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2-aminoethoxydiphenylborate (2-APB) inhibits release of phosphatidylserine-exposing extracellular vesicles from platelets

Published version
Peer-reviewed

Change log

Authors

Davies, Jess 
Wei, Hao 

Abstract

Activated, procoagulant platelets shed phosphatidylserine (PS)-exposing extracellular vesicles (EVs) from their surface in a Ca2+- and calpain-dependent manner. These PS-exposing EVs are prothrombotic and proinflammatory and are found at elevated levels in many cardiovascular and metabolic diseases. How PS-exposing EVs are shed is not fully understood. A clearer understanding of this process may aid the development of drugs to selectively block their release. In this study we report that 2-aminoethoxydiphenylborate (2-APB) significantly inhibits the release of PS-exposing EVs from platelets stimulated with the Ca2+ ionophore, A23187, or the pore-forming toxin, streptolysin-O. Two analogues of 2-APB, diphenylboronic anhydride (DPBA) and 3-(diphenylphosphino)-1-propylamine (DP3A), inhibited PS-exposing EV release with similar potency. Although 2-APB and DPBA weakly inhibited platelet PS exposure and calpain activity, this was not seen with DP3A despite inhibiting PS-exposing EV release. These data suggest that there is a further target of 2-APB, independent of cytosolic Ca2+ signalling, PS exposure and calpain activity, that is required for PS-exposing EV release. DP3A is likely to inhibit the same target, without these other effects. Identifying the target of 2-APB, DPBA and DP3A may provide a new way to inhibit PS-exposing EV release from activated platelets and inhibit their contribution to thrombosis and inflammation.

Description

Keywords

Drug development, Mechanism of action

Journal Title

Cell Death Discovery

Conference Name

Journal ISSN

2058-7716
2058-7716

Volume Title

6

Publisher

Nature
Sponsorship
Wellcome Trust (200702/Z/16/Z)
British Heart Foundation (PG/16/45/32152)
Royal Society (RG170381)
J.E.D. was supported by British Heart Foundation Project Grant PG/16/45/32152 to M.T.H. Work in Dr. Harper’s lab was also supported by Wellcome Trust Seed Award 200702/Z/16/Z and Royal Society Research Grant RG170381.