Apoptosis-inducing factor triggered by poly(ADP-ribose) polymerase and Bid mediates neuronal cell death after oxygen-glucose deprivation and focal cerebral ischemia

• Delayed neuronal cell death occurring hours after reperfusion is a hallmark of ischemic stroke and a primary target for neuroprotective strategies. In the present study, we investigated whether apoptosis-inducing factor (AIF), a caspase-independent proapoptotic protein, is responsible for neuronal cell death after glutamate toxicity and oxygen-glucose deprivation (OGD) in vitro and after experimental stroke in vivo. AIF translocated to the nucleus in which it colocalized with DNA fragmentation and nuclear apoptotic morphology after exposure to glutamate or OGD in cultured neurons or after transient middle cerebral artery occlusion (MCAo) in mice. Small inhibitory RNA-mediated downregulation of AIF reduced glutamate- and OGD-induced neuronal apoptosis by 37 and 60%, respectively (p < 0.01). Moreover, Harlequin mutant mice, which express AIF at low levels (approximately 20% of wild-type mice), displayed smaller infarct volumes (-43%; p < 0.03) and showed dramatically reduced cell death in the ischemic penumbra after 45 min of MCAo compared with wild-type littermates. Inhibition of poly(ADP-ribose) polymerase and Bid reduced nuclear AIF translocation. These results provide the first evidence for a causal role of AIF in ischemic neuronal cell death. Therefore, caspase-independent cell death signaling may provide a promising novel target for therapeutic interventions in cerebrovascular diseases.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Fysiologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Physiology (hsv//eng)

Nyckelord

Animals

Apoptosis/*physiology

Apoptosis Inducing Factor/genetics/*physiology

BH3 Interacting Domain Death Agonist Protein/genetics/*physiology

Brain Ischemia/enzymology/genetics/*metabolism/*pathology

Cell Death/physiology

Cell Line

Transformed

Cells

Cultured

Comparative Study

Energy Metabolism/genetics

Glucose/*metabolism

Male

Mice

Mice

Inbred C57BL

Mice

Mutant Strains

Neurons/enzymology/metabolism/pathology

Oxygen/*metabolism

Poly(ADP-ribose) Polymerases/genetics/*physiology

Rats

Research Support

Non-U.S. Gov't

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)