Journal Article

SARS-CoV-2 binds platelet ACE2 to enhance thrombosis in COVID-19

Wang, Yuyan, Yang, Li, Zhang, Yi, Hu, Liang, Zhang, Si, Liu, Mengduan, Li, Haishan, Ding, Zhongren, Fan, Zhichao, Zhao, Xiaoyan, Xie, Youhua, Yang, Yan, Wang, Xiaofang, Zhang, Shenghui, Dong, Jianzeng, Liu, Yangyang, Yuan, Zhenghong

2020

Overview

Background Critically ill patients diagnosed with COVID-19 may develop a pro-thrombotic state that places them at a dramatically increased lethal risk. Although platelet activation is critical for thrombosis and is responsible for the thrombotic events and cardiovascular complications, the role of platelets in the pathogenesis of COVID-19 remains unclear. Methods Using platelets from healthy volunteers, non-COVID-19 and COVID-19 patients, as well as wild-type and hACE2 transgenic mice, we evaluated the changes in platelet and coagulation parameters in COVID-19 patients. We investigated ACE2 expression and direct effect of SARS-CoV-2 virus on platelets by RT-PCR, flow cytometry, Western blot, immunofluorescence, and platelet functional studies in vitro, FeCl 3 -induced thrombus formation in vivo, and thrombus formation under flow conditions ex vivo. Results We demonstrated that COVID-19 patients present with increased mean platelet volume (MPV) and platelet hyperactivity, which correlated with a decrease in overall platelet count. Detectable SARS-CoV-2 RNA in the blood stream was associated with platelet hyperactivity in critically ill patients. Platelets expressed ACE2, a host cell receptor for SARS-CoV-2, and TMPRSS2, a serine protease for Spike protein priming. SARS-CoV-2 and its Spike protein directly enhanced platelet activation such as platelet aggregation, PAC-1 binding, CD62P expression, α granule secretion, dense granule release, platelet spreading, and clot retraction in vitro, and thereby Spike protein enhanced thrombosis formation in wild-type mice transfused with hACE2 transgenic platelets, but this was not observed in animals transfused with wild-type platelets in vivo. Further, we provided evidence suggesting that the MAPK pathway, downstream of ACE2, mediates the potentiating role of SARS-CoV-2 on platelet activation, and that platelet ACE2 expression decreases following SARS-COV-2 stimulation. SARS-CoV-2 and its Spike protein directly stimulated platelets to facilitate the release of coagulation factors, the secretion of inflammatory factors, and the formation of leukocyte–platelet aggregates. Recombinant human ACE2 protein and anti-Spike monoclonal antibody could inhibit SARS-CoV-2 Spike protein-induced platelet activation. Conclusions Our findings uncovered a novel function of SARS-CoV-2 on platelet activation via binding of Spike to ACE2. SARS-CoV-2-induced platelet activation may participate in thrombus formation and inflammatory responses in COVID-19 patients.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: ACE2 / Adult / Aged / Angiotensin-Converting Enzyme 2 / Animals / Antibodies / Betacoronavirus - genetics / Betacoronavirus - metabolism / Blood clots / Blood platelets / Blood Platelets - metabolism / Caco-2 Cells / Cancer Research / Coronavirus Infections - metabolism / Coronavirus Infections - virology / Coronaviruses / COVID-19 / Disease transmission / Ethics / Female / Ferric chloride / Flow cytometry / Genetic engineering / Health aspects / Health care / HeLa Cells / Hematology / Humans / Hyperactivity / Immunofluorescence / Inflammation / Influenza / Laboratories / Male / MAP kinase / Medical research / Medicine / Medicine & Public Health / Mice / Mice, Inbred C57BL / Mice, Transgenic / Middle Aged / Monoclonal antibodies / Oncology / PAC1 protein / Pandemics / PC-3 Cells / Peptidyl-Dipeptidase A - genetics / Peptidyl-Dipeptidase A - metabolism / Platelet activation / Platelet aggregation / Platelet Aggregation - immunology / Platelet Count / Pneumonia, Viral - metabolism / Pneumonia, Viral - virology / Polymerase chain reaction / Proteins / Ribonucleic acid / RNA / RNA, Viral - blood / SARS-CoV-2 / Scanning electron microscopy / Serine / Serine Endopeptidases - metabolism / Serine proteinase / Severe acute respiratory syndrome coronavirus 2 / Spike Glycoprotein, Coronavirus - metabolism / Spike protein / Thrombin / Thrombosis / Thrombosis - metabolism / Thrombosis - virology / TMPRSS2 / Transgenic mice / Viruses