Poly(ADP-ribose) polymerase inhibition prevents both apoptotic-like delayed neuronal death and necrosis after H(2)O(2) injury.
J Neurochem. 2002 Jul; 82(1):19-29.JN

Abstract

Toxic reactive oxygen species (ROS) such as hydrogen peroxide, nitric oxide, superoxide, and the hydroxyl radical are generated in a variety of neuropathological conditions and cause significant DNA damage. We determined the effects of 3-aminobenzamide (AB), an inhibitor of the DNA repair enzyme poly(ADP-ribose) polymerase (PARP), on cell death in differentiated PC12 cells, a model of sympathetic neurons, after H(2) O(2) injury. Exposure to 0.5 mm H(2) O(2) resulted in a significant decrease in intracellular NAD(H), NADP(H), and ATP levels. This injury resulted in the death of 90% of the cells with significant necrosis early (2 h) after injury and increased apoptosis (12-24 h after injury), as measured by PS exposure and the presence of cytoplasmic oligonucleosomal fragments. Treatment with 2.5 mm AB restored pyridine nucleotide and ATP levels and ameliorated cell death (65% versus 90%) by decreasing the extent of both necrosis and apoptosis. Interestingly, we observed that H(2) O(2) -induced injury caused a delayed cell death exhibiting features of apoptosis but in which caspase-3 like activity was absent. Moreover, pretreatment with AB restored caspase-3-like activity. Our results suggest that apoptosis and necrosis are both triggered by PARP overactivation, and that maintenance of cellular energy levels after injury by inhibiting PARP shifts cell death from necrosis to apoptosis.

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Authors+Show Affiliations

Cole KK
Department of Anatomy and Neurosciences, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555-0652, USA.
Perez-Polo JR
No affiliation info available

MeSH

Adenosine TriphosphateAnimalsApoptosisBenzamidesCaspase 3CaspasesCell DeathCell SurvivalDNA FragmentationDose-Response Relationship, DrugEnzyme InhibitorsHydrogen PeroxideNADNADPNecrosisNeuronsNeuroprotective AgentsPC12 CellsPoly Adenosine Diphosphate RibosePoly(ADP-ribose) Polymerase InhibitorsPoly(ADP-ribose) PolymerasesRats

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

12091461