Mitochondrial DNA damage and altered membrane potential (ΔΨ) in pancreatic acinar cells induced by reactive oxygen species

Richard A. Ehlers, Ambrosio Hernandez, L. Scott Bloemendal, Richard T. Ethridge, Buckminster Farrow, B. Mark Evers

Research output: Contribution to journalArticlepeer-review

40 Scopus citations

Abstract

Background. Reactive oxygen species (ROS) have been implicated in the induction of acute pancreatitis. Mitochondria possess a distinct genome (mtDNA) that is more susceptible to ROS-induced damage than nuclear DNA (nDNA). The purpose of our study was to determine the effect of ROS on mitochondrial function and membrane potential (ΔΨ(mt)), to identify signal transduction mechanisms activated by ROS, and to quantify damage to mtDNA in an in vitro pancreatitis model. Methods. Pancreatic acinar cells, AR4-2J, were treated with saline solution (control) or hydrogen peroxide (H2O2), a representative ROS. Mitochondrial function was assessed with the 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay; to determine ΔΨ (mt), rhodamine-123 uptake was measured. Intracellular calcium levels and c-Jun N-terminal kinase activity was determined; gel mobility shift assays were performed to assess induction of the transcription factor NF- κB. To quantitate DNA damage, a novel polymerase chain reaction-based procedure was performed. Results. Mitochondrial function and ΔΨ(mt) were significantly decreased with oxidative damage. H2O2 treatment resulted in increased intracellular calcium levels, activation of c-Jun N-terminal kinase, and induction of NF-κB DNA binding. Treatment of AR4-2J cells with H2O2 resulted in selective mtDNA damage; nDNA was not affected. Conclusions. Our data demonstrate that pancreatic mtDNA is more susceptible to oxidative damage than nDNA; this damage is associated with decreases in mitochondrial function and ΔΨ(mt) and activation of downstream signal transduction pathways. Mitochondrial damage mediated by ROS may play a central role in pancreatic cell injury associated with acute pancreatitis.

Original languageEnglish
Pages (from-to)148-155
Number of pages8
JournalSurgery
Volume126
Issue number2
DOIs
StatePublished - 1999

Bibliographical note

Funding Information:
Supported by grants from the National Institutes of Health (R01 DK48498, R01 AG10885, P01 DK35608 and T32 DK07639). R.A.E. is the recipient of an NIH Fellowship Award (F32 CA79187) and a Jeane B. Kempner Scholar Award.

ASJC Scopus subject areas

  • Surgery

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