calpain-2 and cleavage of talin1 were attenuated by treatment with XST. Taken together, our results suggest that XST inhibits shear-induced platelet aggregation via targeting the Piezo1 channel to prevent Piezo1-mediated Ca2+ signaling and downstream calpain-2 and talin1 signal pathway, thus providing novel insights into the mechanism of the therapeutic action of XST on platelet aggregation and thrombosis formation.

Highlights

Cardiovascular diseases (CVD) have emerged as one of the most major causes of mortality and morbidity worldwide
To provide direct evidence to support the notion that XST inhibits shear-induced platelet aggregation via targeting the Piezo1 channel, we examined the effect of treatment with XST on shear-induced Ca2+ responses in platelets, using Ca2+ fluorescent indicator Fluo3-AM
Numerous recent studies have revealed an important role of the Ca2+-permeable Piezo1 channel in sensing mechanical forces and regulating a bewildering number of physiological processes including vascular development, vascular tone and blood flow (e.g., Li et al, 2014; Wang et al, 2016; Beech, 2018)

Summary

Introduction

Cardiovascular diseases (CVD) have emerged as one of the most major causes of mortality and morbidity worldwide. XST Inhibits Shear-Induced Platelet Aggregation maintains the regulation of vascular integrity and blood flow and, if overwhelmed, can lead to clot formation and blood vessel occlusion. Endothelial cells and circulating coagulation proteins, blood flow is a crucial factor in vascular hemostasis and thrombosis (Holinstat, 2017; Koupenova et al, 2017). Flow-induced shear stress has significant influence on arterial thrombus formation. A recent study has reported that the PI3K-C2α lipid kinase mediates shear-dependent regulation of platelet adhesive function via altering the internal membrane structures (Mountford et al, 2015). A recent study suggests that the Piezo channel plays a role in mediating Ca2+ entry into platelets and thrombus formation under arterial shear stress (Ilkan et al, 2017)

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