STRATEGIES FOR ALTERATION OF PRO-INFLAMMATORY GENE EXPRESSION IN CYSTIC FIBROSIS.

Cystic fibrosis (CF) is an autosomal recessive disorder caused by defective function of the cystic fibrosis transmembrane receptor (CFTR) gene product, a cAMP-regulated chloride channel. The main cause of morbidity and mortality in CF patients is a lung chronic inflammation due to several infections from pathogens like Pseudomonas aeruginosa. Chronic inflammatory process leads to elevated concentrations of several pro-inflammatory cytokines (i.e. IL-6, TNFα, IL1β) and chemokines (i.e. IL-8) released from airway epithelial cells and found in the bronchoalveolar fluid of CF patients. We studied the cytokines expression in IB3-1 cells, the cellular model for CF, when inflammation was induced by Pseudomonas aeruginosa infection or TNFα treatment. IL-8 was significantly more expressed compared to all cytokines studied. So far, therapies have been directed at improving airway clearance of secretions and treating pulmonary infection. Recently, among several new therapeutic approaches, a strategy to directly reduce the excessive inflammatory response in the airways has been proposed. In this respect, we focused our attention on two different strategies aiming at the down-regulation of the pro-inflammatory gene expression: · transcription factor decoy (TFD) · natural products as source of new anti-inflammatory compounds Pseudomonas aeruginosa lung infection is known to induce the expression of innate immunity genes by activating different transcription factors (TFs), such as NF-kB, AP-1, Elk-1, and NF-IL-6. Since NF-kB plays a well known pivotal role in inflammatory processes, we chose it as the first molecular target for the TF decoy approach. We show here that NF-kB oligodeoxynucleotide (ODN) decoy on IL-8 promoter partially inhibited the Pseudomonas aeruginosa-dependent transcription of IL-8. The use of ‘‘decoy’’ molecules to inhibit IL-8 driven inflammation represents a promising strategy for CFTR related lung disease. The second approach focused on the natural anti-inflammatory effect of some medicinal plant extracts, including Bergamot from Lebanon, Emblica officinalis and Saraca asoka from Bangladesh and on the identification of the constituents addressing this effect. We show here that all three plant extracts reduced IL-8 gene expression in IB3-1 cells induced to hyper secretion of pro-inflammatory chemokines by TNF-a. The results sustain the anti-inflammatory properties of these plant extracts and suggest a possible use to control the inflammatory process associated with the cystic fibrosis airway pathology.