Inhibition of PARP prevents oxidant-induced necrosis but not apoptosis in LLC-PK1 cells

Dragana M. Filipovic, Xianmin Meng, W. Brian Reeves

Research output: Contribution to journalArticle

66 Scopus citations

Abstract

Oxidant-induced cell injury has been implicated in the pathogenesis of several forms of acute renal failure. The present studies examined whether activation of poly(ADP-ribose)polymerase (PARP) by oxidant-induced DNA damage contributes to oxidant injury of renal epithelial cells. H2O2 exposure resulted in an increase in PARP activity and decreases in cell ATP and NAD content. These changes were significantly inhibited by 10 mM 3-aminobenzamide (3-ABA), a PARP inhibitor. In contrast, H2O2-induced DNA damage was not prevented by 3-ABA. Exposure of LLC-PK1 cells to 1 mM H2O2 for 2 h induced necrotic cell death as measured by increased lactate dehydrogenase (LDH) release; 3-ABA completely prevented the H2O2-induced LDH release. Live/dead fluorescent staining confirmed the protection by 3-ABA. These results are consistent with the view that oxidant-induced DNA damage activates PARP and that the subsequent ATP and NAD depletion contribute to necrotic cell death. Of note, although protected from necrosis, cells treated with H2O2 and 3- ABA underwent apoptosis as evidenced by DNA fragmentation and bis-benzimide staining. In conclusion, activation of PARP contributes to oxidant-induced ATP depletion and necrosis in LLC-PK1 cells. However, PARP inhibition may target cells toward an apoptotic form of cell death.

Original languageEnglish (US)
Pages (from-to)F428-F436
JournalAmerican Journal of Physiology - Renal Physiology
Volume277
Issue number3 46-3
DOIs
StatePublished - Sep 1999
Externally publishedYes

Keywords

  • 3- aminobenzamide
  • Adenosine 5'-triphosphate
  • Deoxyribonuclease damage
  • Oxidant injury
  • Poly(adenosine 5'-diphosphate-ribose)polymerase

ASJC Scopus subject areas

  • Physiology
  • Urology

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