Endothelial GATA3 is involved in coagulofibrinolytic homeostasis during endotoxin sepsis

Sepsis-induced acute lung injury represents a significant threat to human health and is frequently associated with pulmonary thrombosis due to dysregulation of the coagulofibrinolytic system. Plasmin, the major protease that degrades fibrin aggregates, is activated predominantly by tissue-plasminogen activator (tPA), whereas tPA is negatively regulated by plasminogen activator inhibitor (PAI-1). Under septic conditions, the imbalance between coagulation and fibrinolysis results in excessive microthrombosis. Pulmonary capillary endothelial cells serve as a primary source of tPA and PAI-1. The molecular pathways regulating their expression levels depend on the differential activity of transcription factors. In this study, we elucidated the role of the zinc-finger transcription factor GATA3 in response to sepsis-induced pulmonary embolism. Endothelial cell-specific GATA3-deficient mice (G3-ECKO) presented increased susceptibility to bacterial endotoxin-induced pulmonary embolism, which was associated with increased PAI-1 expression levels and decreased tPA expression levels in the lungs. Septic lung extracts from G3-ECKO mice consistently presented decreased plasmin activity, which likely underlies the increased coagulation. These results demonstrate that GATA3 plays a protective role against bacterial endotoxin-induced pulmonary vascular embolism. Our findings will contribute to understanding the molecular mechanisms involving GATA3 in preventing pulmonary embolism.