Figure 5.

The effects of DHB on the skin fibroblasts derived from the V141E COQ7 patient. (A) HPLC chromatograms of quinone extracts from V141E skin fibroblasts. The patient cells showed a substantial reduction in UQ₁₀ levels and a large accumulation of DMQ₁₀. After treatment with 0.75 mM DHB, there was a significant increase in UQ₁₀ levels, which was accompanied with a lesser accumulation of DMQ₁₀. Cells with the same amount of protein (2.1 mg) were used for quinone extraction and HPLC quantitation. (B) Basal mitochondrial respiration rates measured using a Seahorse XF24 Analyzer. Data were collected from five cultures in each group and are expressed as means ± S.D. **P < 0.01, ****P < 0.0001 (one‐way anova followed by Tukey's multiple comparison test). (C) DHB increases UQ₁₀ production and decreases DMQ₁₀ accumulation in the V141E patient cells. Quinone levels are expressed as HPLC‐UV peak area normalized to protein content, and shown as mean ± S.E.M. (n = 2). *P < 0.05, **P < 0.01 (one‐way anova followed by Tukey's multiple comparison test). (D) The effect of DHB treatment on mitochondrial respiration in V141E skin fibroblasts. (E) The effect of UQ₁₀ on mitochondrial respiration in V141E skin fibroblasts. The experimental condition and data acquisition in D and E are the same as in Figure 4. Shown on the left are representative OCR traces. Quantitative data are graphed on the right as mean ± S.D. (n = 9–10/group). *P < 0.05, ***P < 0.001, ****P < 0.0001 by two‐way anova with Sidak's multiple comparison test.