ABSTRACT
Objective To investigate the role of Bmi1 on the migration of human umbilical vein endothelial cells (HUVECs) in response to low shear stress. Methods A parallel plate flow chamber system was used to generate low (0.5 Pa) or normal (1.5 Pa) laminar shear stress. HUVECs were isolated, cultured and exposed to flow for 12 hours. The mRNA and protein levels of Bmi1 were analyzed by real-time PCR and Western blot, respectively. Meanwhile, wound healing assay was performed to determine the migration of HUVECs. Bmi1 specific small interference RNA (siRNA) was used to silence Bmi1 gene. Results Low shear stress (0.5 Pa) significantly inhibited migration of HUVECs compared with normal shear stress (1.5 Pa). Similarly, compared with HUVECs exposed to normal shear stress, the expression of Bmi1 significantly increased in HUVECs exposed to low shear stress. Small interfering RNA knockdown of Bmi1 attenuated low shear stress-induced inhibition of HUVECs migration. Conclusions Low shear stress may inhibit the migration of HUVECs through up-regulation of Bmi1 expression. Knockdown of Bmi1 may reverse the HUVECs migration inhibited by low shear stress．