Conjugated linoleic acid (CLA) reduces HFD-induced obesity by enhancing BAT thermogenesis and iWAT browning via the CD36-AMPK pathway

The antiobesity effect of conjugated linoleic acid (CLA) has been reported. However, the underlying mechanisms have not been fully clarified. Thus, this study aimed to investigate the effects of CLA on thermogenesis of interscapular brown adipose tissue (iBAT) and browning of inguinal subcutaneous white adipose tissue (iWAT) and explore the possible signaling pathway. The in vivo results showed that CLA enhanced the O2 consumption and heat production in HFD (high-fat diet)-fed female mice by roughly 38%. Meanwhile, CLA increased the average iBAT temperature by 2 degrees C at the room temperature and cold exposure, respectively. Correspondingly, CLA caused 1.6- and 2.4-fold increases in the expression of UCP1 (uncoupling protein 1) of BAT and iWAT, respectively, suggesting the activated iBAT thermogenesis and iWAT browning in HFD-fed female mice. Meanwhile, CLA could promote the formation of brown and beige adipocytes in differentiated stromal vascular cells (SVCs) isolated from iBAT and iWAT (the expressions of UCP1 were promoted by about twofold changes). In possible mechanisms, CLA stimulated the expression of CD36 and the activation of the AMPK pathway in mice iBAT and iWAT as well as the differentiated SVCs. However, inhibition of CD36 and AMPK (adenosine 5 '-monophosphate-activated protein kinase) abolished the promotive effects of CLA on brown and beige adipocytes formation. Hence, we showed that CLA reduced HFD-induced obesity through enhancing iBAT thermogenesis and iWAT browning via the CD36-AMPK pathway. Conjugated linoleic acid (CLA) could reduce HFD-induced obesity accompanied with the elevated energy metabolism. In vivo, CLA enhanced the interscapular brown adipose tissue (iBAT) thermogenesis and inguinal subcutaneous white adipose tissue (iWAT) browning in HFD-fed mice. In vitro, CLA promoted the formation of brown and beige adipocytes in differentiated stromal vascular cells (SVCs) isolated from iBAT and iWAT. In possible mechanisms, CLA supplementation stimulated the expression of CD36 and the activation of AMPK alpha in mice iBAT and iWAT as well as the differentiated SVCs. However, inhibition of CD36 and AMPK alpha eliminated the promotive effects of CLA on the formation of brown and beige adipocyte. In conclusion, we showed that CLA reduced HFD-induced obesity through enhancing BAT thermogenesis and WAT browning via the CD36-AMPK alpha pathway.