Figure 4.

Endogenous PGC-1α is a target for drugs designed to restore electron transport chain expression. Treatment with pioglitazone (concentration of 10 μM, 48 hours of treatment) pervasively activated the PGC-1α-ERRα circuit. It induced a statistically significant 5-fold increase in expression of endogenous PGC-1α, a significant 2-3-fold increase in endogenous ERRα, and a resulting significant 2–5-fold-trans-activation of their endogenous electron transport chain target genes compared to cells treated with vehicle alone. Mean ± SEM shown (N = 10 for each treatment). ∗ denotes P value ≤ 0.05. ∗∗ denotes P value ≤ 0.005.