title: Mitochondrial activation in the growth-restricted fetus of monochorionic twins.
abstract: OBJECTIVE
  To study the regulatory mechanisms of selective intrauterine growth restriction (sIUGR) independent of confounding genetic factors, monochorionic (MC) twins are the ideal model, because they have identical genomic DNA. We hypothesize that the intrauterine growth restriction fetus has mitochondrial activation compared with its larger counterpart, and sought to demonstrate this using the MC twin model.
  
  
  METHODS
  Fetal cord blood and amniotic fluid of MC twins were prospectively collected during delivery. Mitochondrial DNA of cord blood was measured using real-time quantitative polymerase chain reaction (PCR), and mitochondria in amniotic fluid mesenchymal stem cells (AFMSCs) were analyzed with MitoTracker staining.
  
  
  METHODS
  Tertiary referring center.
  
  
  METHODS
  Forty-three pairs of MC twins, including 24 pairs with sIUGR and 19 pairs without.
  
  
  METHODS
  None.
  
  
  METHODS
  Mitochondrial DNA contents were measured and presented as fold difference between the small and large fetuses. After staining with MitoTracker, mitochondrial intensity in AFMSCs was analyzed with the Image J program.
  
  
  RESULTS
  The fold differences of the cord blood mitochondrial DNA content between the small and large twins were significantly higher in the MC twins with sIGUR (2.5 ± 1.2, n = 24 pairs) than in those without sIUGR (1.2 ± 0.3, n = 19 pairs). In addition, mitochondrial staining intensities were significantly higher in the AFMSCs derived from growth-restricted fetuses than from control fetuses.
  
  
  CONCLUSIONS
  Mitochondrial activation in the sIUGR fetus of MC twins was likely regulated by locally adverse placental and blood flow conditions, instead of genetic factors.
authors.affiliation: Department of Obstetrics and Gynecology, Chang Gung Memorial Hospital, Linkou and Chang Gung University, College of Medicine, Taoyuan, Taiwan.
authors.forename: Yao-Lung
authors.initials: YL
authors.lastname: Chang
authors.forename: Chao-Nin
authors.initials: CN
authors.lastname: Wang
authors.forename: Pei-Cih
authors.initials: PC
authors.lastname: Wei
authors.forename: Hsiu-Huei
authors.initials: HH
authors.lastname: Peng
authors.forename: An-Shine
authors.initials: AS
authors.lastname: Chao
authors.forename: Shuenn-Dyh
authors.initials: SD
authors.lastname: Chang
authors.forename: Po-Jen
authors.initials: PJ
authors.lastname: Cheng
authors.forename: Tzu-Hao
authors.initials: TH
authors.lastname: Wang
mesh_terms: D000328:Adult; D002478:Cells, Cultured; D004272:DNA, Mitochondrial / Q000378:metabolism*; D005260:Female; D005312:Fetal Blood / Q000378:metabolism; D005317:Fetal Growth Retardation / Q000175:diagnosis / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D011247:Pregnancy; D011446:Prospective Studies; D014430:Twins, Monozygotic / Q000235:genetics*
chemical_list: D004272:DNA, Mitochondrial