RESUMO
Objective To investigate the relationship between abnormal methylation in promoter regions for OPN and VSMC phenotype switching in varicosity.Methods Immunohistochemistry and Western-blot were used to evaluate the expression of SMA and OPN in VSMC.Methylation-specific PCR was used to evaluate the methylation level of OPN in VSMC of vein samples.Ultrastructure change of VSMC was observed by transmission electron microscope (TEM).Results Compared to normal vein,OPN in VSMCs were significantly highly expressed,mainly in the neointimal region (P ＜ 0.01).SMA in neointima region was in low expression (P ＜ 0.01).The density of OPN in varicose group was significantly higher (P ＜0.01).DNA methylation level of OPN was lower in varicose veins.Conclusions Hypomethylation of the promoter regions for OPN may cause high expression of OPN leading to VSMC phenotype switching and development of varicosity.