Figure 3. The effect of partial mtDNA depletion on mitochondrial function.

Cells were harvested 72 h post transfection and oxygen consumption rate (OCR) was measured using the Seahorse XF24 Analyzer. OCR in TFAM-429 cells (n = 8) was severely impaired compared to that of Scrambled (n = 8) and Shocked (n = 8) control cells (A). Mitochondrial activity was measured following injection of oligomycin, an inhibitor of Complex V (ATP Synthase), followed by two sequential injections of FCCP to uncouple respiration and induce maximal respiration, and finally antimycin, an inhibitor of Complex III (Ubiquinol-Cytochrome c Reductase) preventing electron transfer and subsequently abolishing the proton gradient required for ATP synthesis. Basal and maximal respiratory capacity (B) and ATP synthesis by oxidative phosphorylation (OXPHOS) (C) were calculated as described previously [30]–[32]. Data were normalised to protein concentration and are presented means ± SEM. * p<0.5, ** p<0.001, *** p<0.0001.