title: Elevated levels of miR-145 correlate with SMAD3 down-regulation in cystic fibrosis patients.
abstract: MicroRNAs (miRNAs) have recently emerged as important gene regulators in Cystic Fibrosis (CF), a common monogenic disease characterized by severe infection and inflammation, especially in the airway compartments. In the current study, we show that both miR-145 and miR-494 are significantly up-regulated in nasal epithelial tissues from CF patients compared with healthy controls (p<0.001 and p<0.01, respectively) by Quantitative Real-Time PCR. Only miR-494 levels showed a trend of correlation with reduced CFTR mRNA expression and positive sweat test values, supporting the negative regulatory role of this miRNA on CFTR synthesis. Using computational prediction algorithms and luciferase reporter assays, SMAD family member 3 (SMAD3), a key element of the TGF-β1 inflammatory pathway, was identified as a target of miR-145. Indeed, miR-145 synthetic mimics suppressed by approximately 40% the expression of a reporter construct containing the SMAD3 3'-UTR. Moreover, we observed an inverse correlation between SMAD3 mRNA expression and miR-145 in CF nasal tissues (r=-0.68, p=0.0018, Pearson's correlation). Taken together, these results confirm the pivotal role of miRNAs in the CF physio-pathogenesis and suggest that miRNA deregulation play a role in the airway disease severity by modulating CFTR levels as well as the expression of important molecules involved in the inflammatory response. miR-494 and miR-145 may, therefore, be potential biomarker and therapeutic target to specific CF clinical manifestations.
authors: Department of Experimental Medicine, Sapienza University of Rome, Italy. Electronic address: francesca.megiorni@uniroma1.it.
authors: Francesca
authors: F
authors: Megiorni
authors: Samantha
authors: S
authors: Cialfi
authors: Giuseppe
authors: G
authors: Cimino
authors: Riccardo Valerio
authors: RV
authors: De Biase
authors: Carlo
authors: C
authors: Dominici
authors: Serena
authors: S
authors: Quattrucci
authors: Antonio
authors: A
authors: Pizzuti
mesh_terms: D000328:Adult; D003550:Cystic Fibrosis / Q000378:metabolism*; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000502:physiology; D015536:Down-Regulation; D005260:Female; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000378:metabolism*; D009297:Nasal Mucosa / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D051900:Smad3 Protein / Q000378:metabolism*; D015854:Up-Regulation / Q000502:physiology
chemical_list: C505032:CFTR protein, human; C541010:MIRN145 microRNA, human; C547168:MIRN494 microRNA, human; D035683:MicroRNAs; C497790:SMAD3 protein, human; D051900:Smad3 Protein; D019005:Cystic Fibrosis Transmembrane Conductance Regulator
keywords: Cystic Fibrosis; MiR-145; MicroRNA expression; Nasal epithelium; Post-transcriptional regulation; SMAD3