UCP2 promotes fatty acid oxidation in mtDNA mutator mitochondria.

<p>(A) Steady-state levels of mitochondrial glucose and fatty acid transporters: insulin-regulated glucose transporter (GLUT4), basal glucose transporter 1 (GLUT1) and mitochondrial carnitine palmitoyltransferase I (CPT1B) in wild type (wt), mtDNA mutator (mut), UCP2-deficient wild type (ko) and mtDNA mutator (dm) mice. Cytoplasmic calnexin was used as loading control. (B) Quantification of Western blots from (A). (C) Oxygen consumption rates in intact mitochondria in presence of pyruvate-glutamate-malate as substrates. State III (substrates+ADP); State IV (+oligomycin); MAX (+CCCP). (D) Oxygen consumption rates in intact mitochondria in the presence of medium (OC - octanoyl-carnitine) or long chain (PALM - palmitoyl-carnitine) fatty acids as substrates. (E) Maximal oxygen consumption rates upon addition of octanoyl-carnitine+glutamate (OC+Glut) or palmitoyl-carnitine+glutamate (PALM+Glut) to intact mitochondria. (n = 4–6). Bars indicate mean levels ± standard error of the mean (S.E.M.). Statistically significant differences between mut and dm are presented with thick lines. Asterisks indicate level of statistical significance (*p<0.05 **p<0.01 ***p<0.001, Student's <i>t</i>-test).