Inhibition of ADAMTS-13 by Doxycycline Reduces von Willebrand Factor Degradation During Supraphysiological Shear Stress: Therapeutic Implications for Left Ventricular Assist Device-Associated Bleeding.
JACC Heart Fail
; 3(11): 860-9, 2015 Nov.
Article
em En
| MEDLINE
| ID: mdl-26454844
ABSTRACT
OBJECTIVES:
The aim of this study was to investigate a potential therapy for left ventricular assist device (LVAD)-associated bleeding.BACKGROUND:
Nonsurgical bleeding is the most frequent complication of LVAD support. Recent evidence has demonstrated that supraphysiological shear stress from continuous-flow LVADs accelerates von Willebrand factor (vWF) metabolism by the action of a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS-13) (the vWF protease). An acquired vWF deficiency causes bleeding. This suggests that ADAMTS-13 is a clinical target to reduce vWF degradation. We tested the hypothesis that inhibition of ADAMTS-13 with doxycycline, an inexpensive, clinically approved drug, reduces vWF degradation during shear stress.METHODS:
Whole blood was collected from human donors (n = 15), and purified, recombinant ADAMTS-13 protein was obtained. An enzyme-linked immunosorbent assay (ELISA) was used to quantify the dose relationship between doxycycline and ADAMTS-13 activity prior to shear stress (n = 10). To determine the effect of shear stress, plasma and recombinant ADAMTS-13 were exposed to LVAD-like supraphysiological shear stress (approximately 175 dyne/cm(2)). vWF multimers and degradation fragments were characterized with electrophoresis and immunoblotting (n = 10). Förster resonance energy transfer was used to quantify plasma ADAMTS-13 activity (n = 10). An ELISA was used to quantify vWFcollagen binding activity. Platelet aggregometry was performed with adenosine 5'-diphosphate, collagen, and ristocetin (vWF-platelet pathway) agonism (n = 10).RESULTS:
Doxycycline significantly decreased plasma ADAMTS-13 activity (p = 0.01) and the activity of recombinant human ADAMTS-13 protein by 21%. After plasma was exposed to shear stress, the same pattern of vWF degradation was observed as previously reported for LVAD patients, and vWFcollagen binding activity decreased significantly (p = 0.002). Doxycycline significantly decreased ADAMTS-13 activity (p = 0.04) and the activity of recombinant ADAMTS-13 by 18%, protected large vWF multimers from degradation, and significantly decreased the levels of the 5 smallest vWF fragments by 12 ± 2% (p < 0.05). As a result, vWFcollagen binding activity was significantly restored (p = 0.004). ADAMTS-13 inhibition with doxycycline did not hyperactivate platelets.CONCLUSIONS:
Inhibition of ADAMTS-13 by doxycycline decreased vWF degradation and improved vWF function during supraphysiological shear stress without hyperactivating platelets. ADAMTS-13 is a clinical target to reduce vWF degradation, improve vWF function, and potentially reduce bleeding during LVAD support.Palavras-chave
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Fator de von Willebrand
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Coração Auxiliar
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Doxiciclina
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Proteínas ADAM
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Hemorragia
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Antibacterianos
Tipo de estudo:
Risk_factors_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article