Targeting NINJ1-mediated Plasma Membrane Rupture to Prevent Thrombosis

Project Summary/Abstract This proposal focuses on investigating the role of plasma membrane rupture (PMR) of pyroptotic macrophages in thrombosis and examine the potential therapeutic approaches targeting pyroptosis and PMR. Thrombotic complications remain a leading cause of morbidity and mortality worldwide. Current antithrombotic therapies target platelets and the coagulation cascade, common pathways for normal blood clotting upon injury (hemostasis) and the pathological formation of blood clot (thrombosis). These treatments often carry bleeding risks by disrupting hemostasis and do not address the inflammatory roots of thrombosis. Inflammation- dependent blood clotting is part of the body's response to pathogens, but excessive inflammation can result in thrombosis. Emerging research underscores inflammation's pivotal role in thrombosis across various conditions, including heart disease, deep vein thrombosis, sepsis, and COVID-19. Targeting PMR offers a strategy to simultaneously manage inflammation and thrombosis while preserving normal clotting mechanisms. Pyroptosis, a lytic form of cell death in monocytes/macrophages triggered by inflammasomes, is crucial in responding to bacterial infection and sterile inflammation, with PMR being a terminal event in this process. Our previous research has identified macrophage pyroptosis as a key contributor to thrombosis, through the release of microvesicles containing tissue factor (a key initiator of the coagulation cascade together with factor VII/VIIa). This mechanism is linked to PMR, highlighting PMR as a potential trigger of thrombosis and as a desirable inflammatory target. Because it is the final step in a chain of inflammatory processes, targeting PMR may carry low risk of immunosuppression. NINJ1, initially identified in nerve injury, emerges as the executioner of PMR that was previously thought to be passive and uncontrollable. This discovery unveils a potential new target for thrombosis intervention. Our preliminary studies showed reduced NINJ1 expression decreased thrombosis and the release of pyroptotic microvesicles. This research aims to investigate the role of myeloid NINJ1 in thrombosis, the mechanisms behind the release of pyroptotic microvesicles, and the feasibility of targeting pyroptosis and NINJ1-mediated PMR for thrombosis prevention. The expected results will enhance our understanding of NINJ1-mediated PMR in immune cell-induced thrombosis, potentially leading to targeted treatments for thrombosis-related conditions like heart disease, venous thromboembolism, cancer, and infectious disease.