Hydroxynonenal-induced leukotriene B
biosynthesis and 5-lipoxygenase and 5-lipoxygenase-activating protein expression in human osteoarthritis chondrocytes. Cells were treated with single addition of 10 μM 4-hydroxynonenal for different incubation time periods, as indicated above. (a) Leukotriene B4 (LTB4) production was evaluated by enzyme immunoassay commercial kit. (b) 5-lipoxygenase-activating protein (FLAP) and (c) 5-lipoxygenase (5-LOX) mRNA expression was measured by real-time RT-PCR. Data are means ± standard errors of the mean, n = 5, expressed as percentages of untreated cells. Student's unpaired t test: *P < 0.05, **P < 0.01, ***P < 0.001.