Effects of hypothermia and cerebral ischemia on cold-inducible RNA-binding protein mRNA expression in rat brain.
CIRP (cold-inducible RNA-binding protein) mRNA is highly expressed in hypothermic conditions in mammalian cells, and the relationship between CIRP and neuroprotection for cerebral ischemia under hypothermia has been focused upon. At present, however, the expression characteristics of CIRP under hypothermia and cerebral ischemia in vivo are not clearly elucidated. In this study, CIRP mRNA expression in various regions of rat brain was examined by reverse transcriptase polymerase chain reaction (RT-PCR). CIRP expression levels were found to be similar in the hippocampus and cortex. Real-time quantitative PCR analysis revealed increasing CIRP mRNA expression in the cortex during the 24-h observation period following treatment with hypothermia or cerebral ischemia, with a greater increase in the hypothermia group. When cerebral ischemia was induced following hypothermia, CIRP mRNA expression in the cortex again showed a significant increasing tendency, but ischemia delayed the appearance of this increase. To reveal the relationship between CIRP and energy metabolism in the rat brain, lactate and pyruvate concentrations in the cortex of the rats treated with hypothermia, ischemia and ischemia after hypothermia were determined by spectrophotometric assay, and levels of phosphofructokinas-1 (PFK-1), the major regulatory enzyme of the glycolytic pathway, in the rat cortex in the three groups was also analyzed by Western blot. Using linear correlation, lactate and pyruvate concentrations, and PFK-1 levels, were each analyzed in the three groups in association with CIRP mRNA expression levels. The analysis did not reveal any correlation between the three metabolic parameters and CIRP mRNA expression induced by hypothermia, suggesting that while playing a role in neuroprotection under hypothermia, CIRP does not affect cerebral energy metabolism.
Liu
Aijun
A
Department of Neurosurgery, The First Affiliated Hospital of PLA General Hospital, Beijing, China. liuaj719@yahoo.com
Zhang
Zhiwen
Z
Li
Anmin
A
Xue
Jinghui
J
D000704:Analysis of Variance; D000818:Animals; D001921:Brain / Q000378:metabolism*; D003080:Cold Temperature; D004195:Disease Models, Animal; D004734:Energy Metabolism / Q000502:physiology; D005786:Gene Expression Regulation / Q000502:physiology*; D007035:Hypothermia / Q000473:pathology*; D020925:Hypoxia-Ischemia, Brain / Q000473:pathology*; D019344:Lactic Acid / Q000378:metabolism; D008297:Male; D010732:Phosphofructokinase-1 / Q000378:metabolism; D019289:Pyruvic Acid / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013223:Statistics as Topic
D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D019344:Lactic Acid; D019289:Pyruvic Acid; D010732:Phosphofructokinase-1