Polyunsaturated fatty acids of marine origin induce adiponectin in mice fed a high-fat diet.
OBJECTIVE
Diets rich in n-3 polyunsaturated fatty acids, namely eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), protect against insulin resistance and obesity in rodents and increase insulin sensitivity in healthy humans. We tested whether the anti-diabetic effects of EPA and DHA involve enhanced production of the endogenous insulin sensitiser, adiponectin.


METHODS
We studied the effects, in an obesity-promoting high-fat diet, of partial replacement of vegetable oils by EPA/DHA concentrate (6% EPA, 51% DHA) over a 5-week period in adult male C57BL/6J mice that either had free access to food or had their food intake restricted by 30%. At the end of the treatment, systemic markers of lipid and glucose metabolism and full-length adiponectin and leptin were measured. Adiponectin (Adipoq) and leptin (Lep) gene expression in dorsolumbar and epididymal white adipose tissue (WAT) and isolated adipocytes was quantified and adipokine production from WAT explants evaluated.


RESULTS
In mice with free access to food, plasma triacylglycerols, NEFA, and insulin levels were lower in the presence of EPA/DHA, while glucose and leptin levels were not significantly altered. Food restriction decreased plasma triacylglycerols, glucose, insulin and leptin, but not adiponectin. EPA/DHA increased plasma adiponectin levels, independent of food intake, reflecting the stimulation of Adipoq expression in adipocytes and the release of adiponectin from WAT, particularly from epididymal fat. Expression of Lep and the release of leptin from WAT, while being extremely sensitive to caloric restriction, was unaltered by EPA/DHA.


CONCLUSIONS
Intake of diets rich in EPA and DHA leads to elevated systemic concentrations of adiponectin, largely independent of food intake or adiposity and explain, to some extent, their anti-diabetic effects.
Flachs
P
P
Department of Adipose Tissue Biology, Institute of Physiology, Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic.
Mohamed-Ali
V
V
Horakova
O
O
Rossmeisl
M
M
Hosseinzadeh-Attar
M J
MJ
Hensler
M
M
Ruzickova
J
J
Kopecky
J
J
D000091162:AMP-Activated Protein Kinase Kinases; D017667:Adipocytes / Q000737:chemistry / Q000378:metabolism; D052242:Adiponectin / Q000096:biosynthesis* / Q000097:blood / Q000235:genetics*; D000273:Adipose Tissue / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D001823:Body Composition; D031204:Caloric Restriction; D004041:Dietary Fats / Q000008:administration & dosage / Q000494:pharmacology*; D004281:Docosahexaenoic Acids / Q000008:administration & dosage / Q000494:pharmacology*; D004435:Eating; D015118:Eicosapentaenoic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D004789:Enzyme Activation; D005786:Gene Expression Regulation; D005947:Glucose / Q000378:metabolism; D007328:Insulin / Q000097:blood / Q000502:physiology; D007333:Insulin Resistance; D020738:Leptin / Q000032:analysis / Q000097:blood / Q000235:genetics / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009765:Obesity / Q000503:physiopathology / Q000517:prevention & control; D011494:Protein Kinases / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014280:Triglycerides / Q000097:blood
D052242:Adiponectin; D004041:Dietary Fats; D007328:Insulin; D020738:Leptin; D014280:Triglycerides; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid; D011494:Protein Kinases; D000091162:AMP-Activated Protein Kinase Kinases; D005947:Glucose