Protection of Ischemic/Traumatic Brain Injruy in SOD-Transgenic Mouse

SOD 转基因小鼠缺血/创伤性脑损伤的保护作用

• 批准号: 06044024
• 负责人: YOSHIMOTO Takashi
• 金额: $ 2.82万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for international Scientific Research
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 无数据
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06044024/
• 关键词: Superoxide; ischemia; trauma; brain edema; SOD; stress protein; c-fos; free radical

Oxygen-derived free radicals have been implicated in the pathogenesis of vasogenic edema and infarction caused by ischemia. Liposome-entrapped CuZn superoxide dismutase (SOD) ameliorated ischemic brain edema and infarction in rats. Although these studies provide potential therapeutic precedents for the management of brain injury, alternative experimental approaches are neede to address the issues of the role of oxygen free radicals and the mode of action of SOD in ischemic brain injury. To investigate directly the increased brain CuZn-SOD in the pathogenesis of brain injuries presumed to involve superoxide radicals, we have used trangenic (Tg) mice carrying the human CuZn-SOD gene.First, We have compared the c-fos protooncogene and 70kDa-heat shock protein (hsp70) mRNA induction between Tg mouse (3.1 fold increased SOD activity) and nonTg mouse following 10min and 60 min of middle cerebral artery (MCA) occlusion. And also we have examined the effect of nitric oxide synthase (NOS) inhib … More itors, L-NAME (neuronal and endothelial NOS inhibitor) and 7-NI (selective neuronal NOS inhibitor) and 7-NI (selective neuronal NOS inhibitor) on brain infarction in both mice, since nitric oxide (NO) has been considered to react with superoxide radicals and form peroxynitrite, a strong oxidant. In 60min ischemia the area of c-fos and hsp70 mRNA induction was significantly attenuated in Tg mice than nonTg mice. However, the prolonged expression of c-fos and hsp70 mRNA was demonstrated in Tg mice compared to nonTg mice after the recircualtion following 10min MCA occlusion. In the NOS inhibitor experiment, L-NAME treated-Tg mice showed significantly bigger infarct volume than saline-treated ones, whereas 7-NI showed the tendency to decrease the infarction in Tg mice. These resuts suggest that SOD could protect brain from severe ischemic insults causing infarction and that the NO generated by neuronal NOS results in the brain injury depending the superoxide content.Secondarily, it was also investigated that the brain edema formation and the induction of hsp70 and c-fos mRNA following traumatic injury using nonTg mice, and heterozygous and homozygous Tg mice (1.5,3.1, and 5.0 fold increased SOD activityies. The water content of injured parietal cortex and Evans Blue dye leakage were attenuated in Tg mice in a SOD dose dependent manner. The areas of hsp70 and c-fos mRNA induction were smaller in Tg mice than in nonTg mice following injury. In chronic stage, the neurological function was significantly improved in Tg mice compared to nonTg mice.Finally, we have measured the electrical resistance through the single layr of the brain endothelial cell culture from Tg and/or nonTg mice following the treatment with superoxide generating agent, menadion, in order to evaluate the effect of superoxide on the BBB permeability. Adversely, the permeability was significantly increased in Tg than nonTg mice. This increase is likely due to the depletion of scavenging system of hydrogen peroxide and forming hydroxyl radical through superoxide-dirven Fenton type Haber-Weise reaction since this increase was antagonized by adding desferroxamine.From these results, the increase of SOD activity could be toxic by generating hydroxyl radicals under the special circumstance although SOD has a strong brain protective effect against the ischemic and traumatic insult in vivo. And it is also suggested that the scavenging system of hydrogen peroxide is essential for SOD to perform the protective effect by eliminating superoxide radicals. Less

氧气衍生的自由是由缺血引起的加血管水肿的发病机理。脱离氧气自由基和Mi C脑损伤的模式。已经比较了C-FOS原季型和70kDa-Heat Shock7 0）TG小鼠（3.1倍增加了SOD活性）和10分钟和60分钟的大脑动脉（MCA）闭塞之间的mRNA指示。氧化物合酶（NOS）抑制RS，L--名称（神经元和基质NOS抑制剂）和7-Ni（选择性）神经元NOS NOS抑制剂）对两只小鼠的脑梗塞中的氧化物（NO），因为具有超氧化物自由基的一氧化氮（NO）在60分钟的氧化剂中，在TG小鼠中，TG小鼠的C-FOS和HSP70 mRNA诱导区域与Nontg小鼠相比，在10分钟MCA闭合后，TG小鼠的氧化剂显着减弱在TG小鼠中显示出明显更大的梗塞体积盐水处理的盐水处理。使用NONTG NONTG小鼠（1.5、3.1和5.0倍增加了SOD活性）创伤性损伤后HSP70和C-FOS mRNA的诱导。在SOD中，TG小鼠在TG小鼠的SOD中减弱了水的皮层和Evans Blue泄漏在慢性阶段，TG小鼠的剂量依赖性方式。 TG和 /或NONTG小鼠的脑培养物的脑培养物在TG中与NONTG小鼠相比，TG的渗透性显着增加。类型的haber-weise反应是通过地址胺固定的。从这些结果中，在特殊情况下，通过产生羟基自由基，使SOD活性增加是有毒的。建议通过消除超氧化物的自由基进行保护效应，使其对SOR SOD进行清除

项目成果

PaK H.Chan: "SOD-1 transgenic mice as a model for studies of Newoprotection in stroke and brain trauma." Annals of the New York Academy of Scinece. 738. 93-103 (1994)

PaK H.Chan：“SOD-1 转基因小鼠作为中风和脑外伤中 Newo 保护研究的模型。”

Hideyuki Kamii: "Expression of c-fos mRNA after a mild focal cerebral ischemia in SOD-1 transgenic mice" Brain Research. 662. 240-244 (1994)

Hideyuki Kamii：“SOD-1 转基因小鼠轻度局灶性脑缺血后 c-fos mRNA 的表达”大脑研究。

Takeo Kondo: "Effect of free radicals on the permeability of the blood brain barrier-Using in vitro blood brain barrier model of human-SOD transgenic mice." Brain and Nerve. 46. 1155-1161 (1994)

Takeo Kondo：“自由基对血脑屏障通透性的影响——使用人SOD转基因小鼠的体外血脑屏障模型。”

Hiroyuki Kinouchi: "Induction of NGFI-A mRNA following middle cerebral artery occlusion in rats:in situ hybridization study." Neuroscience Letters. 171. 163-166 (1994)

Hiroyuki Kinouchi：“大鼠大脑中动脉闭塞后 NGFI-A mRNA 的诱导：原位杂交研究。”

近藤健男: "培養脳血管内皮細胞系における活性酸素種の血液脳関門透過性に対する影響-ヒトSOD遺伝子導入トランスジェニックマウスを用いて-" 脳と神経. 12. 1155-1161 (1994)

Takeo Kondo：“活性氧对培养的脑血管内皮细胞系统中血脑屏障通透性的影响 - 使用人类 SOD 转基因小鼠”《大脑与神经病学》12. 1155-1161 (1994)。