Mitochondria are critical for respiration in all tissues; however, in liver, these organelles also accommodate high-capacity anaplerotic/cataplerotic pathways that are essential to gluconeogenesis and other biosynthetic activities. During nonalcoholic fatty liver disease (NAFLD), mitochondria also produce ROS that damage hepatocytes, trigger inflammation, and contribute to insulin resistance. Here, we provide several lines of evidence indicating that induction of biosynthesis through hepatic anaplerotic/cataplerotic pathways is energetically backed by elevated oxidative metabolism and hence contributes to oxidative stress and inflammation during NAFLD. First, in murine livers, elevation of fatty acid delivery not only induced oxidative metabolism, but also amplified anaplerosis/cataplerosis and caused a proportional rise in oxidative stress and inflammation. Second, loss of anaplerosis/cataplerosis via genetic knockdown of phosphoenolpyruvate carboxykinase 1 (
Santhosh Satapati, Blanka Kucejova, Joao A.G. Duarte, Justin A. Fletcher, Lacy Reynolds, Nishanth E. Sunny, Tianteng He, L. Arya Nair, Kenneth Livingston, Xiaorong Fu, Matthew E. Merritt, A. Dean Sherry, Craig R. Malloy, John M. Shelton, Jennifer Lambert, Elizabeth J. Parks, Ian Corbin, Mark A. Magnuson, Jeffrey D. Browning, Shawn C. Burgess
Propionate tracers do not perturb basal hepatic flux.