Figure 5

Nuclear PDC activity in response to TGF-β1. (A) Representative bright-field and fluorescent (DAPI) confocal images of intact nuclei isolated from UUOF. Top bar = 5 µm, bottom bar = 10 µm. (B) PDC activity in isolated nuclei and mitochondria with or without TGF-β1 (1 ng/mL) pre-treatment was determined by LC–MS/MS (cps, counts per second). Freshly prepared isolates of TGF-β1 or vehicle-treated UUOF were incubated with ¹³C₂-pyruvate for 10 h at 37 °C after which metabolites were extracted for quantitation of ¹³C₁-acetyl CoA. Nuclear PDC activity was higher in TGF-β1-treated UUOF compared to vehicle-treated cells, whereas mitochondrial PDC activity was lower in the TGF-β1-treated group compared to control isolates. Plot shows mean ± SEM of pooled data from 2 independent experiments (5 isolates in each experimental group). *P < 0.05; ***P < 0.001. P-values were determined in (B) using two-way ANOVA with Sidak’s multiple comparisons test.