Effects Of Nicotine On FIbrinolytic Function Of The Cultured Human Umbilical Vein Endothelial Cells And Relevance With ET-1 And IL-6

BackgroudThe smoke of cigar includes several kinds of substances, most of them are harmful to thehealth. Nicotine thus belongs to one of the harmful substances which damage vascularendothelial cells and lead to thrombosis. As the major anticoagulation system in the body,fibrinolytic saystem relies heavily on the activity of tissue-type plasminogen activator(t-PA) andtissue-type plasminogen inhibitor-1(PAI-1) released by vascular endothelial cells, whichdetermine the fibrinolysis system function. Smoking can damage the endothelial cells , leadind torelease t-PA and PAI-1. Inflammation factors can damage fibrinolytic function of the endothelialcells. Whether nicotine can lead to fibrinolytic function disorders of the endothelial cells andwhether it is related to inflammation factors, there are rare cases reported.ObjectsTo study the effects of nicotine on the expression of protein of Endothelin-1(ET-1),Interleukin-6(IL-6) and tissue-type plasminogen activator(t-PA),Plasminogen activorinhibitor-1(PAI-1) in Human Umbilical Vein Endothelial Cell(HUVECs) on the differentexperimental conditions, and futher analysis its relevance among ET-1,IL-6 and t-PA,PAI-1. Toinvestigate the possible mechanism of nicotine restricted the fibrinolytic function of endothelialcells.MethodsChoose HUVECs to carry the following experiment. HUVECs were cultured in 25cm2culture flasks and randomly divided into the controlling team and the experiment team to carrythe following experiment.①controlling team: to add culturefluid which has the same volumewith nicotine.②experiment team: to divide the cells into four groups. And add culturefluid intonitocine respectively which have no same volume. HUVECs were incubated respectively with0.1, 1.0, 10, 100μmol/L nicotine for 12 hours. The supematants were collected respectively. Theexpression of ET-1,IL-6,t-PA and PAI-1 were determined by the enzyme linkedimmunosorbent assay (ELISA).Results(1) Effect of nicotine on the fibinolytic balance of HUVECs: compared with control group andnicotine treated group, the expression levels of PAI-1 protein of 100μmol/L nicotine treatedgroup were increased significantly(P﹤0.05). However, the PAI-1 protein expression of othernicotine group had no significant difference(P>0.05, respectively).The levels of t-PA protein ofeach group had no significant difference(P>0.05, respectively). (2) Effect of nicotine on the cytokine of HUVECs: compared with controlling team andexperiment team, The levels of ET-I and IL-6 protein of each group had significant difference( P﹤0.05, respectively).(3) Correlation Analysis: the expression levels of ET-1 and IL-6 protein of 100μmol/L nicotinetreated group were positively correlated(r＝0.666, P﹤0.05；r＝0.731, P﹤0.05).ConclusionConclusions(1) Nicotine can increase the expression of PAI-1 protein in HUVECs, and had no significanteffect on the expression of t-PA protein. Nicotine may break the balance between t-PA andPAI-1, thus it restrict the endothelial cells fibrinolytic function.(2) Nicotine can increase the expression of ET-1 and IL-6 protein in HUVECs, thusendothelial injury and inflammation may take part in nicotine-induced HUVECs fibrinolyticdisorders.