FIGURE 6.

Suppression of expression of NDUFAF5 and oxygen consumption. Expression of NDUFAF5 in 143B cells was suppressed three times with siRNA at 72 h intervals. Part A, effect on levels of transcripts for control and NDUFAF5-depleted cells (white and hatched histograms, respectively) 48 h after each suppression. The values are normalized to endogenous β-actin, and error bars show the standard deviation. Parts B and C, oxygen consumption rates (OCR) of negative control and NDUFAF5 siRNA-treated cells (white and shaded histograms, respectively) 120 h (B) and 192 h (C) after the first transfection, respectively. OCR was normalized to cell number. Rates were measured after successive additions of 2-deoxyglucose, rotenone, duroquinol, and antimycin, or 2-deoxyglucose, oligomycin, carbonylcyanide p-(trifluoromethoxy)-phenylhydrazone (FCCP), and a combination of rotenone and antimycin A. The OCR for complex I represents the rate for 2-deoxyglucose-treated cells minus the rate for rotenone-treated cells, and those for complex III are the OCR values for duroquinol minus antimycin A. The E/L ratio (FCCP/oligomycin) is an index of the maximum oxygen consumption capacity of the electron transport system (E) relative to the magnitude of uncoupled respiration (L).