Mitochondrial impairment induced by poly(ADP-ribose) polymerase-1 activation in cortical neurons after oxygen and glucose deprivation.
Neuronal cells injured by ischemia and reperfusion to a certain extent are committed to death in necrotic or apoptotic form. Necrosis is induced by gross ATP depletion or 'energy crisis' of the cell, whereas apoptosis is induced by a mechanism still to be defined in detail. Here, we investigated this mechanism by focusing on a DNA damage-sensor, poly(ADP-ribose) polymerase-1 (PARP-1). A 2-h oxygen and glucose deprivation (OGD) followed by reoxygenation (Reox) induced apoptosis, rather than necrosis, in rat cortical neurons. During the Reox, PARP-1 was much activated and autopoly(ADP-ribosyl)ated, consuming the substrate, NAD+. Induction of apoptosis by OGD/Reox was suppressed by overexpression of Bcl-2, indicating mitochondrial impairment in this induction process. Mitochondrial permeability transition (MPT), or membrane depolarization, and a release of proapoptotic proteins, i.e. cytochrome c, apoptosis-inducing factor and endonuclease G, from mitochondria were observed during the Reox. These apoptotic changes of mitochondria and the nucleus were attenuated by PARP-1 inhibitors, 1,5-dihydroxyisoquinoline and benzamide, and also by small interfering RNA specific for PARP-1. These results indicated that PARP-1 plays a principal role in inducing mitochondrial impairment that ultimately leads to apoptosis of neurons after cerebral ischemia.
Tanaka
Seigo
S
Laboratory of Molecular Clinical Chemistry, Institute for Chemical Research, Kyoto University, Uji, Kyoto, Japan. seigo@scl.kyoto-u.ac.jp
Takehashi
Masanori
M
Iida
Shinya
S
Kitajima
Takashi
T
Kamanaka
Yoshihisa
Y
Stedeford
Todd
T
Banasik
Marek
M
Ueda
Kunihiro
K
D036002:ADP Ribose Transferases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000187:drug effects / Q000201:enzymology* / Q000503:physiopathology; D004594:Electrophysiology; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005947:Glucose / Q000172:deficiency*; D000860:Hypoxia / Q000503:physiopathology*; D007425:Intracellular Membranes / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D009243:NAD / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000201:enzymology*; D010100:Oxygen / Q000494:pharmacology; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D034741:RNA, Small Interfering / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar
D004791:Enzyme Inhibitors; D024101:Mitochondrial Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D034741:RNA, Small Interfering; D009243:NAD; D036002:ADP Ribose Transferases; C499322:Parp1 protein, rat; D000071137:Poly (ADP-Ribose) Polymerase-1; D011065:Poly(ADP-ribose) Polymerases; D005947:Glucose; D010100:Oxygen