%0 Journal Article
%T Implication of NADPH Oxidases in the Early Inflammation Process Generated by Cystic Fibrosis Cells
%A Nushjira Pongnimitprasert
%A Margarita Hurtado
%A Foudil Lamari
%A Jamel El Benna
%A Corinne Dupuy
%A Mich¨¨le Fay
%A Marie-Jos¨¦ Foglietti
%A Maguy Bernard
%A Marie-Anne Gougerot-Pocidalo
%A Fran£¿oise Braut-Boucher
%J ISRN Inflammation
%D 2012
%R 10.5402/2012/481432
%X In cystic fibrosis (CF) patients, pulmonary inflammation is a major cause of morbidity and mortality. The aim of this study was to further investigate whether oxidative stress could be involved in the early inflammatory process associated with CF pathogenesis. We used a model of CFTR defective epithelial cell line (IB3-1) and its reconstituted CFTR control (S9) cell line cultured in various ionic conditions. This study showed that IB3-1 and S9 cells expressed the NADPH oxidases (NOXs) DUOX1/2 and NOX2 at the same level. Nevertheless, several parameters participating in oxidative stress (increased ROS production and apoptosis, decreased total thiol content) were observed in IB3-1 cells cultured in hypertonic environment as compared to S9 cells and were inhibited by diphenyleneiodonium (DPI), a well-known inhibitor of NOXs; besides, increased production of the proinflammatory cytokines IL-6 and IL-8 by IB3-1 cells was also inhibited by DPI as compared to S9 cells. Furthermore, calcium ionophore (A23187), which upregulates DUOX and NOX2 activities, strongly induced oxidative stress and IL-8 and IL-6 overexpression in IB3-1 cells. All these events were suppressed by DPI, supporting the involvement of NOXs in the oxidative stress, which can upregulate proinflammatory cytokine production by the airway CFTR-deficient cells and trigger early pulmonary inflammation in CF patients. 1. Introduction Cystis fibrosis (CF) is a fatal autosomal genetic disorder caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The CFTR protein provides cAMP-regulated chloride conductance and acts as a regulator of apical Na+ absorption. Although many organs are affected in CF, lung disease is the major cause of morbidity and of virtually all mortality [1]. In CF, loss of CFTR function results in altered ion transport of the airway epithelium and rise in mucus viscosity. Increased mucus viscosity with reduced mucociliary clearance is a critical event in the susceptibility to bacterial infections [2¨C4]. A pathological feature of lung disease in CF is the presence of early and excessive inflammation [3, 5]. However, following the finding of neutrophil dominated inflammation in the absence of detectable bacterial or viral pathogens in bronchial lavages obtained from CF infants [6], the sequence of events at the onset of airway inflammation has been the subject of debates, hence, the proposal that inflammation could precede infection by some direct contribution of the defective CFTR [7, 8]. Furthermore, in vitro data have shown that lung epithelial
%U http://www.hindawi.com/journals/isrn.inflammation/2012/481432/