Cysteamine re-establishes the clearance of Pseudomonas aeruginosa by macrophages bearing the cystic fibrosis-relevant F508del-CFTR mutation

Cell Death Dis. 2017 Jan 12;8(1):e2544. doi: 10.1038/cddis.2016.476.

Abstract

Cystic fibrosis (CF), the most common lethal monogenic disease in Caucasians, is characterized by recurrent bacterial infections and colonization, mainly by Pseudomonas aeruginosa, resulting in unresolved airway inflammation. CF is caused by mutations in the gene coding for the cystic fibrosis transmembrane conductance regulator (CFTR) protein, which functions as a chloride channel in epithelial cells, macrophages, and other cell types. Impaired bacterial handling by macrophages is a feature of CF airways, although it is still debated how defective CFTR impairs bacterial killing. Recent evidence indicates that a defective autophagy in CF macrophages leads to alterations of bacterial clearance upon infection. Here we use bone marrow-derived macrophages from transgenic mice to provide the genetic proof that defective CFTR compromises both uptake and clearance of internalized Pseudomonas aeruginosa. We demonstrate that the proteostasis regulator cysteamine, which rescues the function of the most common F508del-CFTR mutant and hence reduces lung inflammation in CF patients, can also repair the defects of CF macrophages, thus restoring both bacterial internalization and clearance through a process that involves upregulation of the pro-autophagic protein Beclin 1 and re-establishment of the autophagic pathway. Altogether these results indicate that cysteamine restores the function of several distinct cell types, including that of macrophages, which might contribute to its beneficial effects on CF.

MeSH terms

  • Animals
  • Beclin-1 / biosynthesis
  • Beclin-1 / genetics*
  • Bone Marrow Cells / metabolism
  • Bone Marrow Cells / microbiology
  • Cysteamine / administration & dosage
  • Cystic Fibrosis / drug therapy*
  • Cystic Fibrosis / genetics
  • Cystic Fibrosis / microbiology
  • Cystic Fibrosis Transmembrane Conductance Regulator / genetics*
  • Cystic Fibrosis Transmembrane Conductance Regulator / metabolism
  • Gene Expression Regulation / drug effects
  • Humans
  • Inflammation / drug therapy
  • Inflammation / genetics
  • Inflammation / microbiology
  • Lung / metabolism
  • Lung / pathology
  • Macrophages / drug effects
  • Macrophages / metabolism*
  • Mice
  • Mice, Transgenic
  • Pseudomonas Infections / drug therapy*
  • Pseudomonas Infections / genetics
  • Pseudomonas Infections / microbiology
  • Pseudomonas aeruginosa / drug effects
  • Pseudomonas aeruginosa / pathogenicity

Substances

  • Beclin-1
  • Cystic Fibrosis Transmembrane Conductance Regulator
  • Cysteamine