Inactivation of Pdks improves insulin sensitivity in IrsLDKO mice.

<p>A, Insulin tolerance tests (ITT) were performed in age-matched control and knockout mice (n = 8–20). B, Fasting plasma insulin was analyzed in age-matched control and knockout mice (n = 5–9). C, HOMA-IR (homeostatic model assessment-insulin resistance) was analyzed using fasting glucose and insulin data. Data are presented as means ± SEM. *, <i>P</i><0.05 relative to corresponding controls.</p

Deletion of the <i>Pdk4</i> gene improves hyperglycemia in IrsLDKO mice.

<p>A, Blood glucose was measured in overnight fasted control and knockout mice. B, Blood glucose was measured in <i>ad libitum</i> fed control and knockout mice. Data are presented as means ± SEM, n = 8–23. *, <i>P</i><0.05 relative to corresponding controls.</p

Pdk2 or Pdk4 knockdown has no significant effect on insulin tolerance in IrsLDKO mice.

<p>A, Insulin tolerance tests were performed on IrsLDKO mice (n = 4–5) that were injected with shGFP, shPdk2, and shPdk4 adenoviruses. B, Area under curve was analyzed for the above ITT data. C–F, Akt phosphorylation was analyzed in the liver and skeletal muscle of mice injected with shGFP, shPdk2, and shPdk4 adenoviruses. Western blot signals were also quantified using the Quantity One software. Data are presented as means ± SEM. *, <i>P</i><0.05 relative to corresponding controls.</p

Insulin signaling analysis in the control and knockout mice.

<p>A and B, Animals were stimulated with 5 units of human insulin (saline as a vehicle control) for 3 min before liver and skeletal muscle samples were collected for Akt and Erk phosphorylation analyses. Western blot signals were quantified using the Quantity One software (Bio-Rad). Data are presented as means ± SEM. *, <i>P</i><0.05 relative to corresponding controls.</p

Hepatic Pdk4 knockdown moderately improves glucose tolerance in IrsLDKO mice.

<p>A, Gene knockdown efficiency was analyzed by real-time PCR in IrsLDKO livers transduced with shRNA adenoviruses against GFP (shGFP), Pdk2 (shPdk2), or Pdk4 (shPdk4). B, Glucose tolerance tests were performed in shRNA adenoviruses infected IrsLDKO mice. C, Area under curve analysis (AUC) was performed for the above glucose tolerance test data. Data are presented as means ± SEM, n = 4–5. *, <i>P</i><0.05 relative to corresponding controls.</p

Ablation of Pdks improves glucose tolerance in IrsLDKO mice.

<p>A, Glucose tolerance tests (GTT) were performed in age-matched control and knockout mice (n = 8–12). B and C, Expression of gluconeogenic genes <i>Pck1</i> and <i>G6pc</i> was analyzed in the liver of overnight fasted control and knockout mice (n = 3). Data are presented as means ± SEM. *, <i>P</i><0.05 relative to corresponding controls.</p

Knockout of the <i>Pdk</i> genes in wild-type and IrsLDKO mice.

<p>A, Control wild-type and IrsLDKO mice (n = 3) were fasted overnight for 16 hours and half of them were fed for 4 hours immediately after the fasting. <i>Pdks</i> gene expression in the liver was analyzed by real-time PCR and data were normalized to an internal control gene — Ppia. B, Western blot analysis of liver lysates from control and knockout mice. C, Body weight measurements in control and knockout mice (n = 6–20). D, Serum triglycerides (TG) were measured in overnight fasted control and knockout mice (n = 6–8). E, Liver TG analysis in control and knockout mice (n = 6–8). Pdk2KO, Pdk2 knockout; Pdk4KO, Pdk4 knockout; IrsLDKO, Irs1/2 liver-specific double knockout. Data are presented as means ± SEM. *, <i>P</i><0.05 relative to corresponding controls.</p