Heyu Ni

Research Interests: 1) Platelet Physiology and Thrombosis: Thrombotic diseases such as heart attack and stroke are the leading causes of mortality and mobility worldwide. Dr. Ni and his colleagues established an intravital microscopy thrombosis model at Harvard to study thrombus formation in real-time in live mice. Through direct monitoring of platelet adhesion and aggregation in vivo, Dr. Ni was the first to observe that platelet aggregation and thrombus formation still occurs in mice lacking both von Willebrand factor (VWF) and fibrinogen (Fg). This surprising discovery challenged the established theory of thrombosis that required VWF and Fg for thrombus formation. This finding suggested that other unidentified molecule(s) may also be involved in thrombosis and hemostasis and may provide novel targets for anti-thrombotic therapies. Dr. Ni's team is in the process of identifying these mystery molecules at St. Michael's Hospital using several state-of-the-art techniques such as proteomics and confocal intravital microscopy. 2) Platelet Immunology and Maternal Immune Response to Fetal Antigens: Dr. Ni’s laboratory recently published two important papers in Blood investigating: 1) How ITP mediated by anti-b3 integrin and anti-GPIba antibodies differ, finding that these two antibody specificities may respond to therapy differently. This has important implications for human ITP and potential screening of patients in order to successfully treat this disease. 2) Dr. Ni’s laboratory also established the first animal model of fetal and neonatal alloimmune thrombocytopenia (FNAITP), and characterized the disease and its response to intravenous immunoglobulin G (IVIG) therapy. Currently, the laboratory is studying the molecular and cellular basis for ITP, and the maternal immune responses to fetal platelet antigens, and the roles of anti-angiogenesis and apoptosis in the patho-progression of FNAITP.