Study on development of drugs for cerebral nerve by new approach

新途径开发脑神经药物的研究

基本信息

批准号：
15590072
负责人：
TAKAHASHI Noriko
金额：
$ 2.11万
依托单位：
Hoshi University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

项目摘要

Acetoacetyl-CoA(AA-CoA) synthetase (acetoacetyl-CoA ligase, EC 6.2.1.16) is a novel cytosolic acetoacetate-activating enzyme pulified as the acetoacetyl-specific ligase. In mammals, AA-CoA synthetase is present in liver, brain, adipose tissues and other various tissues, and this enzyme was highly expressed in rat and human brain. In the liver, AA-CoA synthetase is considered to be related cholesterol biosynthesis and fatty acid synthesis. However, except in the liver, the physiological role of AA-CoA synthetase is not clear yet. In order to clarify the physiological role of AA-CoA synthetase in the brain, (1)distribution of AA-CoA synthetase protein and mRNA in various regions of rat brain, (2)localization of AA-CoA synthetase mRNA in the brain by in situ hybridization, (3)comparison between AA-CoA synthetase mRNA distribution and other lipid synthesis enzymes' in the brain, and (4)effect of streptozotocin(STZ)-induced diabetes on the AA-CoA synthetase and various enzymes. First, AA-Co … More A synthetase mRNA and protein were widely expressed in rat brain, and these expression were particularly high in pons, medulla oblongata, midbrain, cerebral cortex and hypothalamus. Furthermore, the localization of AA-CoA synthetase mRNA in rat brain slices was found to be especially high in cerebellum white matter, hippocampus cornu ammonis and dentate gyrus. In the cerebral cortex including hippocampus, the hybridization signals are apt to express in neurocyte. The expression of the enzyme was high in neurocyte of the regions suggest that this enzyme may have the important role in memory and learning function. Furthermore, expression pattern of the AA-CoA synthetase mRNA was also similar to that of HMG-CoA reductase (the rate-determining enzyme of cholesterol biosynthesis) and not similar to that of Succinyl-CoA transferase (mitochondrial ketone body metabolic enzyme). These results suggest that AA-CoA synthetase is involved in the roles of cholesterol biosynthesis than the generation of metabolic energy in the brain. Next, in order to investigate the participation of insulin-depleted diabetes on AA-CoA synthetase, effect of streptozotocin administration on expression of this enzyme mRNA was examined in rat brain, heart, kidney and liver. As a result, STZ-induced diabetic rats showed markedly decreased AA-CoA synthetase mRNA expression in all tissues compared with normal control rats. Furthermore, compared effect of streptozotocin-induced diabetes on the AA-CoA synthetase mRNA with lipid synthesis and ketone body metabolic enzymes' in the brain because insulin has also been known to be important for lipogenic enzyme expression. Diabetic rats were markedly decreased AA-CoA synthetase, HMG-CoA reductase, Acetyl-CoA carboxylase mRNA expression but was hardly change Succinyl-CoA transferase mRNA. These results suggest that AA-CoA synthetase expression is regulated by insulin similarly lipid systhesis enzyme. In conclusion, AA-CoA synthetase is likely to play an important role in memory and learning function through ketone body metabolism for synthesis of cholesterol in the brain. Less

乙酰乙酰基-COA（AA-COA）合成酶（乙酰乙酰基-COA连接酶，EC 6.2.1.16）是一种新型的胞质乙酰乙酸乙酸酯激活酶，纯化为乙酰乙酰基特异性连接酶。在哺乳动物中，AA-COA合成酶在肝脏，脑，脂肪组织和其他各种组织中呈现，该酶在大鼠和人脑中高度表达。在肝脏中，AA-COA合成酶被认为是相关的胆固醇生物合成和脂肪酸合成。但是，除了肝脏中，AA-COA合成酶的身体作用尚不清楚。为了阐明AA-COA合成酶在大脑中的身体作用，（1）（1）AA-COA合成酶蛋白和大鼠大脑各个区域中AA-COA合成酶蛋白和mRNA的分布，（2）（2）通过原位杂交在脑中AA-COA合成酶mRNA的定位，（3）AA-COA合成酶MRNA分布（3） AA-COA合成酶和各种酶的链蛋白酶（STZ）诱导的糖尿病的糖尿病。首先，AA-CO…更多的合成酶mRNA和蛋白在大鼠脑中广泛表达，这些表达在PON，Medulla oblongata，Midbrain，Midbrain，Cerebral Cortex和Hypothalamus中特别高。此外，发现AA-COA合成酶mRNA在大鼠脑切片中的定位在小脑白质，海马氨基氨和齿状回中的定位特别高。在包括海马的脑皮质中，杂交信号易于在神经细胞中表达。该酶在该区域的神经细胞中的表达很高，表明该酶在记忆和学习功能中可能具有重要作用。此外，AA-COA合成酶mRNA的表达模式也类似于HMG-COA还原（胆固醇生物合成的速率确定酶）的表达模式，并且与琥珀酰基-COA转移的酶（线粒体酮体酮体代谢代谢代谢酶）不同。这些结果表明，与大脑中代谢能的产生相比，AA-COA合成酶参与胆固醇生物合成的作用。接下来，为了研究胰岛素缺失的糖尿病对AA-COA合成酶的参与，在大鼠脑，心脏，肾脏，肝脏和肝脏中检查了链蛋白酶施用对这种酶mRNA表达的影响。结果，与正常对照大鼠相比，STZ诱导的糖尿病大鼠始终显示出AA-COA合成酶mRNA的明显降低。此外，比较了链蛋白酶诱导的糖尿病对大脑中脂质合成和酮体代谢酶的AA-COA合成酶mRNA的作用，因为胰岛素也已知对脂源酶表达很重要。糖尿病大鼠明显改善了AA-COA合成酶，HMG-COA还原，乙酰-COA羧化酶mRNA的表达，但几乎不会改变琥珀酰-COA转移酶mRNA。这些结果表明，AA-COA合成酶的表达受胰岛素的调节，类似地脂质系统酶。总之，AA-COA合成酶可能通过酮体代谢在大脑中胆固醇的合成中在记忆和学习功能中起重要作用。较少的