Effects of nicotine on the release of t-PA and PAI-1 in cultured human umbilical vein endothelial cells

AIM: To study the effect of nicotine on the release of tissue plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) in human umbilical vein endothelial cells (HUVECs).METHODS: HUVECs were cultured in 24-well tissue-culture plates and randomly divided into control group and nicotine treatment groups. In nicotine treatment groups, HUVECs were either incubated with nicotine at the concentrations of 0.1, 1, 10 and 100 μmol/L for 12 h, or exposed to 100 μmol/L nicotine for 0 h, 4 h, 6 h, 8 h, 12 h and 24 h. The cells in control group were exposed to the same volume of PBS instead of nicotine at corresponding time points. The supernatants were collected for determining the concentrations of t-PA and PAI-1 by ELISA. RESULTS: (1) Compared with control group, the protein levels of PAI-1 in 100 μmol/L nicotine treatment group increased significantly (P<0.01). No significant difference of t-PA protein among the groups was observed (P>0.05). (2) After stimulated with 100 μmol/L nicotine for 4 h, 6 h, 8 h, 12 h and 24 h, the protein levels of PAI-1 in the cells increased over time and reached the peak at 12 h, which was significantly higher than those in the control cells (P<0.05). However, no significant difference of t-PA protein in these cells was found as compared to the controls (P>0.05).CONCLUSION: Nicotine inhibits the fibrinolytic activity in HUVECs in vitro, thereby damaging the vascular endothelial cells.