Low fluid shear stress promoted ciliogenesis via Dvl2 in hUVECs

Abstract

This study aims to explore the mechanism of fluid shear stress in regulating the primary cilia assembly or disassembly in human umbilical vein endothelial cells (hUVECs) using microfluidic chamber experiments. Immunofluorescence analysis showed that primary cilia assembled under disturbed fluid shear stress (DF) of 1dyne/cm2, while disassembled under unidirectional shear stress (USS) of 15dynes/cm2. Disheveled (Dvl2) in Wnt signaling pathway was effectively co-immunoprecipitated with Bardet-Biedl syndrome proteins 8 (Bbs8) and γ-tubulin. Compared with those in the control group, the percentages of ciliated cells with Dvl2 overexpression were found to be 67% and 59.667%, respectively, under USS and DF (an increment of 21-38.7%); while, those with Dvl2 silencing were 16% and 32.667%, respectively, under USS and DF (a decrement of 23-30%). Further, the expression of Bbs8 and γ-tubulin was decreased by RNA interference of Dvl2 but increased with Dvl2 overexpression. The results indicated that Dvl2 played a pivotal role during DF-induced primary cilia assembly, and was important for apical docking of basal bodies through Bbs8 and γ-tubulin.