| Co-Investigator(Kenkyū-buntansha) |
MASE Mitsuhito Nagoya City University, Graduate School of Medical Sciences, Associate Professor, 大学院・医学研究科, 助教授 (60238920)
UMEMURA Atsushi Nagoya City University, Graduate School of Medical Sciences, Assistant Professor, 大学院・医学研究科, 講師 (00244567)
AIHARA Noritaka Nagoya City University, Graduate School of Medical Sciences, Assistant Professor, 大学院・医学研究科, 講師 (00264739)
YAMADA Kazuo Nagoya City University, Graduate School of Medical Sciences, Professor, 大学院・医学研究科, 教授 (90150341)
ASAI Kiyofumi Nagoya City University, Graduate School of Medical Sciences, Professor, 大学院・医学研究科, 教授 (70212462)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2005: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 2004: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Research Abstract |
MSP(myelencephalic-specific protease) is often found in human brain and spinal white matter, especially in oligodendrocytes, microglias and neurons. Trypsin-like activity leads to the possibility of function related to regeneration of the basement membrane and extracellular matrix, growth of oligodendrocyte, hydolysis of myelin, neural growth and synaptic plasticity. We confirmed expression of MSP mRNA in rat brain using middle cerebral artery occlusion model. In situ hybridization (ISH) of MSP mRNA demonstrated a higher level in the corpus callosum and around the ischemic area from 12h to 14days after MCA reperfusion, with the peak of expression coming 3days after reperfusion in both regions. Immunohistochemically, the expression of protein was found 1day autoradiography, immunostaining and double immunohistochemical labeling revealed the expression of MSP to be located mainly in the oligodendrocytes. Analysis of MSP mRNA after cryogenic injury by ISH revealed a higher level of expres
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sion around the cryogenic area than on the contralateral side at 2-7 days after injury, with peak expression occurring 7days. Immunohistochemical analysis demonstrated expression of MSP protein at 1day after injury, in the area around the lesion. Double immunohistochemical labeling revealed that MSP was expressed mainly in oligodendrocytes. These results suggest that expression of MSP may be related to the turnover of myelin-associated proteins and extracellular matrix proteins after cold injury. We performed quantitative evaluation of white matter damage in diffuse axonal injury (DAI) with silver impregnation method using modified Marmarou's model, which revealed the number of dark axons at the cerebral peduncle increased during the experimental period. There was a significant difference between the number of dark axons 180 days after the injury and 1, 3, 7, 30, or 60 days after the injury. Since this model showed 20% motality rate, we decided to employ DAI model using fluid percussion injury with higher reproducibility and to equip fluid percussion injury machine (Dragonfly) in our laboratory. According to the method by Kita et al., central fluid percussion (maximum positive pressure 1000mg, maximum negative pressure 160mg) is supposed to be delivered through bone window on parietal region of Wister rats, making DAI with histologically confirmation. Unfortunately, we could not elicit the whole result of our project, we are planning to examine the expression of MSP mRNA and protein using this model and to perform transfection of the gene in ventricles with liposome, followed by analysis of the effect of suppression by siRNA. Less
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