Protein kinase C delta cleavage initiates an aberrant signal transduction pathway after cardiac arrest and oxygen glucose deprivation.
Protein kinase C (PKC) isozymes have been known to mediate a variety of complex and diverse cellular functions. deltaPKC has been implicated in mediating apoptosis. Using two models of cerebral ischemia, cardiac arrest in rats and oxygen glucose deprivation (OGD) in organotypic hippocampal slices, we tested whether an ischemic insult promoted deltaPKC cleavage during the reperfusion and whether the upstream pathway involved release of cytochrome c and caspase 3 cleavage. We showed that cardiac arrest/OGD significantly enhanced deltaPKC translocation and increased its cleavage at 3 h of reperfusion. Since deltaPKC is one of the substrates for caspase 3, we next determined caspase 3 activation after cardiac arrest and OGD. The maximum decrease in levels of procaspase 3 was observed at 3 h of reperfusion after cardiac arrest and OGD. We also determined cytochrome c release, since it is upstream of caspase 3 activation. Cytochrome c in cytosol increased at 1 h of reperfusion after cardiac arrest/OGD. Inhibition of either deltaPKC/caspase 3 during OGD and early reperfusion resulted in neuroprotection in CA1 region of hippocampus. Our results support the deleterious role of deltaPKC in reperfusion injury. We propose that early cytochrome c release and caspase 3 activation promote deltaPKC translocation/cleavage.
Raval
Ami P
AP
Department of Neurology and Neuroscience Program, Cerebral Vascular Disease Research Center, University of Miami School of Medicine, Florida 33101, USA. perezpinzon@miami.edu
Dave
Kunjan R
KR
Prado
Ricardo
R
Katz
Laurence M
LM
Busto
Raul
R
Sick
Thomas J
TJ
Ginsberg
Myron D
MD
Mochly-Rosen
Daria
D
Pérez-Pinzón
Miguel A
MA
D000818:Animals; D001794:Blood Pressure; D002545:Brain Ischemia / Q000378:metabolism* / Q000473:pathology; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D016923:Cell Death / Q000502:physiology; D045304:Cytochromes c / Q000378:metabolism; D004562:Electrocardiography; D005947:Glucose / Q000378:metabolism / Q000494:pharmacology; D006323:Heart Arrest / Q000378:metabolism* / Q000473:pathology; D006624:Hippocampus / Q000201:enzymology / Q000473:pathology; D009410:Nerve Degeneration / Q000378:metabolism* / Q000473:pathology; D009924:Organ Culture Techniques; D010100:Oxygen / Q000378:metabolism / Q000494:pharmacology; D011493:Protein Kinase C / Q000378:metabolism*; D051745:Protein Kinase C-delta; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000502:physiology*
D045304:Cytochromes c; C497260:Prkcd protein, rat; D011493:Protein Kinase C; D051745:Protein Kinase C-delta; C505410:Casp3 protein, rat; D053148:Caspase 3; D020169:Caspases; D005947:Glucose; D010100:Oxygen