Figure 4. Depleted CoQ10 and COQ7 in Skeletal Muscle.

(A) HPLC chromatograms of quinone extracts from muscle biopsy samples. Flash-frozen skeletal muscle obtained from a 31-year-old male volunteer was used as a control. (B) HPLC chromatograms of quinone extracted from 1.2 mg of muscle biopsy sample from sibling 2. One sample was spiked with 65 ng of CoQ₁₀ standard before HPLC injection. The result show that the area of the peak of interest is greater in the CoQ₁₀-spiked sample, providing further confirmation of the CoQ₁₀ peak identity and allowing quantitation of CoQ₁₀. (C) Quantitation indicated that the muscle of sibling 2 has 67% less CoQ₁₀ than the control muscle. (D) Western blot analysis of expression of COQ7. Compared with the control, there is a severely diminished level of COQ7 in the muscle sample from sibling 2. Skeletal muscles from an adult-onset COQ7-knockout³⁸ or a wild-type mouse were used for verification of the COQ7 band identity. The mitochondrial outer membrane protein, porin, was used as a loading control. Western blots were cropped to show only relevant bands. CoQ₁₀ = coenzyme Q₁₀; HPLC = high-performance liquid chromatography.