ABSTRACT
ObjectiveRecent studies revealed that the transcription factor EB (TFEB) plays an important role in regulating autophagy, reducing intracellular lipids, and inhibiting atherosclerosis. This study aims to explore the effects of atorvastatin (ATV) on autophagy and cholesterol levels of foam cells by activating TFEB.MethodsHuman mononuclear cell line THP-1 was cultured in vitro and induced to differentiate into macrophages using phorbol ester. Oxidized low-density lipoprotein (oxLDL) was added to macrophages, which were induced for 48 hours to establish a foam cell model. The experiment was divided into four groups: blank group, model group (oxLDL group), oxLDL+ Chloroquine (CQ) group, oxLDL+ ATV group, and oxLDL+CQ+ ATV group. Cells in each group were treated with drugs for 48 h. The toxicity of ATV and chloroquine on the cells was detected by the CCK8 method. Oil red O staining was used to test the level of lipid droplets. Oxidase method was used to detect levels of intracellular free cholesterol (FC), total cholesterol (TC) and others related to. Cholesterol efflux fluorescence analysis was used to determine the cholesterol efflux rate of the cells. Expression of I, P62, TFEB, LAMP 1 protein was determined by Western blot.ResultsThe results of the CCK8 method showed that the cell survival rate decreased significantly with the increase of ATV and CQ concentrations (P<0.01). Compared to the blank group, the levels of lipid droplets, FC, TC, and CE/TC in the model group significantly increased (P<0.05), and the cholesterol outflow rate significantly decreased (P<0.05). Compared to the model group, the intracellular lipid droplets, FC, TC, and CE/TC levels in the oxLDL+CQ group elevated significantly (P<0.05), while the cholesterol outflow rate decreased significantly (P<0.05). The intracellular lipid droplets, FC, TC, and CE/TC contents in the oxLDL+ATV group decreased significantly (P<0.05), and the cholesterol outflow rate increased significantly (P<0.05). Compared to the oxLDL+CQ group, the intracellular lipid droplets, FC, TC, and CE/TC content in the oxLDL+CQ+ATV group decreased significantly (P<0.05), while the cholesterol outflow rate increased significantly (P<0.05). Western blotting results showed that protein expression levels of LC3II/I, P62 and TFEB were decreased in the model histone in comparison to the blank group (P<0.05). Compared to the expression levels of LC3II/I, P62, TFEB and LAMP1 ((1.006±0.052), (0.183±0.013), (0.333±0.020), and (0.957±0.026)) in the model group, the expression levels of oxLDL+CQ histamine ((1.594±0.017), (0.257±0.006), (0.477±0.024), and (0.957±0.026)) were significantly higher (P<0.05).The protein expression levels of LC3II/I, TFEB and LAMP1 in oxLDL+ATV group ((1.146±0.060), (0.540±0.031), and (1.027±0.054)) were increased, while the protein expression levels of P62 (0.115±0.009) were decreased (P<0.05). Compared to LC3II/I and P62 in oxLDL+CQ group, the expression level of oxLDL+CQ+ATV histone was decreased ((1.419±0.036) and (0.165±0.006)), and the difference was statistically significant (P< 0.05).ConclusionATV can increase the cholesterol outflow rate of macrophages, reduce the level of cholesterol and lipid droplets in macrophages, and reduce the formation of foam cells. The mechanisms behind this are still unknown, which may be related to the activation of TFEB by ATV and influencing the process of autophagy.
ABSTRACT
<p><b>BACKGROUND</b>Aldehyde dehydrogenase 2 (ALDH2) is involved in the pathophysiological processes of cardiovascular diseases. Recent studies showed that mutant ALDH2 could increase oxidative stress and is a susceptible factor for hypertension. In addition, wild-type ALDH2 could improve the endothelial functions, therefore reducing the risk of developing atherosclerosis. The aim of the present study was to explore the frequency of the Glu504Lys polymorphism of the ALDH2 gene and its relation to carotid intima-media thickness (CIMT) in a group of patients with essential hypertension (EH) and to investigate the association between the Glu504Lys polymorphism and CIMT in Chinese Han patients with EH.</p><p><b>METHODS</b>In this study, 410 Chinese Han patients with EH who received physical examinations at the People's Hospital of Sichuan Province (China) were selected. DNA microarray chip was used for the genotyping of the Glu504Lys polymorphism of the ALDH2 gene. The differences in CIMT among patients with different Glu504Lys ALDH2 genotypes were analyzed.</p><p><b>RESULTS</b>The mean CIMT of the patients carrying AA/AG and GG genotypes was 1.02 ± 0.31 mm and 0.78 ± 0.28 mm, respectively. One-way ANOVA showed that the CIMT of the patients carrying the AA/AG genotype was significantly higher than in the ones carrying the GG genotype (P < 0.001). Multivariate logistic regression showed that the Glu504Lys AA/AG genotype of the ALDH2 gene was one of the major factors influencing the CIMT in patients with EH (odds ratio = 3.731, 95% confidence interval = 1.589-8.124, P = 0.001).</p><p><b>CONCLUSIONS</b>The Glu504Lys polymorphism of the ALDH2 gene is associated with the CIMT of Chinese Han patients with EH in Sichuan, China.</p>