Site-specific regulation of gene expression by n-3 polyunsaturated fatty acids in rat white adipose tissues

• Published in: Journal of lipid research Vol. 38; no. 10; pp. 1963 - 1972
• Main Authors: Raclot, T, Groscolas, R, Langin, D, Ferré, P
• Format: Journal Article
• Language: English
• Published: United States Elsevier 01.10.1997
• Subjects: Adipose Tissue - metabolism; Animals; Blotting, Northern; Body Weight; Carboxy-Lyases - genetics; Carboxy-Lyases - metabolism; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Docosahexaenoic Acids - metabolism; Eicosapentaenoic Acid - metabolism; Fatty Acid Synthases - genetics; Fatty Acid Synthases - metabolism; Fatty Acids - analysis; Fatty Acids - chemistry; Fatty Acids, Omega-3 - administration & dosage; Fatty Acids, Omega-3 - pharmacology; Gene Expression Regulation; Insulin - analysis; Insulin - blood; Leptin; Lipoprotein Lipase - genetics; Lipoprotein Lipase - metabolism; Male; Nuclear Proteins - genetics; Nuclear Proteins - metabolism; Proteins - genetics; Proteins - metabolism; Rats; Rats, Wistar; Regression Analysis; RNA, Messenger - genetics; RNA, Messenger - metabolism; Sterol Esterase - genetics; Sterol Esterase - metabolism; Triglycerides - analysis; Triglycerides - chemistry
• ISSN: 0022-2275; 1539-7262
• DOI: 10.1016/s0022-2275(20)37127-3

Dietary n-3 polyunsaturated fatty acids (n-3 PUFAs) limit abdominal fat depot hypertrophy. This could be due to regulation of the expression of proteins involved in adipose tissue metabolism. We investigated in vivo whether fatty acid synthase (FAS), hormone-sensitive lipase (HSL), lipoprotein lipase (LPL), phosphoenolpyruvate carboxykinase (PEPCK), CCAAT/enhancer binding protein alpha (C/EBP alpha), and leptin mRNA levels are affected in retroperitoneal (RP) and subcutaneous adipose tissues (SC) of rats fed n-3 PUFAs. For 4 weeks rats were fed high fat diets (20% fat) containing n-3 PUFAs given as eicosapentaenoic acid (EPA group), docosahexaenoic acid (DHA group), a mixture of these two fatty acids (MIX group), or native fish oil (FO group). A control group was fed with lard plus olive oil (LOO group). Final mean fat cell weight in RP ranged according to: LOO > or = EPA > or = DHA = FO = MIX. There was no difference in fat cell size of SC when comparing the LOO and MIX groups. The fatty acid compositions of RP and SC were similar and resemble that of dietary fat within each experimental group. In RP and compared to the LOO group, FAS, HSL, PEPCK, LPL, C/EBP alpha, and leptin mRNA levels decreased although not significantly in the EPA group, and were 40-75% lower in the DHA and MIX groups. mRNA levels were positively correlated to fat cell size in RP. In contrast, n-3 PUFAs had no effect on gene expression in SC. We conclude that n-3 PUFAs and mainly 22:6n-3 affect gene expression in a site-dependent manner in white adipose tissues via possible antiadipogenic effects.