Increased DNA Damage in Progression Of COPD: A Response By Poly(ADP-Ribose) Polymerase-1

Chronic oxidative stress (OS), a major mechanism of chronic obstructive pulmonary disease (COPD), may cause significant damage to DNA. Poly(ADP-ribose) polymerase (PARP)-1 is rapidly activated by OS-induced DNA lesions. However, the degree of DNA damage along with the evolution of COPD is unclear. In peripheral blood mononuclear cells of non-smoking individuals, non-obstructive smokers, patients with COPD of all stages and those with COPD exacerbation, we evaluated DNA damage, PARP activity and PARP-1 mRNA expression using Comet Assay IV, biotinylated-NAD incorporation assay and qRT-PCR, respectively and subjected results to ordinal logistic regression modelling. Adjusted for demographics, smoking-related parameters and lung function, novel comet parameters, tail length/cell length ratio and tail migration/cell length ratio, showed the greatest increase along the study groups corresponding to the evolution of COPD [odds ratio (OR) 7.88, 95% CI 4.26-14.57; p