Induced forms of αk-macroglobulin neutralize heparin and direct oral anticoagulant effects

Alpha2-macroglobulin (alpha 2M) is a physiological macromolecule that facilitates the clearance of many proteinases, cytokines and growth factors in human. Here, we explored the effect of induced forms of alpha 2M on anticoagulant drugs. Gla-domainless factor Xa (GDFXa) and methylamine (MA)-induced alpha 2M were prepared and characterized by electrophoresis, immunonephelometry, chromogenic, clot waveform and rotational thromboelastometry assays. Samples from healthy volunteers and anticoagulated patients were included. In vivo neutralization of anticoagulants was evaluated in C57Bl/6JRj mouse bleeding-model. Anticoagulant binding sites on induced alpha 2M were depicted by computer-aided energy minimization modeling. GDFXa-induced alpha 2M neutralized dabigatran and heparins in plasma and whole blood. In mice, a single IV dose of GDFXa-induced alpha 2M following anticoagulant administration significantly reduced blood loss and bleeding time. Being far easier to prepare, we investigated the efficacy of MA-induced alpha 2M. It neutralized rivaroxaban, apixaban, dabigatran and heparins in spiked samples in a concentration-dependent manner and in samples from treated patients. Molecular docking analysis evidenced the ability of MA-induced alpha 2M to bind non-covalently these compounds via some deeply buried binding sites. Induced forms of alpha 2M have the potential to neutralize direct oral anticoagulants and heparins, and might be developed as a universal antidote in case of major bleeding or urgent surgery.

Automated summary

This study investigated the effect of induced forms of alpha 2M on anticoagulant drugs, revealing that GDFXa-induced alpha 2M can neutralize dabigatran and heparins in blood, and may be developed as a universal antidote.