Biochemical and Biophysical Research Communications, Vol.370, No.1, 134-139, 2008
Links between enhanced fatty acid flux, protein kinase C and NF kappa B activation, and apoB-lipoprotein production in the fructose-fed hamster model of insulin resistance
In the current study, we show evidence, in a fructose-fed hamster model of insulin resistance, that free fatty acid (FFA) can induce hepatic insulin resistance in part via PKC activation leading to increased production of atherogenic apoB100-containing lipoproteins. Interestingly, I kappa B-kinase beta (IKK beta)-dependent NF-kappa B was activated in hepatocytes from the fructose-fed hamster as an indication for PKC activation. Treatment of hepatocytes with oleate for 16 h showed the activation of the PKC isoforms, PKC alpha/beta II, in a dose dependent manner. Strikingly, the general PKC inhibitor, bisindolylmaleimide-I, Bis-I (5 mu M) was found to ameliorate fructose-induced insulin resistance, restoring the phosphorylation status of PKB and suppressing apoB100 overproduction in ex vivo and in vivo. The data suggest that hepatic PKC activation, induced by increased circulating FFA may be an important factor in the development of insulin resistance and dyslipidemia seen in the fructose-fed hamster model. (c) 2008 Elsevier Inc. All rights reserved.