Different mechanisms of cis-9,trans-11- and trans-10,cis-12- conjugated linoleic acid affecting lipid metabolism in 3T3-L1 cells.
Conjugated linoleic acid (CLA) has been shown to reduce body fat mass in various experimental animals. It is valuable to identify its influence on enzymes involved in energy expenditure, apoptosis, fatty acid oxidation and lipolysis. We investigated isomer-specific effects of high dose, long treatment of CLA (75.4 μmol/L, 8 days) on protein and gene expression of these enzymes in cultured 3T3-L1 cells. Proteomics identified significant up- or down-regulation of 52 proteins by either CLA isomer. Protein and gene expression of uncoupling protein (UCP) 1, UCP3, perilipin and peroxisome proliferator-activated receptor (PPAR) α increased whereas UCP2 reduced for both CLA isomers. And eight-day treatment of trans-10,cis-12 CLA, but not cis-9,trans-11 CLA, significantly up-regulated protein and mRNA levels of PKA (P<.05), CPT-1 and TNF-α (P<.01). Compared to protein expression, both isomers did not significantly influence the mRNA expression of HSL, ATGL, ACO and leptin. In conclusion, high-dose, long treatment of cis-9,trans-11 CLA did not promote apoptosis, fatty acid oxidation and lipolysis in adipocytes, but may induce an increase in energy expenditure. trans-10,cis-12 CLA exhibited greater influence on lipid metabolism, stimulated adipocyte energy expenditure, apoptosis and fatty acid oxidation, but its effect on lipolysis was not obvious.
State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yatsen University, Guangzhou 510060, China.
Jia-jie
JJ
Zhai
Zhao-liang
ZL
Liu
Jie-mei
JM
Li
Jian-ping
JP
Chen
Lin
L
Jiang
Dong-mei
DM
Wang
Jin
J
Yuan
Jian-Gang
JG
Shen
De-Po
DP
Yang
Jia-Qi
JQ
Chen
D041721:3T3-L1 Cells; D017667:Adipocytes / Q000378:metabolism; D000818:Animals; D002352:Carrier Proteins; D015536:Down-Regulation; D007473:Ion Channels / Q000235:genetics / Q000378:metabolism; D020738:Leptin / Q000235:genetics / Q000378:metabolism; D044243:Linoleic Acids, Conjugated / Q000378:metabolism*; D050356:Lipid Metabolism; D008066:Lipolysis; D051379:Mice; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism; D010084:Oxidation-Reduction; D047493:PPAR alpha / Q000235:genetics / Q000378:metabolism; D000070778:Perilipin-1; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D040901:Proteomics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D000071256:Uncoupling Protein 1; D000071247:Uncoupling Protein 3; D015854:Up-Regulation
D002352:Carrier Proteins; D007473:Ion Channels; D020738:Leptin; D044243:Linoleic Acids, Conjugated; D024101:Mitochondrial Proteins; D047493:PPAR alpha; D000070778:Perilipin-1; D010750:Phosphoproteins; D012333:RNA, Messenger; C000604372:Ucp1 protein, mouse; C000604393:Ucp3 protein, mouse; D000071256:Uncoupling Protein 1; D000071247:Uncoupling Protein 3; C496197:trans-10,cis-12-conjugated linoleic acid; C046938:9,11-linoleic acid