Early disturbance of a mitochondrial DNA expression in gerbil hippocampus after transient forebrain ischemia.
The level of mRNA for cytochrome c oxidase subunit I (COX-I), which is encoded by mitochondrial DNA (mtDNA), progressively decreased in the hippocampal CA1 neurons of gerbils from 1-3 h of the reperfusion after 3.5 min of transient forebrain ischemia, and completely disappeared at 7 days. The activity of cytochrome c oxidase (COX) protein also showed the early decrease in the CA1 cells, and was followed by the reduction of the level of COX-I DNA after 2 days. However, the activity of succinic dehydrogenase (SDH), a mitochondrial enzyme that is encoded by nuclear DNA, maintained normal activity until 1 day in the CA1 cells, and significantly decreased at 7 days. These results suggest that the early onset and the progressive disturbance of a mitochondrial DNA expression found selectively in the CA1 neurons could cause progressive failure of energy production of the cells that eventually results in the neuronal cell death.
Department of Neurology, Tohoku University School of Medicine, Sendai, Japan.
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K
Abe
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Kawagoe
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K
Kogure
D000818:Animals; D015152:Blotting, Northern; D015139:Blotting, Southern; D002540:Cerebral Cortex / Q000378:metabolism; D004272:DNA, Mitochondrial / Q000096:biosynthesis*; D003576:Electron Transport Complex IV / Q000096:biosynthesis; D005849:Gerbillinae; D006624:Hippocampus / Q000378:metabolism*; D017403:In Situ Hybridization; D002546:Ischemic Attack, Transient / Q000378:metabolism*; D008297:Male; D012333:RNA, Messenger / Q000096:biosynthesis; D013385:Succinate Dehydrogenase / Q000378:metabolism
D004272:DNA, Mitochondrial; D012333:RNA, Messenger; D013385:Succinate Dehydrogenase; D003576:Electron Transport Complex IV