PPARβ/δ Agonism with GW501516 Increases Myotube PGC-1α Content and Reduces BCAA Media Content Independent of Changes in BCAA Catabolic Enzyme Expression

Figure 8

Effect of GW501516 on lipid content and related molecular targets. (a) Effect of GW at 1 μM for 24 hours on lipid content (indicated by Nile red staining) both without and with normalization to nuclei content, with representative images at right. (b) Time trial of the effect of GW on mRNA expression of peroxisome proliferator-activated receptor gamma (Pparg), sterol regulatory element-binding protein (Srebp), CCAAT/enhancer-binding protein alpha (Cebpa), stearoyl-CoA desaturase (Scd1), and fatty acid translocase (Fat or CD36). (c) Effect of treatment with GW at 1 μM for 24 hours on myotube protein expression of peroxisome proliferator-activated receptor gamma (PPARγ) and sterol regulatory element-binding protein (SRECP1c). Notes: * indicates between groups. Lipid staining was performed using individual replicates per treatment condition repeated across two independent experiments with per group in the final analysis. Images in panel “a” are representative individual myotubes imaged using the 20× objective with green line indicating 150 μm. Time course gene expression was analyzed using one-way ANOVA with Dunnett’s correction for multiple comparisons. Target gene expression was normalized to tata binding protein (Tbp) using three replicates per group across two independent experiments with for the final analysis. Student’s t-test was used to assess differences in metabolism, lipid content, and protein expression following 24-hour treatment. Western blots were performed using three replicates per group across two independent experiments with each target quantified in duplicate for each sample, with for the final analysis.

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