Investigation of a novel pathogenesis of thrombosis-regulation of protein S by sex hormones and its abnormality-

1.性激素对S蛋白基因启动子调控机制的研究利用携带人蛋白S基因启动子区域和荧光素酶基因的表达载体，在体外培养的人肝癌细胞中检测了不同性激素对S基因启动子活性的影响。雌激素抑制了人蛋白S基因的转录活性。结论：1.人蛋白S基因启动子上的12个碱基对区域参与了雌激素对S蛋白基因转录的抑制作用。蛋白质S测定方法的发展及蛋白S在小鼠体内的调节机制研究通过对人蛋白S测定方法的改进，建立了一套小鼠蛋白质S测定系统。利用该系统，我们研究了性激素对小鼠S蛋白水平的影响。雌激素、人促性腺激素治疗及妊娠均可降低血浆S蛋白水平。日本女性S蛋白多态性与血浆蛋白S水平的相关性研究我们检测了日本普通人群的血浆游离蛋白S水平，并探讨了S蛋白基因的单核苷酸多态性(SNP)与血浆蛋白S水平的关系。在379名年龄在50-75岁的日本女性中，有3人血浆游离蛋白S降低，其中一人在PROS1基因中存在杂合错义突变(R275C)。此外，11名个体为K155E突变杂合子携带者。我们得出结论，估计日本女性遗传性蛋白S缺乏症的患病率至少为3.2%。关联分析表明，PROS1基因的启动子SNP与游离蛋白S水平显著相关。

1. Investigation of regulatory mechanism of the protein S gene by sex hormoneThe effect of various sex hormones on promoter activity of the human protein S gene was examined using plasmid constructs carrying the promoter region of the human protein S gene and luciferase gene in cultured human hepatoma cells. Estrogen suppressed the transcriptional activity of the human protein S gene. Twelve base pairs region in the promoter of the human protein S gene was involved in the inhibitory effect of estrogen on protein S gene transcription.2. Development of protein S measurement and investigation of regulatory mechanism of protein S in miceAn assay system of mouse protein S was developed by modification of human protein S measurement method. Using this system, we investigated the effects of sex hormones on the protein S level in mice. The plasma level of protein S decreased by treatment of estrogen and human gonadotropin as well as by pregnancy.3. Association study of protein S polymorphism with the plasma protein S level in Japanese womenWe examined the plasma free protein S level in a general Japanese population, and investigated the association of single nucleotide polymorphisms (SNPs) of the protein S gene (PROS1) with the plasma protein S level. Three of 379 Japanese women aged 50-75 years showed reduced plasma free protein S. One of these three had a heterozygous missense mutation (R275C) in the PROS1 gene. Furthermore, 11 individuals were heterozygous carriers with a K155E mutation. We conclude that the estimated prevalence of inherited protein S deficiency in Japanese women is at least 3.2% (12/379). Association analyses showed that a promoter SNP in the PROS1 gene was significantly associated with the free protein S level.