Cx43 facilitates mesenchymal transition of endothelial cells induced by shear stress

Abstract

Objectives This study aimed to determine the function of Cx43 in the endothelial-to-mesenchymal transition (EndMT) process of endothelial cells (ECs) and to explore the potential signaling pathways underlying these functions. Methods Endothelial cells (ECs) were extracted from rat aorta. ECs was transfected with Cx43 cDNA, Cx43 siRNA and then exposed to 5 or 12 dyne/cm2. Immunofluorescence staining was used to detect the expression of SM22α in ECs, Cx43 and acetylated-α tubulin in ECs. Western Blotting was used to detected the protein expression of α-SMA, CD31, Cx43, H1-caponin, Ift88 and p-smad3 in ECs. Results The expression of αSMA, SM22α and Cx43 was significantly increased and CD31 was markedly decreased in ECs treated with laminar shear stress at 5 dyn/cm2. The Cx43 cDNA transfection could induce the expression of SM22α or H1-caponin, and attenuate CD31 expression in the ECs. Also, Cx43 overexpression harms cilia formation in ECs exposed to 5dyn/cm2, accompanied with the regulated Ift88 and smad signaling. Conclusions This study found that laminar shear stress at 5 dyn/cm2 would increase the expression of Cx43, and interfere with primary cilia formation by inhibiting the expression of Ift88 in ECs.