Mitochondrial DNA damage analysis in bronchoalveolar lavage cells of preterm infants.
In mechanically ventilated preterm infants, the combination of immaturity, volutrauma, oxidative stress, and inflammatory processes can lead to chronic lung injury. Mitochondrial DNA (mtDNA) is more susceptible to oxidative damage than nuclear DNA. We aimed to investigate the level of mtDNA damage (deletions, mutations and changes in copy number) in bronchoalveolar lavage (BAL) cells from 10 preterm infants (27-30 weeks). A first BAL (BAL1) was done within 24 h of endotracheal intubation and BAL2 was performed 30-103 h thereafter. Deletions were analyzed by long range PCR, point mutations by heteroduplex analysis of the D-loop region, and copy number changes by real-time PCR. Using these methods, no deletions were found in any of the BAL samples. When BAL1 and BAL2 samples were compared no new mutations were found. In contrast, a marked decrease in mtDNA copy number was observed in 5 patients. In conclusion, we found that exposure of preterm infants to short term mechanical ventilation did not lead to detrimental consequences for the mtDNA in the form of mutations or deletions.
Zoer
Bea
B
Department of Pediatrics Maastricht University Medical Center, GROW School for Oncology and Developmental Biology, 6202 AZ Maastricht, The Netherlands.
Been
Jasper Valentijn
JV
Jongen
Eveline
E
Debeer
Anne
A
Hendrickx
Alexandra
A
Smeets
Hubertus J
HJ
Zimmermann
Luc Jacques
LJ
Villamor
Eduardo
E
D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology*; D056915:DNA Copy Number Variations / Q000235:genetics; D004249:DNA Damage / Q000235:genetics*; D004252:DNA Mutational Analysis; D017931:DNA Primers / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics*; D006801:Humans; D007231:Infant, Newborn; D009426:Netherlands; D047928:Premature Birth / Q000235:genetics*; D012121:Respiration, Artificial / Q000009:adverse effects*
D017931:DNA Primers; D004272:DNA, Mitochondrial