title: Lack of association between increased mitochondrial DNA4977deletion and ATP levels of sputum cells from chronic obstructive pulmonary disease patients versus healthy smokers.
abstract: In this study we looked at smokers with and without chronic obstructive pulmonary disease (COPD) patients in order to evaluate the incidence of 4977 base pair (bp) mtDNA (mtDNA4977) deletion and mtDNA copy number in sputum cells and in peripheral blood leukocytes (PBLs) in relation to mitochondrial function and oxidative stress status. Twenty-five COPD patients who were current smokers, 22 smokers and 23 healthy nonsmokers (for only PBLs studies) participated in this study. The 4977-bp deletion was detected in all examined samples within 40 cyles of PCR amplification, using a quantitative real time PCR. The frequency of the mtDNA4977was significantly higher in the sputum cells of patients with COPD compared to smokers without COPD (p < 0.0001). This difference was not observed in PBLs. Levels of cellular oxidative stress were significantly higher in the sputum cells of subjects with COPD than in the smoker group. However, mtDNA copy number, mitochondrial membrane potential (ΔΨm) and cellular ATP levels in PBLs and sputum cells were not significantly different between the studied groups. The Pearson analysis revealed no correlations between the accumulation of mtDNA4977, and intracellular ATP content and ΔΨm values of the sputum cells, although there was a positive correlation between the increase in the percentage of deleted mtDNA4977and the levels of cellular oxidative stress in COPD patients (r = 0.80, p < 0.0001). Our studies may suggest that the accumulation of mtDNA4977in the sputum cells of smokers with COPD does not seem to have an important impact on mitochondrial dysfunction in relation to ATP production and ΔΨm when compared to those of healthy smokers.
authors.affiliation: a Department of Medical Biology and Genetics, Cerrahpasa Faculty of Medicine , Istanbul University , Istanbul , Turkey.
authors.forename: A
authors.initials: A
authors.lastname: Karimova
authors.affiliation: b Department of Nutrition and Dietetics, Health Sciences Faculty , Biruni University , Istanbul , Turkey.
authors.forename: Y M
authors.initials: YM
authors.lastname: Oltulu
authors.affiliation: c Department of Medical Genetics, School of Medicine , Istanbul Medipol University , Istanbul , Turkey.
authors.forename: H
authors.initials: H
authors.lastname: Azaklı
authors.affiliation: d Department of Genetics, School of Medicine , Mugla University , Mugla , Turkey.
authors.forename: M
authors.initials: M
authors.lastname: Kara
authors.affiliation: c Department of Medical Genetics, School of Medicine , Istanbul Medipol University , Istanbul , Turkey.
authors.forename: D
authors.initials: D
authors.lastname: Ustek
authors.affiliation: e Department of Pneumology, Cerrahpasa Faculty of Medicine , Istanbul University , Istanbul , Turkey.
authors.forename: B
authors.initials: B
authors.lastname: Tutluoglu
authors.affiliation: a Department of Medical Biology and Genetics, Cerrahpasa Faculty of Medicine , Istanbul University , Istanbul , Turkey.
authors.forename: I
authors.initials: I
authors.lastname: Onaran
mesh_terms: D000255:Adenosine Triphosphate / Q000032:analysis*; D000073865:Cigarette Smoking; D005260:Female; D054629:Genome, Mitochondrial; D006801:Humans; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000235:genetics* / Q000378:metabolism; D017384:Sequence Deletion; D000074285:Smokers; D013183:Sputum / Q000737:chemistry* / Q000378:metabolism
chemical_list: D000255:Adenosine Triphosphate
keywords: ATP; COPD; common mutation; mitochondrial DNA; smoking; sputum