3-oxo-C12-HSL attenuates mitochondrial respiration in bronchial epithelial cells. (A) BEAS-2B cells were treated with 100 μM 3-oxo-C12-HSL for 6 hours and then the amount of ATP normalized to protein was measured in cellular lysates. 3-oxo-C12-HSL significantly reduced the level of ATP present in cells. (B–F) BEAS-2B cells were treated with 50, 100, or 200 μM 3-oxo-C12-HSL for 6 hours and then analyzed using the Seahorse XF Mito Stress Test assay. (B) OCR was measured real time at baseline and then in response to a series of injections to interrogate various aspects of the electron transport chain. 3-oxo-C12-HSL significantly attenuated basal respiration (C) maximal respiration (D) spare respiratory capacity (E) and ATP-linked respiration (F). Results are mean ± SEM. For A, * p < 0.05 by unpaired two-tailed t test, n = 3 independent experiments. For C-F * p < 0.05, **p < 0.01, ***p < 0.001 by one-way ANOVA with Tukey’s multiple comparisons test, n = 6 independent experiments.