Abstract: Objective: to investigate the effects of homocysteine on the expression of IκB and NF-κB in the human umbilical veins endothelial cells and explore the role of homocysteine in the development of atherosclerosis. Methods:The HUVECs were randomly divided into 5 groups,and each group was cultured with 0 mmol/L Hcy,2.5 mmol/L Hcy ,5 mmol/L Hcy,10 mmol/L Hcy ,15 mmol/L Hcy for 24 hours. MTT assay was used to detect cell viability.The expression of NF-κB p65 mRNA was observed by RT-PCR, and the expression of IκB-α was observed by Western blot,and the expression of NF-κB p65 protein was observed by immunohistochemistry. Results: After HUVECs were exposed to Hcy at different concentrations, the HUVECs were inhibition. The expression of NF-κB p65 mRNA and NF-κB p65 protein were increased significantly, however, the expression of IκB-α was reduced. Conclusion: Hcy can reduce cell viability. Hcy can increase the expression of NF-κB p65 mRNA obviously, and reduce the expression of IκB-α,and increase NF-κB nuclear translocation. In a word, Hcy can increase the activity of NF-κB.

Key words: Human Umbilical Veins Endothelial Cells, homocysteine, 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide, Nuclear factor κB, theinhibitor ofNFκB