Thromb Haemost 2014; 111(02): 279-289
DOI: 10.1160/TH13-06-0490
Platelets and Blood Cells
Schattauer GmbH

Anfibatide, a novel GPIb complex antagonist, inhibits platelet adhesion and thrombus formation in vitro and in vivo in murine models of thrombosis

Xi Lei*
1   Keenan Research Center, Li Ka Shing Knowledge Institute, St. Michael’s Hospital, and Toronto Platelet Immunobiology Group, University of Toronto, Toronto, Ontario, Canada
,
Adili Reheman*
1   Keenan Research Center, Li Ka Shing Knowledge Institute, St. Michael’s Hospital, and Toronto Platelet Immunobiology Group, University of Toronto, Toronto, Ontario, Canada
,
Yan Hou
1   Keenan Research Center, Li Ka Shing Knowledge Institute, St. Michael’s Hospital, and Toronto Platelet Immunobiology Group, University of Toronto, Toronto, Ontario, Canada
2   Jilin Provincial Center for Disease Prevention and Control, Changchun, Jilil, China
,
Hui Zhou
1   Keenan Research Center, Li Ka Shing Knowledge Institute, St. Michael’s Hospital, and Toronto Platelet Immunobiology Group, University of Toronto, Toronto, Ontario, Canada
,
Yiming Wang
1   Keenan Research Center, Li Ka Shing Knowledge Institute, St. Michael’s Hospital, and Toronto Platelet Immunobiology Group, University of Toronto, Toronto, Ontario, Canada
3   Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
4   Canadian Blood Services, Toronto, Ontario, Canada
,
Alexandra H. Marshall
1   Keenan Research Center, Li Ka Shing Knowledge Institute, St. Michael’s Hospital, and Toronto Platelet Immunobiology Group, University of Toronto, Toronto, Ontario, Canada
,
Chaofan Liang
5   Lee’s Pharmaceutical holdings limited, Shatin, Hong Kong, China
,
Xiangrong Dai
6   Zhaoke Pharmaceutical co. limited, Hefei, Anhui, China
,
Benjamin Xiaoyi Li
5   Lee’s Pharmaceutical holdings limited, Shatin, Hong Kong, China
,
Karen Vanhoorelbeke
7   Laboratory for Thrombosis Research, IRF Life Sciences, KU Leuven Kulak, Kortrijk, Belgium
,
Heyu Ni
1   Keenan Research Center, Li Ka Shing Knowledge Institute, St. Michael’s Hospital, and Toronto Platelet Immunobiology Group, University of Toronto, Toronto, Ontario, Canada
3   Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
4   Canadian Blood Services, Toronto, Ontario, Canada
8   Department of Physiology and Department of Medicine, University of Toronto, Toronto, Ontario, Canada
› Author Affiliations

Financial support: This work was supported partially by Canadian Institutes of Health Research and National Natural Science Foundation of China (China-Canada Joint Health Research Initiative Program), Lee’s Pharmaceutical Holdings limited, Canadian Institutes of Health Research (MOP 119540), Heart and Stroke Foundation of Canada, and Canadian Foundation for Innovation. Yan Hou is a recipient of State Scholarship Fund from China Scholarship Council (CSC) and Yiming Wang is a recipient of a Ph.D. Graduate Fellowship from Canadian Blood Services and the Meredith & Malcolm Silver Scholarship in Cardiovascular Studies from the Department of Laboratory Medicine and Pathobiology, University of Toronto.
Further Information

Publication History

Received: 17 July 2013

Accepted after major revision: 25 September 2013

Publication Date:
27 November 2017 (online)

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Summary

Platelet adhesion and aggregation at the sites of vascular injury are key events for thrombosis and haemostasis. It has been well demonstrated that interaction between glycoprotein (GP) Ib and von Willebrand factor (VWF) initiates platelet adhesion and contributes to platelet aggregation, particularly at high shear. GPIb has long been suggested as a desirable antithrombotic target, but anti-GPIb therapy has never been successfully developed. Here, we evaluated the antithrombotic potential of Anfibatide, a novel snake venom-derived GPIb antagonist. We found Anfibatide inhibited washed murine platelet aggregation induced by ristocetin and recombinant murine VWF. It also blocked botrocetin-induced binding of murine plasma VWF to recombinant human GPIb . Interestingly, Anfibatide did not inhibit botrocetin- induced aggregation of platelet-rich plasma, indicating that its binding site may differ from other snake venom-derived GPIb antagonists. Anfibatide strongly inhibited platelet adhesion, aggregation, and thrombus formation in perfusion chambers at high shear conditions and efficiently dissolved preformed thrombi. Anfibatide also inhibited thrombus growth at low shear conditions, though less than at high shear. Using intravital microscopy, we found that Anfibatide markedly inhibited thrombosis in laser-injured cremaster vessels and prevented vessel occlusion in FeCl3-injured mesenteric vessels. Importantly, Anfibatide further inhibited residual thrombosis in VWF-deficient mice, suggesting that Anfibatide has additional antithrombotic effect beyond its inhibitory role in GPIb-VWF interaction. Anfibatide did not significantly cause platelet activation, prolong tail bleeding time, or cause bleeding diathesis in mice. Thus, consistent with the data from an ongoing clinical trial, the data from this study suggests that Anfibatide is a potent and safe antithrombotic agent.

* X. Lei and A. Reheman contributed equally to this work.