p53-independent transient p21(WAF1/CIP1) mRNA induction in the rat brain following experimental traumatic injury.
The expression of the cyclin-dependent kinase inhibitor p21(WAF1/CIP1) mRNA after traumatic brain injury in rats was investigated using an in situ hybridization technique, along with regulating gene p53 and stress response gene hsp70 mRNA levels. At 3 h postinjury, p21(WAF1/CIP1) mRNA was markedly increased in the cortex, white matter, thalamus, CA2, a part of CA1,3 and dentate gyrus of the injured side. Hybridization signals remained elevated at 6 h in injured cortex and hippocampus and returned to the baseline by 24 h post-insult. On the other hand, p53 mRNA induction was not observed in any brain sections throughout the post-injury time course. Slight expression of hsp70 mRNA was detected in the injured cortex 3-6 h following injury and this was similar to the temporary pattern of p21(WAF1/CIP1) mRNA expression. This study showed p21(WAF1/CIP1) mRNA to be transiently induced after traumatic brain injury, independent of p53, this possibly being an early stress response to protect cells by arresting them in the cycle and allow DNA repair.
Department of Neurosurgery, Nagoya City University Medical School, Nagoya, Japan.
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H
Katano
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Masago
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H
Taki
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Nakatsuka
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Fuse
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Yamada
D000818:Animals; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D001930:Brain Injuries / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D050759:Cyclin-Dependent Kinase Inhibitor p21; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors; D016213:Cyclins / Q000235:genetics*; D004791:Enzyme Inhibitors / Q000378:metabolism; D007839:Functional Laterality; D005786:Gene Expression Regulation; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics; D008297:Male; D009928:Organ Specificity; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D014158:Transcription, Genetic; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
C493958:Cdkn1a protein, rat; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D004791:Enzyme Inhibitors; D018840:HSP70 Heat-Shock Proteins; D012333:RNA, Messenger; D016159:Tumor Suppressor Protein p53; D018844:Cyclin-Dependent Kinases