Project/Area Number |
02044044
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Research Category |
Grant-in-Aid for international Scientific Research
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Allocation Type | Single-year Grants |
Section | Joint Research |
Research Institution | The University of Tokyo |
Principal Investigator |
SEYAMA Yousuke The University of Tokyo, Faculty of Medicine, Professor, 医学部(医), 教授 (90010082)
|
Co-Investigator(Kenkyū-buntansha) |
SALEN Gerald University of Medicine and Dentistry of New Jersey, Professor, 医学部, 教授
SHEFER Sarah University of Medicine and Dentistry of New Jersey, Professor, 医学部, 教授
BJOERKHEM IN カロリンスカ研究所, 教授
笠間 健嗣 東京医科歯科大学, 医学部, 助手 (80124668)
KUBOTA Shunichiro The University of Tokyo, Faculty of Medicine, Associate Professor, 医学部(医), 助教授
HOSHITA Takahiko Hiroshima University School of Medicine, Professor, 医学部, 教授 (60033966)
YONEMOTO Kyozo Jikei University School of Medicine,Professor, 医学部, 教授 (80056572)
BIOERKHEM Ingemar Karolinska Institutet, Huddinge University Hospital, Professor
KASAMA Takeshi Tokyo Medical and Dental University, Faculty of Medicine, Associate
EGGERTSEN Go カロリンスカ研究所, 講師
BJORKHEM Ing カロリンスカ研究所, 教授
TINT Stephen ニュージャージ医科歯科大学, 医学部, 教授
SHEFER Sarah ニュージャージ医科歯科大学, 医学部, 教授
SALEN Gerald ニュージャージ医科歯科大学, 医学部, 教授
永田 和哉 東京大学, 医学部, 助手 (60189131)
清水 孝雄 東京大学, 医学部, 教授 (80127092)
BUCHMAN Mari オスロ大学, 医学部, 教授
|
Project Period (FY) |
1990 – 1992
|
Project Status |
Completed (Fiscal Year 1992)
|
Budget Amount *help |
¥6,000,000 (Direct Cost: ¥6,000,000)
Fiscal Year 1992: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1991: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1990: ¥2,000,000 (Direct Cost: ¥2,000,000)
|
Keywords | cerebrotendinous xanthomatosis / CTX / cholestanol / genetic diagnosis / PCR / restriction enzyme / experimental model animal / gallstone formation / 帯状角膜変性症 / コレスタノ-ル / 胆石症 / 26位水酸化酵素 |
Research Abstract |
Cerebrotendinous xanthomatosis is a metabolic disease, characterized by neurologic dysfunction, tendon xanthomas and juvenile cataracts. CTX patients have an impaired capacity to convert cholesterol to bile acids, due to a defect of hepatic enzyme, which catalyzes the oxidation of side chains of sterol intermediates. The first case in Japan was reported by Shibasaki in 1969. We intended first to clarify the genetic mutations in CTX patients, and secondly to establish an experimental model animal of this disease. 1. Genetic abnormalities in CTX patients : In collaboration with Ingemar Bjoerkhem, we (Seyama, Yonemoto, Hoshita and Kubota) analyzed the nucleotide sequence of cDNA encoding the sterol 27-hydroxylase. Direct sequencing of RT-PCR products revealed a mutation at the heme-ligand binding site in five CTX patients. Arginine at the 441 position was replaced by glutamine or tryptophan, and one base deletion was also found in one patient at the position encoding 445th amino acid. In pa
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tients with replacement of arginine by glutamine, a new restriction site with "Stu I" appeared. In patients with a replacement of arginine by tryptophan, "Hpa II" site disappeared. These findings suggest a possibility of genetic diagnosis using RFLP. 2. Establishment of experimental model animal of CTX : In collaboration with Salen and Shefer, we (Seyama and Kasama) established an experimental model animal by feeding cholestanol diet. After feeding 1% cholestanol in the diet, gallstones developed in 20 % of the mice and were associated with gallbladder mucosal inflammation and serosal vessel wall thickening. Hepatic HMG-CoA reductase activity rose by 51 % In contrast cholesterol 7a-hydroxylase activity was severely depressed. Discontinuing cholestanol from the diet for 1 month, reduced the elevated serum and liver cholestanol concentrations, and restored hepatic HMG-CoA reductase and cholesterol 7a-hydroxylase to normal. The combination of increased cholesterol synthesis with decreased bile acid formation promotes gallstone formation in cholestanol fed mice. Less
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