Altered iron metabolism in cystic fibrosis macrophages: the impact of CFTR modulators and implications for Pseudomonas aeruginosa survival

Sci Rep. 2020 Jul 2;10(1):10935. doi: 10.1038/s41598-020-67729-5.

Abstract

Cystic fibrosis (CF) is a genetic disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene, resulting in chronic bacterial lung infections and tissue damage. CF macrophages exhibit reduced bacterial killing and increased inflammatory signaling. Iron is elevated in the CF lung and is a critical nutrient for bacteria, including the common CF pathogen Pseudomonas aeruginosa (Pa). While macrophages are a key regulatory component of extracellular iron, iron metabolism has yet to be characterized in human CF macrophages. Secreted and total protein levels were analyzed in non-CF and F508del/F508del CF monocyte derived macrophages (MDMs) with and without clinically approved CFTR modulators ivacaftor/lumacaftor. CF macrophage transferrin receptor 1 (TfR1) was reduced with ivacaftor/lumacaftor treatment. When activated with LPS, CF macrophage expressed reduced ferroportin (Fpn). After the addition of exogenous iron, total iron was elevated in conditioned media from CF MDMs and reduced in conditioned media from ivacaftor/lumacaftor treated CF MDMs. Pa biofilm formation and viability were elevated in conditioned media from CF MDMs and biofilm formation was reduced in the presence of conditioned media from ivacaftor/lumacaftor treated CF MDMs. Defects in iron metabolism observed in this study may inform host-pathogen interactions between CF macrophages and Pa.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aminophenols / pharmacology
  • Aminopyridines / pharmacology
  • Benzodioxoles / pharmacology
  • Biofilms / drug effects
  • Child
  • Culture Media, Conditioned / pharmacology
  • Cystic Fibrosis / metabolism*
  • Cystic Fibrosis Transmembrane Conductance Regulator / drug effects*
  • Cystic Fibrosis Transmembrane Conductance Regulator / genetics
  • Cystic Fibrosis Transmembrane Conductance Regulator / physiology
  • Drug Combinations
  • Female
  • Gene Expression Profiling
  • Host-Pathogen Interactions
  • Humans
  • Iron / metabolism*
  • Iron-Regulatory Proteins / biosynthesis
  • Iron-Regulatory Proteins / genetics
  • Macrophages / metabolism*
  • Male
  • Middle Aged
  • Pseudomonas aeruginosa / physiology*
  • Quinolones / pharmacology
  • Sputum / microbiology

Substances

  • Aminophenols
  • Aminopyridines
  • Benzodioxoles
  • CFTR protein, human
  • Culture Media, Conditioned
  • Drug Combinations
  • Iron-Regulatory Proteins
  • Quinolones
  • lumacaftor, ivacaftor drug combination
  • Cystic Fibrosis Transmembrane Conductance Regulator
  • Iron