Role of adenosine 5'-monophosphate-activated protein kinase in α-linolenic acid-induced intestinal lipid metabolism.
n-3 Long-chain PUFA up-regulate intestinal lipid metabolism. However, whether these metabolic effects of PUFA on intestine are mediated by AMP-activated protein kinase (AMPK) remains to be elucidated. To determine the effects of α-linolenic acid (ALA) on intestinal fatty acid (FA) metabolism and whether these effects were affected by AMPK deletion, mice deficient in the catalytic subunit of AMPKα1 or AMPKα2 and wild-type (WT) mice were fed either a high-fat diet (HF) or HF supplemented with ALA (HF-A). The results showed that ALA supplementation decreased serum TAG content in WT mice. ALA also increased mRNA expression of genes (carnitine palmitoyltransferase 1a, acyl-CoA oxidase 1, medium-chain acyl-CoA dehydrogenase, cytochrome P450 4A10 and pyruvate dehydrogenase kinase isoenzyme 4a) involved in intestinal lipid oxidation and mRNA expression of TAG synthesis-related genes (monoacylglycerol O-acyltransferase 2, diacylglycerol O-acyltransferases 1 and 2) in WT mice. Consistent with these, expression levels of phosphorylated AMPKα1 and AMPKα2 were also increased in WT mice after ALA addition. However, in the absence of either AMPKα1 or AMPKα2, ALA supplementation failed to increase intestinal lipid oxidation. In addition, no significant effects of either diet (HF and HF-A) or genotype (WT, AMPKα1(-/-) and AMPKα2(-/-)) on FA uptake in the intestine and faecal TAG output were observed. Our results suggest that AMPK is indispensable for the effects of ALA on intestinal lipid oxidation.
1Key Laboratory of Animal Nutrition and Feed Science,Ministry of Agriculture, Zhejiang Provincial Laboratory of Feed and Animal Nutrition,Institute of Feed Science,Zhejiang University,Hangzhou,Zhejiang 310058,People's Republic of China.
Xihong
X
Zhou
1Key Laboratory of Animal Nutrition and Feed Science,Ministry of Agriculture, Zhejiang Provincial Laboratory of Feed and Animal Nutrition,Institute of Feed Science,Zhejiang University,Hangzhou,Zhejiang 310058,People's Republic of China.
Jingqing
J
Chen
1Key Laboratory of Animal Nutrition and Feed Science,Ministry of Agriculture, Zhejiang Provincial Laboratory of Feed and Animal Nutrition,Institute of Feed Science,Zhejiang University,Hangzhou,Zhejiang 310058,People's Republic of China.
Weiche
W
Wu
1Key Laboratory of Animal Nutrition and Feed Science,Ministry of Agriculture, Zhejiang Provincial Laboratory of Feed and Animal Nutrition,Institute of Feed Science,Zhejiang University,Hangzhou,Zhejiang 310058,People's Republic of China.
Xinxia
X
Wang
1Key Laboratory of Animal Nutrition and Feed Science,Ministry of Agriculture, Zhejiang Provincial Laboratory of Feed and Animal Nutrition,Institute of Feed Science,Zhejiang University,Hangzhou,Zhejiang 310058,People's Republic of China.
Yizhen
Y
Wang
D055372:AMP-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D059305:Diet, High-Fat / Q000009:adverse effects; D019587:Dietary Supplements; D004790:Enzyme Induction; D005243:Feces / Q000737:chemistry; D015228:Hypertriglyceridemia / Q000097:blood / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control; D007082:Ileum / Q000201:enzymology / Q000378:metabolism; D007413:Intestinal Mucosa / Q000201:enzymology / Q000378:metabolism*; D007583:Jejunum / Q000201:enzymology / Q000378:metabolism; D050356:Lipid Metabolism; D008297:Male; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D014280:Triglycerides / Q000009:adverse effects / Q000032:analysis / Q000097:blood / Q000378:metabolism; D015854:Up-Regulation; D017962:alpha-Linolenic Acid / Q000627:therapeutic use*
D014280:Triglycerides; D017962:alpha-Linolenic Acid; C548179:Prkaa1 protein, mouse; C534978:Prkaa2 protein, mouse; D055372:AMP-Activated Protein Kinases
ALA α-linolenic acid; AMP-activated protein kinase; AMPK AMP-activated protein kinase; FA fatty acid; HF high-fat diet; HF-A high-fat diet supplemented with ALA; Intestine; Lipid metabolism; WT wild type; α-Linolenic acid