Homocysteine Inhibits Human Umbilical Vein Endothelial Cells Proliferation through Cell Cycle G1 / S Arrest

【Objective】 To investigate the effect of moderate concentration of homocysteine (Hcy) on human umbilical vein endothelial cells (HUVEC) proliferation,cell cycle,and possible signaling mechanisms. 【Method】 HUVEC were cultured in M199 medium supplemented with 20% fetal bovine serum,0.06 g / L endothelial cell growth supplement and 0.05 g / L heparin. HUVEC were divided into control,adenosine (50 μmol / L,A50),Hcy (50 μmol / L,H50) and Ade plus Hcy (A50H50) groups. Cell proliferation was assessed by cell counting and MTT method. Cell cycle distribution was assessed by flow cytometry. The phosphorylation status of extracellular signal-regulated protein kinase (ERK) was detected by Western blot analysis. 【Results】 Cell number and viability were significantly decreased in A50H50 group compared with control,A50 and H50 groups (P 0.05). The percentage of G1 phase cells of A50H50 group was significantly increased,while the percentage of S phase cells was significantly decreased compared with control group (P 0.05),which represented an obvious G1 / S arrest in A50H50 group. The phosphorylated ERK of A50H50 group was significantly decreased compared with the other 3 groups. 【Conclusion】 Hcy combined with Ade induced G1 / S arrest leading to impaired HUVEC proliferation,which was associated with decreased phosphorylation of ERK.