title: cis9, trans11-Conjugated Linoleic Acid Differentiates Mouse 3T3-L1 Preadipocytes into Mature Small Adipocytes through Induction of Peroxisome Proliferator-activated Receptor γ.
abstract: Dietary conjugated linoleic acid (CLA) has been reported to exhibit a number of therapeutic effects in animal models and patients, such as anti-hypertensive, anti-hyperlipidemic, anti-arteriosclerotic, anti-carcinogenic, and anti-diabetic effects. However, the underlying mechanism is not well-characterized. In the present study, the effects of cis(c)9, trans(t)11-CLA on the differentiation of mouse 3T3-L1 preadipocytes into mature adipocytes were examined. Treatment with c9, t11-CLA in the presence of insulin, dexamethasone, and 3-isobutyl-1-methyl-xanthine (differentiation cocktail) significantly stimulated the accumulation of triacylglycerol. The microscopic observation of cells stained by Oil Red O demonstrated that c9, t11-CLA increases the amount and proportion of small mature adipocytes secreting adiponectin, a benign adipocytokine, when compared to the differentiation cocktail alone. Furthermore, c9, t11-CLA increased bioactive peroxisome proliferator-activated receptor γ (PPARγ) levels in a nuclear extract of 3T3-L1 cells, suggesting the enhancing effect of this fatty acid on the nuclear transmission of PPARγ, a master regulator of adipocyte differentiation, in 3T3-L1 cells. These results suggest that the therapeutic effects of c9, t11-CLA on lifestyle-related diseases are partially due to the enhanced formation of small adipocytes from preadipocytes via PPARγ stimulation.
authors.affiliation: Laboratory of Physiological Chemistry, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Sakuma
authors.forename: Yuki
authors.initials: Y
authors.lastname: Nishioka
authors.forename: Ryohta
authors.initials: R
authors.lastname: Imanishi
authors.forename: Kenji
authors.initials: K
authors.lastname: Nishikawa
authors.forename: Hirotada
authors.initials: H
authors.lastname: Sakamoto
authors.forename: Junji
authors.initials: J
authors.lastname: Fujisawa
authors.forename: Koichiro
authors.initials: K
authors.lastname: Wada
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Kamisaki
authors.forename: Yohko
authors.initials: Y
authors.lastname: Fujimoto