Pravastatin attenuates the action of the ETS domain‐containing protein ELK1 to prevent atherosclerosis in apolipoprotein E‐knockout mice via modulation of extracellular signal‐regulated kinase 1/2 signal pathway
Clinical and Experimental Pharmacology and Physiology
Published online on February 14, 2017
Abstract
Oxidative stress plays an important role in atherosclerosis, a vascular disease with high morbidity and mortality. The ETS domain‐containing protein ELK1 is an oxidative stress‐sensitive factor modulated by the extracellular signal‐regulated kinase (ERK) 1/2 pathway. However, the role of ELK1 in the prevention of atherosclerosis by pravastatin remains unclear. In the present study, male apolipoprotein E‐knockout (apoE−/−) mice fed a diet containing 1.25% cholesterol (w/w) were divided into two groups, one treated with pravastatin (80 mg/kg, 2‐2.4 mg/mouse per day) for 8 weeks and the other not. Male C57BL/6J mice fed with a normal diet were used as a control group. Human umbilical vein endothelial cells (HUVEC) were cultured and treated with pravastatin (10 μmol/L) for 18 hours before testing for the presence or absence of 100 μmol/L H2O2 (24 hours). Examination of pathological sections from mice aortas revealed that pravastatin treatment almost prevented atherosclerotic plaque formation. Pravastatin also inhibited increases in serum and aortic levels of oxidized low‐density lipoprotein and aortic malondialdehyde levels and decreases in aortic reduced glutathione, and the activities of superoxide dismutase, catalase and glutathione peroxidase. H2O2‐induced increases in reactive oxygen species in HUVECs were reversed by pravastatin by 48%. Pravastatin blocked the phosphorylation of ELK1 and ERK1/2 proteins and reduced mRNA levels of early growth response 1, a known atherogenic transcription factor upregulated by the ROS/ERK/ELK1 pathway, in mice. In conclusion, pravastatin attenuates the action of ELK1 induced by oxidative stress to prevent atherosclerosis, which is dependent partly on modulation of ERK1/2 signalling.