Effects of inhibition of NADPH oxidase by apocynin, xanthine oxidase by allopurinol and mitochondrial complex I by rotenone on actinomycin D-induced apoptosis in pancreatic (CFPAC-1) and tracheal (CFT-2) cystic fibrosis cells (n = 5).

<p>Data are expressed in percentage of inhibition of actinomycin D-induced apoptosis.</p><p>*<i>p</i><0.05.</p

The SOD mimetic MnTMPyP reduces the increased sensitivity to apoptogenic agents of cells with CFTR dysfunction.

<p>(A) At confluence, PANC-1 (n = 6, black bars) and CFPAC-1 (n = 6, open bars) and (B) NT-1 (n = 6, dark gray bars) and CFT-2 (n = 6, light gray bars) cells were treated with MnTMPyP (Mn) for 30 min before treatment with actinomycin D (Act D) or staurosporine (St) for 24 h, or without any treatment (CTL). Cells were permeabilized with 70% ethanol and hypodiploid DNA was quantified by the use of propidium iodide. * <i>p</i><0.05, *** <i>p</i><0.001 significantly different from respective control cells; † <i>p</i><0.05 significantly different between in the absence and in the presence of Mn.</p

Representative schema showing that, in CF cells, increased apoptosis and NF-κB activation are associated with high levels of oxidative stress.

<p>Apoptotic stimuli seem activate NF-κB pathway which regulate reactive oxygen species (ROS) production. Whereas in pancreatic CF cells ROS are derived from mitochondria (red lines), in tracheal CF cells ROS are produced mainly by NADPH oxidase (blue lines). In addition, in both types of CF cells, a reduced anti-oxidant defense mechanism at least in part via diminished EC-SOD activity and reduced Cu/Zn-SOD and Mn-SOD expressions lead to exacerbate oxidative stress.</p

Activity of SODs in pancreatic and tracheal cells.

<p>At confluence, PANC-1 (n = 5, black bars) and CFPAC-1 (n = 5, open bars), NT-1 (n = 5, dark gray bars) and CFT-2 (n = 5, light gray bars) cells were treated with actinomycin D (Act D) or staurosporine (St) for 24 h, or without any treatment (CTL). Activity of both Cu/Zn-SOD and Mn-SOD are measured in A and B, and activity of EC-SOD in C and D. Enzymatic activity is expressed in absorbance units (A) per total protein concentration (µg/µl). † <i>p</i><0.05, †† <i>p</i><0.01, ††† <i>p</i><0.001 significantly different between both types of cells.</p

Expression of SOD in pancreatic and tracheal cells.

<p>At confluence, PANC-1 (n = 5, black bars) and CFPAC-1 (n = 5, open bars), NT-1 (n = 5, dark gray bars) and CFT-2 (n = 5, light gray bars) cells were treated with actinomycin D (Act D) or staurosporine (St) for 24 h, or without any treatment (CTL). Five determinations yielding similar results were performed. A β-actin control was included. Western-Blot were performed for Cu/Zn-SOD (A, B), for Mn-SOD (C, D) and for EC-SOD (E, F). SOD expressions were quantified by densitometric analysis and measurements were normalized with respect to β-actin. Densitometry values are given as mean ± SEM * <i>p</i><0.05 significantly different from respective control cells; † <i>p</i><0.05, †† <i>p</i><0.01 significantly different between both types of cells.</p