Mice with skeletal muscle over-expression of SOCS3 have suppressed basal AMPK signaling.

<p>(<b>A</b>) α2AMPK activity, (<b>B</b>) AMPK signaling, (<b>C</b>) expression of genes involved in fatty acid oxidation, (<b>D</b>) β-hydroxyacyl-CoA dehydrogenase activity (HADH), (<b>E</b>) citrate synthase activity (CS), and (<b>F</b>) COXI DNA content in skeletal muscle of SOCS3/MCK and control mice on a chow diet. Soleus, EDL or gastrocnemius muscles from 5-month-old chow-fed male mice were evaluated for AMPK activity using an immune complex assay. Phosphorylation and total protein levels of AMPK and ACC were measured by immunoblotting. Gene expression was measured by Real-time RT-PCR and corrected with cyclophilin levels. HADA and CS activities were determined spectrophotometrically using skeletal muscle (gastrocnemius) homogenates. Mitochondrial DNA content was measured in muscle (gastrocnemius) DNA samples by Real-time PCR using primer/probe sets corresponding to mitochondrial DNA-encoded cytochrome c oxidase subunit I (COXI) gene and normalized with nuclear DNA-encoded gene UCP2. Data are expressed as Mean ± SE, n = 6–8. *p<0.05 vs. control SOCS3 mice in (<b>A</b>), (<b>C</b>), (<b>D</b>), and (<b>F</b>); p = 0.05 vs. control SOCS3 mice in (<b>E</b>).