FIG. 7.

Evidence that metformin and pioglitazone regulate mitochondrial copper. A: H4IIE cells were grown in serum-free medium for 2 h before treatment with (right) or without (left) 100 μM pioglitazone for 3 h. In each case, the cells were incubated in the presence of the copper-specific probe, before washout and visualization on the confocal microscope as discussed in research design and methods. Scale bars, 10 μm. B and C: Cells were serum-starved for 2 h before treatment for 3 h with 100 μM pioglitazone (B) or 2 mM metformin (C). The cells were incubated in the presence of the copper-specific probe (green channel, ii) and a mitochondrial marker (far red channel, iv), before washout and visualization on the confocal microscope as discussed in research design and methods. Hoechst staining (blue channel, i) marks the nucleus. All channels are merged in v to demonstrate colocalization. Panel iii is phase-contrast. (A high-quality digital representation of this figure is available in the online issue.)