The Translational Research Center in Thrombotic and Hemostatic Disorders at Washington University is dedicated to understanding the role of proteases in the pathophysiology of thrombosis, which is a serious complication of many common diseases. This Center will pursue an interactive, multi-disciplinary approach involving 5 Projects and 4 Core Units that focus on microvascular and macrovascular thrombosis. Project 1 will characterize the molecular basis of ADAMTS13 substrate specificity, develop optimized assays to investigate the role of ADAMTS13 deficiency in thrombotic microangiopathy, and evaluate treatments to prevent relapses in thrombotic thrombocytopenic purpura. Project 2 will employ genomic sequencing to identify defects in complement regulation and hemostasis that cause thrombotic microangiopathy, including atypical hemolytic uremic syndrome, preeclampsia, and autoimmune disorders, and determine the biochemical mechanism by which these mutations cause disease. Project 3 will engineer an improved thrombin variant with exclusive activity toward protein C to optimize its anticoagulant and anti-inflammatory activity for treating thrombosis and sepsis. Project 4 will characterize new inhibitors of tissue factor and evaluate their efficacy in animal models of thrombosis, sepsis, HUS, and cancer progression. Project 5 will develop a first-in-class nanoparticle-based direct thrombin inhibitor with dual antiplatelet activity, and evaluate it for therapeutic dissolution and magnetic resonance imaging of thrombi. These projects rely on Core Units for logistics and oversight (Core A), patient enrollment and sample banking (Core C), and genomic analysis (Core D). New investigators will receive mentoring and training in translational and clinical research (Core B). The experimental approaches of the Center encompass basic molecular and state-of-the-art genetic methods, animal models, and biochemical and physiological studies of informative patients, as well as clinical studies to assess mechanism-based therapeutic approaches. These projects will facilitate the rapid translation of basic research discoveries into innovations in clinical care.