Salivary Extracellular DNA and DNase Activity in Periodontitis

Abstract

Extracellular DNA (ecDNA) is a potential marker and predictor in several inflammatory diseases. Periodontitis, a chronic inflammatory disease, is associated with epithelial cell death and could lead to release of DNA. Our aim was to analyze salivary DNA concentration and deoxyribonuclease (DNase) activity in periodontitis patients. We hypothesized that salivary ecDNA will be higher than in controls and could serve as a marker of periodontitis severity. Samples of saliva were collected from 25 patients with chronic periodontitis and 29 age-matched controls. DNA was quantified fluorometrically in whole saliva, as well as in supernatants after centrifugation (depletion of cells at 1600× g) and in double-centrifuged supernatants (depletion of cell debris at 1600× g and 16,000× g). The subcellular origin of ecDNA was assessed using real-time PCR. In comparison to controls, patients with periodontitis had twofold higher salivary DNA (p < 0.01), higher mitochondrial DNA in centrifuged supernatants (p < 0.05) and lower nuclear ecDNA in double-centrifuged samples (p < 0.05). No correlations were found between salivary DNA and oral health status, but mitochondrial DNA positively correlated with papillary bleeding index in centrifuged samples. Salivary DNase activity was comparable between the groups. In conclusion, we proved that salivary DNA is higher in periodontitis. The source of the higher mitochondrial DNA in cell-free saliva and the causes of lower nuclear ecDNA remain to be elucidated. Further studies should focus on the role of mitochondrial DNA as a potential driver of inflammation in periodontitis.

Shielding of Viruses such as SARS-CoV-2 from Ultraviolet Radiation in Particles Generated by Sneezing or Coughing: Numerical Simulations of Survival Fractions

“…In using calculated S p to improve the use of UVGI in reducing the transmission of disease, a sense of the ranges of measured concentrations of UV-absorbing molecules such as nucleic acids can be beneficial. Konec̆ná et al (2020) reported average dsDNA concentrations in whole saliva of 0.24 g/l in healthy subjects and 0.5 g/L in persons with periodontitis. However, in the supernatants from centrifuged (1600× g ) samples they measured average concentrations of DNA of 0.054 g/l in healthy subjects and 0.07 g/l in persons with periodontitis.…”

Impact of Circulating Cell-Free DNA (cfDNA) as a Biomarker of the Development and Evolution of Periodontitis

“…DNases are a group of enzymes that hydrolyze cfDNA, allowing its removal from the body fluids. It could be possible that the incorrect functioning of the salivary DNases is another reason why the cfDNA level increases in periodontitis [ 79 ]. It was seen that periodontal bacteria could influence the activities of DNases [ 80 ].…”

“…This study did not show differences in the activity of DNases between patients affected by periodontitis and healthy patients. These results could be linked to the fact that the samplings were frozen and stored [ 79 ]. Therefore, it is not yet clear whether there is a correlation with cfDNA concentration.…”

“…Konečná et al [ 79 ] studied the salivary cfDNA concentration in 25 periodontopathic and 29 healthy patients. The results of this study showed that the total salivary cfDNA level in patients with periodontitis was higher than in healthy patients.…”

Shielding of viruses such as SARS-Cov-2 from ultraviolet radiation in particles generated by sneezing or coughing: Numerical simulations of survival fractions

“…In using calculated S p to improve the use of UVGI in reducing the transmission of disease, a sense of the ranges of measured concentrations of UV-absorbing molecules such as nucleic acids can be beneficial. Konec n et al (2020) reported average dsDNA concentrations in whole saliva of 0.24 g/l in healthy subjects and 0.5 g/L in persons with periodontitis. In supernatants from centrifuged (1600× g) samples they measured average concentrations of DNA of 0.054 g/l in healthy subjects and 0.07 g/l in persons with periodontitis.…”