COUP-TFII switches responses of venous endothelium to atherosclerotic factors through controlling the profile of various inherent genes expression.

Endothelial cells of arteries (AEC) have a strikingly greater responsiveness to atherosclerosis factors than venous endothelial cells (VEC). However, the reasons for this phenomenon remain unclear. Chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII) plays an important role in regulating embryonic arterial-venous differentiation. We therefore investigate whether COUP-TFII is related to this different susceptibility between AEC and VEC. It is first confirmed that COUP-TFII is expressed in VEC but not in AEC in the adult. Using a siRNA strategy, we identified the expression of Jagged1 and Notch1 in cultured human VEC, which usually exist only in AEC, after knocking down of COUP-TFII. To further elucidate the role of COUP-TFII, we performed DNA microarrays in VEC transfected with the siRNA of COUP-TFII and subsequently stimulated with angiotensin II (AngII) and compared the expression profiles of 112 genes involved in various atherosclerosis-related pathways. The results indicated that expression of atherogenic genes was significantly upregulated after AngII stimulation in VEC transfected with COUP-TFII siRNA. Moreover, in vitro cell functional assay showed that knockdown of COUP-TFII in VEC increased not only basal but also AngII-induced cell adhesions. These results demonstrate that COUP-TFII suppresses the susceptibility of VEC to atherosclerosis through controlling the expression of various atherosclerosis-related molecules.