Figure 4. Nampt is Required for Maintenance of Mitochondrial Respiration Following PKCε Activation.

(a,b) Western blot analysis of the particulate fraction from the WT mouse cortex 1 hour following intraperitoneal injection of ΨεRACK. Gels were run under the same experimental conditions. Blots displayed are cropped and full-length blots are presented in Supplementary Figure S1. (b) PKCε protein levels increased in the particulate fraction following a 0.75 mg/kg dose of ΨεRACK, indicating PKCε activation. (c) Real-time qPCR performed 24 hours following intraperitoneal injection of ΨεRACK showed no change in SIRT5 mRNA levels. (d–f) Mitochondria were isolated from mouse cortices and the rate of oxygen consumption was measured in the presence of complex I-linked substrates (malate (mal) and pyruvate (pyr)), complex II-linked substrates (succinate (succ) and G3P), and complex IV-linked substrates (ascorbate (asc) and TMPD) in the presence of ADP. Mitochondria from ΨεRACK-treated mice exposed to the Nampt inhibitor FK866 (50 μM) displayed reduced respiration in the presence of complex II and complex IV substrates compared to Tat-treated mice. *p < 0.05.