Trans-10, cis-12, but not cis-9, trans-11 CLA isomer, inhibits brown adipocyte thermogenic capacity.
Conjugated linoleic acid (CLA) is reported to have health benefits, including reduction of body fat. Previous studies have shown that brown adipose tissue (BAT) is particularly sensitive to CLA-supplemented diet feeding. Most of them use mixtures containing several CLA isomers, mainly cis-9, trans-11 and trans-10, cis-12 in equal concentration. Our aim was to characterize the separate effects of both CLA isomers on thermogenic capacity in cultured brown adipocytes. The CLA isomers showed opposite effects. Hence, on the one hand, trans-10, cis-12 inhibited uncoupling protein (UCP) 1 induction by norepinephrine (NE) and produced a decrease in leptin mRNA levels. These effects were associated with a blockage of CCAAT-enhancer-binding protein-alpha and peroxisome proliferator-activated receptor-gamma(2) mRNA expression. On the other hand, cis-9, trans-11 enhanced the UCP1 elicited by NE, an effect reported earlier for polyunsaturated fatty acids and also observed here for linoleic acid. These findings could explain, at least in part, the effects observed in vivo when feeding a CLA mixture supplemented diet as a result of the combined action of CLA isomers (reduction of adipogenesis and defective BAT thermogenesis that could be through trans-10, cis-12 and enhanced UCP1 thermogenic capacity through cis-9, trans-11).
Rodríguez
Enrique
E
Departament de Biologia Fonamental i Ciències de la Salut, Universitat de les Illes Balears, Cra Valldemossa, 07071 Palma de Mallorca, Spain.
Ribot
Joan
J
Palou
Andreu
A
D017667:Adipocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D002001:Adipose Tissue, Brown / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D000818:Animals; D001833:Body Temperature Regulation / Q000187:drug effects / Q000502:physiology; D022763:CCAAT-Enhancer-Binding Protein-alpha / Q000235:genetics / Q000378:metabolism; D022762:CCAAT-Enhancer-Binding Proteins / Q000235:genetics / Q000378:metabolism; D002352:Carrier Proteins / Q000096:biosynthesis; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D007473:Ion Channels; D020738:Leptin / Q000235:genetics / Q000378:metabolism; D019787:Linoleic Acid / Q000737:chemistry / Q000494:pharmacology*; D008297:Male; D008565:Membrane Proteins / Q000096:biosynthesis; D026901:Membrane Transport Proteins; D051379:Mice; D024101:Mitochondrial Proteins; D009638:Norepinephrine / Q000037:antagonists & inhibitors / Q000494:pharmacology; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism; D013237:Stereoisomerism; D051780:Sterol Regulatory Element Binding Protein 1; D013329:Structure-Activity Relationship; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D000071256:Uncoupling Protein 1; D000071246:Uncoupling Protein 2
D022763:CCAAT-Enhancer-Binding Protein-alpha; D022762:CCAAT-Enhancer-Binding Proteins; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D007473:Ion Channels; D020738:Leptin; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D024101:Mitochondrial Proteins; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; C497388:Srebf1 protein, mouse; D051780:Sterol Regulatory Element Binding Protein 1; D014157:Transcription Factors; C000604372:Ucp1 protein, mouse; D000071256:Uncoupling Protein 1; D000071246:Uncoupling Protein 2; D019787:Linoleic Acid; D009638:Norepinephrine