title: Long-term fructose consumption prolongs hepatic stearoyl-CoA desaturase 1 activity independent of upstream regulation in rats.
abstract: Dietary fructose is considered a risk factor for metabolic disorders, such as fatty liver disease. However, the mechanism underlying the effects of fructose is not well characterized. We investigated the hepatic expression of key regulatory genes related to lipid metabolism following fructose feeding under well-defined conditions. Rats were fed standard chow supplemented with 10% w/v fructose solution for 5 weeks, and killed after chow-fasting and fructose withdrawal (fasting) or chow-fasting and continued fructose (fructose alone) for 14 h. Hepatic deposition of triglycerides was found in rats from both groups. As expected, fructose alone increased mRNA levels of lipogenesis-related genes and correspondingly decreased mRNA levels of lipid oxidative genes in the liver. Interesting, hepatic levels of stearoyl-CoA desaturase (SCD)1 mRNA remained elevated under fructose withdrawn conditions, although expression levels of other genes, including two key transcription factors (carbohydrate response element binding protein (ChREBP) and sterol regulatory element-binding protein (SREBP)-1c) fell to normal levels, indicating that long-term fructose intake increased SCD1 activity, independent of upstream regulatory genes, such as ChREBP and SREBP-1c. In conclusion, SCD1 overexpression in fatty liver disease is not affected by fasting after long-term fructose consumption in rats. Regulation of SCD1 plays an important role in fructose-induced hepatic steatosis.
authors.affiliation: Faculty of Basic Medical Sciences, Chongqing Medical University, Chongqing 400016 China.
authors.forename: Li
authors.initials: L
authors.lastname: Liu
authors.affiliation: Faculty of Basic Medical Sciences, Chongqing Medical University, Chongqing 400016 China.
authors.forename: Shang
authors.initials: S
authors.lastname: Wang
authors.affiliation: The Laboratory of Traditional Chinese Medicine, Chongqing Medical University, 400016 China.
authors.forename: Ling
authors.initials: L
authors.lastname: Yao
authors.affiliation: The Laboratory of Traditional Chinese Medicine, Chongqing Medical University, 400016 China.
authors.forename: Jin-Xiu
authors.initials: JX
authors.lastname: Li
authors.affiliation: Faculty of Basic Medical Sciences, Chongqing Medical University, Chongqing 400016 China.
authors.forename: Peng
authors.initials: P
authors.lastname: Ma
authors.affiliation: Faculty of Basic Medical Sciences, Chongqing Medical University, Chongqing 400016 China.
authors.forename: Li-Rong
authors.initials: LR
authors.lastname: Jiang
authors.affiliation: The Second Affiliated Hospital, Chongqing Medical University, Chongqing 400010 China.
authors.forename: Da-Zhi
authors.initials: DZ
authors.lastname: Ke
authors.affiliation: The Laboratory Animal Center, Chongqing Medical University, Chongqing 400016 China.
authors.forename: Yong-Quan
authors.initials: YQ
authors.lastname: Pan
authors.affiliation: The Laboratory of Traditional Chinese Medicine, Chongqing Medical University, 400016 China. Electronic address: wjwcq68@163.com.
authors.forename: Jian-Wei
authors.initials: JW
authors.lastname: Wang
mesh_terms: D000818:Animals; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000235:genetics; D001835:Body Weight; D004040:Dietary Carbohydrates / Q000008:administration & dosage / Q000009:adverse effects* / Q000378:metabolism; D005215:Fasting; D005234:Fatty Liver / Q000235:genetics / Q000378:metabolism*; D005632:Fructose / Q000008:administration & dosage / Q000009:adverse effects* / Q000378:metabolism; D005786:Gene Expression Regulation; D050155:Lipogenesis / Q000235:genetics; D008099:Liver / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D008297:Male; D009929:Organ Size; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013230:Stearoyl-CoA Desaturase / Q000235:genetics / Q000378:metabolism*; D051780:Sterol Regulatory Element Binding Protein 1 / Q000235:genetics; D014280:Triglycerides / Q000097:blood / Q000378:metabolism
chemical_list: D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D004040:Dietary Carbohydrates; C442825:Mlxipl protein, rat; D012333:RNA, Messenger; C497389:Srebf1 protein, rat; D051780:Sterol Regulatory Element Binding Protein 1; D014280:Triglycerides; D005632:Fructose; D013230:Stearoyl-CoA Desaturase; C000594769:stearoyl-CoA desaturase SCD-1, rat
keywords: Fasting; Fructose; Nonalcoholic fatty liver disease (NAFLD); Stearoyl-CoA desaturase (SCD)1