BID mediates neuronal cell death after oxygen/ glucose deprivation and focal cerebral ischemia

Abstract

Mitochondria and cytochrome c release play a role in the death of neurons and glia after cerebral ischemia. In the present study, we investigated whether BID, a proapoptotic promoter of cytochrome c release and caspase 8 substrate, was expressed in brain, activated after an ischemic insult in vivo and in vitro, and contributed to ischemic cell death. We detected BID in the cytosol of mouse brain and primary cultured mouse neurons and demonstrated, by using recombinant caspase 8, that neuronal BID also is a caspase 8 substrate. After 2 h of oxygen͞glucose deprivation, BID cleavage was detected in neurons concurrent with caspase 8 activation but before caspase 3 cleavage. Bid ؊/؊ neurons were resistant to death after oxygen͞glucose deprivation, and caspase 3 cleavage was significantly reduced; however, caspase 8 cleavage did not differ from wild type. In vivo, BID was cleaved 4 h after transient middle cerebral artery occlusion. Infarct volumes and cytochrome c release also were less in Bid ؊/؊ mice (؊67% and ؊41%, respectively) after mild focal ischemia. These findings suggest that BID and the mitochondrial-amplification pathway promoting caspase activation contributes importantly to neuronal cell death after ischemic insult.

In vivoContributions of BH3-Only Proteins to Neuronal Death Following Seizures, Ischemia, and Traumatic Brain Injury

“…Bid-deficient mice were the first BH3-only protein knockouts to be examined for in vivo neurologic injury phenotypes. Bid À/À mice were found to be normal with regard to brain development (Leonard et al, 2001;Plesnila et al, 2001;Yin et al, 1999Yin et al, , 2002. The impact of Bid deficiency on seizure damage was investigated recently, in genetically modified C57BL/6 mice lacking bid, which were developed by Strasser's group (Kaufmann et al, 2007).…”

Release of Bradykinin and Expression of Kinin B2 Receptors in the Brain: Role for Cell Death and Brain Edema Formation After Focal Cerebral Ischemia in Mice

“…Transient focal cerebral ischemia was performed as previously described (Plesnila et al, 2001b(Plesnila et al, , 2004. Briefly, anesthesia was initialized with 4% halothane, 30% O 2 , and 66% N 2 O and maintained with 1% halothane, 30% O 2 , and 69% N 2 O for the whole duration of surgery (o20 mins).…”

“…Infarct area was quantified on cresyl violet/Nissl-stained 10 mm coronal sections (n ¼ 12) taken at 750 mm intervals using an image analysis system (Optimas 5.1, MediaCybernetics, Carlsbad, CA, USA). Lesion volume was calculated as previously described (Plesnila et al, 2001b;Zweckberger et al, 2003). Data are expressed as percent of contralateral hemisphere to correct for differences in brain size and brain edema.…”

“…Motor function was tested using a five-point score (0 to 4), as previously described (Plesnila et al, 2001b): 0 ¼ normal motor function, 1 ¼ flexion of torso and contralateral forelimb on lifting the animal by the tail or failure to extend the forepaw when suspended vertically, 2 ¼ circling to contralateral side but normal posture at rest, 3 ¼ leaning to contralateral side at rest, and 4 ¼ no spontaneous motor activity.…”

Cellular and Molecular Pathways of Ischemic Neuronal Death

“…Bid, another pro-apoptotic Bcl-2 family, also mediates the caspase-8 dependent-neuronal death after oxygen-glucose deprivation, and focal cerebral ischemia. Also, Bid-/-mice are resistant to ischemic injuries against focal cerebral ischemia (Plesnila et al, 2001).…”