The origin of DNA associated with mucus glycoproteins in cystic fibrosis sputum

Abstract

The relative importance of host and bacteria-derived deoxyribonucleic acid (DNA) in the increased viscoelasticity of purulent sputum in cystic fibrosis (CF) and other airway diseases is unclear. We report the identification of the DNA associated with mucus glycoproteins purified from the purulent sputum of 9 patients with CF. Mucus glycoproteins were purified from CF sputum by gel exclusion chromatography and the co-purifying DNA isolated by phenol extraction. Electrophoresis indicated that the DNA preparations had a size of approximately 300 to greater than 50,000 bases. The origin of the DNA was determined by slot blotting and subsequent hybridization with 32P-labelled DNA probes specific for human DNA sequences and those from bacterial species commonly isolated from CF sputum. The results indicated that in all cases the DNA was almost entirely human in origin. This implies that it is the patient's own DNA which may contribute to the rheological abnormalities of CF sputum.

Engineering in vitro models of cystic fibrosis lung disease using neutrophil extracellular trap inspired biomaterials

“…40,41 Other extracellular DNA sources may include that from necrotic host cells, especially neutrophils, not undergoing NETosis. 27…”

“…The final concentration of sNET was based upon reported concentrations of extracellular DNA in CF sputum samples, which span a wide range of up to B10 mg ml À1 but average around 3 mg ml À1 . 27,28,[37][38][39] In contrast, one study reported healthy human mucus contains an average extracellular DNA concentration of 0.006 AE 0.003 mg ml À1 . 37 Previous studies have found that approximately 50% of the measured extracellular DNA in CF sputum is in complexation with proteins indicating the formation of NETs.…”

“…26 Though sputum samples expectorated by individuals with CF contain NETs, NET and extracellular DNA concentration can vary substantially from patient to patient. 27,28 HAE cells derived from CF donors produce minimal extracellular DNA and are unable to produce NETs without co-culture and stimulation of neutrophils. 18,29 To overcome these limitations, we developed a new approach to model the alterations to mucus in CF and recapitulate the impacts of NETs on disease pathogenesis.…”

“…26 Though sputum samples expectorated by individuals with CF contain NETs, NET and extracellular DNA concentration can vary substantially from patient to patient. 27,28 HAE cells derived from CF donors produce minimal extracellular DNA and are unable to produce NETs without co-culture and stimulation of neutrophils. 18,29…”

Hybrid inhalable microparticles for dual controlled release of levofloxacin and DNase: physicochemical characterization and in vivo targeted delivery to the lungs

“…4 The capability of P. aeruginosa to mutate into a mucoid-type strain with enhanced production of exopolysaccharide alginate, combined with high amounts of DNA from cell lysis, generates a strong bacterial biofilm niche where the bacteria can grow protected from the environment. 5 All these elements contribute to the deterioration of lung functions in CF patients, causing airway obstruction and drastically worsen the patient's health. In this context, an early treatment of the pulmonary manifestations as well as effective antibiotic therapies is desirable to increase the life expectancy and quality of patients.…”