Figure 3.

MIA caused mitochondrial dysfunction and ROS production, and inhibition of p66shc alleviated MIA-induced mtROS production in human chondrocytes.

Notes: (A, B) Extent of cytotoxicity following MIA treatment, according to time and dose. (C, D) The oxygen consumption rate (OCR), which reflects mitochondrial function, and the extracellular acidification rate (ECAR), which indicates lactate production, were obtained using a Seahorse XF24 analyzer in cells treated with 2 µg/mL oligomycin (an ATPase inhibitor), 5 µM cyanide m-chlorophenylhydrazone (CCCP; an uncoupler), or 2 µM rotenone (a mitochondrial complex I inhibitor). Area under the curve (AUC) for basal OCR and ECAR were measured from the first to the third timepoints. The AUC for maximal OCR was measured from the seventh to the ninth timepoints. Data represent the mean ± SEM (error bars) of three experiments. **P < 0.01, ***P < 0.001 (derived via one-way ANOVA); MIA vs control. (E) MitoSOX fluorescence imaging of human chondrocytes expressing Ad/LacZ and Ad/sh-p66shc. (F) Quantification of MitoSOX fluorescence. (G) Schematic diagram of p66shc-related pathway.

Abbreviation: ROS, reactive oxygen species.