Expression of synaptopodin in endothelial cells exposed to laminar shear stress and its role in endothelial wound healing (LB272)

Abstract

Laminar shear stress (LSS) due to orderly blood flow contributes to the vascular health by multiple mechanisms including promotion of endothelial wound healing. The purpose of the present study was to identify LSS‐inducible actin‐binding proteins which might play a role in endothelial wound healing processes. Analysis of gene expression profiles of human umbilical vein endothelial cells under static and LSS‐exposed conditions provided a list of actin‐binding proteins whose mRNA levels were significantly increased by LSS. The list includes synaptopodin (SYNPO) whose expression or function in endothelial cells has rarely been reported. Western blot and immunocytochemistry showed that the SYNPO protein level was significantly increased by LSS. In the in vitro scratch wound healing assay, LSS treatments of endothelial cells before and/or after wound creation enhanced wound closure, and such effects were attenuated when SYNPO expression was suppressed using small interfering RNA. In addition, overexpression of exogenous SYNPO enhanced endothelial wound closure in the absence of LSS. This study demonstrated that SYNPO is expressed in endothelial cells in response to LSS and mediates the wound healing process.