Journal: International Journal of Molecular Sciences
Article Title: The Ca 2+ –NO–ROS Crosstalk Induced by Arachidonic Acid in Human Lung Fibroblasts: Implications for Pulmonary Fibrosis
doi: 10.3390/ijms27094016
Figure Lengend Snippet: AA-induced ROS generation in WI-38 human lung fibroblasts requires intracellular Ca 2+ release, Ca 2+ influx, and NO production. ( A ) Representative traces showing ROS production induced by AA (30 µM, blue) and H 2 O 2 (100 µM, pink). Pre-treatment with the antioxidant NAC (1 mM, 60 min, cyan). The arrow indicates the time of stimulation. For clarity, the baseline of the traces has been adjusted to zero. ( B ) Quantification of peak ROS fluorescence from ( A ), expressed in A.U. Mean ± SEM. Kruskal–Wallis test; ****, p < 0.0001. ( C ) Representative traces of AA-induced ROS production and its modulation by Ca 2+ signalling inhibitors. Cells were stimulated with AA (30 µM) in PSS (blue trace), following pretreatment with the GPR40 antagonist GW1100 (GW; 10 µM, 10 min, purple), the IP 3 Rs inhibitor 2-APB (50 µM; 20 min, brown). The arrow indicates the time of stimulation. For clarity, the baseline of the traces has been adjusted to zero. ( D ) Quantification of peak ROS fluorescence intensities from ( C ), expressed in A.U. Data are the mean ± SEM of ROS production peak amplitudes. The statistical test used was the Kruskal–Wallis test: ****, p < 0.0001. ( E ) Representative traces of AA-induced ROS production under Ca 2+ -free solution (0Ca 2+ ; black) or in the presence of the SOCE inhibitor BTP-2 (20 µM, 20 min, orange) or the TRPV4 inhibitor RN-1734 (20 µM, 60 min, magenta), or the combined treatment (RN + BTP-2; yellow trace). The arrow indicates the time of AA (30 µM) stimulation. For clarity, the baseline of the traces has been adjusted to zero. ( F ) Quantification of peak ROS fluorescence intensities from ( E ). Data are the mean ± SEM of the peak ROS production amplitudes, expressed in A.U. The statistical test used was the Kruskal–Wallis test: **, p < 0.01; ****, p < 0.0001. ( G ) A representative trace showing the effect of NO pathway inhibition on AA-induced ROS production. Signals were recorded in response to AA (30 µM) under control conditions (blue), after NO scavenging with cPTIO (10 µM, 60 min, green), followed by non-selective NOS inhibition with L-NAME (100 µM, 60 min, grey), and subsequently by selective eNOS inhibition with L-NIO (20 µM, 60 min, red). The arrow indicates the time of AA (30 µM) stimulation. For clarity, the baseline of the traces has been adjusted to zero. ( H ) Quantification of peak ROS fluorescence intensities from ( G ). The data are the mean ± SEM of the peak ROS production amplitudes, expressed in A.U. The statistical test used was the Kruskal–Wallis test: ***, p < 0.001; ****, p < 0.0001. For all panels, the n value represents the number of cells analysed, and the number of independent experimental replicates is indicated in parentheses.
Article Snippet: Human foetal human lung fibroblasts (WI-38; CCL-75TM) were obtained from the American Type Culture Collection (ATCC ® , Manassas, VA, USA).
Techniques: Fluorescence, Inhibition, Control