title: Mitochondrial DNA copy number and oxidative DNA damage in placental tissues from gestational diabetes and control pregnancies: a pilot study.
abstract: BACKGROUND
  Available evidence supports the role of reactive oxygen species in the pathogenesis of placental insufficiency, gestational diabetes mellitus (GDM), and other pregnancy complications. Abnormal placental mitochondrial function resulting from reactive oxygen species may also be an important precedent of adverse perinatal outcomes.
  
  
  METHODS
  We investigated the association of placental oxidative stress with placental mitochondrial DNA (mtDNA) copy number, an indicator of placental mitochondrial density and possible mitochondrial dysfunction, using samples collected from GDM cases and controls. 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker of oxidative DNA damage, was measured in placentas of 19 GDM cases and 21 controls using a competitive immunoassay. Placental mtDNA copy number was determined using real-time quantitative PCR. Bivariate and multivariable linear regression procedures were used to evaluate associations of these two biomarkers.
  
  
  RESULTS
  Placental DNA oxidation was positively associated with mtDNA copy number in both GDM and control placentas. After adjusting for maternal age, pre-pregnancy body mass index and gestational age at delivery, mtDNA copy number increased (beta = 67.0; 95% CI 27.8 - 106.2, p = 0.001) for every 0.1 ng/microg increase of placental 8-OHdG among GDM cases and controls.
  
  
  CONCLUSIONS
  These cross sectional data suggest an association of placental mtDNA copy number with oxidative stress. The consequences of placental oxidative stress and mitochondrial dysfunction on the course and outcomes of pregnancy remain to be elucidated in larger prospective studies.
authors.affiliation: Center for Perinatal Studies, Swedish Medical Center, Seattle Washington 98104, USA. Chun-fang.Qiu@Swedish.org
authors.forename: Chunfang
authors.initials: C
authors.lastname: Qiu
authors.forename: Karin
authors.initials: K
authors.lastname: Hevner
authors.forename: Dejene
authors.initials: D
authors.lastname: Abetew
authors.forename: Margaret
authors.initials: M
authors.lastname: Sedensky
authors.forename: Philip
authors.initials: P
authors.lastname: Morgan
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Enquobahrie
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Williams
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D004249:DNA Damage; D004272:DNA, Mitochondrial / Q000235:genetics*; D016640:Diabetes, Gestational / Q000235:genetics* / Q000473:pathology; D005260:Female; D018628:Gene Dosage; D006801:Humans; D016014:Linear Models; D010084:Oxidation-Reduction; D010865:Pilot Projects; D010920:Placenta / Q000378:metabolism* / Q000473:pathology; D011247:Pregnancy
chemical_list: D004272:DNA, Mitochondrial