Comparison of the expression and activity of the lipogenic pathway in human and rat adipose tissue

• Published in: Journal of lipid research Vol. 44; no. 11; pp. 2127 - 2134
• Main Authors: Letexier, Dominique, Pinteur, Claudie, Large, Valérie, Fréring, Vincent, Beylot, Michel
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.11.2003; American Society for Biochemistry and Molecular Biology; Elsevier
• Subjects: Acetyl-CoA Carboxylase; Acetyl-CoA Carboxylase - genetics; acetyl-CoA carboxylase 1; Adipose Tissue; Adipose Tissue - metabolism; Adult; Animals; Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; Body Mass Index; carbohydrate response element binding protein; CCAAT-Enhancer-Binding Proteins; CCAAT-Enhancer-Binding Proteins - genetics; CCAAT-Enhancer-Binding Proteins - metabolism; Coenzymes; Coenzymes - metabolism; DNA-Binding Proteins; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; fatty acid synthase; Fatty Acid Synthases; Fatty Acid Synthases - genetics; Food and Nutrition; Gene Expression Regulation; Humans; Life Sciences; Lipids; Lipids - biosynthesis; Liver; Liver - metabolism; Male; messenger ribonucleic acid; Obesity; Obesity - genetics; Obesity - metabolism; Rats; Rats, Sprague-Dawley; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; RNA, Messenger - genetics; RNA, Messenger - metabolism; stable isotopes; Sterol Regulatory Element Binding Protein 1; sterol regulatory element binding protein 1c; Transcription Factors; Transcription Factors - genetics; stable isotopes; messenger ribonucleic acid; acetyl-CoA carboxylase 1; carbohydrate response element binding protein; sterol regulatory element binding protein 1c; fatty acid synthase
• ISSN: 0022-2275; 1539-7262
• DOI: 10.1194/jlr.M300235-JLR200

Lipogenesis is considered less active in human than in rat adipose tissue. This could be explained by different nutritional conditions, namely high-carbohydrate (HCHO) diet in rats and high-fat (HF) diet in humans. Adipose tissue was sampled (postabsorptive state) in rats and humans receiving HCHO or HF diets, ad libitum fed humans, and obese subjects. We measured 1) mRNA concentrations of fatty acid synthase (FAS), acetyl-CoA carboxylase 1 (ACC1), sterol regulatory element binding protein 1c (SREBP-1c), and carbohydrate response element binding protein (ChREBP), 2) SREBP-1c protein, and 3) FAS activity. FAS, ACC1, ChREBP, and SREBP1-c mRNA concentrations were unaffected by diet in humans or in rats. FAS and ACC1 mRNA levels were lower in humans than in rats (P < 0.05). FAS activity was unaffected by diet and was lower in humans (P < 0.05). SREBP-1c mRNA concentrations were similar in rats and humans, but the precursor and mature forms of SREBP-1c protein were less abundant in humans (P < 0.05). ChREBP mRNA concentrations were lower in humans than in rats. In conclusion, the lipogenic capacity of adipose tissue is lower in humans than in rats. This is not related to differences in diet and is probably explained by lower abundance of SREBP-1c protein. A decreased expression of ChREBP could also play a role.