ABSTRACT
<p><b>OBJECTIVE</b>To investigate the role of ATP-binding cassette transporter G1 (ABCG1) in endothelial dysfunction induced by high glucose.</p><p><b>METHODS</b>Human aortic endothelial cells (HAECs) were incubated in the presence of 5.6 or 30 mmol/L glucose for 24-72 h with or without a 2-h pretreatment with the LXR agonist 22(R)-hydroxycholesterol. Real-time PCR and Western blotting were used to measure the mRNA and protein expressions of ABCG1; the intracellular cholesterol efflux and endothelial nitric oxide synthase (eNOS) activity were measured by scintillation counting.</p><p><b>RESULTS</b>High glucose time-dependently suppressed ABCG1 expression and cholesterol efflux to HDL in HAECs. High glucose also decreased eNOS activity. ABCG1 down-regulation induced by high glucose, along with decreased cholesterol efflux and eNOS activity, was abolished by treatment of the cells with the LXR agonist.</p><p><b>CONCLUSION</b>Endothelial dysfunction induced by high glucose is associated with decreased ABCG1 expression.</p>
Subject(s)
Humans , ATP Binding Cassette Transporter, Subfamily G, Member 1 , ATP-Binding Cassette Transporters , Genetics , Metabolism , Aorta , Cell Biology , Cell Line , Down-Regulation , Endothelial Cells , Cell Biology , Metabolism , Physiology , Glucose , PharmacologyABSTRACT
Objective To investigate the relationship betwe en low-selenium diet and apoptosis of cardiac myocytes in rats and if melatonin c an have protective effects on the damage. Methods The level of myocardial MDA in rats' was measured a nd apoptosis of cardiac myocytes in rats was detected in the three groups of rat s, fed with low-selenium diet, sufficient-selenium diet and low-selenium diet plus intragastric administration of melatonin, respectively. Results The level of MDA in myocardium was significantly hi gher in low-selenium group than that in sufficient-selenium group and low-sel enium group with intragastric administration of melatonin (P
ABSTRACT
Objective To further confirm the role of lipid-peroxidation caused by oxygen free radicals injury played in the pathogenesis of dilsted cardiomypathy. Methods The superoxide dismutase activities and lipids composi tion of erythrocytes in 18 patients with dilated cardiomyopathy and 16 healthy controls were measured. Results ① Su peroxide dismutase(SOD) activites of erythrocytes were lower in dilated cardiomyopathy(DCM) patients than that in healthy controls (P ＜0. 001). ②The lipids composition of erythrocytes has changed in the DCM patients compared with healthy controls: total lipids changed little (P＞0. 05); total phospholipids were lower, but not significantly (P ＞0.05); total cholesterol increased significantly (P ＜0. 05). The cholesterol to phospholipids molecular ratio of erythrocyte membrane has increased remarkably (P＞0. 05). Conclusion It can be supposed that decreased SOD ac tivities play an important role in the damage of membrane system and the pathogensis of DCM.