ZPI prevents ox‐LDL‐mediated endothelial injury leading to inhibition of EndMT, inflammation, apoptosis, and oxidative stress through activating Pi3k/Akt signal pathway

Abstract Oxidized low‐density lipoprotein (ox‐LDL)‐mediated endothelial dysfunction exerts an essential role in the development of atherosclerosis. Protein Z‐dependent protease inhibitor (ZPI), a member of the serine protease inhibitor superfamily, could inhibit the function of activated coagulation factor X (FXa) via interaction with protein Z (PZ). Studies have pointed out that ZPI was statistically related to atherosclerotic diseases, which may have a robust cardiovascular protective effect. However, the underlying mechanism of ZPI on ox‐LDL‐mediated endothelial injury requires further elucidation. Human umbilical vein endothelial cells (HUVECs) were treated with ox‐LDL (100 μg/ml) and ZPI (10 μg/ml). Cell viability was measured by the Cell Counting Kit‐8 (CCK‐8) assay. Cell apoptosis, oxidative stress, and endothelial‐to‐mesenchymal transition (EndMT) were analyzed by immunofluorescence (IF). Cell migration was measured using a wound‐healing assay. Quantitative real‐time polymerase chain reaction and western blot analysis were performed to determine messenger RNA and protein expression. Ox‐LDL (100 μg/ml, 48 h) significantly reduced cell viability and migration, increased EndMT, inflammation, apoptosis, and oxidative stress. The related protein expression of phosphatidylinositol 3 kinase/protein kinase B (Pi3k/Akt) signal pathway in HUVECs was also simultaneously decreased. We also discovered that ZPI treatment could prevent ox‐LDL‐mediated endothelial injury through the improvement of cell viability and alleviation of apoptosis, oxidative stress, EndMT, and inflammation. Thus, the protective effect of ZPI on HUVECs may be mediated by activation of the Pi3k/Akt signal pathway. ZPI may exert an important protective role in HUVECs dysfunction triggered by ox‐LDL via activation of the Pi3k/Akt signal pathway. Therefore, ZPI may possess potential therapeutic effects on atherosclerotic endothelial injury‐related diseases.