Estrogen Sulfotransferase is Highly Expressed in Vascular Endothelial Cells Overlying Atherosclerotic Plaques

Cytosolic estrogen sulfotransferase (SULT1E1) mainly catalyzes the sulfoconjugation and deactivation of estrogens that are known to exert potent anti-atherogenic effects. However, it remains unknown about the connection between SULT1E1 and atherosclerosis. Recently, we reported that SULT1E1 is highly expressed in the aorta with plaques of high fat-fed ApoE knockout (KO) mice (mouse model of atherosclerosis), and interacts with oxidized low-density lipoprotein (Ox-LDL) known as a major component of atherosclerotic lesions. In this study, immunohistochemical staining for SULT1E1 in the aorta of high fat-fed ApoE KO mice showed that SULT1E1 is detected in vascular endothelial cells overlying atherosclerotic plaques. Results from Western blotting showed that Ox-LDL induces the protein expression of both SULT1E1 and peroxisome proliferator-activated receptor (PPAR) γ in human umbilical vein endothelial cells (HUVECs), and then that a PPARγ antagonist GW9662, but not a PPARα antagonist GW6471, inhibited the protein expression of SULT1E1 induced by Ox-LDL. Moreover, GW9662 significantly increased the proliferation of HUVECs induced by Ox-LDL. Our results suggest that SULT1E1 and PPARγ, both of which are increased by Ox-LDL, may interact with each other, and then may reduce cooperatively Ox-LDL-induced proliferation of vascular endothelial cells overlying atherosclerotic plaques, leading to against atherosclerosis.