Fig. 3

Oligomycin increases ROS production in synovial tissue. Synovial tissue frozen sections from OLI-vehicle or OLI injected joints were incubated with a cytoplasmic (DHE; a) or mitochondrial (MitoSox; b) superoxide-sensitive fluorescent dye (red). The nuclei were counterstained with DAPI (blue). Representative images of the different color channels and their merge are shown. DHE (c) or MitoSox (d) fluorescence levels were measured and calculated as described in Methods. Values, expressed in arbitrary units (AU), represent mean ± SEM (n = 7 independent synovial sections for each condition). *P ≤ 0.05 vs OLI-vehicle knees. OLI, oligomycin; DAPI, 4′,6-diamidino-2-phenylindole; DHE, dihydroethidium; MitoSox, MitoSOX™ Red Mitochondrial Superoxide Indicator