scholarly journals Stearoyl-CoA Desaturase 1 Gene Expression Is Necessary for Fructose-mediated Induction of Lipogenic Gene Expression by Sterol Regulatory Element-binding Protein-1c-dependent and -independent Mechanisms

2004 ◽  
Vol 279 (24) ◽  
pp. 25164-25171 ◽  
Author(s):  
Makoto Miyazaki ◽  
Agnieszka Dobrzyn ◽  
Weng Chi Man ◽  
Kiki Chu ◽  
Harini Sampath ◽  
...  
2015 ◽  
Vol 35 (2) ◽  
pp. 803-815 ◽  
Author(s):  
Andreas Bitter ◽  
Andreas K. Nüssler ◽  
Wolfgang E. Thasler ◽  
Kathrin Klein ◽  
Ulrich M. Zanger ◽  
...  

Background/Aims: Sterol regulatory element-binding protein (SREBP) 1, the master regulator of lipogenesis, was shown to be associated with non-alcoholic fatty liver disease, which is attributed to its major isoform SREBP1c. Based on studies in mice, the minor isoform SREBP1a is regarded as negligible for hepatic lipogenesis. This study aims to elucidate the expression and functional role of SREBP1a in human liver. Methods: mRNA expression of both isoforms was quantified in cohorts of human livers and primary human hepatocytes. Hepatocytes were treated with PF-429242 to inhibit the proteolytic activation of SREBP precursor protein. SREBP1a-specifc and pan-SREBP1 knock-down were performed by transfection of respective siRNAs. Lipogenic SREBP-target gene expression was analyzed by real-time RT-PCR. Results: In human liver, SREBP1a accounts for up to half of the total SREBP1 pool. Treatment with PF-429242 indicated SREBP-dependent auto-regulation of SREBP1a, which however was much weaker than of SREBP1c. SREBP1a-specifc knock-down also reduced significantly the expression of SREBP1c and of SREBP-target genes. Regarding most SREBP-target genes, simultaneous knock-down of both isoforms resulted in effects of only similar extent as SREBP1a-specific knock-down. Conclusion: We here showed that SREBP1a is significantly contributing to the human hepatic SREBP1 pool and has a share in human hepatic lipogenic gene expression.


2010 ◽  
Vol 432 (2) ◽  
pp. 249-254 ◽  
Author(s):  
Aldo Grefhorst ◽  
Marijke Schreurs ◽  
Maaike H. Oosterveer ◽  
Victor A. Cortés ◽  
Rick Havinga ◽  
...  

GSD-1 (glycogen storage disease type 1) is caused by an inherited defect in glucose-6-phosphatase activity, resulting in a massive accumulation of hepatic glycogen content and an induction of de novo lipogenesis. The chlorogenic acid derivative S4048 is a pharmacological inhibitor of the glucose 6-phosphate transporter, which is part of glucose-6-phosphatase, and allows for mechanistic studies concerning metabolic defects in GSD-1. Treatment of mice with S4048 resulted in an ~60% reduction in blood glucose, increased hepatic glycogen and triacylglycerol (triglyceride) content, and a markedly enhanced hepatic lipogenic gene expression. In mammals, hepatic expression of lipogenic genes is regulated by the co-ordinated action of the transcription factors SREBP (sterol-regulatory-element-binding protein)-1c, LXRα (liver X receptor α) and ChREBP (carbohydrate-response-element-binding protein). Treatment of Lxra−/− mice and Chrebp−/− mice with S4048 demonstrated that ChREBP, but not LXRα, mediates the induction of hepatic lipogenic gene expression in this murine model of GSD-1. Thus ChREBP is an attractive target to alleviate derangements in lipid metabolism observed in patients with GSD-1.


2007 ◽  
Vol 282 (29) ◽  
pp. 21090-21099 ◽  
Author(s):  
Norimasa Tamehiro ◽  
Yukari Shigemoto-Mogami ◽  
Tomoshi Kakeya ◽  
Kei-ichiro Okuhira ◽  
Kazuhiro Suzuki ◽  
...  

2004 ◽  
Vol 24 (12) ◽  
pp. 2358-2364 ◽  
Author(s):  
Morgan Tréguier ◽  
Chantal Doucet ◽  
Martine Moreau ◽  
Christiane Dachet ◽  
Joëlle Thillet ◽  
...  

2013 ◽  
Vol 109 (9) ◽  
pp. 1590-1597 ◽  
Author(s):  
Min Young Um ◽  
Mi Kyeong Moon ◽  
Jiyun Ahn ◽  
Tae Youl Ha

Coumarin is a natural compound abundant in plant-based foods such as citrus fruits, tomatoes, vegetables and green tea. Although coumarin has been reported to exhibit anti-coagulant, anti-inflammation and cholesterol-lowering properties, the effect of coumarin on hepatic lipid metabolism remains unclear. In the present study, we evaluated the ability of coumarin to protect against hepatic steatosis associated with a high-fat diet (HFD) and investigated potential mechanisms underlying this effect. C57BL/6J mice were fed a normal diet, HFD and HFD containing 0·05 % courmarin for 8 weeks. The present results showed that coumarin reduced weight gain and abdominal fat mass in mice fed the HFD for 8 weeks (P< 0·05). Coumarin also significantly reduced the HFD-induced elevation in total cholesterol, apoB, leptin and insulin (P< 0·05). In the liver of HFD-fed mice, coumarin significantly reduced total lipids, TAG and cholesterol (38, 22 and 9 % reductions, respectively; P< 0·05), as well as lipid droplet number and size. Additionally, thiobarbituric acid-reactive substance levels, as an indicator of hepatic steatosis, were attenuated by coumarin (P< 0·05). Finally, coumarin suppressed the HFD-induced up-regulation in fatty acid synthase (FAS) activity, and the expression of sterol regulatory element-binding protein-1, FAS, acetyl-CoA carboxylase 1, PPARγ and CCAAT/enhancer-binding protein-α in the liver. Taken together, these results demonstrate that coumarin could prevent HFD-induced hepatic steatosis by regulating lipogenic gene expression, suggesting potential targets for preventing hepatic steatosis.


2012 ◽  
Vol 287 (24) ◽  
pp. 20132-20143 ◽  
Author(s):  
Xiong Deng ◽  
Wenwei Zhang ◽  
InSug O-Sullivan ◽  
J. Bradley Williams ◽  
Qingming Dong ◽  
...  

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