title: [Study of synergistic effect of free fatty acid and iron on the establishment of nonalcoholic fatty liver disease model].
abstract: OBJECTIVE
  To establish nonalcoholic fatty liver disease (NAFLD) model induced by free fatty acid (FFA) and iron, and to explore the synergistic effect of FFA and Fe(2+) on the pathogenesis of NAFLD and mechanisms.
  
  
  METHODS
  Human liver carcinoma cell HepG2 was respectively treated with 0.250, 0.500, 1.000 mmol/L oleic acid, 0.500 mmol/L oleic acid+0.125 mmol/L Fe(2+), 0.500 mmol/L oleic acid+0.250 mmol/L Fe(2+), and 0.500 mmol/L oleic acid+0.500 mmol/L Fe(2+). Human liver carcinoma cell HepG2 was normally cultured in the control group. Lipid accumulation of cells were observed by oil red O staining and the determination of the triglyceride (TG) contents by GPO-PAP, then the expression of key genes involved in fatty acid β-oxidation (fatty acyl CoA synthetase-1 (ACSL-1), carnitine acyl transferase 1 (CPT-1a), fatty acid synthetase (FAS)) was determined using RT-PCR. The differences of TG content and ACSL-1, CPT-1a, FAS, mRNA relative value were analyzed among different groups.
  
  
  RESULTS
  The results of oil red O staining indicated that the contents of lipid droplets were obviously elevated with the increase of Fe(2+) concentration in human liver carcinoma cell HepG2 treated with 0.500 mmol/L oleic acid and different concentrations of Fe(2+). The TG contents of HepG2 cell in control group, 0.250, 0.500, 1.000 mmol/L oleic acid groups, 0.500 mmol/L oleic acid+0.125 mmol/L Fe(2+) group, 0.500 mmol/L oleic acid+0.250 mmol/L Fe(2+) group, 0.500 mmol/L oleic acid+0.500 mmol/L Fe(2+) group respectively were (90.0 ± 1.6), (131.7 ± 5.4), (153.7 ± 3.0), (254.1 ± 4.0), (164.5 ± 6.0), (180.1 ± 7.7), (235.6 ± 4.5) nmol/mg (F = 396.00, P < 0.05). The expression levels of ACSL-1 mRNA in 0.500 mmol/L oleic acid group, 0.500 mmol/L oleic acid+0.125 mmol/L Fe(2+) group, 0.500 mmol/L oleic acid +0.250 mmol/L Fe(2+) group, 0.500 mmol/L oleic acid +0.500 mmol/L Fe(2+) group respectively were (0.94 ± 0.02), (0.89 ± 0.04), (0.85 ± 0.02), (0.74 ± 0.04) (F = 50.00, P < 0.05); the mRNA levels of CPT-1a were (0.89 ± 0.03), (0.79 ± 0.05), (0.67 ± 0.04), (0.51 ± 0.05) (F = 79.00, P < 0.05); the mRNA levels of FAS were (1.31 ± 0.05) , (1.44 ± 0.03), (1.51 ± 0.05), (1.56 ± 0.06 ) (F = 79.70, P < 0.05).
  
  
  CONCLUSIONS
  The NAFLD liver cell model could be established by oleic acid and Fe(2+) in HepG2 cells. FFA and iron might be involved in the pathogenesis of NAFLD through the intervention of fatty acid β-oxidation.
authors.affiliation: Department of Nutrition and Food Hygiene, College of Public Health, Harbin Medical University, Harbin 150081, China.
authors.forename: Yuping
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of Nutrition and Food Hygiene, College of Public Health, Harbin Medical University, Harbin 150081, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Ye
authors.affiliation: Department of Nutrition and Food Hygiene, College of Public Health, Harbin Medical University, Harbin 150081, China.
authors.forename: Quansen
authors.initials: Q
authors.lastname: Zheng
authors.affiliation: Department of Nutrition and Food Hygiene, College of Public Health, Harbin Medical University, Harbin 150081, China.
authors.forename: Lijia
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Nutrition and Food Hygiene, College of Public Health, Harbin Medical University, Harbin 150081, China. Email: amyzhaoyan@sina.com.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D002334:Carnitine O-Palmitoyltransferase; D003066:Coenzyme A Ligases; D054890:Fatty Acid Synthase, Type I; D005227:Fatty Acids; D005230:Fatty Acids, Nonesterified / Q000009:adverse effects*; D056945:Hep G2 Cells; D006801:Humans; D007501:Iron / Q000009:adverse effects*; D065626:Non-alcoholic Fatty Liver Disease / Q000139:chemically induced*; D019301:Oleic Acid; D012333:RNA, Messenger; D014280:Triglycerides
chemical_list: D005227:Fatty Acids; D005230:Fatty Acids, Nonesterified; D012333:RNA, Messenger; D014280:Triglycerides; D019301:Oleic Acid; D007501:Iron; C577474:CPT1A protein, human; D002334:Carnitine O-Palmitoyltransferase; D054890:Fatty Acid Synthase, Type I; D003066:Coenzyme A Ligases; C583414:ACSL1 protein, human