Alcoholic Hepatosteatosis Research Articles

Lactobacillus GG Treatment Increases Intestinal Barrier Protecting Factors and Ameliorates Alcohol-Induced Intestinal Dysfunction and Alcoholic Hepatosteatosis

Lactobacillus GG Treatment Increases Intestinal Barrier Protecting Factors and Ameliorates Alcohol-Induced Intestinal Dysfunction and Alcoholic Hepatosteatosis

C/EBP beta and C/EBP delta expression is elevated in the early phase of ethanol-induced hepatosteatosis in mice

Alcohol, which is predominantly metabolized in the liver, is a major hepatic toxicant that readily induces hepatic steatosis. The expression of CCAAT enhancer binding protein (C/EBP), especially the C/EBP delta variety, is increased in the early phase of adipogenesis. However, the role of C/EBP delta in ethanol-induced hepatosteatosis is unclear. Male C57BL/6J mice were randomized to one of four groups: a control group, a group receiving orally administered ethanol (4 g ethanol/kg body weight) (EtOH), a high-fat-diet (HF) group and an EtOH+HF group. Mice were sacrificed after 5 or 10 weeks for various measurements. The in vitro effect of ethanol on the expression of C/EBP alpha, beta and delta was studied in HepG2 cells. By week 5, ethanol treatment had significantly increased liver C/EBP delta and beta protein expression (by 2.3- and 1.4-fold, respectively), which then returned to the control level by week 10. In contrast, the expression of C/EBP alpha was evident only at week 10. The in vitro study shows that C/EBP delta expression was elevated significantly at 24 h but not at 48 or 72 h. C/EBP beta expression was highest at 48 h, whereas C/EBP alpha expression was highest at 72 h. We also found that a low concentration of ethanol plus oleic acid enhanced C/EBP delta expression in HepG2 cells. C/EBP delta expression appears to play an important role in the early phase of ethanol-induced hepatosteatosis in mice and in ethanol-treated HepG2 cells. In addition, EtOH+HF enhances the expression of C/EBP delta in HepG2 cells. Thus, C/EBP delta might be a therapeutic target in alcoholic hepatosteatosis.

Adipose Differentiation‐Related Protein Is a Reliable Lipid Droplet Marker in Alcoholic Fatty Liver of Rats

Adipose differentiation-related protein (ADRP) is a lipid droplet-associated protein that coats cytoplasmic lipid droplets. The present study evaluated whether alcohol feeding enhances ADRP expression and whether ADRP is a lipid droplet marker in alcoholic fatty liver of rats. Because medium-chain triglycerides (MCT) reduce alcoholic hepatosteatosis, their effects on ADRP were also evaluated. Fatty liver was induced in rats by the consumption of the Lieber-DeCarli alcohol liquid diet with or without replacement of long-chain triglycerides (LCT) by MCT (32% of calories). Immunohistochemical staining for ADRP was performed in formalin-fixed, paraffin-embedded liver sections. ADRP immunostaining was quantified by image analysis. Triacylglycerol was measured chemically. ADRP mRNA and protein were analyzed by real-time polymerase chain reaction and western blot, respectively. Double staining technique was performed to distinguish ADRP from glycogen in hepatocytes. Alcohol feeding for 21 days increased ADRP staining in the centrilobular and mid zonal regions of the liver lobules coincident with fat deposition in the liver. Replacing LCT in the alcohol diet with MCT diminished ADRP immunostaining in parallel with reduced steatosis. MCT also attenuated the up-regulation of ADRP mRNA and protein after alcohol. In steatotic hepatocytes ADRP selectively stained the surface of macrovesicular and microvesicular lipid droplets. ADRP immunostaining quantitatively correlated with hepatic triacylglycerol levels, validating ADRP as a reliable lipid droplet marker. Compared with hematoxylin and eosin stains, ADRP was more sensitive in detecting microvesicular lipid droplets. ADRP immunostaining also distinguished lipid droplets from glycogen, as demonstrated by double staining for ADRP and glycogen. Alcohol induction of fatty liver enhances ADRP expression and MCT oppose the alcohol effects. ADRP is a reliable and sensitive marker for lipid droplets in alcoholic fatty liver. ADRP immunostaining permits quantification of fatty change in hepatocytes and can be used as an ancillary technique in assessing the efficacy of diets or drugs against hepatosteatosis.