Plasminogen Activator Inhibitor-1 is internalized by endothelial cells via macropinocytosis to evade degradation.

According to a preprint abstract, researchers have found that plasminogen activator inhibitor-1 (PAI1), a protein involved in blood clotting and a biomarker for cardiovascular disease, can be internalized by endothelial cells in an energy-dependent manner. This internalization allows PAI1 to persist in the cell for at least 6 hours and evade degradation, which in turn inhibits endothelial nitric oxide synthase (eNOS). The mechanism of internalization is not dependent on specific cell surface receptors or clathrin-mediated endocytosis, but rather occurs through macropinocytosis. This research provides insights into the intracellular biology of PAI1 and its potential role in cardiovascular disease. [Extracted from the article]