title: Elevated Mirc1/Mir17-92 cluster expression negatively regulates autophagy and CFTR (cystic fibrosis transmembrane conductance regulator) function in CF macrophages.
abstract: Cystic fibrosis (CF) is a fatal, genetic disorder that critically affects the lungs and is directly caused by mutations in the CF transmembrane conductance regulator (CFTR) gene, resulting in defective CFTR function. Macroautophagy/autophagy is a highly regulated biological process that provides energy during periods of stress and starvation. Autophagy clears pathogens and dysfunctional protein aggregates within macrophages. However, this process is impaired in CF patients and CF mice, as their macrophages exhibit limited autophagy activity. The study of microRNAs (Mirs), and other noncoding RNAs, continues to offer new therapeutic targets. The objective of this study was to elucidate the role of Mirs in dysregulated autophagy-related genes in CF macrophages, and then target them to restore this host-defense function and improve CFTR channel function. We identified the Mirc1/Mir17-92 cluster as a potential negative regulator of autophagy as CF macrophages exhibit decreased autophagy protein expression and increased cluster expression when compared to wild-type (WT) counterparts. The absence or reduced expression of the cluster increases autophagy protein expression, suggesting the canonical inverse relationship between Mirc1/Mir17-92 and autophagy gene expression. An in silico study for targets of Mirs that comprise the cluster suggested that the majority of the Mirs target autophagy mRNAs. Those targets were validated by luciferase assays. Notably, the ability of macrophages expressing mutant F508del CFTR to transport halide through their membranes is compromised and can be restored by downregulation of these inherently elevated Mirs, via restoration of autophagy. In vivo, downregulation of Mir17 and Mir20a partially restored autophagy expression and hence improved the clearance of Burkholderia cenocepacia. Thus, these data advance our understanding of mechanisms underlying the pathobiology of CF and provide a new therapeutic platform for restoring CFTR function and autophagy in patients with CF.
authors.affiliation: a Department of Microbial Infection and Immunity, Center for Microbial Interface Biology , The Ohio State University , Columbus , OH , USA.|b Davis Heart and Lung Research Institute , The Ohio State University , Columbus , OH , USA.
authors.forename: Mia F
authors.initials: MF
authors.lastname: Tazi
authors.affiliation: b Davis Heart and Lung Research Institute , The Ohio State University , Columbus , OH , USA.
authors.forename: Duaa A
authors.initials: DA
authors.lastname: Dakhlallah
authors.affiliation: a Department of Microbial Infection and Immunity, Center for Microbial Interface Biology , The Ohio State University , Columbus , OH , USA.|b Davis Heart and Lung Research Institute , The Ohio State University , Columbus , OH , USA.
authors.forename: Kyle
authors.initials: K
authors.lastname: Caution
authors.affiliation: a Department of Microbial Infection and Immunity, Center for Microbial Interface Biology , The Ohio State University , Columbus , OH , USA.|b Davis Heart and Lung Research Institute , The Ohio State University , Columbus , OH , USA.
authors.forename: Madelyn M
authors.initials: MM
authors.lastname: Gerber
authors.affiliation: b Davis Heart and Lung Research Institute , The Ohio State University , Columbus , OH , USA.|c Department of Veterinary Biosciences , The Ohio State University , Columbus , OH , USA.
authors.forename: Sheng-Wei
authors.initials: SW
authors.lastname: Chang
authors.affiliation: d Department of Molecular Biology, Genetic Engineering and Biotechnology Research Institute , University of Sadat City , Egypt.
authors.forename: Hany
authors.initials: H
authors.lastname: Khalil
authors.affiliation: e Nationwide Children's Hospital , Columbus , OH , USA.
authors.forename: Benjamin T
authors.initials: BT
authors.lastname: Kopp
authors.affiliation: a Department of Microbial Infection and Immunity, Center for Microbial Interface Biology , The Ohio State University , Columbus , OH , USA.|b Davis Heart and Lung Research Institute , The Ohio State University , Columbus , OH , USA.
authors.forename: Amr E
authors.initials: AE
authors.lastname: Ahmed
authors.affiliation: a Department of Microbial Infection and Immunity, Center for Microbial Interface Biology , The Ohio State University , Columbus , OH , USA.|b Davis Heart and Lung Research Institute , The Ohio State University , Columbus , OH , USA.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Krause
authors.affiliation: c Department of Veterinary Biosciences , The Ohio State University , Columbus , OH , USA.
authors.forename: Ian
authors.initials: I
authors.lastname: Davis
authors.affiliation: b Davis Heart and Lung Research Institute , The Ohio State University , Columbus , OH , USA.
authors.forename: Clay
authors.initials: C
authors.lastname: Marsh
authors.affiliation: a Department of Microbial Infection and Immunity, Center for Microbial Interface Biology , The Ohio State University , Columbus , OH , USA.
authors.forename: Amy E
authors.initials: AE
authors.lastname: Lovett-Racke
authors.affiliation: a Department of Microbial Infection and Immunity, Center for Microbial Interface Biology , The Ohio State University , Columbus , OH , USA.|b Davis Heart and Lung Research Institute , The Ohio State University , Columbus , OH , USA.
authors.forename: Larry S
authors.initials: LS
authors.lastname: Schlesinger
authors.affiliation: b Davis Heart and Lung Research Institute , The Ohio State University , Columbus , OH , USA.|c Department of Veterinary Biosciences , The Ohio State University , Columbus , OH , USA.
authors.forename: Estelle
authors.initials: E
authors.lastname: Cormet-Boyaka
authors.affiliation: a Department of Microbial Infection and Immunity, Center for Microbial Interface Biology , The Ohio State University , Columbus , OH , USA.|b Davis Heart and Lung Research Institute , The Ohio State University , Columbus , OH , USA.
authors.forename: Amal O
authors.initials: AO
authors.lastname: Amer
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D000818:Animals; D000070416:Antagomirs / Q000494:pharmacology; D001343:Autophagy / Q000187:drug effects / Q000235:genetics*; D000071183:Autophagy-Related Proteins / Q000378:metabolism; D057508:Burkholderia cenocepacia / Q000502:physiology; D002478:Cells, Cultured; D003550:Cystic Fibrosis / Q000235:genetics* / Q000382:microbiology / Q000473:pathology*; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects; D006720:Homozygote; D008168:Lung / Q000378:metabolism / Q000382:microbiology / Q000473:pathology; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D041681:NIH 3T3 Cells
chemical_list: D020413:3' Untranslated Regions; D000070416:Antagomirs; D000071183:Autophagy-Related Proteins; C575895:MIRN17-92 microRNA, mouse; D035683:MicroRNAs; C093349:cystic fibrosis transmembrane conductance regulator delta F508; D019005:Cystic Fibrosis Transmembrane Conductance Regulator
keywords: Burkholderia cenocepacia; CFTR function; Mirc1/Mir17-92 cluster; autophagy; cystic fibrosis; macrophages