Oxidative stress modulates the expression of genes involved in cell survival in ΔF508 cystic fibrosis airway epithelial cells

Abstract

Although cystic fibrosis (CF) pathophysiology is explained by a defect in CF transmembrane conductance regulator (CFTR) protein, the broad spectrum of disease severity is the consequence of environmental and genetic factors. Among them, oxidative stress has been demonstrated to play an important role in the evolution of this disease, with susceptibility to oxidative damage, decline of pulmonary function, and impaired lung antioxidant defense. Although oxidative stress has been implicated in the regulation of inflammation, its molecular outcomes in CF cells remain to be evaluated. To address the question, we compared the gene expression profile in NuLi-1 cells with wild-type CFTR and CuFi-1 cells homozygous for ΔF508 mutation cultured at air-liquid interface. We analyzed the transcriptomic response of these cell lines with microarray technology, under basal culture conditions and after 24 h oxidative stress induced by 15 μM 2,3-dimethoxy-1,4-naphtoquinone. In the absence of oxidative conditions, CuFi-1 gene profiling showed typical dysregulated inflammatory responses compared with NuLi-1. In the presence of oxidative conditions, the transcriptome of CuFi-1 cells reflected apoptotic transcript modulation. These results were confirmed in the CFBE41o- and corrCFBE41o- cell lines as well as in primary culture of human CF airway epithelial cells. Altogether, our data point to the influence of oxidative stress on cell survival functions in CF and identify several genes that could be implicated in the inflammation response observed in CF patients.

Copper-Associated Oxidative Stress Contributes to Cellular Inflammatory Responses in Cystic Fibrosis

“…In fact, this cell type represents the first line of defense against the external infections [ 47 ] and has the advantage of developing a highly polarized cell layer compared to other previously used cell lines [ 28 ]. ROS production in CF cells was independent of CFTR mutation, expression, or function, confirming previously reported data that used other cellular models [ 48 , 49 ]. Our results also demonstrate the decrease in the antioxidant response that was not corrected by the expression of CFTR-wt protein.…”

Human Cellular Models for the Investigation of Lung Inflammation and Mucus Production in Cystic Fibrosis

“…In order to investigate the role of oxidative stress in CF, bronchial cell lines were compared with primary airway epithelial cells grown at ALI [88]. Several transcripts already reported to be upregulated in CF pathophysiology (IL-6, IL-8, IL-1B, and IL-1A) were found to be significantly higher in CuFi-1 cells as compared with NuLi-1 cells.…”

Cystic fibrosis epithelial cells are primed for apoptosis as a result of increased Fas (CD95)

“…Our finding of altered apoptosis in CF epithelial cells has the potential to impact on epithelial integrity in the lung although it should be pointed out that others have observed altered effects on apoptosis in CF epithelium during Pseudomonas infection [4,[27][28][29] and conditions of oxidative stress [7,30]. Therefore, it seems likely that alterations in apoptosis…”

“…Previous work suggests that apoptosis is dysfunctional in the CF airways with conflicting results. While some reports describe defective apoptosis of epithelial cells expressing mutant forms of CFTR [4][5][6], a number of others report excessive apoptosis in CF cells [7][8][9][10][11][12][13]. In addition, it is unclear how CFTR misfolding and dysfunction contributes to apoptosis or the susceptibility of cells to pro-apoptotic stimuli.…”