Effect Of Rosiglitazone On The Expression Of High Mobility Group Protein B1 In LPS-induced Cultured Human Umbilical Vein Endothelial Cells

Objective:To investigate the expression of HMGB1 on LPS-induced HUVECs in vitro and the effect of rosiglitazone on the expression of HMGB1.Methods:Cultured HUVECs in vitro at passage 3 to 7 were used for experiment. There were three groups:(1)control group;(2)LPS groups;HUVECs were incubated with 1mg/L LPS for different periods to measure cytoactive of HUVECs by MTT colorimetric assay and HMGB1 expression (by ELISA) at 6h , 12h, 24h, Than observe the effect of different concentration rosiglitazone (RSG ) on the cell prolifeferating viaility and HMGB1 expression compared with cntrol group and LPS groups by ELISA and RT-PCR.Results:First,MTT assays were used to characterize the proliferating activity of HUVECs.And the proliferating activity of HUVECs induced by 1mg/L LPS was remarkably decreased when compared with the control group (P<0.01).however, pretreatment of the cells 2 hours with RSG(5,10,15μmol/L) can significantly protect the activity of HUVECs induced by LPS,and the effect of RSG displayed in concentration and time-dependent.(P<0.05,P<0.01).Second,HUVECs didn,t release HMGB1 without stimulation,but the expression of HMGB1 was highly produced on the stimulation of LPS in a time-dependent manner (6,12,24h ). pretreatment with RSG(5,10,15μmol/L) could significantly reduced the HMGB1 expression,which displayed in a concentration-dependent and time-dependent manner.Third, normal HUVECs have little HMGB1mRNA expression, but when induced by LPS, the expression of HMGB1 was remarkly increased.pretreatment of the cells by 2 hours with RSG(5,10,15μmol/L) can significantly reduced the HMGB1mRNA expression,which displayed in a concentration-dependent too.Conclusion:1mg/L LPS could obviously stimulate the production of HMGB1 on HUVECs.And it was remarkably inhibited by Rosiglitazone in a concentration and time-dependent manner.The starts up of HMGB1 expression induced by LPS may thereby be one of the mechanism participated in the pathogenesis of atherosclerosis. PPARγspecific agonist rosiglitazone can improve the impaired HUVECs and down-regulate inflammatory mediators,block the expression of HMGB1 .All these evidence will provide a new idea of RSG inhibiting the initiation and progression of atherosclerosis by LPS.