retinol-palmitate and Liver-Cirrhosis

Approximately 2.7 million Americans are chronically infected with hepatitis C virus (HCV). HCV patients with cirrhosis form the largest group of persons at high risk for hepatocellular carcinoma (HCC). Increased oxidative stress is regarded as a major mechanism of HCV-related liver disease progression. Deficiencies in retinoid and carotenoid antioxidants may represent a major modifiable risk factor for disease progression. This study aims to identify key predictors of serum antioxidant levels in patients with HCV, to examine the relationship between retinoid/carotenoid concentrations in serum and hepatic tissue, to quantify the association between systemic measures of oxidative stress and antioxidant status, and to examine the relationship between retinoids and stellate cell activation.. Patients undergoing liver biopsy (n = 69) provided fasting blood, fresh tissue, urine and completed a diet history questionnaire. Serum and questionnaire data from healthy volunteers (n = 11), normal liver tissue from public repositories and patients without liver disease (n = 11) were also collected. Urinary isoprostanes, serum and tissue retinoid concentrations were obtained by UHPLC-MS-MS. Immunohistochemistry for αSMA was performed on FFPE sections and subsequently quantified via digital image analysis. Associations between urinary isoprostanes, αSMA levels, and retinoids were assessed using Spearman correlation coefficients and non-parametric tests were utilized to test differences among disease severity groups.. There was a significant inverse association between serum retinol, lycopene, and RBP4 concentrations with fibrosis stage. Serum β-carotene and lycopene were strongly associated with their respective tissue concentrations. There was a weak downward trend of tissue retinyl palmitate with increasing fibrosis stage. Tissue retinyl palmitate was inversely and significantly correlated with hepatic αSMA expression, a marker for hepatic stellate cell activation (r = -0.31, P < 0.02). Urinary isoprostanes levels were inversely correlated with serum retinol, β-carotene, and RBP4.. A decrease in serum retinol, β-carotene, and RBP4 is associated with early stage HCV. Retinoid and carotenoid levels decline as disease progresses, and our data suggest that this decline occurs early in the disease process, even before fibrosis is apparent. Measures of oxidative stress are associated with fibrosis stage and concurrent antioxidant depletion. Vitamin A loss is accompanied by stellate cell activation in hepatic tissue.

Topics: Actins; Adult; beta Carotene; Biomarkers; Biopsy; Carcinoma, Hepatocellular; Carotenoids; Chromatography, High Pressure Liquid; Cross-Sectional Studies; Disease Progression; Diterpenes; Enzyme-Linked Immunosorbent Assay; Female; Hepatic Stellate Cells; Hepatitis C, Chronic; Humans; Immunohistochemistry; Isoprostanes; Lipid Peroxidation; Liver; Liver Cirrhosis; Liver Neoplasms; Lycopene; Male; Middle Aged; Oxidative Stress; Retinoids; Retinol-Binding Proteins, Plasma; Retinyl Esters; Risk; Severity of Illness Index; Tandem Mass Spectrometry; Vitamin A

Hepatic stellate cells (HSCs) store retinoids and triacylglycerols in cytoplasmic lipid droplets. Two prominent features of HSC activation in liver fibrosis are loss of lipid droplets along with increase of alpha-smooth muscle actin (alpha-SMA), but the link between these responses and HSC activation remains elusive. In non-adipose cells, adipose differentiation-related protein (ADRP) coats lipid droplets and regulates their formation and lipolysis; however its function in HSCs is unknown. Here, we observed, in human liver sections or primary HSC culture, ADRP localization to lipid droplets of HSCs, and reduced staining coincident with loss of lipid droplets in liver fibrosis and in culture-activated HSCs, consistent with HSC activation. In the LX-2 human immortalized HSCs, with scant lipid droplets and features of activated HSCs, we found that the upregulation of ADRP mRNA by palmitate is potentiated by retinol, accompanied by increased ADRP protein, generation of retinyl palmitate, and lipid droplet formation. ADRP induction also led to decreased expression of alpha-SMA mRNA and its protein, while ADRP knockdown with small interfering RNA (siRNA) normalized alpha-SMA expression. Furthermore, ADRP induction by retinol and palmitate resulted in decreased expression of collagen I and matrix metalloproteinase-2 mRNA, fibrogenic genes associated with activated HSCs, while increasing matrix metalloproteinase-1 mRNA; ADRP knockdown with siRNA reversed these changes. Tissue inhibitor of metalloproteinase-1 was not affected. Thus, ADRP upregulation mediated by retinol and palmitate promotes downregulation of HSC activation and is functionally linked to the expression of fibrogenic genes.

Topics: Actins; Cells, Cultured; Diterpenes; Down-Regulation; Gene Knockdown Techniques; Hepatic Stellate Cells; Humans; Lipids; Liver; Liver Cirrhosis; Membrane Proteins; Palmitates; Perilipin-2; Retinyl Esters; RNA, Messenger; RNA, Small Interfering; Up-Regulation; Vitamin A

Topics: Acute Disease; Chromatography, High Pressure Liquid; Diterpenes; Hepatitis; Humans; Hyperlipidemias; Hypervitaminosis A; Liver Cirrhosis; Reference Values; Retinyl Esters; Specimen Handling; Vitamin A