ERP116236 PRJEB33445 ena-STUDY-CDR St Atnoine-10-07-2019-13:49:50:415-1420 In this project we have performed a miRNOme analysis of CF cells from CF patients cultured in air-liquid interface compared to non-CF cells cultured in the same condition. Cystic fibrosis (CF) is the most common lethal genetic disease, caused by CFTR (cystic fibrosis transmembrane conductance regulator) gene mutations. CF is characterized by an ionic imbalance and thickened mucus, which impair mucociliary clearance, promote bacterial colonization, and the establishment of infection/inflammation cycles. However, the origin of this inflammation remains unclear, although microRNA (miRNA) are suspected to be involved. MiRNA are small non-coding RNA that bind to the 3'-untranslated regions (UTR) of target gene mRNA, thereby repressing their translation and/or inducing their degradation. The goal of this study was to investigate the role of microRNA associated with pulmonary inflammation in CF patients. Through the analysis of all miRNA (miRNome) in human primary air-liquid interface cultures, we demonstrated that miR-199a-3p is the only miRNA downregulated in CF patients compared to controls. Moreover, through RNA sequencing (transcriptome) analysis, we showed that 50% of all deregulated mRNA are linked directly or indirectly to the NF-?B pathway. To identify a specific target, we used bioinformatics analysis to predict whether miR-199a-3p targets the 3'-UTR of IKBKB which encodes IKKß, a major protein in the NF-?B pathway.Subsequently, we used bronchial explants from CF patients to show that miR-199a-3p expression is downregulated compared to controls and inversely correlated with increases in expression of IKKß and IL-8. Through functional studies, we showed that miR-199a-3p modulates the expression of IKBKB through a direct interaction at its 3'-UTR in bronchial epithelial cells from CF patients. In miR-199a-3p overexpression experiments, we demonstrated that for CF cells miR-199a-3p reduced IKKß protein expression, NF-?B activity, and IL-8 secretion. Taken together, our findings show that miR-199a-3p plays a negative regulatory role in the NF-?B signalling pathway and that its low expression in CF patients contributes to chronic pulmonary inflammation. miRNA expression in CF ALI cells Cystic fibrosis (CF) is the most common lethal genetic disease, caused by CFTR (cystic fibrosis transmembrane conductance regulator) gene mutations. CF is characterized by an ionic imbalance and thickened mucus, which impair mucociliary clearance, promote bacterial colonization, and the establishment of infection/inflammation cycles. However, the origin of this inflammation remains unclear, although microRNA (miRNA) are suspected to be involved. MiRNA are small non-coding RNA that bind to the 3'-untranslated regions (UTR) of target gene mRNA, thereby repressing their translation and/or inducing their degradation. The goal of this study was to investigate the role of microRNA associated with pulmonary inflammation in CF patients. Through the analysis of all miRNA (miRNome) in human primary air-liquid interface cultures, we demonstrated that miR-199a-3p is the only miRNA downregulated in CF patients compared to controls. Moreover, through RNA sequencing (transcriptome) analysis, we showed that 50% of all deregulated mRNA are linked directly or indirectly to the NF-?B pathway. To identify a specific target, we used bioinformatics analysis to predict whether miR-199a-3p targets the 3'-UTR of IKBKB which encodes IKKß, a major protein in the NF-?B pathway.Subsequently, we used bronchial explants from CF patients to show that miR-199a-3p expression is downregulated compared to controls and inversely correlated with increases in expression of IKKß and IL-8. Through functional studies, we showed that miR-199a-3p modulates the expression of IKBKB through a direct interaction at its 3'-UTR in bronchial epithelial cells from CF patients. In miR-199a-3p overexpression experiments, we demonstrated that for CF cells miR-199a-3p reduced IKKß protein expression, NF-?B activity, and IL-8 secretion. Taken together, our findings show that miR-199a-3p plays a negative regulatory role in the NF-?B signalling pathway and that its low expression in CF patients contributes to chronic pulmonary inflammation. PUBMED 29732561 ENA-FIRST-PUBLIC 2019-11-12 ENA-LAST-UPDATE 2019-07-10