Format

Send to

Choose Destination
Blood. 2017 Mar 9;129(10):1368-1379. doi: 10.1182/blood-2016-10-747915. Epub 2016 Dec 29.

Alteration of blood clotting and lung damage by protamine are avoided using the heparin and polyphosphate inhibitor UHRA.

Author information

1
Centre for Blood Research.
2
Department of Pathology and Laboratory Medicine.
3
Department of Microbiology and Immunology, and.
4
Department of Medicine, University of British Columbia, Vancouver, BC, Canada.
5
Centre for Innovation, Canadian Blood Services, Vancouver, BC, Canada.
6
Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL; and.
7
Michael Smith Laboratories, Department of Chemical and Biological Engineering, and.
8
Department of Chemistry, University of British Columbia, Vancouver, BC, Canada.

Abstract

Anticoagulant therapy-associated bleeding and pathological thrombosis pose serious risks to hospitalized patients. Both complications could be mitigated by developing new therapeutics that safely neutralize anticoagulant activity and inhibit activators of the intrinsic blood clotting pathway, such as polyphosphate (polyP) and extracellular nucleic acids. The latter strategy could reduce the use of anticoagulants, potentially decreasing bleeding events. However, previously described cationic inhibitors of polyP and extracellular nucleic acids exhibit both nonspecific binding and adverse effects on blood clotting that limit their use. Indeed, the polycation used to counteract heparin-associated bleeding in surgical settings, protamine, exhibits adverse effects. To address these clinical shortcomings, we developed a synthetic polycation, Universal Heparin Reversal Agent (UHRA), which is nontoxic and can neutralize the anticoagulant activity of heparins and the prothrombotic activity of polyP. Sharply contrasting protamine, we show that UHRA does not interact with fibrinogen, affect fibrin polymerization during clot formation, or abrogate plasma clotting. Using scanning electron microscopy, confocal microscopy, and clot lysis assays, we confirm that UHRA does not incorporate into clots, and that clots are stable with normal fibrin morphology. Conversely, protamine binds to the fibrin clot, which could explain how protamine instigates clot lysis and increases bleeding after surgery. Finally, studies in mice reveal that UHRA reverses heparin anticoagulant activity without the lung injury seen with protamine. The data presented here illustrate that UHRA could be safely used as an antidote during adverse therapeutic modulation of hemostasis.

PMID:
28034889
PMCID:
PMC5345737
DOI:
10.1182/blood-2016-10-747915
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center