c-Myc and AMPK Control Cellular Energy Levels by Cooperatively Regulating Mitochondrial Structure and Function
Fig 5
Redox states in cytoplasmic and mitochondrial compartments of WT and KO MEFs.
(A) Live cell confocal images of WT MEFs stably expressing roGFP-mito and roGFP-cyto demonstrating specific mitochondrial and cytoplasmic localization, respectively. Nuclear counter-staining was with Hoechst 3334. (B) Live cell confocal microscopy of KO MEFs expressing roGFP-mito. Cells were untreated or exposed to 1 mM H2O2 or 10 mM DTT for 30 min prior to obtaining images. (C) Quantification of redox differences between WT and KO MEFs. Monolayer cultures were grown for 24 hr. in the absence or presence of 4HT. Flow cytometry was then used to quantify the mean fluorescence ratios of oxidized and reduced roGFP. Each bar represents the average ± 1 SEM of mean fluorescence intensities obtained from 3 independent plates of cells. * = P<0.001. Similar results were independently obtained in 2 repeat experiments as well as in 2 experiments performed following a longer period of MycER activation (7 days, not shown). The 4 bars on the right represent control experiments in which WT cells expressing roGFP-cyto were exposed under the conditions described in (B). These values define the maximal possible degree of oxidation or reduction capable of being achieved under the most extreme conditions.