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Development of drugs targeting neurosteroid-metabolizing enzymes

开发针对神经类固醇代谢酶的药物

基本信息

批准号：
11557195
负责人：
HARA Akira
金额：
$ 4.67万
依托单位：
Gifu Pharmaceutical University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2001
项目状态：
已结题

项目摘要

3α-Hydroxysteroid dehydrogenase (HSD) and 20α-HSD in animal brains have been shown to be involved in the synthesis and metabolism of neuroactive steroids. In humans, one 20α-HSD and three 3α-HSDs (type 1 - 3) are present, and the roles of the enzymes in the neurosteroid metabolism are unknown, but clinical investigations provide evidence for an involvement of the neuroactive steroids in conditions such as premenstrual syndrome, catamenial epilepsy and depressive disorders. This study focused the following six points on the two human enzymes as targets for developing new drugs for management of such disorders.1. Roles of the human enzymes in the neurosteroid metabolism. Tissue distribution and substrate specificity for neurosteroids of the enzymes suggest that in the brain 20α-HSD inactivates the neuroactive steroids and their precursor, progesterone, and that 3α-HSD type 3 is involved in the synthesis of the neuroactive steroids.2. Search of activators and inhibitors. Only 3α-HSD type … More 1 was activated by several therapeutic drugs and thyroxine. Of several inhibitors for the enzymes, benzbromarone and its derivatives specifically and strongly inhibited 20α-HSD, which suggests that they are lead compounds to develop the drugs.3. Structure-function relationship of the enzymes. The site-directed mutagenesis study of 20α-HSD and 3α-HSD type 1 identified or suggested several amino acids in their active centers and binding sites for the activators and inhibitors. The crystallographic study of 20α-HSD is now in progress.4. Regulation of gene expression. Ethacrynic acid enhanced the expression of the enzymes, except 3α-HSD type 1 in several cultured human cells. The investigation of expression of liver-specific 3α-HSD type 1 indicated that three hepatocyte nuclear factors regulate the transcription of the enzyme gene.5. Genetic polymorphism. Analyses of expressed mRNA and gene for 3α-HSD type 1 in specimens identified a variant gene which encodes a enzyme with low catalytic activity.6. Establishment of evaluation system for drugs using cells and animals transfected with the enzymes or their genes The system using the cells was established, but that using the animal models could not be achieved, because the expression of the enzyme was too little to affect the brain function. The establishment of the latter system will be continued. Less

动物大脑中的3α-羟基类固醇脱氢酶（HSD）和20α-HSD已被证明参与神经活性类固醇的合成和代谢。在人类中，存在一种 20α-HSD 和三种 3α-HSD（1-3 型），这些酶在神经类固醇代谢中的作用尚不清楚，但临床研究提供了神经活性类固醇参与经前综合症、经期癫痫和抑郁症等疾病的证据。本研究重点关注以下六点，以两种人类酶为目标，开发治疗此类疾病的新药。1．人类酶在神经类固醇代谢中的作用。酶的组织分布和对神经类固醇的底物特异性表明，在大脑中20α-HSD使神经活性类固醇及其前体黄体酮失活，并且3α-HSD 3型参与神经活性类固醇的合成。2．寻找激活剂和抑制剂。只有 3α-HSD 1 型被几种治疗药物和甲状腺素激活。在几种酶抑制剂中，苯溴马隆及其衍生物特异性强地抑制20α-HSD，这表明它们是开发该药物的先导化合物。3．酶的结构-功能关系。 20α-HSD 和 3α-HSD 1 型的定点诱变研究鉴定或提出了其活性中心的几个氨基酸以及激活剂和抑制剂的结合位点。 20α-HSD的晶体学研究正在进行中。 4．基因表达的调节。在几种培养的人类细胞中，依他尼酸增强了除 1 型 3α-HSD 之外的酶的表达。肝脏特异性3α-HSD 1型表达的研究表明，3种肝细胞核因子调控该酶基因的转录。5．遗传多态性。对标本中3α-HSD 1型表达的mRNA和基因进行分析，鉴定出编码低催化活性酶的变异基因。6．利用转染酶或其基因的细胞和动物建立药物评价体系利用细胞建立了评价体系，但利用动物模型无法实现，因为酶的表达量太少，无法影响脑功能。后一制度的建立将继续进行。较少的