FIG. 4.

ERRα induces endogenous PPARα expression. (A) Northern analyses to characterize the expression of regulators of mitochondrial fatty acid oxidation, PPARα, PGC-1α, and ERRα in cardiac myocytes expressing GFP, ERRα, or PGC-1α. (B) Quantification of PPARα and PPARβ mRNA levels in response to ERRα overexpression in cardiac myocytes and C₂C₁₂ myotubes by real-time PCR. Data represent mean arbitrary units (± standard error) corrected to the glyceraldehhyde-3-phosphate dehydrogenase (GAPDH) transcript and normalized to the values in GFP-expressing myocytes (= 1.0).