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Ferrata Storti Foundation
Platelet Biology & its Disorders
NLRP3 regulates platelet integrin aIIbβ3 outside-in signaling, hemostasis and arterial thrombosis
Haematologica 2018 Volume 103(9):1568-1576
1Blood Diseases Institute, Xuzhou Medical University, China; 2Department of Hematology, the Affiliated Hospital of Xuzhou Medical University, China; 3Key Laboratory of Bone Marrow Stem Cell, Jiangsu Province, Xuzhou, China; 4Australian Centre for Blood Diseases, Monash University, Melbourne, Australia and 5ACRF Department of Cancer Biology and Therapeutics, John Curtin School of Medical Research, Australian National University, Canberra, Australia
Jianlin Qiao,1,2,3# Xiaoqing Wu,1# Qi Luo,1# Guangyu Wei,1 Mengdi Xu,1,2,3 Yulu Wu,1 Yun Liu,1 Xiaoqian Li,2 Jie Zi,2 Wen Ju,1,2,3 Lin Fu,1,2,3 Chong Chen,1,2,3 Qingyun Wu,1,2,3 Shengyun Zhu,1,2,3 Kunming Qi,2 Depeng Li,2 Zhenyu Li,1,2,3 Robert K. Andrews,4 Lingyu Zeng,1,3* Elizabeth E. Gardiner5* and Kailin Xu1,2,3*
#JQ, XW and QL, contributed equally to this study. *LZ, EEG and KX contributed equally to this study.
ABSTRACT
In addition to their hemostatic function, platelets play an important role in regulating the inflammatory response. The platelet NLRP3 inflammasome not only promotes interleukin-1β secretion, but was also found to be upregulated during platelet activation and thrombus for- mation in vitro. However, the role of NLRP3 in platelet function and thrombus formation in vivo remains unclear. In this study, we aimed to investigate the role of NLRP3 in platelet integrin aIIbβ3 signaling trans- duction. Using NLRP3-/- mice, we showed that NLRP3-deficient platelets do not have significant differences in expression of the platelet-specific adhesive receptors aIIbβ3 integrin, GPIba or GPVI; however, NLRP3-/- platelets transfused into wild-type mice resulted in prolonged tail-bleed- ing time and delayed arterial thrombus formation, as well as exhibiting impaired spreading on immobilized fibrinogen and defective clot retrac- tion, concomitant with decreased phosphorylation of c-Src, Syk and PLCγ2 in response to thrombin stimulation. Interestingly, addition of exogenous recombinant interleukin-1β reversed the defect in NLRP3-/- platelet spreading and clot retraction, and restored thrombin-induced phosphorylation of c-Src/Syk/PLCγ2, whereas an anti-interleukin-1β antibody blocked spreading and clot retraction mediated by wild-type platelets. Using the direct NLRP3 inhibitor, CY-09, we demonstrated sig- nificantly reduced human platelet aggregation in response to threshold concentrations of collagen and ADP, as well as impaired clot retraction in CY-09-treated human platelets, supporting a role for NLRP3 also in regu- lating human platelet aIIbβ3 outside-in signaling. This study identifies a novel role for NLRP3 and interleukin-1β in platelet function, and provides a new potential link between thrombosis and inflammation, suggesting that therapies targeting NLRP3 or interleukin-1β might be beneficial for treating inflammation-associated thrombosis.
Introduction
The primary platelet-specific receptors glycoprotein (GP)VI, which binds colla- gen and fibrin, and GPIba, which binds von Willebrand factor, initiate platelet aggregation (thrombus formation) by recognition of exposed von Willebrand fac- tor/collagen in the damaged blood vessel wall.1,2 Engagement of platelet receptors initiates intra-platelet signaling pathways, which shift platelet integrin aIIbβ3 from
Correspondence:
lihmd@163.com
Received: February 20, 2018. Accepted: May 17, 2018. Pre-published: 24 May, 2018.
doi:10.3324/haematol.2018.191700
Check the online version for the most updated information on this article, online supplements, and information on authorship & disclosures: www.haematologica.org/content/103/9/1568
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