Unbalanced expression of ADAMTS13 and von Willebrand factor in mouse endotoxinemia

IntroductionSecondary ADAMTS13 deficiency may occur in septic patients. The expression of ADAMTS13 in mouse endotoxinemia was studied.MethodsThe blood and mRNA expression levels of ADAMTS13 and von Willebrand factor were measured in lipopolysaccharide-injected mice.ResultsThe plasma ADAMTS13 activity in wild-type mice was significantly decreased at 2 h after lipopolysaccharide injection, and this decrease in ADAMTS13 activity preceded the decrease in ADAMTS13 mRNA expression in the liver and continued for 24 h. However, no decreases in the plasma ADAMTS13 activity after lipopolysaccharide injection were observed in mice pretreated with a neutrophil elastase inhibitor or in plasminogen-deficient mice, suggesting that the decrease in ADAMTS13 activity was processed efficiently by the coordinated actions of plasmin and neutrophil elastase. von Willebrand factor mRNA was abundantly expressed in the lung and moderately in the kidney, but showed relatively low expression in the liver without lipopolysaccharide injection. However, von Willebrand factor mRNA expression in the liver was significantly increased after lipopolysaccharide injection and this high expression level continued for 24 h after the injection. The von Willebrand factor and ADAMTS13 mRNA expression levels in these organs changed in the opposite manners following lipopolysaccharide administration. Furthermore, the blood von Willebrand factor level increased after lipopolysaccharide administration, in contrast to the decrease in the blood ADMTS13 level after lipopolysaccharide administration.ConclusionThese data suggest that imbalance between the blood von Willebrand factor and ADAMTS13 levels may occur in endotoxinemia, and that this may partly contribute to the thrombotic state associated with endotoxinemia.