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PMID:19053045

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Citation

Rodríguez-Calvo, R, Barroso, E, Serrano, L, Coll, T, Sánchez, RM, Merlos, M, Palomer, X, Laguna, JC and Vázquez-Carrera, M (2009) Atorvastatin prevents carbohydrate response element binding protein activation in the fructose-fed rat by activating protein kinase A. Hepatology 49:106-15

Abstract

High fructose intake contributes to the overall epidemic of obesity and metabolic disease. Here we examined whether atorvastatin treatment blocks the activation of the carbohydrate response element binding protein (ChREBP) in the fructose-fed rat. Fructose feeding increased blood pressure (21%, P < 0.05), plasma free fatty acids (59%, P < 0.01), and plasma triglyceride levels (129%, P < 0.001) compared with control rats fed standard chow. These increases were prevented by atorvastatin. Rats fed the fructose-rich diet showed enhanced hepatic messenger RNA (mRNA) levels of glycerol-3-phosphate acyltransferase (Gpat1) (1.45-fold induction, P < 0.05), which is the rate-limiting enzyme for the synthesis of triglycerides, and liver triglyceride content (2.35-fold induction, P < 0.001). Drug treatment inhibited the induction of Gpat1 and increased the expression of liver-type carnitine palmitoyltransferase 1 (L-Cpt-1) (128%, P < 0.01). These observations indicate that atorvastatin diverts fatty acids from triglyceride synthesis to fatty acid oxidation, which is consistent with the reduction in liver triglyceride levels (28%, P < 0.01) observed after atorvastatin treatment. The expression of Gpat1 is regulated by ChREBP and sterol regulatory element binding protein-1c (SREBP-1c). Atorvastatin treatment prevented fructose-induced ChREBP translocation and the increase in ChREBP DNA-binding activity while reducing SREBP-1c DNA-binding activity. Statin treatment increased phospho-protein kinase A (PKA), which promotes nuclear exclusion of ChREBP and reduces its DNA-binding activity. Human HepG2 cells exposed to fructose showed enhanced ChREBP DNA-binding activity, which was not observed in the presence of atorvastatin. Furthermore, atorvastatin treatment increased the CPT-I mRNA levels in these cells. Interestingly, both effects of this drug were abolished in the presence of the PKA inhibitor H89. Conclusion: These findings indicate that atorvastatin inhibits fructose-induced ChREBP activity and increases CPT-I expression by activating PKA.

Links

PubMed Online version:10.1002/hep.22570

Keywords

Animals; Basic Helix-Loop-Helix Leucine Zipper Transcription Factors/antagonists & inhibitors; Basic Helix-Loop-Helix Leucine Zipper Transcription Factors/metabolism; Cell Line, Tumor; Cyclic AMP-Dependent Protein Kinases/metabolism; Dietary Carbohydrates/pharmacology; Enzyme Activation/drug effects; Fatty Acids, Nonesterified/blood; Fructose/pharmacology; Glycerol-3-Phosphate O-Acyltransferase/metabolism; Heptanoic Acids/pharmacology; Humans; Male; Pyrroles/pharmacology; RNA, Messenger/metabolism; Rats; Rats, Sprague-Dawley; Sterol Regulatory Element Binding Protein 1/metabolism

Significance

Annotations

Gene product Qualifier GO Term Evidence Code with/from Aspect Extension Notes Status

RAT:GPAT1

involved_in

GO:0009750: response to fructose

ECO:0000270: expression pattern evidence used in manual assertion

P

Seeded From UniProt

complete


See also

References

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